WO2000066008A1

WO2000066008A1 - Surgical instruments for accessing and stabilizing a localized portion of a beating heart

Info

Publication number: WO2000066008A1
Application number: PCT/US2000/012239
Authority: WO
Inventors: Lawrence W. Hu; David J. Paul; Eugene Edward Reis; Harry Leonard Ii Green; Joshua K. Wallin; Dwight P. Morejohn; Charles S. Taylor; Gary B. Weller; Richard M. Ferrari
Original assignee: Cardiothoracic Systems, Inc.
Priority date: 1999-05-04
Filing date: 2000-05-04
Publication date: 2000-11-09
Also published as: US20100210916A1; US7736307B2; US6685632B1; US9498198B2; AU4701800A; US20040143168A1

Abstract

Surgical devices for stabilizing the heart are disclosed which facilitate anastomosis under beating heart conditions. Various instruments or devices may be maneuvered and secured on a retractor device to provide stabilization of the heart. An instrument mount is provided which is preferably configured to accept a surgical instrument, such as a tissue stabilizer, and to allow the instrument to be easily maneuvered to a desired position and subsequently locked into position with a simple operation of a single locking actuator. Further disclosed are stabilizer devices each having at least one surface for contacting the heart and each being adapted to be mounted to the retractor while having the ability to be positioned in the desired location against the heart.

Description

SIJRGTCAL INSTRUMENTS FOR ACCESSING AND STABILIZING A LOCALIZED

PORTION OF A BEATING HEART

FIELD OF THE INVENTION The present invention relates generally to surgical instruments, and more particularly to a surgical instrument mount apparatus and surgical retractor system useful for positioning and securing a variety of instruments including tissue stabilizer devices for use during coronary artery bypass graft surgery.

BACKGROUND OF THE INVENTION

Diseases of the cardiovascular system affect millions of people each year and are a leading cause of death throughout the world. The cost to society from such diseases is enormous both in terms of the number of lives lost as well as in terms of the costs associated with treating patients through traditional surgical techniques. A particularly prevalent form of cardiovascular disease is a reduction in the blood supply leading to the heart caused by atherosclerosis or other condition that creates a restriction in blood flow at a critical point in the cardiovascular system that supplies blood to the heart.

Treatment of such a blockage or restriction in the blood flow leading to the heart is, in many cases, treated by a surgical procedure known as a coronary artery bypass graft (CABG) procedure, more commonly known as a "heart bypass" operation. In the CABG procedure, the surgeon "bypasses" the obstruction to restore normal blood flow to the heart either by attaching an available source vessel to the obstructed target coronary artery or by removing a portion of a vein or artery from another part of the body, to use as a graft, and installing the graft between a point on a source vessel and a point on a target artery.

To restore the flow of blood to the heart, the CABG procedure requires that a fluid connection be established between two vessels. This procedure is known as an "anastomosis." Typically, a source vessel, such as a source artery with an unobstructed blood flow, i.e., the left internal mammary artery (LIMA), or a bypass-graft having one to end sewn to an unobstructed blood source such as the aorta, is sewn to a target occluded coronary artery, such as the left anterior descending (LAD) artery or other vessel, that provides blood flow to the muscles of the heart. Although the CABG procedure has become relatively common, the procedure itself is lengthy and traumatic and can damage the heart, the cardiovascular system, the central nervous system, and the blood supply itself. In a conventional CABG procedure, the surgeon makes an incision down the center of the chest, cuts through the sternum, performs several other procedures necessary to attach the patient to a heart-lung bypass machine, cuts off the blood flow to the heart, and then stops the heart from beating m order to complete the bypass The most lengthy and traumatic surgical procedures are necessary, m part, to connect the patient to a cardiopulmonary bypass (CPB) machine to contmue the circulation of oxygenated blood to the rest of the body while the bypass is completed In recent years, a growing number of surgeons have begun performing CABG procedures usmg surgical techniques especially developed so that the CABG procedure could be performed while the heart is still beatmg In such procedures, there is no need for any form of cardiopulmonary bypass, no need to perform the extensive surgical procedures necessary to connect the patient to a cardiopulmonary bypass machine, and no need to stop the heart As a result, these beatmg heart procedures are much less invasive and the entire procedure can typically be achieved through a small number, typically one or two, comparatively small incisions in the chest

Despite the advantages, the beatmg-heart CABG procedure is not universally to practiced, at least m part, because of the difficulty m performing the necessary surgical procedures usmg conventional surgical instruments For example, it has been difficult for the surgeon to access the required areas of the heart requirmg revasculaπzaUon In addition, the vaπous surgical steps that are required to be performed on the heart itself are more difficult to perform because the heart muscle continues to move and contract to pump blood throughout the duration of the procedure

The specific portion of the surgical procedure that creates the anastomosis m the beatmg-heart CABG procedure is particularly difficult Completion of the anastomosis requires placmg a senes of sutures through extremely small vessels on the surface of the heart while the heart muscle continues to beat Moreover, the sutures must be carefully placed to ensure that the source vessel or graft is firmly attached and will not leak when blood flow through the vessel is established In cases where the target coronary artery is temporaπly obstructed, for example, to improve the surgeon's visibility and avoid excessive blood loss, it is also important that the anastomosis procedure be performed rapidly to avoid lschemic damage to the heart

Further adding to the difficulty of the procedure is the fact that the working space and visual access are often quite limited The surgeon may be working through a small incision m the chest, for example, or may be viewing the procedure on a video monitor if the site of the surgery is viewed via surgical scope The vessel, and particularly the arteπotomy to which a source vessel is to be anastomosed, may also be very difficult for the surgeon to see as it may be obscured more or less by layers of fat or other tissue

The beatmg-heart CABG procedure could be greatly improved if the heart could be accessed and stabilized dunng the procedure such that the motion of the heart, particularly at the site of the anastomosis, is minimized even though the heart continues to beat and supply blood to the body The beatmg-heart CABG procedure could be-further improved if the target vessel, and specifically the arteπotomy was presented to the surgeon m a way that allows sutures to be easily placed

In view of the foregomg. it would be desirable to have improved devices for accessing and effectively stabilizing the beatmg heart at the site of the anastomosis It would be desirable to have a retractor system that provides unobstructed and organized access to the areas of the heart requiring revasculaπzation It would be further desirable to have a low-profile, a traumatic stabilizing device that stabilizes the beatmg heart at the site of the anastomosis and provides a favorable presentation of the target vessel and the arteπotomy It would be further desirable to provide a mount for the stabilizing device, or other instruments, that allows the stabilizing device to be easily maneuvered to the desired position and onentation, fixedly secured until the procedure is completed, and then easily removed from the site of the anastomosis

SUMMARY OF THE INVENTION The present mvention will be generally descnbed for use m performing CABG surgery, but the mvention is not limited thereto, and is contemplated to be useful for other surgical procedures reqmπng surgical instruments to be positioned and secured through an incision mto a patient

The present mvention mvolves vaπous aspects of an instrument mount useful for positioning and securing surgical instruments, for example, dunng a CA procedure on a beatmg heart One aspect of the present mvention mvolves a low-profile, flexible, πght-angle instrument mount for maneuvering and securing a wide anay of surgical instruments

One aspect of the present mvention mvolves an instrument mount apparatus for positioning a surgical instrument compnsmg a mount body havmg a base portion moveably coupled at a first articulating jomt and a side portion moveably coupled at a second articulating jomt, the first and second articulating jomts bemg freely moveable when m an unlocked condition and substantially immovable when in a locked condition which may be accomplished through mampulation of a smgle actuator

The actuator may mclude a base post assembled thorough the base portion and the mount body and interconnected at a first end to a cam operatively interfacing a contact surface on the mount body, and a tie pm hav g a slotted portion which receives the base post Operation of the cam draws the base post toward the cam and mto a locked position A ramped portion of the base post dnves the tie pm mto the locked position

A gnp member may be mcluded, which forms an opening with the side portion for receiving a surgical instrument The tie pm may be connected, at a first end, to the gnp member, preferably by a pair of flexible prongs Movement of the tie pm to the locked position draws and locks the gnp member against the side portion and also locks the second articulating jomt The tie pin may further be releasably connected to a release button at a second end, such that pressing of the release button extends the tie pin and grip member to allow removal of the grip member to exchange surgical instruments.

Preferably, the first articulating joint is at an angle relative to the second articulating joint. The angle between the first and second articulating joints is typically less than about 130 degrees, more typically less than 120 degrees. In a prefened embodiment, the angle is between about 100 degrees and about 45 degrees, most preferably about 90 degrees.

The articulating joints may be any mechanical configuration which provides the desired degrees of freedom for maneuvering a surgical instrument. Preferably, the first articulating joint comprises a ball-type joint or a ball and socket joint. The ball and socket joint may comprise a ball- shaped member extending from the base portion and a to cooperating socket formed within the mount body. The second articulating joint may preferably comprise a ball and socket joint or a rotational joint. When the second articulating joint is configured as a rotational joint, it may comprise a frustoconical member extending from the side portion and a cooperating frustoconical cavity within the mount body.

The side portion and the base portion may include a number of other features or structures connected thereto for a variety of purposes which take advantage of the movement of the side portion relative to the base portion provided by the articulating joints. For example, the side portion may further include a grip member. The side portion and the grip member may be positioned to form an opening therebetween for receiving a surgical instrument. The grip member may have an unlocked condition relative to the side portion wherein the opening allows relatively free movement of the surgical instrument and a locked condition wherein the grip member and the side portion are forced together to lock the instrument against relative movement.

The base portion may be adapted to cooperatively engage a rail member. The rail member may generally have a T-shaped cross-section. In a prefeπed embodiment, the rail has a top portion and a bottom portion, the bottom portion having a nanowed region adjacent the top portion forming first and second tabs on the top portion and the base portion further comprises first and second hooks adapted to engage the first and second tabs. Preferably at least one of said hooks is moveable relative to the other to allow the base portion to lock onto and release from the first and second tabs. The rail is preferably fixed or otherwise associated with a sternal or rib retractor.

Another aspect of the present invention involves an instrument mount apparatus for positioning and securing a surgical instrument which includes a mount body having a base portion moveably coupled at a first articulating joint and a side portion moveably coupled at a second articulating joint. A post preferably extends through the first articulating joint along a first axis and has a first end portion engaging the base portion. A pin preferably extends through the second articulating jomt along a second axis and has an end portion engaging the side portion and a threaded portion A knob is may be provided havmg an internal bore for receivmg at least a portion of the pm. the internal bore havmg threads adapted to engage the threaded portion of the pm The knob may preferably have a thrust surface associated therewith adapted to engage and move the post as the knob traverses over the threaded portion of the pm m response to rotation of the knob

Again, the articulatmg jomts may be any mechanical configuration which provides the desired degrees of freedom for maneuvering a surgical mstrument Preferably, the first articulatmg jomt compnses a ball-type jomt or a ball and socket jomt The ball and socket jomt may compnse a ball- shaped member extending from the base portion and a cooperatmg socket formed within the mount body The second articulatmg joint may to preferably compnse a ball and socket jomt or a rotational jomt When the second articulatmg joint is configured as a rotational jomt, it may compπse a frustoconical member extending from the side portion and a cooperating frustoconical cavity within the mount body

The post may preferably further compπses a cam surface positioned to mate with the thrust surface, whereby rotation of the knob along the threaded portion causes translation of the thrust surface m a direction along the second axis, the thrust surface engagmg the cam surface to move the post m a direction generally along the first axis The knob may mclude a first end adapted to be grasped by a user and a housmg end adapted to be received within the mount body The thrust surface may be located on the housmg end of the knob In another configuration, the thrust surface may be provided on a lift member which is slidable along the second axis The lift member may have a first end havmg the thrust surface and a second end The housmg end of the knob is preferably positioned to engage the second end of the lift member such that when the knob is traversed along the second axis, it engages the lift member which causes the thrust surface to engage the cam surface thus causmg the post to move along the first axis When the post is urged m a first direction along the first axis, the first articulatmg jomt preferably becomes locked When the first articulatmg jomt is a ball and socket jomt formed between a ball extending from the base portion and a socket formed within the mount body, the ball and socket become locked by operation of the first end of the post which engages the base portion and forces the two together as the post is urged upwards When the post moves in the opposite direction, the articulatmg joint returns to a condition which allows relatively free articulation A second end of the post is may be constrained within a top openmg provided m the mount body Preferably, the second end is slidable within the top opening generally along the first axis

These and other features of the present mvention will become more fully apparent from the following descπption and appended claims BRIEF DESCRIPTION OF THE DRAWINGS

Figure 1 is a perspective view illustrating a cardiac surgery system according to the principles of the present mvention

Figure 2 is a perspective view illustrating a retractor assembly according to the principles of the present mvention

Figure 3 is a perspective view illustratmg a prefeπed retractor dnve assembly

Figure 4 is a perspective view illustrating an exemplar bar assembly

Figure 5 is a perspective view illustrating a moveable housmg associated with the retractor dnve Figure 6 is a perspective view illustratmg a retractor dnve handle assembly

Figure 7 is a top plan view illustratmg a prefeπed platform blade and retractor dnve assembly m an unengaged position

Figure 8 is a top view in partial cross-section illustratmg the platform blade and retractor dnve assembly in an engaged position Figure 9 is a cross-sectional view taken along lme 9-9 shown in Figure 8

Figure 10 is a partial top view illustrating a prefeπed suture stay aπangement associated with a platform blade

Figures 11A, 1 IB, and 1 IC illustrate a prefened platform blade latch Figure 11A and 1 IB are top and front plan views, respectively Figure 1 IC is a cross-sectional view 10 taken along lme 1 lC-1 IC as shown in Figure 11 B

Figure 12 is a perspective view showing a prefeπed suture lock

Figure 13 is a perspective view illustrating an mstrument mount assembly according to the principles of the present mvention

Figure 14 is an exploded assembly illustration of the mstrument mount assembly of Figure 13 Figures 15A and 15B are perspective views illustratmg the assembly of the mount cam to the mount base

Figures 16A and 16B are top and front plan views, respectively, illustratmg a prefeπed mount cam

Figure 17 is a front plan view illustrating a prefeπed mount lunge Figure 18 is an exploded view illustratmg the assembly of the mount body to the mount base

Figure 19 is an exploded view illustrating the assembly of the mstrument clamp to the mount body.

Figure 20 is a cross-sectional view taken through a hoπzontal plane of the mstrument stem gnp of Figure 19 Figure 21 is a front plan view showing an assembled instrument mount operably positioned on a platform blade according to the principles of the present invention.

Figures 22A and 22B are front and top plan views, respectively, of an alternate instrument mount assembly according to the principles of the present invention. Figure 23 is a cross-sectional view taken along line 23-23 as shown in Figure 21.

Figure 24 is an offset cross-sectional view taken along line 24-24 as shown in Figure 22 illustrating the mount assembly of Figures 21 and 22 in the closed position.

Figure 25 is an offset cross-sectional view illustrating the mount assembly of Figures 21 and 22 in the open position. Figure 26 is an exploded assembly view showing selected components of a 15 prefeπed closing mechanism.

Figure 27 is a perspective view illustrating a prefeπed instrument mount cam post.

Figure 28 is a perspective view illustrating a prefeπed instrument mount release button.

