WO2011066533A1

WO2011066533A1 - Clip assembly and method for approximating a wound in tissue

Info

Publication number: WO2011066533A1
Application number: PCT/US2010/058321
Authority: WO
Inventors: Warren P. Williamson, Iv
Original assignee: Clevex, Inc.
Priority date: 2009-11-30
Filing date: 2010-11-30
Publication date: 2011-06-03

Abstract

A clip assembly (10) and method for approximating a wound in tissue includes a first clip (14) and a second clip (13). The first clip (14) and second clip (13) each include tissue approximating structure (21, 22), such as tissue penetrating elements and/or non-penetrating elements. These elements are movable between an open condition for receiving the tissue adjacent to the wound and a closed condition in which the elements (21, 22) or other tissue approximating structure engages the tissue as the clips close the wound. The first and second clips (14, 13) are positioned generally adjacent to each other and tissue approximating structure (22) of the first clip (14) is configured to engage a first portion of the tissue and the tissue approximating structure (21) of the second clip (13) is configured to engage a second portion of the tissue located proximal to the first portion when moving from the open condition to the closed condition. Connecting structure (15) couples the first and second clips (14, 13) together in a manner allowing movement between the open and closed conditions.

Description

CLIP ASSEMBLY AND METHOD FOR APPROXIMATING A WOUND IN TISSUE Cross-Reference to Related Application

[0001 ] This application claims the priority of U.S. Provisional Patent Application

Serial No. 61 /264,998, filed on November 30, 2009 (pending), the disclosure of which is incorporated by reference herein.

Technical Field

[0002] This invention generally relates to the surgical approximation of tissue.

Background

[0003] Skin biopsy is one of the most important diagnostic tests for skin disorders. Skin biopsy procedures are performed in many ways. If an improper technique is used to remove a lesion and it turns out to be malignant, proper diagnosis of the stage of cancer may be impossible. However, once a pathologist has established the presence of malignant cells, a second surgery is almost always performed to make certain all remnants of the cancerous tissue have been removed; this procedure is called a full depth excisional biopsy with margin. As such, these procedures must take out large portions of tissue to be certain that not only are the malignant cells removed but that there is sufficient clear margin of healthy tissue surrounding the malignant tissue. The margin and diagnosis must be confirmed through histopathology preparation of the biopsy sample and cross-sections of the excised tissue reviewed by a pathologist. Therefore, in contrast to a simple biopsy procedure which is more exploratory than curative in nature, a full depth excision is much more invasive and leaves a larger and deeper wound to close.

[0004] There are many techniques and surgical tools that can be used to remove a tissue sample for diagnosis. When the lesion in question is less than 6 mm in diameter a punch biopsy is most commonly used to cut a circle around the lesion freeing it from the skin. The lesion is then pulled up above the skin and the base of the biopsy sample is severed from the adipose layer of the dermis. When lesions larger than 8 mm need to be removed, a football shaped excision is made cutting deeply down to the reticular dermis and fat level. The shape of this incision is the easiest to close with sutures. It also lends itself to a layered closure if needed. Most commonly, a scalpel is used to make this type of surgical incision, and a hemostatic device, such as a cautery tool or clotting agent, is used to stop the bleeding while removing the tissue in question and approximating the severed edges with sutures to close the wound for healing. (See reference document: Fusiform Excision by Thomas J. Zuber M.D.). [0005] When full depth excisions get to be larger than about 8mm it is recommended that the surgeon use a layered closure technique. Layered closures include a subcutaneous set of interrupted sutures to approximate the base layers of the wound, and a second set of epidermis or surface layer sutures to approximate the epidermis layer of the skin. If the surgeon does not use a layered closure there is a high probability that a hollow pocket will form below the skin surface. If such a pocket were to form, it would quickly fill with blood or thrombus, which turns into a clot that is then replaced by cellular and fibrous structures which form a scar. To create an appealing cosmetic wound closure, it is important to prevent any excess of clotted material from forming below the skin surface. A layered closure solves this problem by approximating the base layers of the skin directly above the fat. This layer is known as the reticular dermis. This layer of the skin is highly fibrous and represents the strongest tensile strength portion of the organ. Therefore, when a large wound needs to be closed the majority of the stresses required to close the wound are taken up by the reticular dermis.

[0006] Typically, when a skin lesion is removed for biopsy analysis, the resulting wound is closed to promote quick healing with a minimum of scar tissue formation. The wound is closed by various methods, most often with sutures or adhesive strips. Small biopsy wounds are sometimes left to heal with no interference, sometimes called secondary intention. When a wound is larger than about 6mm in length, it will not heal unless closed with a mechanical closure, be it surface bandage like a Steri-strip¹ (butterfly) or other type of closure. Wounds exceeding 10mm in length are generally considered to need layered closure. While small wounds in the flesh from 6 to 10mm are able to be closed with a single surface layer of sutures, a layered closure is required for a size threshold at around 10-12mm in length, or when the skin has been fully penetrated and is bleeding profusely. A layered closure requires that a primary set of sutures be placed deep in the wound base to

approximate or bring together the subcutaneous layer of tissue. By having a deep set of sutures in the wound base, the high tensional forces required to rejoin the tissue are buttressed deeply at the fascia layer making up for the material that was removed. This prevents "pocketing" where a large clot can form in an enlarged pool below the skin's surface. A pocketed wound can result in a weak or infected wound. The deeper tissue layers heal more completely when brought into close approximation during healing. This also allows for a more delicate suturing of the thin epidermis layers to minimize the scar. This is important when making a cosmetic repair of the skin. Skin

¹ Steri-Strip™ Adhesive Skin Closures, 3M™ St. Paul, MN 55144-1000 reacts to being stretched by filling in the stretched area with collagen; these are commonly seen as stretch marks or scars. When sutures are pulled tightly across a wound to hold it closed, it induces a large stress at the entry/exit point of the suture. Concentrated stretching will produce a collagen reaction which shows up as a shiny, light colored scar. This is why tiny tracks are seen in an interrupted suture line.

[0007] If a large wound is not closed properly, over time the byproducts from healing can erupt to the skin surface exposing the shiny collagen structure seen in a large scar. Unless the patient is in a combat or trauma situation, surgeons for the most part try to make a cosmetically appealing wound closure. Plastic surgeons are taught special techniques to make especially aesthetic healing lines. However, these are time-consuming and tedious procedures. Certain features of this invention reduce the residual scar material and thus make it more desirable to use by the general surgeon or dermatologist.