Figure 29 is a perspective view illustrating a prefeπed instrument mount follower post. Figure 30 is a perspective view of a prefeπed instrument mount stem clamp.

Figure 31 is a perspective view of a prefeπed instrument mount conical clutch.

Figure 32 is a perspective view of a threaded collar associated with the instrument mount stem clamp.

Figure 33 is a perspective view illustrating an alternative instrument mount assembly having a single knob locking mechanism according to the principles of the present invention.

Figure 34 is a top plan view of the instrument mount assembly of Figure 33.

Figure 35 is an exploded perspective view of the instrument mount assembly of Figure 33.

Figure 36 is a cross-sectional view taken along line 36-36 as shown in Figure 33.

Figure 37A is a perspective view of the prefeπed base post for the instrument mount assembly shown in Figures 33-36.

Figure 37B is a perspective view of an alternative embodiment of a lifter.

Figures 38 and 39 are exploded perspective and cross-sectional views respectively of a handle mechanism of a prefeπed tissue stabilizer.

Figure 40 is an exploded perspective view of a contact member of the stabilizer shown in Figures 38 and 39.

Figure 41 is a rear plan view of the contact member of Figures 38, 39 and 40.

Figure 42 is a cross-sectional view of the contact member of Figure 41 taken along line 42-42.

Figure 43 is a perspective view illustrating a stabilizer base embodiment having an offset stem connection. Figure 44 is a perspective view illustratmg an alternative offset stabilizer base m use over a target vessel

Figures 45A and 45B are respectively front and side plan views of the off set stabilizer base embodiment of Figure 44 Figure 46 is a perspective view of a tissue stabilizer havmg a moveable ball/post

Figure 47 is a perspective view illustratmg another tissue stabilizer embodiment 5 havmg a moveable ball/post

Figure 48 is a partial cross-section taken through the ball/post of Figure 47 showing a spring biased ball/post Figure 49 is a partial cross-section showing the ball/post of Figure 48 utilizing a locking clip to secure the ball/post

Figure 50 is a perspective view of the locking clip of Figure 49

Figure 51 is a perspective view illustratmg another moveable ball/post stabilizer embodiment Figure 52 is a front perspective exploded view of a stabilizer base assembly havmg an adjustable ball/post position

Figure 53 is a rear perspective view of the stabilizer base of Figure 52 Figures 54A and 54B are front and rear perspective views of the stabilizer base assembly of Figure 52

Figure 55 is a partial cross-sectional view through a portion of the rear guide slot of the stabilizer base of Figure 52

Figure 56A is a perspective view of a stabilizer base embodiment havmg a smgle contact member and bail construction

Figure 56B is an end plan view of the stabilizer embodiment of Figure 56A Figures 57A and 57B are perspective views illustratmg another stabilizer base embodiment havmg a smgle contact member and bail construction

Figures 58 and 59 are perspective views illustratmg stabilizer base embodiments havmg a smgle contact member and a bail havmg a mechanical dnve

Figure 60 is a perspective view of a prefeπed cardiac surgery system dunng operation according to the principles of the present mvention

DETAILED DESCRIPTION

The present mvention mvolves surgical instruments for accessmg and stabilizing the heart and methods for their use The present mvention may mvolve a retractor system or assembly for accessmg the heart The present mvention may also mclude a mount that allows vaπous instruments to be easily positioned within the surgical workmg space, locked or secured mto a desired posmon for the duration of a particular surgical procedure, and then easily and safely removed from the workmg space According to a preferred embodiment the mstrument may be a device to facilitate stabilization of the heart dunng coronary surgery

Although the mstruments and methods of the present mvention may have application m both conventional stopped-heart and beating heart procedures, they are preferably used to access and stabilize the beatmg heart dunng a minimally mvasive coronary artery bypass graft (CABG) operation which has been specially developed to facilitate completion of an anastomosis, typically between a target artery and a bypass graft or source artery, without requirmg cardiac arrest such as cardioplegia or fibπllation and without cardiopulmonary bypass (CPB) Further, although the mstruments for accessmg and stabilizmg the beatmg heart can be applied m a number of different surgical contexts involving vanous incisions and surgical approaches to the heart as are known m the art, the mstruments and devices descπbed herem are most advantageously employed m a CABG procedure wherem the heart is accessed through only one or two minimally mvasive incisions in the chest

Although the particular source vessel and target artery of the anastomosis are determined clinically, a common minimally invasive bypass procedure on the beatmg heart mcludes an anastomosis which forms a connection between the left inteπ-al mammary artery (LIMA) as the source artery, and the left anteπor descending artery (LAD) as the target artery To complete the anastomosis, the surgeon must dissect a portion of the LIMA by separating it from the internal chest cavity Once dissection of the LIMA is achieved, the surgeon may attach the dissected LIMA to the target coronary artery, I e , the LAD by way of creatmg an anastomosis

In this example, the present mvention may mvolve a number of discrete components that facilitate access to the anastomosis site, allow vanous mstruments or devices to be maneuvered and secured m place, and provide stabilization of the heart The retractor of the present mvention may be used to provide access to the anastomosis site of the target artery on the heart itself The vaπous stabilizer embodiments of the present mvention may be used to stabilize the beatmg heart dunng at least the portion of the procedure dunng which the surgeon completes the anastomosis of the LIMA to the LAD The mount of the present mvention may be used to facilitate convement mampulation of the stabilizer, and other mstruments or devices, to their desired position and allows the devices to be secured m that desired position Although the LIMA to LAD anastomosis is provided as one example, it is readily appreciated that the techmques and mstruments descnbed herem may be applied to other procedures depending on the clinical diagnosis and the patient's anatomy

Although each component of the present mvention may be used separately with great benefit, the components are preferably used m unison to provide a surgical system which provides an unobstructed and organized surgical field, exceptional mstrument maneuverability and access to the heart facilitating total revasculaπzation of the heart if required, and effective vessel stabilization dunng the anastomosis procedure Although the present mvention will have application whether access to the heart is achieved by way of a full-sternotomy, mini-sternotomy, para-sternotomy, thoracotomy or other known to approach, the exemplar embodiments descnbed below will be generally descnbed with reference to a coronary artery bypass procedure usmg a mid-sternal approach Referring to the figures wherem like numerals mdicate like elements, an exemplar surgical system for performing a mid-sternal surgical procedure on the beatmg heart is illustrated m Figure 1 and mcludes retractor assembly 10, mount assembly 20 and stabilizer assembly 30

Retractor assembly 10 generally mcludes a pair of opposmg blades adapted to engage opposite sides of a sternal incision, or other incision, and a dnve mechamsm constructed to force the blades, and thus the sternum apart Usmg the dnve mechamsm, the sternum may be spread to the desired opening, thus providing the desired access and direct visualization of the thoracic cavity If desired, the heart may be positioned or onented to best present the target vessels for anastomosis This positioning may be established, for example, through the strategic placement and tensiomng of sutures m the peπcardial sac, by appropπately placmg the patient in the Trendelenburg position, or by usmg a heart positioned m the form or a strap or pad or the like

Once the target vessel is m the desired position, at least one component of stabilizer assembly 30 is brought mto contact with the beatmg heart adjacent the target site of the anastomosis The surgeon then applies a stabilizmg force to the beatmg heart via the stabilizer assembly 30 which may then be fixed m place, preferably to the retractor assembly 10 by way of mount assembly 20 The stabilizmg force supplied by the stabilizer assembly substantially eliminates movement of the heart in the area of the anastomosis so that the surgeon may accurately and efficiently perform the required anastomosis (or other surgical procedure) After the anastomosis has been completed, the stabilizmg force is released and the contacting component of stabilizer assembly 30 is removed from the anastomotic site Each of the pπncipal components, the prefeπed surgical system, and their methods of use are separately descnbed m detail below A prefened retractor accordmg to the principles of the present mvention is descnbed below with reference to Figures 212 A prefened stabilizer or mstrument mount accordmg to the principles of the present mvention is descπbed below with reference to Figures 13-32 Prefeπed stabilizer embodiments accordmg to the principles of the present mvention are descnbed below with respect to Figures 33-44 A prefeπed surgical system and methods for performing a coronary artery bypass on a beatmg heart according to the principles of the present mvention is descnbed below with respect to Figure 45 The Retractor Accordmg to the principles of the present invention, the retractor generally mvolves a dnve mechamsm and a pair of opposmg blades adapted for insertion mto an incision and for engagmg opposite sides of the incision The dnve mechamsm functions m some manner to urge the opposmg blades apart, thus forcmg opposite sides of the incision open to allow surgical access through the incision For purposes of performing a coronary artery bypass, the incision may be any suitable incision which provides the desired access to the thoracic cavity, and more specifically a desired area of the heart For purposes of example only, the retractor of the present mvention will be descπbed with respect to a mid-sternal incision, however skilled artisans will recognize that many aspects of the mvention are equally applicable to other surgical approaches to the heart, for example, by way of a thoracotomy, or other suitable access approach

When the heart is accessed by way of an incision through all or a portion of the sternum, the opposmg blades are adapted to be mserted mto and engage opposite sides of a sternal incision such that the severed sternum may be forced apart by the action of the opposmg blades to create a workmg space for operatmg on the heart Typically, the dnve mechamsm is constructed to spread the opposmg blades apart m a generally parallel fashion, however, the parting motion may also have a significant curvilinear or angular component as well In one embodiment, the blades may be permanently, integrally, or mseparably formed with a dnve mechamsm Preferably however, at least a portion of the blades are separable from the dnve mechamsm That is, at least some of the features and functions associated with the retractor blades are allocated to a structural component which is separate, separable, or otherwise detachable from the dnve mechamsm The separate component and the dnve mechamsm may be manufactured mdependently and then subsequently assembled at the factory or, more preferably, at the pomt of use A retractor construction havmg a separable component allows the features and functions of the dnve mechamsm to remam separate from the remainder of the retractor assembly and vice versa This allows a greatly simplified or depopulated dnve mechamsm and allows the separable component to have a much more sophisticated construction with mcreased features and functionality Accordmgly, the simplified dnve mechamsm, which is typically required to be made from a hardened steel, is easier and more economical to manufacture and easier to maintain, clean and stenhze post surgically Moreover, the separate component can be economically made from matenals or processes that allow for the mtπcate structural features which provide supenor functionality

In a prefeπed embodiment, the dnve mechamsm is constructed to be re stenhzed and reused a relatively large number of times, and the feature-nch separate component is constructed to be disposable, I e discarded after a smgle surgical use Thus, the depopulated dnve mechamsm. which will be used over and over, can afford to be constructed to be quite robust with a view to matenals and manufacturing processes that will support the ngors of such extended surgical service The separable component, free from the typical functional requirements of the dnve mechanism and the service requirements of extended surgical re-use, may preferably be constructed from any number of engmeeπng matenals to produce an economical component havmg the desired features and which may be discarded after a smgle use if desired

In a prefeπed embodiment, retractor assembly 10 compπses a dnve 12 and first and second platform blades 14 and 16 detachably connected to dnve 12. as illustrated m Figure 2 Preferably first platform blade 14 and second platform blade 16 each have one or more channels or engagmg members 18 adapted to engage opposite sides of an access incision Activation of dnve 12 forces apart first and second platform blades 14 and 16 thereby causmg engagmg members 18 to coπespondingly force the incision open to provide access to the desired surgical site

In the example of a sternal approach to the heart, engagmg members 18 are adapted to engage each side of the incised sternum to reliably hold and engage the sternum as the sternum is forced open to expose the thoracic cavity and ultimately the heart As best seen m Figure 9, which illustrates a cross-section of second platform blade 16 engaging member 18 is generally in the form of a channel or the like, preferably having a U-shape, curved shape, or other shape suitable for engagmg the mcised sternum Preferably, engagmg member 18 generally has a concave mteπor profile 17 for engagmg and holding the sternum and a coπesponding convex extenor profile 19 that is relatively smooth so as not to interfere with other surgical instruments, snag sutures or create other such difficulties The engagmg members 18 are preferably constructed to have sufficient strength to withstand the loads required to spread the sternum yet maintain a suitably low profile to facilitate easy insertion mto the access incision and to require as little space within the workmg incision as possible

It may be desirable to provide engagmg members 18 with features to reduce trauma to the incision site, mcrease the traction against the sides of the incision, or both A thin pad or layer of non- slip or a traumatic matenal (not shown) may be fixed, by way of an adhesive or other suitable fastemng technique, to the mteπor profile 17 if desired to reduce slippage and trauma to the severed stemum or suπounding tissue Alternatively, the desired features may be integrally fabncated mto engagmg members 18 For example, when platform blades 14 and 16 are injection molded components, traction features such as raised bumps, πbs, indentations, or the like can be molded integral mto engagmg members 18

Referring to Figures 2-6, dnve 12 is preferably constructed to force the platform blades apart m generally opposite directions Any type of dnve mechamsm which provides the desired separating action of the blades may be suitable A common, substantially straight-line parting motion may be provided by a ratchet or rack aπangement as is generally known m the art Figure 3 illustrates a prefeπed dnve 12 which mvolves a bar 15, moveable housing 22 and handle assembly 24 which facilitates movement of moveable housmg 22 relative to bar 15 A first end of first blade 14 may be operably attached to moveable housmg 22 and second blade 16 to bar 15 In a prefeπed embodiment, bar 15 is a substantially ngid bar havmg a stationary or fixed housing 21 assembled thereto and thus forming bar assembly 23 Fixed housmg 21 may be fastened to one end of bar 15 usmg one or more mechanical fasteners, an interference fit. suitable adhesive or bonding compounds, welding, or any other suitable fastemng technique A first end of second blade 16 is preferably operably attached to fixed housmg 21 As with moveable housmg 22, fixed housmg 21 may be of any configuration which provides for the structural attachment of first and second platform blades 14 and 16

Bar 15 preferably includes a number of teeth 13 evenly spaced along at least a portion of its length Teeth 13 may have substantially parallel side portions 11 and may have radiused tops 25 The extenor edges of teeth 13 may be broken or radiused or have a chamfer 26 as shown Handle assembly 24 preferably mcludes a means for engagmg teeth 13 so as to dnve moveable housmg 22 relative to bar 15 to any desired position under load where it remains so positioned against the load without need for any applied mput or holdmg force The means for engagmg teeth 13 could be any suitable gear, ratchet, cog or like mechamsm Bar 15 may also be adapted and used for receivmg an mstrument mount, such as those descnbed m detail below

In a preferred embodiment, moveable housmg 22 is dnven usmg one or more dnve pms which may successively engage teeth 13 in a coggmg manner Handle assembly 24 mcludes dnve handle 29 connected to first and second cylmdncal dnve bearings 31 and 32 Dnve beanng 31 preferably has a raised boss 34 extendmg from one end to which dnve handle 29 may be pivotally connected by way of pm 33 At the opposite end, dnve beanng 31 has first dnve pm 27 and second dnve pm 28 extendmg therefrom and termmatmg at second dnve beanng 32 First and second dnve bearings 31 and 32 are spaced apart a distance 35 which is selected to be slightly greater than the thickness 38 of bar 15 such that a portion of bar 15 may be received between first and second dnve bearings 31 and 32 The outside diameters of dnve bearings 31 and 32 are selected so as to fit within guide holes provided in moveable housmg 22 For example, the outside diameter of second dnve beanng 32 is sized to accurately rotate within guide hole 36

Moveable housmg 22 has a bore 37 extendmg therethrough for receivmg bar 15 Bore 37 generally has a shape coπesponding to the dimensions of the cross-section of the potion of the bar 15 which is to pass through bore 36 With handle assembly 24 properly positioned within the guide holes provided m moveable housmg 22, it may be assembled to bar 15 by placmg the end of bar 15 within bore 36 and turning handle 29 such that first and second dnve pms 27 and 28 become engaged with teeth 13 Once assembled in this manner, moveable housmg 22 may be forced one way or the other along the length of bar 15 by turning handle 29, and thus dnve bearings 31 and 32, to cause first and second dnve pins 27 and 28 to progressively engage teeth 13 along bar 15 As mentioned above, first and second platform blades 14 and 16 may be removably assembled to moveable housing 22 and fixed housing 21, respectively. Platform blades 14 and 16 may be attached in any suitable fashion including, for example, threaded connections or other mating features on the platform blades and housings themselves, ordinary or specialized mechanical fasteners, and cam or latching mechanisms adapted to secure the platform blades to the housings. In a prefeπed embodiment, both moveable housing 22 and fixed housing 21 are constructed with features that engage, secure and support first and second platform blades 14 and 16 in an operable position on drive 12, thus providing an assembled retractor 10 which is ready for surgical use.

Referring to Figures 7 and 8, second platform blade 16 is shown before and after assembly onto fixed housing 21. Preferably, at least one of the platform blade 16 or the fixed housing 21 has an extending protuberance, post or like feature which can be receivably engaged by the other of the platform blade or housing. In a prefened. embodiment, fixed housing 21 is preferably constructed to have a latch post 42 adapted to be received within latch post cavity 45 provided in platform blade 16. Latch post 42 may have a hole, notch, protuberance, or other feature formed therein which may be engaged in any convenient manner by the platform blade 16 so that platform blade 16 becomes releasably locked in place for use.

In a prefeπed embodiment, latch post 16 has a notch which defines latch surface 51 and stop surface 52. Platform blade 16 has a latch member 48, best seen in Figures 11A-11A, having a latch body 50 constructed with surfaces 53 and 54 for engaging latch surface 51 and stop surface 52 respectively. Generally transverse to latch post cavity 45, platform blade 16 has a latch body cavity 56 having an opening towards upper surface 57 of platform blade 16 for receiving latch body 50 of latch 48.

Latch 48 is preferably constructed to engage and disengage latch post 42 by manual rotation of latch knob 49. Latch body 50 includes cylindrical portion 55 which provides for controlled rotation within latch body cavity 56. Latch body 50 may be biased towards the engaged position shown in Figure 8 by way of any suitable spring element. Preferably, latch post 42 is provided with an angled tip 43 having a lead-in angle 44 which allows angled tip 43 to slide against second engaging surface 54 as latch post 42 begins to be received within latch post cavity 45. As latch post 42 is advanced further within latch post cavity 45, angled tip 43 causes latch 48 to rotate out of the way about cylindrical portion 55. Near the end of the advancement of latch post 42 within latch post cavity 45, the angled tip is advanced beyond latch body 50, and latch 48 (which is biased towards an engaged position) rotates into the engaged position with second engaging surface 54 biased against stop surface 52. With latch 48 and latch body 50 snapped into the engaged position, any separating force encountered between platform blade 16 and fixed housing 21 is resisted by action of first engaging surface 53 against latch surface 51. With this configuration, the reaction force at first engaging surface 53 is advantageously borne by latch body 50 pπmanly m compression Thus, since the loading is pπmanly compressive m nature, a high strength matenal is not required, and latch 48 can be made from standard engmeermg polymers, for example, such as polycarbonate

When it is desired to remove platform blade 16 from dnve 12, the operator simply turns latch knob 49, causmg latch body 50 to be placed m a disengaged position relative to latch post 42 With latch 48 disengaged, latch post 42 of fixed housmg 21 is free to be removed from latch post cavity 45 of platform blade 16 As is apparent from the Figures, a minor image of the latch assembly descπbed with reference to platform blade 16 and fixed housmg 21 is provided to releasably attach platform blade 14 to moveable housmg 22 When the retractor assembly is used to gam access to the thoracic cavity, a good deal of force must be generated to create the desired openmg For example, a separating force in excess of 100 pounds may be required to be generated at each engagmg member 18 to achieve the desired separation of a particular sternum Such loads must be earned by the engagmg members and transmitted to dnve 12 by way of platform blades 14 and 16 Smce platform blades are preferably made from a suitable engmeeπng polymer (for example, a glass filled thermoplastic polyurethane resm), it may be desirable to provide a reinforcmg member for each of platform blades 14 and 16 to ensure that platform blades 14 and 16 will not break or otherwise rendered moperable as a result of the loads encountered dunng use

Although the reinforcmg members may be a permanent or removable members within the platform blades themselves, the reinforcing members are preferably one or more substantially ngid members extendmg from each of the fixed housmg 21 and the moveable housmg 22 In a prefeπed embodiment, fixed and moveable housings 21 and 22 have a pm extendmg therefrom which may be received within a matmg cavity within first and second platform blades 14 and 16 The pm operates to spread the load developed m the mechamsm over a larger internal area within the platform blades 14 and 16 and reduces the effective beam length of umemforced platform blade matenal subjected to the operating loads The pm may be straight pm 40 illustrated m Figure 3 More preferably, fixed and moveable housmgs 21 and 22 have tapered pms 40 and platform blades 14 and 16 have mating tapered cavities 41 for receivmg tapered pms 40 The tapered construction tends to allow the user to easily align pm 40 with cavity 41 and allows the pms 40 to fit relatively snugly within cavities 41 without significant bmdmg dunng insertion that could otherwise occur between elongate pins and mating cavities which are designed to be very close fitting

To provide sufficient load beanng reinforcement, the reinforcmg pms 40 are preferably constructed of a substantially ngid matenal, such as steel, and are preferably at least about 0 75 mches long, more preferably at least about 1 125 mches long, and most preferably between about 1 25 mches to about 2 25 mches long In a prefeπed embodiment, reinforcmg pins 40 are made from AISI 420 stainless steel havmg a length of about 1 5 mches. an outside diameter near the housmg of about 0 25 mches, and a 2 degree taper angle decreasmg towards the free end of the reinforcmg pms 40

In the preferred embodiments just discussed, platform blade 16 can be removed from dnve 12 with a substantially straight-line relative motion as indicated by aπow 46 This engagement action not only provides for simple and mtuitive assembly m the operatmg room, but also represents a sigmficant safety feature Under certain rare circumstances, for example where the dnve through neglect or misuse has become sufficiently damaged dunng use that it is unable to close and disengage from the sternum, an extremely dangerous situation can be created for the patient In such exigent circumstances, the configuration descπbed above may allow the dnve to be separated from the in situ platform blades by releasmg the latches and applymg a sufficient amount of force m the direction mdicated by aπow 46 Once the dnve has been removed, the detached platform blades may be easily removed from the patient

In addition to engagmg members 18. detachable platform blades 14 and 16 may incorporate a wide vanety of additional features which enhance the performance of the retractor system For example, one or both of platform blades 14 and 16 may have mountmg features to which vaπous mstruments used dunng the procedure can be secured In the case where a stabilizer is to be secured to a retractor for operating on a beatmg heart, it is cntical to minimize or substantially eliminate the amount of flex and motion attributable to each component and each connection between each component, from the component engagmg the beatmg heart to the component which provides the sternal attachment To this end, the engagmg features 18 which engage the sternum are preferably part of a unitary platform blade structure which also mcludes mountmg features to which a stabilizer and other instruments can be mounted Smce the mountmg features and the sternal engagmg features are part of the same component, and therefore there is no mechanical connection between the two, the stability of an attached mstrument against the forces of a beating heart is greatly improved In a preferred embodiment, each of first and second platform blades 14 and 16 mclude mount features m the form of rails The rails allow one or more mstruments to be positioned at any desired location along the operable length of the rail Preferably, the rails are onented m a direction generally perpendicular to the direction of separation, m this case perpendicular to bar 15 The rails may be a recessed feature within the body of platform blades 14 and 16 More preferably, the mounting rails extend upwardly from the body of platform blades 14 and 16

Referring to Figures 7-9, πght platform blade 16 has rail 60 extendmg over at least a portion of the length of platform blade 16 Rail 60 may have a top portion and a bottom portion havmg a naπowed region adjacent said top portion In one embodiment, rail 60 preferably has a T-shaped cross-section The T-shaped configuration has a top portion 61 and a narrowed portion 62, thus forming mounting tabs 63 and 64 which can be gπpped by a number of appropπately constructed mounts

The rail may be straight, curved, or a combmation of straight and curved portions Preferably, at least a portion of the T-shaped rail is curved m a manner which more closely follows the profile of the access or incision site (as seen, for example, see Figure 45) In a curved rail configuration, mstruments extendmg perpendicular to a generally central axis 67 of rail 60 will naturally pomt more towards a central area between the platform blades 14 and 16, and thus may require less positional adjustment or mampulation from their normal, natural or beginning position In addition, all or a portion of top portion 61. and more specifically mounting tabs 63 and 64. may be tilted or angled inwardly at an angle 65 as shown

Platform blade 16 may be also be provided with a number of suture holders or stays which can be used to organize or capture vaπous sutures used m the course of a particular surgery Smce certain sutures are placed near the beginning of a CABG procedure, such as peπcardial sutures used to position the heart, the placement of the suture stays m a manner which does not mterfere with subsequent procedures and mstruments is an important aspect of the present invention Preferably, the suture stays are positioned such that placmg and manipulating the sutures or the vanous instruments and mstrument mounts employed dunng surgery can be accomplished without interfering with each other Preferably, the location of the suture stays position the sutures below the level of the mounting tab 63 and 64 so that a matmg mstrument mount may traverse the entire operable length of rail 60 without interfering with the sutures

Rail 60 may have one or more grooves, channels, slots or passageways for receivmg a suture In addition, a suture lock may be provided m the rail or elsewhere on platform blade 16 so that the suture may be fixed m place To accommodate the use of pencardial sutures, which are often subjected to a sigmficant amount of tension when used to position the heart, the suture locks must be adapted to hold the suture matenal even while under a sigmficant amount of tensile loading

In a preferred aπangement for organizing and locking sutures, and m particular tensioned pencardial sutures, rail 60 has at least one open slot or passageway formed therein for receivmg the free end portions of a surgically placed suture The passageways preferably extend across rail 60 and have a depth which allows the suture to lay at an elevation sufficiently below mounting tabs 63 and 64 so as not to mterfere with an mstrument mount sliding along rail 60 In a preferred embodiment the passageways extend through at least a portion of naπowed portion 62 Thus, the height 66 of naπowed portion 62 may be selected not only to provide sufficient space for a desired mstrument mount to attach, but also to ensure that mounting tabs 63 and 64 are sufficiently raised above the surrounding features of platform blade 16 so that an mstrument mount may be positioned and repositioned along rail 60 without disturbmg or disruptmg the sutures withm the vanous passageways The passageways may be a smgle channel for receivmg both free ends of a surgically placed suture or each end may have a separate channel In a prefeπed embodiment, rail 60 has a number of bifurcated channels 70 at predetermined intervals along its length Referring to Figure 10. bifurcated channel 70 has a smgle entrance channel 71 which bifurcates mto first and second exit channels 72 and 73 Entrance channel 71 and either one of exit channel 72 or 73 can be used m the same manner as a smgle channel, with both free ends 76 and 77 bemg routed together Alternatively, both suture ends may be received withm entrance channel 71 and then separated, one end withm exit channel 72 and one end withm exit channel 73

A means for clamping the suture agamst movement withm the suture channels may be provided on any of entrance channel 71 or exit channels 72 or 73 Preferab . suture locks are provided on each exit channel 72 and 73 This allows the surgeon to positively identify and unlock a desired suture end for further tension adjustments or other mampulation without unlocking or loosenmg the other end of the suture In addition, placmg each suture end 76 and 77 m separate exit channels 72 and 73, each with a dedicated suture lock, mcreases the maximum amount of tension that can be applied to a given suture Exit channels 72 and 73 may have recesses 74 and 75, respectively associated therewith for receivmg a suture lock adapted to secure the suture matenal withm the channels

A prefeπed suture lock 80 is illustrated m Figures 10 and 12 Suture lock 80 has a relatively ngid body 83 havmg a fixed or pivot end 81 which allows body 83 to pivot within the mating profile of recess 74 or 75 Pivoting the body 83 about pivot end 81 selectively engages and disengages free end 84 agamst the wall 78 of exit channel 72 or 1073 Alternatively, suture lock 80 may be made from a more flexible matenal which, by nature of the elastic properties of the matenal, tends to flex about its fixed end mstead of rotate In a prefeπed embodiment, fixed or pivot end 81 is substantially cylmdncal and recesses 74 and 75 have matmg cylmdncal surfaces Preferably, the suture lock is angled relative to the wall 78 so that it is self-locking m one direction That is, the suture ends 76 or 77 (or both) operate on the free end 84 m such a way as to force it towards wall 78, and thus agamst the suture matenal, m proportion to the tension, T encountered by suture ends 76 or 77 Thus, withm practical limits, the higher the tension the harder free end 84 will press or bite agamst the sutures placed therein Conversely, when the suture ends are pulled m the direction mdicated by arrow 79, the suture forces tend to pivot body 83 about pivot 81 such that free end 84 is rotated away from wall 84 allowing the suture to move relatively freely Preferably, angle 79 between body 83 and wall 78 is nominally about 1 degree to about 30 degrees, more preferably about 5 degrees to about 15 degrees, most preferably about 10 degrees Of course, angle 79 is greater as body 83 pivots to accept a suture placed withm the suture channel Suture lock 80 may be biased towards the locked position, preferably usmg a small spring between the suture lock and the recess 75 In a prefeπed embodiment, a piece of resilient closed cell foam 85 is fixed to body 83 to provide the desired biasmg effect Free end 84 may optionally have a number of teeth or πdges 82 to ensure acceptable traction agamst the suture matenal Platform blades 14 and 16 may also be provided with soft tissue retainers to help control and retain the mcised tissue and fat m the immediate vicinity of the blades Referring to Figures 8 and 9, platform blade 16 mcludes integrally attached tissue retainer 85 Tissue retainer 85 is generally at a small distance 88 above the top of the engagmg members 18 Tissue retainer 85 may be made from a flexible matenal, such as an elastomer, preferably a polyurethane elastomer havmg a durometer m the range of about 45 to about 75 Shore D, more preferably about 55 Shore D In a prefeπed embodiment tissue retainer 85 is injection molded over the platform blade to form a permanent and inseparable assembly Tissue retainer 85 may have a raised outer lip 86 and optionally havmg a plurality of slots 87 formed therein to receive and organize any loose suture ends Tissue retainer 85 ensures that the tissue suπounding the access incision does not mterfere with the operation of rail 60 or the suture holders and also provides a convement location for attaching surgical drapes of the like without interfering with the operation of the retractor assembly

Although some of the features of the present mvention have been descnbed, for illustration only, with respect to only one of the platform blades 14 and 16. it should be apparent that both platform blades 14 and 16 may have similar or identical features Although not necessaπly so, first platform blade 14 and second platform blade 16 are preferably substantially minor images of each other