[0008] Sometimes a practitioner may try to close the wound with a single line of interrupted sutures when a double layer would be indicated. An undesirable scar may result after suturing a wound without a layered closure. The use of only a single line of sutures may result in a wound closure that alternates between being too tight and too loose. To combat this, surgeons typically place sutures more closely together than are required for healing, and over-tighten sutures to make sure that as the swelling is reduced around the incision, the wound will not dehisce or open up. Overly tightened sutures stretch the skin and the skin reacts to this trauma by making scar tissue around the stretched area (suture exit point) which results in the "tracks" seen across poorly sutured wounds.

[0009] The choice of suture materials also plays an integral role in the cosmesis of wound healing. A surgeon concerned with the appearance of the final scar will use a monofilament for the top layer approximation. Monofilament is known as a nonreactive suture material. However it is far more expensive than the standard materials. Monofilament is also non-absorbable; therefore, it is never used for the buried base layer sutures since it will leave behind a permanent knot, which in most cases will try to erupt through the skin surface.

[0010] Another procedural complication arises when more than one buried suture is required. For instance, if three buried sutures are required to close a wound the surgeon will not be able to complete each buried suture in series, because as he approximates the base layers the wound continues to close up. It then takes an enormous amount of skill and dexterity to place the next base suture needle correctly because the wound closes and the surgeon does not have access to the proper layers of tissue. Therefore, one skilled in this procedure will use many separate sutures and place all of the sutures in the base first while leaving their loose ends splayed above the wound. Then the surgeon will tie each set of knots and drive the knots down below the skin level into the lowest layers of the wound, in series, cinching up the base layer tissue along the way. It is much easier to drive a knot deep into the wound than it is to gain visual access to the proper layers to place the needles after the wound closes from the adjacent base layer suture. Exact placement of the entry point of the needle will determine whether or not the layers of skin approximate evenly when they are cinched closed. Therefore, misplacement of the needle due to compromised visual access will result in a wavy or uneven healed scar. While this technique is taught and practiced every day, it requires a new suture needle combination for each base layer. Sometimes the doctor can use one half of the length of the suture for the first placement, then cut it in half for a second placement. Proper technique for suturing requires at least 6 to 8 inches of free suture length to be able to tie the knots with gloves on. Therefore, this technique requires many suture packages for a single wound closure resulting in an inefficient and expensive use of suture, not to mention a time-consuming procedure for the doctor or surgeon. As mentioned previously, the base layer sutures are made of an absorbable material either natural (gut) or synthetic. The body must be able to break down this material to absorb it. The absorption process leaves behind scar material in the wound.

[0011 ] Another important aspect to consider when suturing large wounds is the effect of edema or swelling of the surrounding tissues. Whenever trauma to the skin occurs, natural vasoconstriction results as the body tries to prevent blood loss. In addition to the natural traumatic tissue responses most local anesthetics, like lidocaine, which are used to numb the pain sensation at the incision site, also contain a vasoconstrictive agent such as epinepherine to help staunch bleeding at the incision site. Arterial side pressure builds up fluid at the trauma site with no venous outlet and so edema results. This resultant edema makes it impossible to have the suture at the same "proper" tightness initially, during the wound closure and after the swelling has reduced the bulk or fullness of the tissue. This means that the surgeon is taught to "over-tighten" the suture knots to make up for the slackening of the sutures as the swelling subsides (so that the wound will not reopen after about 24 hours). The looseness of the skin once the swelling has been reduced can cause the suture line to open and the wound to dehisce. This can leave a large gap to fill with scar tissue and may be susceptible to infection. Therefore, it is very difficult to pre-tension the suture properly so that it will not be too tight during the vasoconstriction period or too loose once the edema has resolved. The problem with sutures that are too tight is that the skin stretching that occurs at the suture exit points creates scars. Skin reacts to stretching very quickly (evidenced in the common, permanent stretch marks that pregnant women can develop). In the case of wound closures, the point of highest tension is at the suture exit points, therefore elongated (stretched) holes or tracks at the suture exit can develop.

[0012] In the prior art, there have been attempts to provide mechanically enhanced wound closure techniques; most are as time consuming as suturing itself. In addition, because of the lack of effective and novel skin engaging points or tines, there is a lack of control of the tissue which cannot be overcome. Over or under penetration of the skin engaging portions of wound closure devices can be detrimental or make it impossible to consistently control the wound edges. Devices that employ slits in the skin (into which mechanical holding legs are inserted) without some way to engage the dermis will likely fail to keep the wound approximated and result in slippage of the wound edges or worse. In addition, the geometry of prior art clips had no way of achieving the perfect alignment and edge eversion of this novel skin engaging tooth profile.

[0013] Three elements of good wound closure are:

[0014] Deep approximation of tissue to prevent pocketing combined with fine surface sutures and proper skin tension by surface sutures.

[0015] Proper wound tension throughout the healing process to keep the wound edges together during the healing process.

[0016] Precise alignment of the tissue layers for cosmetic improvement of the scar.

Summary

[0017] The present invention, in one embodiment, provides a clip assembly for approximating a wound in tissue. The clip assembly includes a first clip and a second clip. The first and second clips each include tissue penetrating structure movable between an open condition for receiving the tissue adjacent to the wound and a closed condition in which the tissue penetrating structure of the first and second clips penetrates the tissue as the clips close the wound. The first and second clips are positioned generally adjacent to each other. The tissue penetrating structure of the first clip is configured to penetrate into a deeper portion of the tissue than the tissue penetrating structure of the second clip when moving from the open condition to the closed condition. Connecting structure couples the first and second clips together in a manner allowing movement of the first and second clips between the opened and closed conditions.

[0018] The first and second clips may be annular in shape, in the open condition, and the tissue penetrating structure may be carried on an inwardly facing portion of each clip. The tissue penetrating structures of the first and second clips may each comprise opposed teeth with sharpened points directed toward each other. The opposed teeth of each clip move toward each other and into the tissue when the first and second clips are moved from the open condition to the closed condition. The teeth of at least one of the first and second clips may respectively interdigitate in the closed condition. The first and second clips may increase in length along a longitudinal axis upon moving from the open condition to the closed condition. The tissue penetrating structure of the first clip may be configured to approximate the reticular bed of a wound in skin tissue, and the tissue penetrating structure of the second clip may be configured to approximate the epidermis of the wound in the skin tissue. At least some of the opposed teeth of the first clip may be longer than at least some teeth of the second clip, and the first and second clips may each be formed from flat plates. The opposed teeth of the first clip may be angled downwardly in a direction configured toward the tissue to be approximated. The first and second clips may each include hinge structure at opposite ends. The tissue penetrating structure on each of the annularly shaped first and second clips may be included on respective straight and angled portions in the open condition. The angled portions may then become more straightened along the longitudinal axis of each clip when moving to the closed condition.