The retractor assembly just descnbed, provides a simplified dnve mechamsm for use m conjunction with mufti-featured platform blades In addition, a number of different platform blades may be provided for use with a smgle dnve, for instance, tailored to different sized anatomy or the specifics of different surgical procedures Thus, a number of platform blade configurations can be provided to an operating room and, based upon pertinent prevailing clinical factors, the proper configuration can be selected, mounted to dnve 12, and used as descnbed above to provide access to a desired location Also, with the modular configuration new features and advancements can be rapidly incorporated mto the platform blades and immediately mtroduced for use with existing simplified dnves already m place m the operating rooms

The platform blades themselves represent a surgical platform that allows instruments to be mounted and stabilized m virtually any position, even over already placed and secured sutures from the surgical site accessed by the retractor assembly Descnbed below are prefeπed instrument mounts for use m conjunction with rail 60 to secure a beatmg heart stabilizer or other instruments such as heart positioners, saline or medical air blowers, suction devices, surgical clamps, or vessel occluders The Instrument Mount

Referring to Figure 13. a prefeπed instrument mount assembly 20 is shown for mounting an mstrument, such as stabilizer assembly 30. to an mstrument mounting rail such as descπbed above with respect to rail 60 of platform blades 14 and 16 Mount assembly 20 mcludes mount base 115 havmg features to secure mount assembly 20 at a desired position on an appropπately configured mating rail or other suitable structure and mcludes a stem locking mechamsm for controlling and securing an mstrument delivery stem m a desired position and onentation

One important aspect of instrument mount assembly 20 is to provide the necessary degrees of freedom to allow the mstrument to be easily maneuvered to whatever position may be required by a particular procedure As discussed above, an additional aspect with respect to stabilizmg the beating heart is to eliminate or minimize the flex or motion attributable to the vanous components and connections of mstrument mount assembly 20 As will be discussed m more detail below, mstrument mount assembly 20 is uniquely suited for use in stabilizmg the beatmg heart because it allows sufficient degrees of freedom to easily manipulate the position of an mstrument secured thereto, allows the degrees of freedom to be frozen or locked m place and, once locked m place, does not sigmficantly flex or allow movement at any of the articulating or mechanical jomts or connections

Instrument mount assembly 20 provides a number of different controllable articulating jomts that, when m a released condition, allows motion m one or more predetermined directions or about one or more degrees of freedom Although mstrument mount assembly 20 may be used to secure any mountmg delivery stem configuration from straight substantially ngid shafts to curved substantially ngid tubes to malleable deliver}' systems to multi-link or segmented ball and socket type delivery stems which are relatively flexible until themselves locked m some manner at each jomt along the delivery stem length, it is most advantageously constructed to provide the jomts or connections required to position an mstrument havmg a straight, substantially ngid shaft or a curved, substantially ngid tubular member

In a prefeπed embodiment, mstrument mount assembly 20 has three releasable jomts or connections for controlling the location and position of the mstrument mount assembly and mstrument attached thereto The mount base may be positioned at a desired location along an appropπate rail and secured by rail gnps 114 and 116 The position and onentation of the instrument is then determined by ball omt (or ball and socket jomt) 112 between mount base 125 and mount body 110, a rotational jomt 157 between mount body 110 and stem hub assembly 160, and a stem clamping mechanism withm stem hub assembly 160 which may allow translation, rotation, or both of delivery stem 3 relative to stem hub assembly 160

Ball jomt 112 is preferably of the ball and socket type havmg 3 rotational degrees of freedom Rotational jomt 157 allows rotation of stem hub assembly 160 about axis 121 as mdicated by arrow 113 The stem clamping mechamsm allows translation of mstrument delivery stem 3 as mdicated by arrows 111 as well as rotation about the delivery stem itself as mdicated by arrow 117 As will be discussed later, a further ball joint-type connection 201 may be employed between delivery stem 3 and the particular end-effector of the instrument Instrument mount assembly 20, havmg the particular jomts and connections identified above, allows all the required areas of the heart to be convemently and intuitively accessed by a stabilizer connected to one end of a substantially ngid shaft or, more preferably, a curved, substantially ngid tubular member as shown m Figure 13, for example Certainly, instrument mount assembly 20 could be provided with more or less degrees of freedom for maneuvering a particular mstrument For example, to add additional degrees of freedom rotational jomt 157 could be replaced with a ball jomt and to eliminate degrees of freedom delivery stem 3 could be keyed within stem hub assembly 160 or ball jomt 112 could be replaced with a rotation only joint However, it should be noted that excessive degrees of freedom may tend to make mstrument adjustment mcreasmgly difficult and cumbersome to control while too few degrees of freedom may not allow the mstrument to be easily placed m the desired position or onentation

In one embodiment, the vanous jomts and connections are locked mto a desired position by way of a senes of knobs The degrees freedom provided by ball jomt 112 is locked by activation of top mount knob 120 Both rotational jomt 157 and the stem clamping mechamsm of stem hub assembly 160 is locked m place by the activation of side mount knob 118 Base 125 is locked m position on the rail by activation of mount lever 122 Ball jomt 201, as will be discussed m greater detail below, may be locked in position by activation of knob 504 This particular sequence of knobs used to lock down the degrees of freedom associated with mstrument mount assembly 20 tends to allow the user greater precision m positioning the mstrument because degrees of freedom unnecessary to a particular desired maneuver of the mstrument can be locked down Most commonly, mount body 110 is placed at a desired angle or onentation and then fixed m place by lockmg ball jomt 112, leavmg final adjustment to take place usmg rotational jomt 157 and the delivery stem movement allowed by the stem clamping mechamsm of stem hub assembly 160

Figures 14-20 show m greater detail the vanous mechanisms which lock and release the jomts or connections associated with instrument mount assembly 20 Figure 20 14 shows an exploded assembly illustration of mstrument mount assembly 20 Instrument mount assembly 20, and more specifically mount base 125 to which all the other components are ultimately secured, is preferably constructed to engage and lock m position on a rail or other suitable feature

Preferably, mstrument mount assembly 20 has a fixed rail gnp 114 adapted to engage mounting tab 64 of rail 60 and a moveable rail gnp 116 adapted to engage mounting tab 63 of rail 60 Rail gnps 114 and 116 may generally have hook-like features for gnppmg mounting tabs 63 and 64 Rail gnp 114 is part of mount base 125 and moveable rail gnp 116 is part of articulatmg hinge member 115. which is pivotally attached to mount base 125 by way of hinge pins 123 and 124, or other suitable fastener Articulation of hmge member 115 and rail gnp 116 m clamping manner towards rail gnp 114 on mount base 125 effectively clamps mount base 125 onto rail 60 at mountmg tabs 63 and 64

Hmge member 115 may be articulated usmg any suitable mechamsm capable of pivotmg hinge member 115 to a closed position and holdmg it there In a prefeπed embodiment, best illustrated m Figures 15A-17, hmge member 115 includes follower surface 155 which may be acted upon by any suitable cam device to dnve hmge member 115 about hmge pms 123 and 124, thus urgmg rail gnp 116 towards rail gnp 114

In a prefeπed embodiment, hmge member 115 is articulated by action of cam 145 havmg cam surface 152 which acts upon follower surface 155 Cam 145 has a center, C about which cam 145 rotates Preferably, cam 145 has bore 127, havmg its central axis coincident with center, C Mount base 125 may have a cam guide 153 around which bore 127 πdes for smooth rotation of cam 45 about center, C Cam surface 152 has a varymg radius, illustrated by exemplar radial lmes Rl, R2, R3, R4, and R5 Thus as cam surface 152 is rotated past follower surface 155, from example from RI to R2, it pushes the follower surface a greater distance away from center, C, thus causmg hmge member 115 to pivot about hinge pms 123 and 124, thus causmg rail gnp 116 to move closer to rail gnp 114

The varymg radius of cam surface 152 may be configured to place hmge member 115, and thus rail gnp 116 m a vanety of positions A first portion of cam surface 1525 may be configured such that follower surface 155 biased agamst cam surface 152 is placed m an position charactenzed in that rail gnp 116 is sufficiently spaced apart relative to rail gnp 114 to allow assembly onto a rail or other structure A second portion of cam surface 152 has an mcreasmg radius such that rotation of cam 145 moves rail gnp 1 16 towards rail gnp 114 to an intermediate position In the intermediate position, rail gnp to 116 has been moved close enough to rail gnp 114 so that it becomes captured on a rail but remains loose enough to slide along the rail A third portion of cam surface 152 has an mcreasmg radius such that the rotation of cam 145 moves rail gnp 116 further towards rail gnp 114 to a completely locked position wherem relative motion between rail gnps 114, 116 and the rail is essentially no longer possible Cam 145 is generally provided with a handle or lever 122 to allow the user to easily turn cam

145 relative to mount base 125 Cam 145 may be captured onto mount base 125 by operation of retaining hook 150 on cam 145 which ndes withm extenor groove 151 on mount base 125 on one side, and projection 154 which is engaged below undercut 156 generally opposite to retaining hook 150 Projection 154 also serves to work against undercut 156 to return hmge member 115 to the open position as cam 145 is rotated m the opposite (open) direction Hmge member 115 preferably has first and second end stops 158 and 159 between which the motion of projection 154 (and thus the rotation of cam 145) is limited. Cam 145 may also have a protective extended portion or cover 163 which shields the area of groove 151 when assembled over mount base 125.

The assembly of cam 145 and hinge member 115 to mount base 125 is illustrated in Figures 15A and 15B. Cam 145 is placed in position relative to hinge member 115 with projection 154 in place below undercut 156. In roughly that position, cam 145 and hinge member 115 are brought over mount base 125 until bore 127 is properly seated over cam guide 153 and retaining hook 150 is positioned within groove 151. Pins 123 and 124 are then pressed in place through holes provided in both mount base 125 and hinge member 115. Ball joint 112 is generally created between ball 129 provided at the top of mount base 125 and a socket or mating cavity within mount body 110 adapted to receive at least a portion of ball 129. Preferably ball 129 includes a generally spherical portion, although other curved shapes providing the desired degrees of freedom may also be suitable. Base post 130 extends vertically upward through bore 126 of mount base 125 and vertical passageway 128 of mount body 110 until enlarged end portion 130 become biased against mount base 125. Top mount knob 120 may then be threaded onto threaded shaft 132 whereby mount base 125 and mount body 110, with ball 129 received within mount base 125, becomes captured between top mount knob 120 and enlarged end portion 130. Continued tightening of top mount knob 120 over threaded shaft 132 forces ball 129 harder against mount body 110 until the friction between mating surfaces on ball 129 and mount body 110 become so great as to effectively resist any relative movement, thus locking ball joint 112.

The assembly of rotational joint 157 and stem hub assembly 160 are shown in Figure 19. Rotational joint 157 is in the form of a conical clutch formed between frustoconical surface 138 of clutch member 135 and mating frustoconical surface 139 in mount body 110. Stem hub assembly 160 is generally formed as upper and lower stem locks 136 and 137 are advanced over stem grip 140 and against instrument delivery stem 3 which is positioned between stem locks 136 and 137 and outer stem guide 144. As clutch member 135 is received over the outside diameter of grip housing 141 of stem grip 140 tang 164 becomes engaged between upper stem lock 136 and lower stem lock 137 thereby preventing relative rotation between clutch member 135 and stem grip 140.

Side mount knob 118 having threaded shaft 119 extends through mount body 110 (and consequently through transverse bore 131 in central portion 167 ofbase post 130), clutch member 135 and into interior threads 142 within grip housing 141 of stem grip 140. Tightening of side mount knob 118 clamps the assembly together. Thus, translation and rotation of instrument delivery stem 3 is prevented as stem grip 140 and clutch member 135 are forced together to clamp or trap instrument delivery stem 3 between stem locks 136 and 137 and outer stem guide 144. Also, relative rotation between frustoconical surface 138 of clutch member 135 and mating frustoconical surface 139 in mount body 110 is prevented as clutch member 135 is forced against mount body 110 One or both of frustoconical surface 138 and matmg frustoconical surface 139 may mclude a number of teeth, ndges, or other features to prevent rotation when clutch member 135 is forced against mount body 110

So that the delivery stem does not become too loose as side mount knob 118 is loosened, a minimum amount of friction between mstrument delivery stem 3 and the clamping surfaces 146 of outer stem guide 144 is preferably maintained by providing a biasmg load against delivery stem 3 Referring to Figure 20, stem biasmg member 147 is provided withm stem gnp 140 to maintain a biasmg load agamst delivery stem 3 Stem biasmg member 147 has a first portion 148 which slides withm counterbore 143 in stem gnp 140 Stem biasmg member 147 may optionally have a second portion 149 having external dimensions sized to be received withm the mside diameter of compression spring 133 Compression spring 133 urges end 134 of stem biasing member 147 agamst delivery stem 3 to force delivery stem 3 agamst clamping surfaces 146 The amount of force is selected to allow mstrument delivery stem 3 to be easily positioned by hand but would generally not allow mstrument delivery stem 3 to slide relative to stem gnp 140 under only its own weight Referring to Figure 21 a prefeπed mstrument mount assembly 20 is shown fixed to a preferred platform blade 16 havmg rail 60 As discussed above, rail 60 has mountmg tabs 63 and 64 over which rail gnps 114 and 116 may be secured Instrument mount assembly 20 can be positioned, maneuvered, and removed virtually anywhere along rail 60 without disturbmg suture 166 locked m place by free end 84 of suture lock 80 below the operatmg features of instrument mount assembly 20 within any one of the suture channels provided in platform blade 16 In addition, rail 60 is placed m close proximity to engagmg member 18 and thus close to the surgical openmg mto the patient providing a more direct access to the heart by an mstrument mounted to mstrument mount assembly 20 Smce the rail 60 moves in unison with platform blade 16, this relationship between rail 60 and engagmg member 18 is maintained no matter how much or how little platform blades 14 and 16 have been spread to create the desired surgical openmg

Figures 22A-32 illustrate a prefeπed embodiment of an alternative instrument mount assembly 220 Preferably, the degrees of freedom available for maneuvering mstrument mount 220 is substantially the same as that of instrument mount assembly 20 Instrument mount assembly 220 preferably has ball jomt 112 between mount base 221 and mount body 222, a rotational jomt 157 between mount body 222, and a stem hub assembly 227 which allows rotation and translation of an mstrument delivery stem held between stem gnp 226 and clutch member 226 of stem hub assembly 227 Instrument mount assembly 220, however, has a different mechanism for controlling or lockmg the vaπous jomts and connections and may also provide a means for releasmg and removing the delivery stem from the bulk of the remainder of mstrument mount assembly 220 As ust mentioned, the jomts and connections themselves are quite similar between mstrument mount assemblies 20 and 220 As before, ball jomt 112 is a ball and socket configuration created between generally sphencal ball 224 provided at the top of mount base 221 and a matmg cavity withm mount body 222 adapted to receive and slide agamst at least a portion of ball 224 Rotational jomt 157 may be m the form of a conical clutch formed between frustoconical surface 243 of clutch member 225 and matmg frustoconical surface 244 m mount body 222 An instrument delivery stem may be clamped m place withm stem hub assembly 227 by forcmg together stem gnp 226 and clutch member 225 thus clos g clamp surface 239 of outer stem guide 233 towards V-shaped channels 273 on stem locks 231 and 232 Instead of lockmg the jomts and connections by way of multiple knobs as descnbed above with respect to mstrument mount assembly 20, mstrument mount assembly 220 preferably uses a mechamsm which releases each of ball jomt 112, rotational jomt 157, and the stem clamping mechamsm of stem hub assembly 227 by activation of a smgle knob, lever, or other suitable manual interface Generally speaking, this is accomplished by utilizing the clamping motion required to lock one or more of the joints or connections along a first axis to also lock the remamder of the jomts or connections along remaining axes