[0019] In another embodiment, a device is provided including a clip assembly as generally discussed, and a clip driver and tissue cutting device carrying the clip. The clip driver and cutting device includes a clip assembly holder, a blade and actuating structure configured to move the clip assembly from the open condition to the closed condition and move the blade for severing a portion of the tissue.

[0020] In another illustrative embodiment, a clip assembly is provided for approximating a wound in tissue. The clip assembly includes a first clip and a second clip. The first and second clips each include tissue approximating structure movable between an open condition for receiving the tissue adjacent to the wound and a closed condition in which the tissue approximating structure of the first and second clips engages the tissue as the clips close the wound. The first and second clips are positioned generally adjacent to each other and the tissue approximating structure of the first clip is configured to engage a first portion of the tissue and the tissue approximating structure of the second clip is configured to engage a second portion of the tissue located proximal to the first portion when moving from the open condition to the closed condition. Connecting structure couples the first and second clips together in a manner allowing movement of the first and second clips between the open and closed conditions.

[0021 ] The first and second clips may be movable independent of each other for at least a portion of the movement from the open to closed condition and/or may move together from the open to the closed condition. The tissue approximating structures may comprise a pair of opposed, at least substantially non-penetrating elements for compressing the tissue. The tissue approximating structure of the first clip may comprise a pair of opposed, at least substantially non-penetrating elements for compressing the tissue, while the second clip comprises a pair of opposed tissue penetrating elements.

[0022] Methods of approximating a wound in tissue are also provided. For example, the method may include placing the clip assembly adjacent the tissue with the first and second clips in the open condition, moving the first and second clips from the open condition towards the closed condition while penetrating the tissue with the tissue penetrating structure of the first and second clips, and penetrating into the tissue more deeply with the tissue penetrating structure of the first clip than with the tissue penetrating structure of the second clip.

[0023] In another method, the clip assembly is placed adjacent the tissue with the first and second clips in the open condition, the first and second clips are moved from the open condition towards the closed condition while engaging the tissue with tissue approximating structure of the first and second clips, and the tissue is engaged more distally with the tissue approximating structure of the first clip than with the tissue approximating structure of the second clip.

[0024] In the various methods, each clip may be compressed so as to elongate the clips and apply tension to the wound along the length thereof while penetrating into the tissue or otherwise engaging the tissue with the first and second clips.

[0025] Various additional features and advantages of the invention will become more readily apparent to those of ordinary skill upon review of the following detailed description of the various embodiments, taken in conjunction with the accompanying drawings. Brief Description of the Drawings

[0026] Figure 1 is a side view of the lesion excision and closure device used to remove unwanted skin lesions and close resulting wound.

[0027] Figure 2 is a top perspective view of the excision device shown in Figure

1 .

[0028] Figure 3 is a perspective view and shows the device placed on a subject lesion.

[0029] Figure 4 is a perspective view similar to Figure 3 showing use of a skin hook.

[0030] Figure 5 is a top view of the double clip assembly including a surface clip placed atop of a subcutaneous clip.

[0031 ] Figure 6 is similar to Figure 5 but shows a partially closed clip assembly.

[0032] Figure 7 shows a cutaway view of the clip assembly depicted in Figure

6.

[0033] Figure 8 shows a cutaway view of clip assembly fully closed.

[0034] Figure 9 shows an isometric view of the clip assembly in fully closed condition with no skin between the teeth.

[0035] Figure 10 shows a clip assembly in the closed condition with everted skin protruding above the top clip surface.

[0036] Figure 1 1 shows a clip assembly partially closed to allow viewing of the different teeth length.

[0037] Figure 12 is an exploded view of the clip assembly containing the surface clip, the deep penetrating clip, and the alignment guide.

[0038] Figure 13 is a transverse cross-sectional view of the clip assembly taken generally perpendicular to the long axis of the assembly.

[0039] Figure 14 is a view similar to Figure 13 but shows the initial driver movement pushing the deep clip into the reticular dermis prior to setting of the surface clip. [0040] Figure 15 is a view similar to Figure 13 but shows where the deep clip and surface clip move together engaging two sides of the lesion to be excised.

[0041 ] Figure 16 shows the final step in the incision and wound closure process whereby the blade transects the lesion.

[0042] Figure 17 is a cross-sectional view of the skin lesion excision and device.

[0043] Figure 18 is a similar cross-sectional depiction to Figure 17, however, showing the lever partially actuated corresponding to Figure 15 in the clip deployment sequence which has both deep and surface clips engaged in skin.

[0044] Figure 19 shows full actuation of the device corresponding to full clip closure and lesion removal depicted in Figure 16.

[0045] Figure 20 is a cross-sectional view of the device showing the top view of the clip assembly in the distal end of the actuating device.

[0046] Figure 21 shows an exploded view of the components that make up the device assembly.

[0047] Figure 22 is a top view and shows an alternate embodiment of the double clip utilizing connection tabs to hold the clips together.

[0048] Figure 23 shows a typical cross-section of skin broken into its geographic descriptions according to depth.

[0049] Figure 23A is a perspective view, cut away to show an alternative embodiment of the clip assembly having an upper or proximal set of tissue

approximating elements in the form of tissue penetrating elements and a lower or distal set of tissue approximating elements in the form of flat, rounded bars interspersed with tissue penetrating teeth.

[0050] Figure 24 is a cutaway view of the colon and endoscopic polyp removal tool with an endoscope for visualization of the procedure and grasper used to pull the polyp up through the aperture of the clip assembly.

[0051 ] Figure 25 is an exploded view of endoscopic device used to deploy and of a clip assembly used for polyp removal inside a body cavity. [0052] Figure 26 is a partially cutaway top view of the tool described in Figure

25, prior to actuating the endoclip.

[0053] Figure 27 is a partially cutaway top view of the endoscopic actuating device showing the clip assembly in the closed position.

[0054] Figure 28 is a perspective view, cut away to show an alternative embodiment of the clip assembly having an upper or proximal set of tissue

approximating elements in the form of tissue penetrating elements and a lower or distal set of tissue approximating elements in the form of flat, rounded bars.

[0055] Figure 29 is a cross sectional view of the clip assembly shown in Figure

28 engaged with tissue, such as mucosal tissue.

Detailed Description

[0056] In various aspects, this invention produces the same closure effect as a layered suture technique by combining the approximation of the deep base layer with a fine controlled surface layer approximation. Stated another way, use of the invention provides both a deep approximating clip closure and a surface tension clip element. Each surface clip element is capable of engaging the thinner upper layers of the skin and spreading the approximation forces out like a washer under a bolt head. By spreading out the approximation forces, the skin is subjected to less localized stretching trauma which results in finer or nonexistent "tracks" adjacent to the wound edges. By interdigitating or alternating the skin engagement hooks, close

approximation of the tissue edges is assured throughout the healing process, despite the changing hemostasis and edema of the surrounding tissues.

[0057] It should be noted here that although this text and its illustrations are directed towards skin lesion removal and closure of the resulting wound, this in no way restricts the applicability of this invention to wound closure in general. In fact, the covenants of this invention will be of particular use in other surgical areas such as skin grafts, plastic surgery, closure of percutaneous access ports, and general repair of surgical incisions. This invention will be applicable to any procedure or anatomical skin incision where a multilayer suture technique is used today. In the body of this disclosure, the terms incision and wound are used interchangeably to refer to the opened area in the tissue which needs to be surgically closed. Since a large number of acute wounds are made in the process of removing suspect skin lesions, a device, according to at least some embodiments of the invention, is directed towards the more common procedures whereby a skin lesion biopsy results in an opening that is much larger than can be comfortably closed by previously disclosed skin clip devices.

[0058] In one embodiment, the skin closure mechanism of the invention comprises two separate elements in a double clip "stacked" configuration -each clip is specifically designed for its role in the closure of the wound. One clip acts as a closure member in the deep portion (e.g., reticular bed) of the wound and a second clip is responsible for the closure of the skin surface or epidermis. The smaller epidermis- engaging teeth approximate and evert the outer edges of the skin to create intimal layer closure. This type of closure is thought of as the best way to close a skin wound, but in practice (with sutures) it is very difficult to obtain. With the inventive clip assembly, it is hard not to obtain excellent skin approximation and epidermis eversion. The long teeth of the deep-penetrating clip engage the skin first, penetrating deeply into the reticular bed and the shorter teeth of the surface clip gather and pinch together the epidermis skin. By spreading the load to the skin over many small teeth used by this invention, the stretching or stress is less at each individual tooth site. Therefore, there is no need to over tighten the wound closure in order to obtain good edge approximation throughout the healing process. The longer base teeth engage the wound first in the pre-cut position compressing the deepest layers at the base of the skin prior to severing the biopsy. The upper layer or surface clip is stacked directly on top of the deep-penetrating clip; it approximates only the upper epidermis during closure. The teeth of the surface clip are constructed especially for surface closure with shorter teeth each spaced by a distance that allows capillary flow to the skin while still interdigitating and compressing the tissue between the rows of teeth on opposite sides of the wound. In addition, the upper clip assures that the inside intima of the skin are held in close approximation during the healing process. In addition, the legs of the clips which fold inward towards the wound have teeth disposed on their inside edges. Because the legs rotate around each end where they bend, the teeth disposed on the legs tend to stretch the wounds into a thin straight line. This has advantages of smoothing out any misalignments and creating a very smooth, flat, straight scar.

[0059] The stacked clips, in illustrative embodiments, are held together with a plastic alignment plate. The alignment plate utilizes posts which extend up through the penetrating clip and surface clip. Flaps fold over each quarter to keep the entire assembly together throughout manufacturing, deployment and healing. The alignment plate is constructed from an injection molded thermoplastic such as polypropylene or polyethylene. It has the additional advantage since these materials are by and large inert which means very few patients will become sensitized to contact dermatitis. It also tends to smooth out the outer surfaces of the clip assembly to prevent snagging on clothing or bath towels. In addition to the teachings on stacked clip, or clip assembly, in this disclosure, it must be noted that other alternative embodiments can be employed without materially diverting from the scope of the invention. Some lesions sized, for instance, between 6 and 9mm require only a single clip. The single clip employs both deep-penetrating and surface teeth on the same clip. Since the overall amount of skin to be gathered and approximated does not have nearly the amount of overall skin stress, staggered high and low teeth would be sufficient. This is also an excellent way to address the problem of thicker skin with smaller lesions. That is to say, when the overall skin thickness increases, one may need to use a special clip with a hybrid tooth design in order to facilitate the gathering and deep approximation that the longer teeth provide. This may be the case even when the overall lesion size may be smaller. Skin such as on the back, thighs or buttocks is typically thinner than those of the belly or arms or the fleshy sides of the lower limbs.

[0060] One or more embodiments of this invention enhance the skin penetrating attributes of the wound tensioning clips by controlling the skin edges with specially fabricated tines, or tooth profiles which engage the skin. The tooth should be sharp enough to initially penetrate the epidermis to fix the tooth into the skin. It takes a rather small, sharp point to penetrate the skin, however if the tooth profile is too long and slender, the tooth can either bend or over-penetrate. Over-penetration is a condition in which the depth of the penetrating tip is not controlled. This will cause a situation where the tooth continues to penetrate into the tissue during the normal course of skin stretching and relaxation during the healing process. The novel tooth profile disclosed in this application solves this problem by having a stepped profile. It combines both an initial sharp penetrating point and a compression point which controls the penetrating depth. Through careful development of the sharpness undercut depth and included angle of the penetrating point versus the secondary compression point, the clip can both penetrate and compress the wound edges at each penetration point. The compression point is equally as important as the penetration control. As the initial penetration stops at the compression point, the further closure of the clip and compression of the tissue urges the edges of the incision together in a very controlled manner. The penetrating points used in the base penetrating layer are of a different shape and configuration with an extended sharp length before the

compression point.

[0061 ] Interestingly, even a suture cannot do this because the suture maintains constant diameter along its entire length. There is no stop point feature along the suture. The penetration is, of course, provided by the needle and wound compression is controlled by the tightness of the knots. However, the force vector for gathering the tissue in a traditional suture has been pulled over top of the wound towards the incision creating undue stress and stretching the tissue. This creates scar tracks at the suture exit wounds. The profile of the penetrating teeth in this invention combines both features (penetration and compression) but again in a way that is more controllable than through standard suturing.