In a prefeπed embodiment, ball 224 of mount base 221 is locked m place relative to housmg 222 by operation of base post 230 Base post 230 is assembled through mount base 221 and mount body 222 from the bottom until bottom flange 259 (see Figure 27) is resisted agamst mount base 221 At the top of base post 230 is upper link portion 256 havmg pivot hole 257 Cam 235 is attached through pivot hole 257 at off-center link pivot 238 usmg a pin or other suitable fastener and is supported by contact surface 236 associated with mount body 222 Contact surface 236 may be an integral feature of mount body 222 or may be m a separate mount bodv cover 254 which may be selected to have superior wear charactenstics With cam 235 m a closed position, as shown m Figure 24, link pivot 238 is drawn to its maximum distance 251 (or slightly less than the maximum if the cam is constructed to rotate over center) from contact surface 236 thus mcreasmg the clamping force between mount body 222 and ball 224 as the assembly is clamped between cam 235 on the top and bottom flange 259 on the bottom With cam 235 m the closed position, ball jomt 112 is effectively locked By rotating cam 235, by way of handle 237, to an open position as illustrated m Figure 25, link pivot 238 is withdrawn to a position closer to contact surface 236 at a distance 252, thus reducmg or relaxing the clamping forces between mount body 222 and 096 ball 224 of mount base 221 With cam 235 m the open position, the friction at ball 224 is reduced to a level that allows the user to easily manipulate mount body 222 relative to mount base 221 Mount base 221 may have an insert 253 secured m the bottom thereof agamst which bottom flange 259 is caused to seat as upper link portion 256 is drawn upwards by operation of cam 235 Preferably, insert 253 mcludes recess 255 for receivmg compression spring 248 captured about base post 230 Compression spring 248 operates between insert 253, and thus mount base 221, and bottom flange 259 to bias base post 230 towards the unlocked position

That same motion of base post 230, created by operation of cam 235, is preferably also used to lock both rotational jomt 157 and the mstrument stem clamping mechanism of stem hub assembly 227 Instead of usmg a threaded shaft to clamp mstrument mount assembly along this axis as did the previous embodiment, mstrument mount assembly 220 preferably utilizes tie pm 240 which is dπven m the direction of anow 245 causmg stem gnp 226 and clutch member 225 to be forced together to clamp an instrument delivery stem placed therein and also causmg fhistocomcal surface 243 of clutch member 225 to forced agamst fhistocomcal surface 244 m mount body 222

Tie pm 240 preferably has a generally cylmdncal back portion 261 and a front portion which is connected m some manner to stem gnp 226 Preferably, the front portion mcludes forward extendmg first and second flexible prongs 262 and 263 Cylmdncal back portion 261 is shdably received withm blmd hole 272 of release button 242 and is preferably biased m the unlocked direction mdicated by aπow 270 by compression spring 247 positioned withm blmd hole 272 behind tie pm 240 Tie pm 240 is preferably dπven m the direction of anow 245 by the movement of base post

230 which is assembled m the space between first and second prongs 262 and 263 of tie pm 240 Preferably, base post 230 has an angled cam or ramp 258 that engages back wall 269 at the base of first and second prongs 262 and 263 As base post 230 is drawn upwards m the direction of aπow 271 by cam 235 from the open position of Figure 25 to the closed position of Figure 24, ramp 258 progressively forces back wall 269, and thus tie pm 240, m the direction of mdicated by aπow 245 Tie pm 240, connected at its front end to stem grip 226, locks an mstrument delivery stem in place and locks rotational jomt 157 m the same manner as did threaded shaft 119 of mstrument mount assembly 20 In sum, tie pm 240 urges stem gnp 226 towards clutch member 225 and mount body 222 The movement of stem grip 226, havmg tang 236 engaged between upper and lower stem locks

231 and 232 of clutch member 225, closes together m a clamping fashion surfaces 239 on stem gnp 226 and V-shaped channels 273 on clutch member 225 At the same time, stem gnp 226 pushes agamst clutch member 225 to force fhistocomcal surface 243 agamst matmg fhistocomcal surface 244 with sufficient force to fhctionally lock the surfaces together, thus preventing relative motion therebetween

The operation of cam 235 has been descnbed as generally moving between an open position, m which the vanous jomts and connections of mstrument mount assembly 220 are free to be easily manipulated about their respective degrees of freedom, and a closed position m which the jomts and connections resist any relative movement and are thus effectively locked m position However, the outer cam profile of cam 235 operating agamst contact surface 236 may be given a profile that has one or more intermediate positions such that link pivot 238 is placed at an intermediate distance from contact surface 236 In an intermediate position, the jomts and connections may be m a stiffened or partially locked state which allows some positional and onentational mampulation with somewhat higher operator forces that the completely released condition In addition, the action of base post 230 may be such that ball jomt 112 becomes fully locked before tie pm 240 has completely locked the remaining degrees of freedom Thus, cam 235 may have a completely released position where mampulation about all degrees of freedom is easily accomplished, an intermediate position m which only ball jomt 112 is fully locked and the remaining degrees of freedom are unlocked or may be partially locked, and final closed position in which all degrees of freedom are locked

Instrument mount assembly 220 may optionally be provided with a release mechamsm allowing stem gnp 226, and thus the mstrument delivery stem shdably assembled therein, to be released from mstrument mount assembly 220 preferably by activation of release button 242 This allows mstruments associated with instrument mount assembly 15 220 to be quickly and convemently removed and replaced or exchanged

In a preferred embodiment, first and second prongs 262 and 263 of tie pm 240 have first and second projections 267 and 268 which releasably attach tie pm 240 to stem gnp 226 Gnp housmg 274 of stem gnp 226 is covered with a sleeve havmg a deep counterbore 278 and small through hole 279 The depth of counterbore 278 is longer than the extenor of gnp housmg 274 so as to form internal space 290 (see Figure 25) when assembled First and second prongs 262 and 263 can be flexed to position projections 267 and 268 relatively close together for insertion through hole 279 where projections 267 and 268 can then expand apart lockmg projections 267 and 268 behind surface 280 Preferably, projections 267 and 268 have lead-ms 291 and 292 which urged projections 267 and 268 together as they are advanced through hole 279 so that stem gnp 226 can simply be aligned with lead-ms 292 and 292 and then snapped mto place without any further action Alignment of hole 279 is generally quite simply accomplished as the cylmdncal extenor surface 277 of sleeve 260 is shdably received m a substantially coaxial aπangement withm center bore 219 of clutch member 225 Clutch member 225 may optionally have first and second flexures 281 and 282 havmg first and second retaining features 283 and 284 so that it may be snapped m place and thereafter retained withm mount body 222

As mentioned above, stem gnp 226 may be released from tie pm 240 To separate tie pm 240, it is necessary to flex first and second prongs 262 and 263 together so that projections 267 and 268 will agam be positioned to fit through hole 280 This may be accomplished by providmg a raised portion 264 havmg a ramp 266 on tie pm 240 A shdmg member may be advanced up tie pm 240 and over ramp 266 and raised portion 264 thus flexing prongs 262 and 263 inwards Preferably, the shdmg member is a tip portion 289 of release button 242 Tie p 240 is shdably received withm blmd hole 272 of release button 242 The internal diameter of blmd hole 272 is small enough so that when it is advanced over ramp 266 and or raised portion 264, prongs 262 and 263 are flexed inwards

Preferably, the entrance to blmd hole 272 has an internal chamfer 288 so that ramp 266 is smoothly engaged as release button 242 is advanced

Release button 242 preferably has a generally cylmdncal body 285 which is shdably received withm matmg bore 294 (see Figure 25) of mount body 222 Release button 242 is retained m place, and its shdmg travel limited, by release button flange 241 on one end and spring clip or e-chp 293 assembled withm e-chp groove 286 on the other end Spring matenal 246, such as a wave spring washer or foam matenal, may be disposed between release button flange 241 and mount body 222 to bias release button 242 outwards Transverse to blind hole 272 tip portion 289 also has a clearance slot 287 through which base post 230 passes For clarity only, Figures 22A-25 have illustrated mstrument mount assembly 220 without hmge member 115 and cam 145 attached However, hmge member 115 havmg rail gnp 116 is preferably pivotally mounted, with cam 145 m place, by way of pms or the like at hmge mount 228 as descnbed above with reference to mstrument mount assembly 20 As discussed above, cam 145 may be rotated about cam guide 223 usmg base lever 122 to secure the mstrument mount to a rail or other suitable structure

Figures 33-37A illustrate a prefened embodiment of another alternative instrument mount assembly 400 which allows the assembly to be locked m a desired position usmg a smgle knob Preferably, the degrees of freedom available for maneuvering mstrument mount 400 is substantially the same as that of mstrument mounts 220 and 20 as previously discussed Instrument mount 400 preferably has ball jomt between mount base 421 and mount body 422, a ball or a rotational jomt between mount body 422 and clutch member 425, and a stem hub assembly which also allows rotation and translation of an mstrument delivery stem held between stem gnp 426 and clutch member 425

Instrument mount assembly 400 preferably allows the vanous articulating or mechanical jomts along first axis 481 and second axis 482 to be maneuvered as desired and then locked m a desired position by actuatmg or operatmg a smgle knob, handle, or other user mterface Such multiple-axis aπangements are beneficial m many surgical settings as it is often desirable to have mstruments mounted as low as possible about an access openmg mto a patient while the mstruments themselves must be maneuvered and secured at sharp angles relative to the access openmg For example, when securing an mstrument for stabilizmg the heart dunng a CABG procedures, the angle between first axis 481 and second axis 482 is preferably less than about 120 degrees, more preferably between about 100 degrees and about 45 degrees, and most preferably about 90 degrees Further, the ability to lock jomts along multiple axes with a smgle knob tends to reduce the operational complexity of the instrument mount while maintaining the ability to easily maneuver and secure instruments through an access incision withm a patient Thus, this configuration provides a low-profile, flexible, nght-angle mount for maneuvering and securing a wide aπay of surgical instruments

In a prefeπed embodiment, the ball jomt between mount base 421 and mount body 422 is preferably a ball and socket configuration which may be created between generally sphencal ball 429 provided at the top of mount base 421 and a matmg cavity or socket 440 withm mount body 422 adapted to receive and slide agamst at least a portion of ball 429 In a prefened embodiment, the ball and socket configuration may also mclude a generally sphencal end 432 on base post 430 which couples with matmg surface 447 m the mtenor of mount base 421 In this configuration, mount base 421 is controlled between spherical end 432 and socket 440 and becomes locked m place as the distance between sphencal end 432 and socket 440 is reduced to a dimension which clamps that portion of mount base 421 residing therebetween The rotational jomt between mount body 422 and clutch member 425 may be m the form of a conical clutch formed between fhistocomcal surface 423 within mount body 422 and mating frustoconical surface 424 on clutch member 425 An mstrument delivery stem may be clamped m place withm the open space 470 between stem gnp 426 and clutch member 425 by urgmg stem gnp 426 towards clutch member 425 In an alternative configuration, clutch member 425 may simply be the first link of a multi-link support member which may have a senes of ball and socket links extendmg away from said instrument mount and terminating m an end effector, such as a tissue stabilizer

Instrument mount assembly 400 preferably has knob 414, the action of which to serves not only to operate upon stem gnp 426 and clutch member 425 to lock the degrees of freedom along first axis 481 but also urges sphencal end 432 of base post 430 towards socket 440 withm mount base 421, thus lockmg the ball jomt along axis 482 Preferably, the locking action along axis 481 is provided by pull p 450 which has threaded section 453 which may be operably engaged by internal threads withm knob 414 or any other suitable cam or mechamsm configured to deliver the required axial force to pull pm 450 Pull pm 450 is preferably a generally ngid member, but may also be a section of wire or cable havmg an appropnate threaded end swaged or otherwise attached thereto For example, when a multi-link support is coupled to mount body 422 as discussed above, pull pm 450 may be part of or attached to the proximal end of the cable used to lock the links of the mufti-link support member

In a prefened embodiment, pull pm 450 is secured withm gnp housmg 441 of stem gnp 426 Preferably, pull pm 450 is secured withm gnp housmg 441 m a manner which does not allow rotation of pull pm 450 withm gnp housing 441 In a prefeπed embodiment, pull pm 450 has knurled section 452 which has an interference fit withm bore 442 Gnp housmg 441 has a counterbore 444 for receivmg head 451 of pull pm 450 Head 450 bottoms agamst the end of counterbore 444 allowing gnp housmg 441 to be pulled against gnp housmg 441

Gnp housmg 441 of stem gnp 426 extends through central bore 420 of clutch member 425 Clutch member 425 is positioned withm mount body 422 with fhistocomcal surface 423 adjacent or agamst mating frustoconical surface 424 of mount body 422 When the internal threads 418 of knob 414 are advanced along threaded section 453 of pull pm 450 by rotation of knob 414 m the appropnate direction generally mdicated by aπow 413 about axis 481, head 451 pulls stem gnp 426 against clutch member 425 which is m turn pulled agamst fhistocomcal surface 423 of mount body 422 As knob 414 is tightened in this manner, the fhctional forces at the stem clamping jomt and the comcal clutch jomt mcrease m proportion to the axial force delivered by pull pm 450 until the degrees of freedom begin to stiffen due to the increased fhctional forces and eventually become functionally locked agamst further relative motion

Base post 430 is generally positioned through internal bore 419 of mount base 421 such that sphencal end 432 abuts mating surface 447 withm mount base 421 Preferably, base post 430 (best seen m Figure 37A) has an extension or support post 436 which is engaged withm a receivmg feature, such as openmg 428 at the top of mount body 422 Base post 430 has a transverse bore through which pull pm 450 passes Base post 430 also has a cam surface 435, preferably supported by or associated with upper flange 434 Cam surface 435 may be used to close the position of base post 430 relative to mount body 422 so as to lock the position of mount body 422 relative to mount base 421 Cam surface 435 may be urged upwards generally along second axis 482 by forcmg a suitable thrust surface mto engagement with cam surface 435 A suitable thrust surface may be urged m the direction mdicated by aπow 483 to contact cam surface 435 causmg base post 430 to move upwards m the general direction mdicated by aπow 484 The thrust surface is generally associated with knob 414 such that advancement or translation of knob 414 along threaded section 453 of pull pin 450 causes cam surface to move up or down m relation to the position of the mating thrust surface The thrust surface may be integral with knob 414 or as discussed below provided on a separate element which is engaged by knob 414

In a prefeπed embodiment, cam surface 435 is urged upwards by operation of lifter 465 which slides over pull pm 450, preferably over a non-threaded or smooth section of pull pm 450 Lifter 465 may have a contoured, shaped, radiused, or chamfered thrust surface 466 configured to mate with cam surface 435 Knob 414 preferably has guide housmg 416 which is sized to fit within matmg guide bore 415 of mount body 422 As knob 414 is tightened, and internal threaded portion 418 is urged along threaded section 453 of pull pm 450, guide housmg 416 pushes lifter 465 m the direction mdicated by arrow 483. thus engagmg cam surface 435 with mating surface 466 causmg base post 430 to move upwardly towards mount body 422 and socket 440 m the direction generally indicated by arrow 484. As with the other mechanical joints, tightening knob 414 proportionally increases the frictional forces at the socket 440/ball 429 and spherical end 432/mating surface 447 interfaces until they become functionally locked against relative motion.