[0062] When using standard suturing techniques the point of entry for the suture is determined by hand. Therefore, if the first and second suture needle puncture points being placed across opposite sides of a wound are not perfectly aligned, both laterally along the incision and spaced back and laterally from the incision edge, a mismatch will occur when the two sides are approximated with the knot. In the disclosed system , long rows of teeth are both the deep-penetrating clip and the surface tensioning clip, each with precision-fabricated, stepped penetrating and gathering features that assure uniform placement and gathering of the tissue edges. By drawing the tissue up between the clip legs before the clip is closed, it assures the clip will set the teeth into the tissue with the proper spacing when the two sides of the wound are brought together. Thus, alignment between the skin edges is assured every time. In addition, since a plurality of teeth lines each side of the wound, a straight, tooth- penetrating line is assured on each edge. The clip assembly closes on the tented skin that is pulled through the aperture; the tines are set into the skin prior to severing the lesion. Therefore, the clip assembly tines are set into two straight lines (top and bottom stacked clips) together as the compressed epidermis everts and rolls back on the top side of each penetrating clip. This creates a very positive condition for healing and minimized scar production. As the wound heals, the tissue above the clip assembly sloughs off and dies. The tissue below the clip assembly remains patent and the wound heals with minimum scar production. When viewed alongside prior art skin clips by the same inventor (such as U.S. application number 12/062,085, the disclosure of which is hereby fully incorporated by reference), the comparison is easy to see that one of the major differences between the two is that the skin engaging teeth are now housed along the inward facing edge of the closure legs.

[0063] Besides the features of stretching and straightness mentioned earlier, the overall size of the clip assembly is reduced when compared to previous disclosures. As one can imagine, with sutures each strand is individual and flexible, therefore discomfort to the patient while the wound is healing is minimal. With a large rigid mass on the wound, one would naturally assume there is less comfort. Interestingly, the majority of the discomfort does not lie in the penetration of the foreign body clip in the skin but, in fact, comes from snagging the clip assembly on clothing or other objects. So, the overall size of the clip assembly, even though temporarily covered with a Band-Aid or adhesive patch, is important to patients. For that reason, the novel improvement of placing the tines on the legs is advantageous to maximize the use of the size of a larger clip assembly capable of engaging a 12mm long excision. It was discovered that by placing teeth on the legs, the legs traveled in a more radial path as they closed in addition to approaching each other from opposite sides. However, from the standpoint of the tissue edges in relationship to the tissue at the center of the wound, the teeth on the legs tend to stretch the wound line from the center outwards to each end as the clip assembly closes. This helps create a very fine approximation line with no puckers or weeping during the healing process. One will also notice that the base layer clip appears to open farther than the surface layer clip. This is because the reticular bed (or base layer/penetrating) clip has longer, deep- penetrating tines which must be set back from the wound edge far enough to get full depth penetration to close the base of the wound and prevent a pocket from forming there. Therefore, as the wound is closed the base layer clip begins its closure process first through external driver mechanisms in the delivery device. Once the base layer tines have been set into the tissue, the driver catches up with the surface layer clip and both clips together are driven the last two thirds of the closure stroke.

[0064] In order to keep the two clips together during both fabrication and shipping, but also to keep them aligned as they are set into the tissue, a plastic alignment guard is placed around each clip and secured from top and bottom to hold the two stacked clips together as a unitary device. Binding posts extend from the base side to the surface side, which also become gliding posts which keep each clip in proper alignment in relationship to the other clip as they close, preventing any skewing between the two clips as they gather the skin for wound closure. The alignment guard is made of a non-sensitizing plastic such as polyethylene or polycarbonate. This has the added feature of preventing the clip material, which can be sharp from coming in contact with the skin and/or clothing or irritating the skin due to abrasion in areas where the body moves and skin stretching is inevitable.

[0065] This clip design lends itself very well to other applications in wound closure. For instance; fistulas within the large and small intestine can be pulled through the clip aperture and severed from the base of the structure. After healing, the clip assembly will slough off and become excreted by the body. A smoother more enclosing alignment guard surrounding the clip assembly would make certain that all exposed edges are smooth and protected during the excretion process. Different sizes and application-specific geometry could also be used in areas such as hemorrhoid isolation. The structure would be drawn through the clip assembly and severed after closure. A smooth alignment guard again would assure that it would be well tolerated in the rectum or sigmoid colon until sloughed off and excreted. In certain

embodiments, a combination of tissue-penetrating teeth and pressure bars may be used.

Description of Illustrative Embodiments

[0066] The device and wound closure clip assembly are used in conjunction to excise skin lesions and close the resulting wound in a single step operation. In order to carry out the procedure, the system consists of three basic units. The first being the excision device 1 , which actuates the closing of the wound clip assembly and excision of the lesion with a blade internal to the device. The second component is the wound closure clip assembly 10, used to approximate the edges of the wound, prevent bleeding and promote healthy, cosmetically pleasing wound closure. The third tool used for this procedure is a skin hook 12. While not part of the inventive structure of this patent, specific geometry and sharpness of the skin hook is essential to a good procedure. For reference, an example is a Miltex™ 21 -90 Cottle type stainless steel skin hook. The skin hook 12 used to draw the lesion up through the aperture 6 of the device 1 in a tented fashion as shown in the figures.

[0067] Figure 1 is a right side view of the skin lesion excision and wound closure device 1 with a proximal end comprising user handle 3 and actuating lever 4. The distal end 2 holds clip assembly; the proximal end 3 is manipulated by the user to close the clip assembly and excise the wound. The distal end of the device 1 houses an oblong-shaped through-hole, or aperture 6 with wound closure clip assembly 10 surrounding the aperture on the lower surface of a skin contact pad. Stabilizing pad 5 allows the user to push the device onto the patient with moderate pressure to stabilize the device 1 during the procedure.

[0068] Figure 2 shows a top view of the skin lesion excision and wound closure device 1 , clearly depicting the aperture 6. This device 1 can be used anywhere where the closure of a wound is required. This end 2 contains an opening or aperture 6 where the skin lesion is drawn up through the aperture and clip assembly 10 is used to close wound prior to the tissue being severed. The device is placed against the patient pushing down on stabilizing pad 5 and helps to hold the device steady while actuating the lever 4. Examples outlined in this disclosure are directed towards the removal of questionable lesions and the closure of the opening produced as a result thereof.