To eliminate the possibility of the instrument mount assembly becoming disassembled during use, knob 414 is preferably captured on pull pin 450. In a prefeπed embodiment, pull pin 450 has an extension 454 having an enlarged portion 455. Knob 455 is assembled over extension 454 until enlarged portion 455 is forced past restriction 476. Once snapped in to place, enlarged portion 455 is free to travel within clearance passage 457 but remains captured by operation of restriction 476 even if knob 414 becomes completely disengaged from threaded section 453. Knob 414 preferably has a non- threaded internal bore 417 which is sized to smoothly traverse over both non threaded portions of pull pin 450 as well as threaded section 453 as may be required over the full travel of guide housing 416 and knob 414. Knob 414 preferably has one or more grip ridges 411 to facilitate convenient operation by a user, typically wearing surgical gloves.

This prefeπed configuration of instrument mount assembly 400 allows the mechanism to perform in a number of ways with only slight modification. For instance, the operation of pull pin 450 and lifter 465 can be configured to have the mechanical joints tighten and lock according in any desirable order or timing preference. In one embodiment, the mechanical stem lock, rotating clutch, and ball joint begin to stiffen generally at the same time. It may be desirable for lifter 465 to be made from a somewhat softer material or initially have a point or line contact with cam surface 435 such that lifter 465 deforms or crushes somewhat as the mechanism is tightened. Lifter 465 may be made from any suitable tough yet relatively soft engineering plastic such as nylon, high density polyethylene, polypropylene, or the like. This allows lifter 465 to stiffen the ball joint initially, and then as knob 414 is tightened further, lifter 465 crushes or deforms so that only modest increases in fhctional forces are imparted to the ball joint while the remaining mechanical joints along pull pin 450 are allowed to tighten significantly. Further tightening of knob 414 eventually locks each of the mechanical joints of instrument mount assembly 400.

In a preferred embodiment, it is desirable for the ball joint between mount base 421 and mount body 422 to tighten slightly ahead of the remainder of the mechanical joints. This allows the user to initially manipulate mount body 422 to the desired position or orientation and begin tightening the knob to substantially stiffen or even lock the ball joint and thus mount body 422. The surgeon may then manipulate the instrument to the to desired position and orientation using the degrees of freedom available in the comcal clutch and stem clamp. At that point, knob 414 can be further tightened to lock the remainder of the mechanical joints. Knob 414 can be loosened slightly to reposition the instrument if required without disturbing the ball joint. Compression spring 460 may be used to operate agamst upper flange 434 to pre-load base post 430 upwardly so that a minimum amount of fictional forces are maintained m the ball jomt between mount base 421 and mount body 422

To force base post 430 to clamp at an earlier pomt as knob 414 is tightened, the lifter may be constructed of a harder matenal and may have a greater contact area agamst cam surface 435 Figure 37B illustrates lifter 490 havmg a greater contact area for engagmg cam surface 435 Lifter 490 has a more extended profile, and may preferably be square or substantially square shaped The extended profile provides the matenal for an enlarged surface 492 for contacting cam surface 435 Smce lifter 490 is no longer symmetncal about its axis, it may be desirable to key lifter 490 relative to cam surface 435 to ensure proper alignment Preferably, lifter 490 has one or more nbs or protrusions 494 to engage matmg surfaces (not shown) within mount body 422 to ensure surface 492 will be aligned with cam surface 435 as bore 496 ndes over pull pm 450

Instrument mount 400 may be secured to any stable location such as, for example, a nb or sternal retractor or other convement mountmg location which is sufficiently stable to secure the desired mstrument As with the previous mstrument mount embodiments, mstrument mount 400 is configured to cooperate with a rail or like structure, preferably associated with the retractor used to create the access openmg through which an mstrument is to be mserted In a prefeπed embodiment, hmge member 412 havmg rail gnp 472 is preferably pivotally mounted to mount base 421 by way of pms or the like at hmge mount 462 as descnbed above with reference to mstrument mount assembly 20 Cam member 445 may be rotated about cam guide 438 usmg base lever 410 causmg hinge member 412 to urge rail gnp 472 towards rail gnp 471 on mount base 421, thus facihtatmg mstrument mount 400 to be secured to a rail or other suitable structure

The retractor and mstrument mounts descπbed above can be used to mount and stabilize a great number of mstruments for use dunng surgery Preferably, the retractor and mstrument mounts are used to mount a mechamcal stabilizer for stabilizmg at least a portion of the beatmg heart dunng CABG surgery or the like Descnbed below are a number of mechamcal stabilizer embodiments that are particularly beneficial for stabilizmg the beatmg heart, especially when used m conjunction with the retractors and mstrument mounts descnbed above Tissue Stabilizers Once access to the heart is achieved, and the heart is positioned if necessary, a means for stabilizmg the beating heart is mtroduced through the opening created and at least one component of the stabilizmg device of the mvention is brought mto contact with the beatmg heart The surgeon then applies a stabilizmg force to the beatmg heart via the stabilizmg means which may then be fixed m place by attachment to a fixed support When a retractor or platform is fixed m an open position to expose the heart, the retractor platform may also provide the stable support structure to which the stabilizing means is affixed When the position of the stabilizmg means is fixed by attachment to a stable support or to the retractor platform, the stabilizing force is maintained for the duration of the procedure.

The structure of the portion of the stabilizing means which contacts the heart may include one or more contact members which exert a stabilizing force on the heart proximate to the site of the anastomosis. A pair of contact members may be plates or rectangular members which are placed on either side of the target coronary artery at the site of the anastomosis and which may have friction means or tissue spreading or compressing apparatus associated therewith. The contact members may also be provided by a platform which may be substantially planar or which may be contoured to fit coriformingly on the surface of the heart. The stabilizing means may also include a delivery system or member which may have any suitable construction that allows the working end of the stabilizing means to be positioned and secured as necessary. The delivery system or member may include flexible multi- link constructions, malleable constructions or other delivery stem having several alternative embodiments to facilitate adjusting the position and orientation of the instrument at the surgical site. For example, the delivery stem may be a common shaft or alternatively, a curved tubular member, and may have an adjustable length and the axis of the delivery stem may have at least one ball joint disposed within its length such that the orientation of the delivery stem relative to another structure such as the contact members or stable support may be continuously varied. As is apparent from the description of the several embodiments, each of the individual embodiments described and illustrated herein has discrete components and features which may be readily separated from or combined with the features of any of the other several embodiments.

Referring to Figures 38-42, a prefeπed stabilizer assembly for stabilizing the beating heart is comprised of a foot or base portion 553 attached to a rigid or semi-rigid delivery stem 3, drawn here, for purposes of example only, as a curved tubular member. Base portion 553 typically has one or more contact members 1 adapted to contact the heart adjacent the site desired to be stabilized. The contact members 1 may be substantially planar, may be slightly curved to conform to the shape of the heart, or may be a non-conforming curve to establish contact between only a to portion of the contact member 1 and the beating heart. The shape of the contact members may be varied depending on the clinical assessment by the surgeon, the design of the other features of the stabilizing means, or the design of other instruments used to complete the anastomosis. In some embodiments the contact members 1 may have apertures, openings or attachments to facilitate connection with sutures or other devices to achieve the requisite stabilization, occlusion of the target vessel, or exposure of the target vessel. Examples of suitable base portions and contact members can be found, for example, in co- pending U.S. Patent Application Serial Number 08/931,158 filed on September 16, 1997, entitled "SURGICAL INSTRUMENTS AND PROCEDURES FOR STABILIZING THE BEATING HEART DURING CORONARY ARTERY BYPASS GRAFT SURGERY." the entirety of which is herem incorporated by reference

Referring to Figures 38 and 39, the proximal end of connecting delivery stem 3 has handle mechamsm 468 assembled thereto which, among other things, provides the user with a means for lockmg an end effector operably attached to the distal end of connecting delivery stem 3 The mechamsm 468 is rotatably secured to the proximal end of the delivery stem 3 and is formed at a selected angle to the delivery stem to permit a surgeon to swivel the mechamsm to a preferred position where the knob 504 is more readily accessible to allow quickly lockmg the delivery stem 3 m the onentation selected In addition, the angled axis of the knob 504 relative to the delivery stem 3 reduces the tendency of the delivery stem 3 to rotate about its axis when a surgeon applies torque to the knob 504 to lock the associated lockmg mechamsm The knob 504 is secured to a screw 539 by suitable means such as press fitting, bondmg, etc Right and left handle covers 540, 541 compnse the handle

503 and provide the support for the handle mechamsm When assembled, the covers define generally a cylmder formed with a selected curvature A secondary inner moldmg, generally mdicated at 542, mcludes vanous mtegrally formed annular walls and shoulders for supportmg and containing the knob

504 and screw 539, as well as a cooperating nut 543, and arcuate wedge 544, a stem retainmg nng 545, the proximal end of the delivery stem 3, and a proximal end of the translatable push rod 505 The proximal end of the delivery stem 3 mcludes an annular retainmg nng slot 546 which secures the proximal end of the delivery stem 3 within suitable annular walls m the corresponding end of the handle covers 540, 541 when the retainmg nng 545, confined by shoulders m the inner moldmg 542, is snapped mto the slot 546 and the covers are assembled The nut 543 is confined by shoulders m the inner moldmg 542, and the arcuate wedge 544 is shdably confined by coπespondingly arcuate walls 547 also formed m the inner moldmg

As may be seen, rotation of the threaded screw 539 withm the confined threaded nut 543, causes translation of the screw, pivotmg and thus translation of the translatable wedge 544 which abuts the screw, and translation of the push rod 505 which abuts the translatable wedge As is further descnbed relative to Figures 40-42, any tightemng or loosening of the screw 539, however slight, will cause a coπesponding translation of the push rod 505 mto or out of the delivery stem 3

As depicted m the Figures, the delivery stem 3 and thus the push rod 505, are formed with a slight arcuate configuration, which permits additional degrees of freedom and movement and onentation of the distal end of the delivery stem 3 and thus of the heart contact member 1 Rotation of the delivery stem 3 about the axis of confinement withm the stem gnp 495 or 495a, moves the distal end of the delivery stem 3 through a circular path while changing the angles through which the contact member 1 can be onented This allows a surgeon to convemently achieve a wider range of positions and onentations of the contact member relative to the patient's heart, while keepmg the proximal end of the delivery stem 3 and handle mechamsm 468 out of the way as much as possible

Figures 40-42 illustrate an associated mechamsm for maneuverably supportmg the vanous embodiments of the contact member 1 and for cooperatively assistmg m the quick locking of the contact member by a partial rotation of the knob 504 once the member is positioned To this end, the distal end of the delivery stem 3 is provided with extenor threads matching mtenor threads m a ball/socket 548 The distal end of ball socket 548 is provided with slots 549, whereby the remaining matenal compnses short extended tips 550 which, when bent m or inwardly formed, form a socket A ball/post 551 mcludes a ball at one end and a post at the other When the mechamsm is assembled, the ball/post 551 is mserted mto place withm the ball socket 548 with the ball m the socket and the post protruding from the ball socket A mechamsm for providmg a preloaded source, such as a compression spring 552, is coupled to the ball/socket 548 abutting the ball The spring 552 is urged by the distal end of the delivery stem 3 to exert a preloaded or constant minimum force against the ball of the ball/post 551 The post of the ball/post 551 is solidly fixed as by press fitting, welding, etc , to the contact member 1 The distal end of the push rod 505 passes through the spnng 552 to abut the ball of the ball post 551 Thus when the screw 539 is not tightened, the distal end of the push rod 505 exerts a slight pressure agamst the ball, however the spπng 552 maintains a preloaded force against the ball sufficient to maintain the contact member 1 at any onentation set by a surgeon When the screw 539 is tightened, the push rod 505 is forced agamst the ball to prevent any further movement of the contact member 1 As may be seen, the contact to member 1 can be tilted to assume many onentations smce the narrow center of the post can tilt mto any of the four slots 549 m the ball/socket 548 In addition, simultaneous rotation of the curved delivery stem 3 provides surgeon with an even greater vanety of onentations of the contact member relative to a patient's heart

The contact member 1 mcludes a prefeπed configuration which improves the size of the area of the heart which is visible to a surgeon while still providmg the required suppression of heart movement necessary to enable the efficient construction of the anastomosis More particularly, the pair of spaced-apart contact members 1 extend from a common base portion 553, which uniquely first extends back away from the tips of the, contact members at the point of attachment to the post, as shown at reference number 554 The spaced contact members 1 then curve downward away from the common base portion 553 and back past the post and away from the delivery stem 3 As may be seen m the Figures 40-42, the contact member 1 of this embodiment uniquely is attached to the post on the same surface as the surface that bears agamst the surface of the beating heart Smce the members 1 separate at the base portion 553 at a pomt 555 behind the distal end of the delivery stem 3, a surgeon has an unobstructed and thus optimum view of the heart even below the distal end of the delivery stem 3 The contact members preferably include friction means 556 selectively secured to the bottom surfaces thereof to more securely engage a beating heart. In addition, the tips of the contact members are bent upward in the form of "ski tips" to lessen their impact when the contact members are firmly pressed against a beating heart to suppress the anastomotic site. Although screw means 539/504/543 is illustrated herein as a locking mechanism to of the handle mechanism 468, it is to be understood that other mechanisms may be employed. For example, a cam/lever mechanism may be attached to a rod which in turn imparts a pivoting movement or translation to a suitable bell crank or pivotable member, which in turn imparts translation to push rod 505 of the delivery stem 3. Thus, locking mechanisms other than those specifically described herein may be used.

The basic configuration as just described with reference to base portion 553 provides the maneuverability necessary to access and stabilize any desired vessel on the surface of the beating heart. However, the exact manner and position in which the stabilizer may be placed relative to the vessel and the surgical techniques prefeπed by an individual surgeon may vary significantly. Accordingly, there is some potential that certain combinations of stabilizer positioning may interfere somewhat with the prefeπed surgical technique of a particular surgeon. The embodiments illustrated below with respect to Figures 43-45B alleviate any such problems.

One useful variation, as illustrated in Figure 43, connects connecting delivery stem 3 to the base portion of the stabilizer at a position which is generally offset from the center or off center. Base portion 710 is again typically formed of a unitary piece of sheet material and has a curved back portion in which connecting delivery stem 3 is attached to an extension of the same surface which carries the contacting members, except that the connecting point 718, to which ball/post 551 is attached is positioned away from the center and therefore away from the space between contact members 712 where the anastomosis would be performed. This configuration tends to ensure that connecting delivery stem 3 will not interfere with the surgical access to the center area of the base portion. Of course; the connection to can be offset from the central region in either direction.