[0069] Figure 3 depicts the beginning of the excision procedure. User has grasped the handle of the device with his left hand and a skin hook 12 being prepared to lift the lesion up through the aperture 6 of the device. The aperture 6 is placed over the skin lesion 1 1 which is to be removed from the patient. The lesion 1 1 is centered within the aperture 6 to be certain that clear, unaffected margins are equal on all sides. Skin hook 12 penetrates the skin adjacent to the lesion 1 1 and is then rotated so that the angled hook portion of the skin hook 12 penetrates directly under the center of the lesion 1 1 . This allows the surgeon to pull up on the lesion 1 1 , drawing it through and above the aperture 6. By pulling up on the lesion 1 1 , it draws the various layers of the skin into intimate contact with the wound closure teeth on the lower side of the skin contact pad.

[0070] Figure 4 shows the proper positioning of the skin hook 12 under the lesion 1 1 and the lesion 1 1 being drawn up through the aperture 6. A larger, cross- sectional detail view of the distal end of the device 1 is shown in Figure 13, where the skin hook 12 has penetrated the lesion 1 1 and drawn it up through the aperture 6.

[0071 ] Figure 5 shows the top view of the double layer stacked skin clip 10 used in the preferred embodiment of this invention. A plastic alignment guard feature holds the clips together. The surface and deep clips are offset prior to actuation to allow the longer teeth of the deep penetrating clip to enter the tissue first then the clips are moved together compressing the lower portions of the wound prior to the top clip engaging in the edges of the skin. It consists of three main parts: the deep-penetrating clip 14, which lies closest to the patient's skin in use; directly adjacent and on top of the deep-penetrating clip 14 lays the surface penetrating clip 13; surrounding both clips 13, 14 is a thermoplastic molded alignment plate 15. This plate 15 sandwiches the two metal clips 13, 14 together, both holding them in place and then guiding them to keep their alignment and relationship to one another as the clip assembly 10 is driven to a closed state with the closure device 1 . The deep clip 14 consists of longer penetrating teeth 22 which are angled down towards the base of the wound. This differs from the surface clip 13 which has shorter teeth 21 used to gather and close the upper layers or epidermis of the skin. The two clips 13, 14 differ because of the needs to close different parts of the wound. Just as interrupted base layer sutures close the reticular dermis of the wound, the long, extended teeth 22 of the deep clip 14 penetrate and hold the base layers of the skin together to prevent pocketing below the surface. These clips 13, 14 have teeth positioned along the inside edges of the legs 27 on the surface clip 13. Initially the teeth on the legs 27 were conceived to make the overall clip assembly 10 more efficient in terms of its collapsed length in relationship to the wound size. While it accomplishes this goal, it had an unintended result as well. The added bonus is a result of the changing geometry of the clip assembly 10 during the closure process.

[0072] In Figure 5 radial foci 24 depicts the radial foci which the teeth will pivot around as the clip assembly is closed.

[0073] As the clip assembly is closed and the legs bend outward as shown in figure 6, the radial foci will travel from radial foci 24 to radial foci 25.

[0074] In doing so, skin which has been penetrated during the beginning of the wound closure starts off at a distance 26a (Fig. 5) from the center line of the clip assembly as in Figure 5, but will end at a closed larger distance 26b (Fig. 6). Taking into account that this happens at each end of the clip assembly 10, skin penetrated by the teeth on the legs 27 will stretch the finished wound closure line from the center teeth evenly outwards on either end. What this does is tension or stretch the wound closure line from the center outwards. The unintended result is that it creates a very thin, straight scar which shows no bunching and heals very smoothly. This

phenomenon cannot happen with a hand sutured closure because there is no frame to create tension from.

[0075] The construction of the clip assembly 10 is as follows: Referring to

Figure 5: the alignment plate 15 is placed first with snap pins 16 facing upward. Deep clip 14 is placed over the alignment pins 16 and then the surface clip 13 is placed on top of the clip 14. The upper ears 28 are folded over on top of the alignment plate pins 16 and snapped in place on the alignment plate. The alignment plate ears 28 have thin, living hinges 29 which allow the ears to fold over easily yet provide easy sliding movement of both metal clips inside the assembled final clip. Because the alignment plate 15 is also made from an inert plastic, it acts as a barrier to prevent direct contact of the metal clip structure 13, 14 with the patient to lessen any dermatitis issues with metal surfaces. Although not shown in the figures, all edges of the alignment plate 15 will be rounded and smoothed to prevent snagging on clothing or covering bandages.

[0076] Figure 7 shows a cross-section through Figure 5, giving greater clarity to the differences between the deep-penetrating clip 14 and the surface clip 13. Note that on the deep-penetrating clip 14 every other tooth is a long deep-penetrating shape which has been bent downward. The reason for this will become more clear when showing a section through the closed clip, such as in Figure 8, where one notices that the deep-penetrating teeth 22 will actually cross over each other. This is used to gather and approximate the reticular dermis and prevent pocketing below the surface.

[0077] Figure 9 depicts a fully closed clip assembly 10 showing the

interdigitation of teeth between the teeth of the surface and deep-penetrating clips. Figure 9 shows the clip assembly closed without any skin between the teeth.

[0078] Figure 10 is a depiction of the everted layers of skin standing above the surface clip 13.

[0079] Figure 1 1 shows a partially closed clip assembly. Bending zones 19 and

20 show where the clip assembly 10 has been narrowed in thickness so that it will bend in a predetermined configuration to go from a generally open shape to a linear closed shape. Driver engagement slots 18 are shown in this figure. These slots 18 help to align the driver and clip assembly in the device 1 to prevent the clip assembly 10 from skewing sideways if any torque is applied by the user during the closing process. If torque is applied without these driver engagement slots, there would be a possibility that the clip assembly 10 will not close properly and the teeth 21 , 22 will not interdigitate but rather hit one another point-to-point. This will then space the clip assembly 10 apart and prevent the wound from being fully closed and prevent the everted tissue edges from approximating.

[0080] Figure 12 shows an exploded view of the clip assembly 10. Surface clip

13 sits above penetrating clip 14. Clips 13 and 14 fit over pins 16 to align both clips with the alignment plate 15. Once clips 13 of 14 have been placed over the guide pins 16, ears 28 are folded over on top of surface clip 13 securing the ears 28 thru an interference fit to the pins 16. The X-shaped feature in the center of the alignment plate 15 is a runner system used to fill the part during injection molding. It also serves to hold the alignment plate 15 in its molded shape to facilitate attaching the clips 13, 14 and fixture the parts for assembly processes. Once the assembly is completed, the four legs of the "X" are removed and discarded.

[0081 ] Figure 13 depicts a cross-section of the distal end 2 of the excision and closure device 1 , the section is taken generally through the aperture 6. This cross- sectional view which corresponds with Figure 4 of the procedure where the tissue has been hooked and is being pulled up through the aperture 6 prior to the closure. Notice how the two clips 13, 14 remain retracted away from the skin at this point. Push driver 31 and pull driver 32 are currently engaging only the deep clip 14 as it will be the first clip to close requiring more travel to travel deeper into the tissue. [0082] Figure 14 shows the same cross-section without a housing being shown. In this Figure, it is important to see how the deep clip teeth 22 have begun to penetrate through the epidermis into the reticular dermis prior to movement of the blade 30 and surface clip 13. This pre-closure of the deep clip 14 also stabilizes the clip assembly and secures the lesion from retracting back below the blade level should the user accidentally relax the tension on the skin hook 12 while squeezing the lever 4, actuating the device.

[0083] Figure 15 shows the point at which the push driver 31 and pull driver 32 are now contacting and driving both clips 13, 14 simultaneously. Teeth on legs begin engaging and stretching the wound laterally. Surface and deep teeth are now moving in a more linear, non-stretching manner with direct opposition across the wound.

Excision blade has moved into position about to begin the excision. During this phase the tips of the teeth 21 , 22 are almost fully penetrated in both clips 13, 14. The deep clip 14 has begun cinching together the walls of the reticular dermis 34 directly above the fat layer 33.

[0084] Figure 16 shows the last step where the clip assembly 10 is completely closed and the blade 30 has traveled across the top of the clip assembly 10 severing the skin lesion 1 1 . It is important to understand the sequence of pre-closing the clip assembly 10 and setting the clip teeth 21 , 22 into the tissue prior to the lesion 1 1 being severed. Figures 17-19 will explain the corresponding mechanical actions inside the driving device 1 which ensure that the clips 13, 14 close properly and that the blade 30 travels at the end of the stroke to sever the tissue.

[0085] Figure 17 is a cross-sectional view through the device 1 showing the handle 9, drivers 31 and 32 and actuator lever 4. The lever 4 is pulled to close the clip assembly 10 and sever the tissue. However, the blade driver 7 is not directly connected to the blade 30. There is a space between the end of the blade driver 7 and the corresponding notch of the blade 30 where it engages to begin pushing the blade 30 partially through the closing stroke. This assures the blade 30 will not travel until the clip assembly 10 is at least partially closed and the clip teeth 21 , 22 have engaged the tissue to stabilize it and pre-clamp the blood supply. The lever 4 pivots around the shaft 36. The lower driver 32 is called a pull driver because as the lever 4 rotates clockwise that driver will pull the distal end of the clip assembly 10 towards the user. The push driver 31 above the shaft 36 pushes on the opposite side of the clip assembly as the lever 4 rotates. In concert then, the two drivers 31 , 32 push and pull to collapse the clip assembly in relation to the rotary movement of the lever 4. [0086] Figure 18 shows the time and sequence when the blade 30 begins to move transversely across the top of the clip assembly 10 beginning to sever the tissue 1 1 (not shown).

[0087] At the end of the stroke depicted in Figure 19 the actuation lever 4 is fully compressed up against handle 9. Push and pull drivers 31 , 32 are now at the limit of their stroke and have completely compressed the clip assembly 10 and blade 30 has severed the tissue 1 1 .

[0088] Figure 20 is a cross-section taken transversely across the distal end of the device 1 along section plane BB in Figure 17. This cross-sectional top view clearly depicts the open clip assembly 10 placed evenly around the aperture 6 pull driver 32 surrounds the distal side of the clip assembly 10 while pusher 31 surrounds the opposite side of the clip assembly 10. Blade 30 is shown transparently above the pull driver 32 and part of the surface clip 13. Details of the push and pull drivers 31 , 32 are more clearly seen in the isometric assembly view of Figure 21 .

[0089] Figure 22 is an alternate embodiment 37 whereby the alignment guide

15 has been eliminated from the assembly. Retention tabs 38 are used instead to hold the two clips 13, 14 together during deployment and healing. The tabs 38 allow a sliding movement between the top and bottom clips 13, 14 while still keeping them tightly held in alignment.

[0090] Figure 23 is a cross-section of a typical section of skin showing the different layers 35 including epidermis, dermis and hypodermis. The thicker, connective tissue in the reticular region 34 is where the deep penetrating teeth 22 penetrate to close the deep wound pocket. The adipose layer 33 is the interface between the reticular region 34 and the fat. The dotted line shows a V-shaped cutting line which depicts the optimal excision shape for removal of a skin lesion performed by this device.

[0091 ] The new wound closure clip assembly disclosed herein can be modified for other tissue clamping uses. One example of this would be a modification for use as a colon polyp removal clip assembly. The clip assembly would still use a surface layer clip and possibly a second clip that would have wider spaced, short teeth along the clip's inner edges. In contrast to the previously disclosed clip, the clip used to compress a colon polyp would not need the deep-penetrating teeth. In one embodiment, shown in Figure 23A, teeth 22 would be interspersed with flat pressure bars 102 between them. The pressure bars 102 would tend to compress the tissue and allow healing of the mucosal surface while the teeth 22 held tissue in place during the healing process. After the tissue has healed, the clip 100' will pass through the digestive system naturally. A smooth outer coating of polyethylene will surround the clip 100' much like the alignment plate in the previous disclosure.

[0092] Figure 24 depicts use of the device in a large bowel or rectum. An elongated, endoscopic type delivery tool will need to be employed to close the clip assembly on a colon polyp. Figure 24 shows an elongated tool 50 with flexible section 56 which can be used to access remote sites of the rectum and large bowel where the polyp 67 is located. In Figure 24, a flexible endoscope 74 with grasper 68 is used to draw the polyp 67 through the aperture of the endo clip 51 . Grasper 68 is used under direct visualization of the fiber-optic endoscope 74. Once the polyp is placed within the jaws of the clip 51 , the driver system of endoscopic tool 50 is fired closing the clip 51 and severing the polyp for biopsy purposes. A more detailed description of the Endo clip 51 is given below.

[0093] Figure 24 shows cutaway view of the large bowel polyp 67 after it has been pulled up through the Endo clip 51 under direct visualization of endoscopic camera 74. Grasper 68 is used to draw polyp up through the clip 51 prior to removal. Driver tool 50 is shown flexed to obtain proper positioning. Once the clip 51 has been fired and the lesion 67 severed from the colon wall, the clip 51 will remain engaged with the tissue until the tissue is healed and the clip 51 sloughs off naturally.