In addition, base portion 710 illustrates a number of features for improving the traction and vessel presentation during a CABG procedure on a beating heart. Contact members 712 of base member 710 have portions 713 having an increased width and which are preferably substantially flat or slightly curved to conform to the heart. This configuration provides a larger area for coined regions 715, which represent indentations on the bottom surface for receiving a traction material, thus providing greater traction against the surface of the heart.

Further, base portion 710 provides a smaller open space between contact members 712. In a preferred embodiment, the spacing 716 between contact members 712 is less than about 0.350 inches, more preferably less than about 0.300 inches, and most preferably about 0.25 inches. This imnimized spacing provides stabilization closer to the vessel and, in some instances, the compressive forces applied through contact members 712 actually tend to present the vessel upwards between contact members 712 in a more favorably pronounced manner. The tip portions 714 of contact members 712 are angled upwards from the surface of the heart to minimize any possible trauma to the heart during use.

As just discussed, the base portions (550 or 710) can be manipulated or oriented relative to the end of the connecting delivery stem 3 by virtue of the ball and socket joint between base portion 553 and connecting delivery stem 3. The amount of angular manipulation or travel available is somewhat limited as ball/post 551 eventually bottoms out or stops against either the bottom of slots 549 or extended tips 550. Thus, the contact members have a limited range of movement relative to connecting delivery stem 3 based upon the nominal to mounting relationship between the contact members and the ball/post. Accordingly, for some procedures, it may be desirable to have a different nominal relationship between the contact members and the ball/post to delivery stem connection. Referring to Figures 44-45B, base member 720 illustrates an alternative orientation of ball/post 551. Instead of being angled away from the contact members, base member 720 has a back portion 721 which allows ball socket 551 to be mounted generally parallel to contact members 722. Ball/post 551 preferably extend towards contact members 722 as shown, but may also extend the opposite direction away from the contact members. The connecting point 723 is preferably offset a distance 724 from the central area between the contact members 722. The connecting point 723 is also off set a greater distance 726 from the contacting place of contact members 722. In nominal position of base portion 722 relative to ball/post 551, this configuration tends to keep the connecting delivery stem 3 clear from the central portion between contact members 722. Furthermore, relative to connecting delivery stem 3, contact members 722 can be maneuvered through a range of motion different from base member 553 due to the initial orientation of ball/post 551. Because the prefeπed location of the attachment of the connecting delivery stem 3 to the base portion may be different from surgeon to surgeon and from procedure to procedure, it may be desirable to have the ball/post moveable to more than one location. In one embodiment shown in Figure 46, for example, ball/post 562 has threaded end 561 which may be threaded into any desired threaded receiving hole 563 provided in stabilizer base 560. Ball post 564 is preferably provided with one or more flats 564 on the exterior thereof to facilitate tightening or loosening of the threaded connection. In the embodiment shown, stabilizer base 560 has threaded receiving holes 563 to provide center, offset right, and offset left connecting positions.

Referring to Figures 47 and 48, ball/post 572 may be captured within slot 571 formed in stabilizer base 570. Slot 571 preferably has two or more positions where the ball/post can be positively locked. In a prefeπed embodiment, slot 571 preferably has two or more key-hole openings 573 Key openings 573 are sized to receive first post portion 577 havmg an outside diameter which closely matches the inside dimension of key openmg 573 First post portion 577 of ball/post 572 is released from key hole 573 by pulling ball post m the direction mdicated by aπow 579 until second post portion 578 is positioned withm keyhole 573 Second post portion 578 is sized to have an outside diameter small enough to fit and traverse through slot 571 Ball/post 572 may then be traversed along the path defined by slot 571 until the next desired key hole is reached, which may then be engaged by first post portion 577 to secure ball/post 572 m position on stabilizer base 570

First post portion 577 may be kept m engagement with keyholes 573 by any, convement manner For example, ball/post 572 may be spnng biased m the locked position between upper flange 574 and lower flange 575, preferably usmg spπng washers 576 as shown Ball/post 572 may also be locked mto operatmg position withm keyholes 573 by usmg a retainmg or lockmg clip, such as locking clip 580 illustrated with reference to Figures 49 and 50 Lockmg clip 580 has slot 584 adapted to slide over second post portion 578 Lockmg clip 580 mcludes a thin portion 585, a thick portion 583, a transition ramp 582 between thin portion 585 and thick portion 583. and a gnp or handle portion 581 With lockmg clip 580 m the open position shown m figure 44, ball to post 572 is free to move upwards m the direction of arrow 579, thus releasmg first post portion 577 from key hole 573 When lockmg clip 580 is moved m the direction mdicated by aπow 586, the outer thickness of thick portion 583 is wedged between lower flange 575 and stabilizer base 570, thus lockmg ball/post 572 m place withm keyhole 573 Stabilizer base 590 m Figure 51 has ball/post 592 mounted to an articulatmg member which is moveable between two or more positions Preferably, ball/post 592 is mounted on first end 594 of pivoting link 591 which is pivotably attached to stabilizer base 590 at pivot pm 596 Preferably, pivot pm 596 is centrally located on pivotmg link 591 At second end 593 of pivotmg link 591, a lockmg knob 595 may be provided to engage stabilizer base 590 Preferably, lockmg knob 595 has a threaded shaft or other such fastemng or lockmg feature which engages matmg threaded holes (typically one positioned under lockmg knob 595 and one under ball post 592) m stabilizer base 590 The ball/post 592 and lockmg knob 595 are preferably spaced equal distances from pivot pm 596 such that when pivoting link 591 is rotated as mdicated by, aπow 597, the position of ball/post 592 and lockmg knob 595 are reversed Another embodiment of a tissue stabilizer havmg an adjustable attachment position of the delivery stem is illustrated in Figures 52-55 Stabilizer base assembly 625 mcludes top member 605 and stabilizer base 600, havmg contact members 606 and 607 and notch or relief 603 under which a vessel may safely pass without bemg occluded At least a portion of stabilizer base 600 has outer profile 601 which is generally curved or circular at a predetermined radius Top member 605 has a mating mtenor curvature such that stabilizer base 600 and top member 605 concentncally rotate relative to each other, preferably about a common center pomt Ball/post 602 may be attached at a convement position, typically centered, on top member 605 Rotation of top member 605 relative to stabilizer base 600, as indicated by aπows 620 and 619, thus adjusts the position of ball/post 602 along an arcuate path relative to contact members 606 and 607 To facilitate the secure attachment and smooth rotation of top member 605 relative to stabilizer base 600, top member 605 may be provided with one or more projections adapted to be received withm guide slots provided m stabilizer base 600 In a prefeπed embodiment, top member 605 has side projections or rails 608 and 609 which snap mto lower slots or channels 611 and 610 m stabilizer base 600 as top member 605 is urged mto a concentπc position over stabilizer base 600 Rails 608 and 609 slide with channel 611 and 610 to maintain a secure attachment and controlled rotation of top member 605 and stabilizer base 600 Top member 605 may optionally have tab 612 adapted to be received withm upper slot 604 on stabilizer base 600 Upper slot 604 may have a plurality of detents or teeth which form a desired number of detented positions as tab 612 is rotated around the path of upper slot 604 In a prefened embodiment, detented position 617 is formed between tooth 613 and slot end 616 and detented position 618 is formed between tooth 614 and tooth 615 Of course, detented positions may be created at any desired location usmg a vanety of alternate constructions Preferably, the detent action of tab 612 allows the operator to manually select a position of ball/post 602, but then holds the position of top member 605 relative to stabilizer base 600 against movement dunng use to ensure effective stabilization of a target vessel on the beatmg heart In addition to the cntical function of stabilizmg the beatmg heart, it is also important for the tissue stabilizer to present the stabilized coronary artery m a manner which allows sutures to be easily placed around the mouth of the artenotomy as required to create the anastomosis Figures 56A-59 illustrate a tissue stabilizer embodiment involving a base portion havmg a smgle contacting surface for stabilizmg a target vessel on the beatmg heart and a mechamcal bail element to facilitate optimal vessel presentation

Referring to Figures 56A and 56B stabilizer base 740 is shown attached to delivery stem 3 usmg ball/post 730 Delivery stem 3 is shown connected generally to the center of stabilizer base 740 at approximately a nght angle, however, as discussed above, the ball post 730 could be connected at any desired offset or onentation or the position of ball/post 730 could be adjustable Stabilizer base 740 preferably has a smgle contacting surface 742 which may be flat or curved to at least partially conform to the surface of the heart Contacting surface 742 is sized to provide sufficient contacting area such that sufficient compressive force can be applied to the beating heart to achieve effective immobilization or stabilization of a target coronary artery

Stabhzer base 740 preferably has an extendmg frame member or bail 745 attached thereto Bail 745 may be a thm, round or square cross-sectioned member, and is preferably a stainless steel wire Bail 740 has a bail portion 756 which is generally parallel to stabilizer base 740 and may have relieved sections 747 formed therein so as not to occlude the vessel dunng use Bail portion 756 may have tissue gnppmg features, such as teeth 755 In an optional embodiment, bail portion 756 may be provided with rotating cover or a spiral wound thread (not shown) so that bail portion may be more easily repositioned, under a stabilizmg load, over the surface of the heart as discussed below

In a prefeπed embodiment, bail 745 is moveable relative to stabilizer base 740 Bail 745 can, be moved or out m the direction mdicated by arrow 750 to cause bail section 756, which is generally parallel with stabilizer base 740, to compress tissue towards stabilizer base 740 or stretch tissue away from stabilizer base 740 Thus, bail 745 can be moved m and out to compress or stretch the tissue surrounding a coronary artery until the optimum presentation for performing the anastomosis is achieved The generally parallel portion may be vertically offset from contacting surface 742 by a distance 757 which is typically about 0 050 mches to about 0 200 mches

Although bail 745 may be attached m a number of ways, bail 745 is preferably formed with first and second end portions 748 and 749 havmg detents or teeth 746 Stabilizer base 740 preferably has channels 751 and 752 for receivmg end portions 749 and 748 respectively Channels 751 and 752 preferably have internal matmg teeth 753 for engagmg teeth 746 End portions 748 and 749 can be incrementally advanced mto channels 752 and 751 as teeth 746 deflect and release from a mated position relative to teeth 753 and then successively engage the next mated position Stabilizer base 740 may mclude cover 754 over channels 751 and 752 So that the stabilizer can be removed from around a completed anastomosis, at least one end of bail 745 is detachable from stabilizer base 740 In a prefened embodiment, stabilizer base 740 is substantially symmetncal allowing bail 745 to be assembled from either side m a nght or left handed configuration

Bail 745 is preferably flexible or semi-flexible relative to stabilizer base 740 As a result of its inherent flexibility, bail 745 applies a predetermined force agamst the heart that, under operating conditions, may be generally mdependent of the stabilizmg force applied to stabilizer base 740 to stabilize the beating heart That is, once stabilizer base 740 is forced against the surface of the heart, the force applied by bail 745 is a function of its mechamcal spnng rate relative to stabilizer base 740 Figures 57A and 57B illustrate another smgle contact stabilizer base havmg a bail 762 which is secured at only one end Stabilizer base 760 may have a housmg 765 havmg a senes of internal teeth (not shown) Bail 762 has a toothed end 766 which is received withm housmg 765 to engage with the mating teeth provided therein As with the embodiment above, bail 762 has a generally parallel portion 763 which is moveable relative to stabilizer base 760 m the direction generally mdicated by aπow 767 to stretch or compress the suπounding tissue for optimum vessel presentation Bail 762 may have tab 761 to facilitate grasping by an instrument, such as for example forceps 761 The free end 764 of bail 762 is preferably rounded or somewhat bulbous so as to be a traumatic Because bail 762 attaches only at one end, the stabilizer can be easily removed from the completed anastomosis without removing bail 762 from stabilizer base 760.

In another embodiment of the stabilizer, the wire frame member or bail may have a drive mechanism for moving the bail relative to the stabilizer base. Referring to Figure 58 stabilizer base 770 has housing 771 which is constructed with guide channel 774 having gear 775 mounted for rotation therein. Bail 772 has a toothed end 773 which may be assembled within guide channel 774 such that rotation of gear 775 causes bail 772 to be moved in and out in the direction indicated by aπow 43. Gear 775 may be driven by any suitable tool, for example, gear 775 may have a drive hole 778 for engagement by a suitable drive tool 771. Another driven bail stabilizer is shown in Figure 59. In this embodiment, stabilizer base 780 has threaded shaft 781 preferably supported at its end portions by bushings or bearings 783 and 784. One end of the threaded shaft is connected to a flexible drive 785 through a flexible or universal joint 791. The flexible drive maybe routed up delivery stem 3. Preferably flexible drive 785 is secured to delivery stem 3 by way of a thin polymeric coating. Bail 782 is connected to threaded collar 787 which cooperates with threaded shaft 781 to move bail in and out relative to stabilizer base 780 in the general direction indicated by arrow 790. The screw and collar drive mechanism is preferably concealed by housing 788 which has only a small slotted opening 786 allowing passage of bail 782.

With each of the flexible bail embodiments described above, stabilization and vessel presentation are relatively independent. First, the beating heart is typically stabilized using a compressive force delivered by way of the single contacting surface provided by the stabilizer base. The bail may then be manipulated in or out to obtain the optimum presentation of the vessel for whatever surgical- procedure is underway. For example, one bail position may be optimal for creating the arteriotomy, another bail position for insertion of a shunt or like device (should one be used), another bail position for creating the anastomosis, and so on. All the while, the stabilization of the beating heart itself remains optimized by the contacting surface of the stabilizer base. The Stabilization System

Prefeπed embodiments for each of the retractor, the instrument mount and the tissue stabilizers have been discussed in detail above. While each component may be utilized separately, superior access and stabilization can be achieved when the multiple components are used together for performing a minimally invasive cardiac surgery, preferably through a sternotomy approach. Referring to Figure 60, retractor assembly 900, including drive mechanism 910 and first and second platform blades 915 and 920, may be used to spread the sternum, providing access and direct visualization to the thoracic cavity. Retractor assembly 900 also allows sutures to be fixed or organized. Stabilizer assembly 800 isolates and provides local immobilization of the target vessel on the beating heart. Instrument mount assembly 850 facilitates precise maneuvering of the stabilizer and ensures a stable, motion free mount at the desired position and onentation

To begin a typical beatmg heart CABG procedure usmg the prefened stabilization system illustrated m Figure 60. dnve mechamsm 910 is preferably placed m the fully closed position with moveable housmg 925 positioned agamst or adjacent fixed housmg 930 First platform blade 915 is then assembled to moveable housmg 925 and a second platform blade 920 is assembled to fixed housmg 930 After ensuring that platform blades 915 and 920 are fully and securely attached to dnve mechamsm 910, engagmg members 935 of platform blades 915 and 920 are securely seated on the mcised sternum created usmg standard surgical procedures Dnve handle 940 may then be rotated clockwise to separate platform blades 915 and 920. thus creating the desired openmg for accessmg the beating heart

If the heart is positioned usmg sutures, the sutures maj be placed through the tissue at the desired location and secured to platform blades 915 and 920 Sutures 945 may be slid mto suture holder slots 950 to engage the suture To ensure proper a proper hold, only one suture strand is preferably engaged withm each suture holder slot 950 Sutures 945 are released from platform blades 915 and 920 by concurrently pulling back and up on suture 945 while pulling the suture through the suture holder slot 950

With the heart positioned as desired, mstrument mount assembly 850 may be assembled to platform blade 920 (or 915) by hooking stabilizer mount base 955 onto rail 960 (or 961) at the desired location and moving the base lever (not visible m this view) clockwise to the closed position to secure mstrument mount assembly 850 onto rail 960 Mount body 110 may be oπented to the desired angle by way of ball jomt 965 and locked mto place by turning the top mount knob 855 clockwise

Stabilizer base 810, havmg contact members 812 and 814, may then be positioned on the epicardmm of the beatmg heart by gently lowering delivery stem 820 usmg one hand to guide stabilizer base 810 onto the target area on the heart Incremental pressure is applied to stabilizer base 810 situated on the epicardmm until the desired immobilization , or stabilization is achieved Delivery stem 820 is secured m the desired position by turning side mount knob 860 clockwise and stabilizer base 810 is secured in the desired position relative to delivery stem 820 by turning the stabilizer stem knob 830 clockwise With the beatmg heart stabilized, the anastomosis, or other desired procedure, is completed

To remove stabilizer base 810, delivery stem 820 is held with one hand while side mount knob 860 is loosened with the other hand Stabilizer base 810 is then carefully removed from the anastomotic site The base lever is moved to the open position to release mstrument mount assembly 850, and stabilizer assembly 800 mounted thereto, from rail 960 on platform blade 920 When the entire bypass procedure is completed, dnve handle 940 is rotated m the counter clockwise direction to close dnve mechamsm 910 and platform blades 915 and 920 Retractor assembly 900 may then be gently removed from the access incision To remove platform blades 915 and 920 from moveable housmg 925 and fixed housmg 930, respectively, release latches 970 are manually activated and platform blades 915 and 920 may be pulled generally straight away from Dnve mechamsm 910 Dnve mechamsm 910 may then be stenhzed and prepared for use in a subsequent procedure

While certain embodiments are illustrated m the drawings and have just been descnbed herem, it will be apparent to those skilled m the art that many modifications can be made to the embodiments without departing from the mventive concepts descnbed For purposes of illustration only, the principles of the present mvention has been generally descnbed with reference to a coronary artery bypass procedure, but may readily be applied to other types surgical procedures not specifically descnbed Many other uses are well-known m the art, and the concepts descnbed herem are equally applicable to those other uses Further, the different components of the vaπous exemplar embodiments descπbed above can be combmed m any desirable construction Accordmgly, the mvention is not to be restricted except by the claims which follow

Claims

What is claimed is:

1. An instrument mount apparatus for positioning a surgical instrument comprising a mount body having a base portion moveably coupled at a first articulating joint and a side portion moveably coupled at a second articulating joint, and an actuator operatively connected to said first and second articulating joints, said first and second articulating joints being freely moveable when said actuator is in an unlocked position, wherein said first and second articulating joints are compressed each into a substantially immovable condition when said actuator is placed in a locked position, and wherein said first articulating joint is at an angle relative to said second articulating joint.

2. The instrument mount apparatus of claim 1 wherein said angle is less than about 120 degrees.

3. The instrument mount apparatus of claim 2 wherein said angle is between about 100 degrees and about 45 degrees.

4. The instrument mount apparatus of claim 2 wherein said angle is about 90 degrees.

5. The instrument mount apparatus of claim 1, wherein said actuator comprises a base post assembled thorough said base portion and said mount body and interconnected at a first end to a cam operatively interfacing a contact surface on said mount body, and a tie pin having a slotted portion which receives said base post, wherein, upon operation of said cam, said base post is drawn toward said cam and said locked position and a ramped portion of said base post drives said tie pin towards said locked position. 6. The instrument mount apparatus of claim 5, wherein said first articulating joint comprises a ball and socket joint and said base post further comprises a flange at a second end opposite said first end, wherein movement of said cam to said locked position draws said flange against said base portion thereby locking said ball and socket joint .

7. The instrument mount apparatus of claim 5, wherein said second articulating joint comprises a rotational joint including a frustoconical member extending from said side portion and a cooperating frustoconical cavity within said mount body.

8. The instrument mount apparatus of claim 7, further including a grip member, said side portion and said grip member positioned to form an opening therebetween for receiving a surgical instrument. 9. The instrument mount apparatus of claim 8, wherein said tie pin is connected, at a first end, to said grip member.

10. The instrument mount apparatus of claim 9, wherein said tie pin comprises a pair of flexible prongs which interconnect at said first end with said grip member.

11. The instrument mount apparatus of claim 10, wherein movement of said tie pin to said locked position draws and locks said grip member against said side portion and also locks said frustoconical member against said frustoconical cavity thereby locking said rotational joint.

12. The instrument mount apparatus of claim 9, wherein said tie pin is releasably connected to a release button at a second end of said tie pin, wherein pressing of said release button extends said tie pin and grip member to allow removal of said grip member to exchange surgical instruments.

13. The instrument mount apparatus of claim 1 , wherein said first articulatmg joint comprises a ball and socket joint. 14. The instrument mount apparatus of claim 13 , wherein said ball and socket joint comprises a ball-shaped member extending from said base portion and a cooperating socket formed within said mount body.

15. The instrument mount apparatus of claim 1, wherein said second articulating joint comprises a ball and socket joint. 16. The instrument mount apparatus of claim 1, wherein said second articulating joint comprises a rotational joint.

17. The instrument mount apparatus of claim 16, wherein said rotational joint comprises a frustoconical member extending from said side portion and a cooperating frustoconical cavity within said mount body. 18. The instrument mount apparatus of claim 17, wherein said side portion further includes a grip member, said side portion and said grip member positioned to form an opening therebetween for receiving a surgical instrument.

19. The instrument mount apparatus of claim 18, wherein said base portion is adapted to cooperatively engage a rail member. 20. The instrument mount apparatus of claim 19, wherein said rail has a top portion and a bottom portion, said bottom portion having a naπowed region adjacent said top portion forming first and second tabs on said top portion and said base portion further comprising first and second hooks adapted to engage said first and second tabs.

21. The instrument mount apparatus of claim 19, wherein said rail is fixed to a sternal retractor.

22. The instrument mount apparatus of claim 19, wherein said rail is fixed to a rib retractor.

23. An instrument mount apparatus for positioning and securing a surgical instrument comprising: a mount body havmg a base portion moveably coupled at a first articulating omt and a side portion moveably coupled at a second articulatmg jomt, a post extendmg through said first articulating jomt along a first axis, said post havmg a first end portion engagmg said base portion, a pm extendmg through said second articulating jomt along a second axis, said pm havmg an end portion engagmg said side portion and a threaded portion, a knob havmg an internal bore for receivmg said at least a portion of said pm. said internal bore havmg threads adapted to engage said threaded portion of said pm, said knob havmg a thrust surface associated therewith adapted to engage and move said post as said knob traverses over said threaded portion of said pm

24 The apparatus of claim 23, wherem said first axis is at an angle relative to said second

25 The apparatus of claim 24, wherem said angle is less than about 120 to degrees

26 The apparatus of claim 25, wherein said angle is between about 100 degrees and about 50 degrees

27 The apparatus of claim 26, wherem said angle is about 90 degrees

28 The apparatus of claim 23, wherem said first articulatmg jomt is a ball and socket jomt

29 The apparatus of claim 28, wherem said ball and socket jomt compnses a ball-shaped member extendmg from said base portion and a cooperatmg socket formed withm said mount body

30 The apparatus of claim 23, wherem said second articulatmg jomt is a ball and socket jomt

31 The apparatus of claim 23, wherem said second articulating jomt is a rotational jomt allowing rotation of said side member about said second axis 32 The apparatus of claim 31, wherein said rotational jomt compnses a fhistocomcal member extendmg from said side portion and a cooperating fhistocomcal cavity withm said mount body

33 The apparatus of claim 23, wherem said post further compnses a cam surface positioned to mate with said thrust surface, whereby rotation of said knob along said threaded portion causes translation of said thrust surface m a direction along said second axis, said thrust surface engagmg said cam surface to move said post m a direction along said first axis

34 The apparatus of claim 33, wherem said first articulating jomt becomes to locked when said post is urged m a first direction along said first axis and returns to a condition which allows articulation when said post is urged m an opposite direction to said first direction along said first axis 35 The apparatus of claim 23, wherem said knob compnses a first end adapted to be grasped by a user and a housmg end adapted to be received within said mount body, 15 said thrust surface bemg located on said housmg end

36 The apparatus of claim 23, further compnsmg a lift member slidable along said second axis, said lift member havmg a first end havmg said thrust surface and a second end, said knob havmg a first end adapted to be grasped by a user and a housmg end adapted to be received with said mount body, said housmg end positioned to engage said second end

37 The apparatus of claim 23, wherem said mount body has a top openmg and said post has a second end constrained withm said top openmg. said second end bemg slidable withm said top opening along said first axis

38 The mstrument mount apparatus of claim 23, wherem said base portion is adapted to cooperatively engage a rail member associated with a retractor apparatus

39 The mstrument mount apparatus of claim 38, wherein said rail has a top portion and a bottom portion, said bottom portion having a naπowed region adjacent said top portion forming first and second tabs on said top portion and said base portion further compnsmg first and second hooks adapted to engage said first and second tabs

40 An apparatus for stabilizmg a localized portion of a beatmg heart, comprising a substantially ngid base member havmg at least one contact area adapted to fhctionally engage the surface of the beatmg heart adjacent a first side of a target vessel, and a wire frame coupled to said base member, said wire frame havmg a frame portion adapted to engage the beating heart adjacent a second side of the target vessel opposite to the first side and at least one leg portion, said leg portion connecting said frame portion to said base member

41 The apparatus of claim 40, further compnsmg a delivery stem havmg a proximal end and a distal end, said base member being operably connected to said distal end 42 The apparatus of claim 41, wherem said delivery stem is substantially ngid

43 The apparatus of claim 42, wherem said delivery stem is curved

44 The apparatus of claim 40, wherem said leg portion is substantially perpendicular to said frame portion

45 The apparatus of claim 40, wherem said wire frame is moveable relative to said base member

46 The apparatus of claim 45, wherem said base member further compnses a channel for shdably receivmg at least a portion of said leg portion

47 The apparatus of claim 46, wherem said leg portion has a plurality of detented positions withm said channel

48. The apparatus of claim 47, wherein said channel further comprises a plurality of teeth and said leg portion further comprises a plurality of mating teeth adapted to engage said teeth.

49. The apparatus of claim 40, wherein said leg portion is substantially flexible relative to said base member. 50. The apparatus of claim 49, wherein said wire frame is formed from a unitary length of wire material.

51. The apparatus of claim 50, wherein said wire material is selected from the group consisting of stainless steel and titanium.

52. The apparatus of claim 40, wherein said frame portion has a first end and a second end and said wire frame comprises a first leg portion attached to said first end and a second leg portion attached to said second end, said first and second leg portions being coupled to said base member.

53. The apparatus of claim 52, wherein said base portion further comprises a first channel and a second channel for slidably receiving said first leg portion and said second leg portion respectively. 54. The apparatus of claim 45, wherein said base member further comprises a pinion gear having a plurality of gear teeth and said leg portion further comprising a rack having a plurality of mating teeth adapted to engage said gear teeth.

55. The apparatus of claim 45, wherein said base member further comprises a threaded shaft rotatably coupled to said base member, and said leg portion further comprises a collar having a threaded interior adapted to receive said threaded shaft.

56. The apparatus of claim 40, wherein said frame portion is vertically offset from said at least one contact area.

57. The apparatus of claim 56, wherein said vertical offset is between about 0.05 inches to about 0.2 inches. 58. The apparatus of claim 56, wherein said at least one contact area is substantially planar.

59. The apparatus of claim 40, wherein said at least one leg portion further comprises a vertically relieved portion.

60. An apparatus for stabilizing a localized portion of a beating heart comprising: a substantially rigid base member formed from a unitary piece of sheet material having a first side and a second side, said base member having a first section adapted to contact the surface of the beating heart and a second section at a fixed angle to said first section, said first section defining a first contact surface, a second contact surface, and an open space therebetween; and a ball-shaped member connected to said second section at a location which is offset from said open space.

61. The apparatus of claim 60, further comprising a post having a first end and a second end, said first end attached to said second section at said location and said second end attached to said ball-shaped member.

62. The apparatus of claim 60, further including a delivery stem having a proximal end and a distal end having a socket operably engaged with said ball-shaped member.

63. The apparatus of claim 62, wherein said delivery stem is curved.

64. The apparatus of claim 62, wherein said delivery stem is a shaft.

65. The apparatus of claim 60, wherein said angle is from about 75 degrees to about 105 degrees. 66. The apparatus of claim 65, wherein said angle is about 90 degrees.

67. The apparatus of claim 66, wherein said post extends from said first side.

68. The apparatus of claim 60, wherein said angle is more than about 120 degrees and said post extends from said second side.

69. An apparatus for stabilizing a localized portion of a beating heart, comprising: a substantially rigid base member having at least one surface adapted to contact the surface of the heart, a post having a first end moveably coupled to said base member and a second end having a ball-shaped member extending therefrom.

70. The apparatus of claim 69, further comprising a delivery stem having a proximal end and a distal end, said distal end having a socket operably engaged with said ball-shaped member. 71. The apparatus of claim 69, wherein said delivery stem is substantially rigid.

72. The apparatus of claim 69, wherein said base member has a first section having at least one surface for contacting the surface of a heart and a second section adjacent said first section, said post being moveably coupled to said second section.

73. The apparatus of claim 72, wherein said second section is at an angle relative to said first section.

74. The apparatus of claim 72, wherein said second section has a slot adapted to receive said first end of said post, said first end being moveable within said slot from a first position to a second position.

75. The apparatus of claim 69, wherein at least a portion of said base member has a curved outer profile and said post is mounted to a top member having an interior profile adapted to engage and concentrically rotate about said curved outer profile.

76. The apparatus of claim 75, wherein said base member has at least one elongate slot and said top member has at least one tab engaged within said at least one slot.

77. An apparatus for stabilizing a localized portion of a beating heart, comprising: a base member having at least one surface adapted to contact the surface of the heart, a link member pivotably coupled to said base member at a predetermined pivot point, said link member having a first link end spaced a distance away from said pivot point; and a post having a first post end attached to said first link end and a second post end having at least a ball shaped member extending therefrom.

78. The apparatus of claim 77, further comprising a delivery stem having a proximal end and a distal end, said distal end having a socket operably engaged with said ball shaped member.

79. The apparatus of claim 78, wherein said delivery stem is substantially rigid.

80. The apparatus of claim 77, wherein said link member has a second link end opposite said first link end, said second link end being releasably locked to said base member to substantially prevent relative movement of said link member relative to said base member.

81. The apparatus of claim 77, wherein said link member pivots about a pivot pin extending from said base member.

82. The apparatus of claim 81, wherein said base member has a first contact surface, a second contact surface, and an open space therebetween.

83. The apparatus of claim 82, wherein said link member has a first position wherein said post is offset from said open space in a first direction and a second position wherein said post is offset from said open space in a second direction.