[0094] Figure 25 shows an exploded view of the clip driver system 50. The

Endo clip 51 is disposed between two driving levers 52 and 53. Levers have pivoting center holes 52 and 53 which they are free to rotate about. A flat spring 54 biases the levers 52, 53 towards each other so that the lever alignment tab 65 will engage in clip alignment slots 66. Driving levers 52, 53 have cam surfaces 70 which engage on ramping surfaces 69 and 72 of a wedge driver 55. When wedge driver 55 is pushed forward, the ramp surfaces 69, 72 engage cam surfaces 70 on the levers 52 and 53 to compress and close the Endo clip 51 . Once the clip 51 is closed on the polyp, the blade driver 57 advances forward. The blade driver 57 has blade 58 connected to it, severing the polyp above the clip. Drivers for the blade 58 and levers 52, 53 have flexible sections 56 and 59 which allow the head of the device 50 to be flexed during use at flexible section 63 and 71 in the housing.

[0095] Figures 26 and 27 show partially cutaway views of the endoscopic tool

50 levers 52 and 53 are shown in their fully open state in Figure 26 holding Endo clip

51 between the levers 52, 53. A spring 54 holds levers 52, 53 tightly against the clip 51 in alignment recesses 66 on the clip sides shown in dotted view. Clip ejector 75 is shown engaging clip 51 but spring 76 is not compressed at this stage. Wedge driver 55 has not yet engaged levers 52 and 53. The blade 58 has not yet traveled forward to sever the tissue.

[0096] Figure 27 shows the wedge driver 55 advanced forward pushing levers

52 and 53 inward towards the center of the device collapsing clip 51 . As the clip collapses, it further compresses spring 76 which will push the clip 51 out of the levers when the wedge driver 55 is retracted at the end of the procedure. The blade 58 moves distally, exiting the end of the housing (blade extended in distal cutting position 78) which then severs the tissue left above the clip surface. Note how ramp surfaces 69 and 72 have bypassed the cam surfaces on the lever 70 to push the levers 52, 53 towards the center of the device 50 and squeeze the clip 51 closed in direction of arrows 77.

[0097] Figure 28 is a sectioned perspective view of an alternative embodiment of a clip assembly 100 which substitutes the lower, deep (distal) penetrating elements or teeth with rounded approximating elements, such as bars 102 configured to engage tissue such as mucosal tissue. Like elements relative to other embodiments are referred to with like reference numerals in Figures 28 and 29. The operation of clip assembly 1 00 may be the same as described previously. Bars 102 may have various forms and may have a roughened surface or slight projections for engaging the tissue 104 with additional friction.

[0098] Figure 29 is a cross sectional view of the clip assembly 100 shown in

Figure 28 engaged with mucosal tissue 104 after removal of, for example, a polyp (not shown).

[0099] These examples should not be construed as limiting the use of this device. For example, this device could be used for large trauma wounds which need layered closure. While this invention is not limited to the removal of skin lesions, this represents one of the largest volume procedures requiring acute wound closure.

[00100] While the present invention has been illustrated by a description of various preferred embodiments, and while these embodiments have been described in some detail, it is not the intention of the Applicants to restrict or in any way limit the scope of the appended claims to such detail. Additional advantages and modifications will readily appear to those skilled in the art. The various features discussed herein may be used alone or in any combination depending on the needs and preferences of the user. [00101 ] Other examples of procedures where this wound closure device would be used are in the large and small bowel or pandiculated structures like the appendix and hemorrhoids or for the sealing of wounds made to gain access to internal organs or spaces percutaneously such as through a trocar assembly for minimally invasive endoscopic access. In these examples, the wound closure device could be incorporated into another medical device such as the trocar assembly or other access device. It will be appreciated that the tissue approximating elements may take many forms, such as the penetrating teeth, flat compression bars, or still other forms as necessitated or desired due to the application needs. Also, depending on the application, these approximating elements may move independent of each other or together from the open to the closed condition. This has been a description of illustrative aspects and embodiments of the present invention, along with the preferred methods of practicing the present invention as currently known. However, the invention itself should only be defined by the appended claims. What is claimed is:

Claims

1 . A clip assembly for approximating a wound in tissue, comprising:

a first clip and a second clip, the first and second clips each including tissue penetrating structure movable between an open condition for receiving the tissue adjacent to the wound and a closed condition in which the tissue penetrating structure of the first and second clips penetrates the tissue as the clips close the wound, the first and second clips positioned generally adjacent to each other, and wherein the tissue penetrating structure of the first clip is configured to penetrate into a deeper portion of the tissue than the tissue penetrating structure of the second clip when moving from the open condition to the closed condition, and

connecting structure coupling the first and second clips together in a manner allowing movement of the first and second clips between the open and closed conditions.

2. The clip assembly of claim 1 , wherein the first and second clips are each annular shaped in the open condition, and the tissue penetrating structure is carried on an inwardly facing portion of each clip.

3. The clip assembly of claim 1 , wherein the tissue penetrating structures of the first and second clips each comprise opposed teeth with sharpened points directed toward each other, wherein the opposed teeth of each clip move toward each other and into the tissue when the first and second clips are moved from the open condition to the closed condition.

4. The clip assembly of claim 3, wherein the opposed teeth of at least one of the first and second clips respectively interdigitate in the closed condition.

5. The clip assembly of claim 1 , wherein the first and second clips each increase in length along a longitudinal axis upon moving from the open condition to the closed condition.

6. The clip assembly of claim 1 for use in closing a wound in skin tissue, wherein the tissue penetrating structure of the first clip is configured to approximate the reticular bed of the wound and the tissue penetrating structure of the second clip is configured to approximate the epidermis of the wound.

7. The clip assembly of claim 3, wherein at least some of the opposed teeth of the first clip are longer than at least some teeth of the second clip.

8. The clip assembly of claim 1 , wherein the first and second clips are formed from flat plates.

9. The clip assembly of claim 3, wherein the opposed teeth of the first clip are angled downwardly in a direction configured toward the tissue to be approximated.

10. The clip assembly of claim 2, wherein the first and second clips each include hinge structure at opposite ends.

1 1 . The clip assembly of claim 2, wherein the tissue penetrating structure on each of the annularly shaped first and second clips is included on respective straight and angled portions in the open condition, and wherein the angled portions become more straightened along the longitudinal axis of each clip when moving to the closed condition.

12. A device for approximating a wound in tissue, comprising:

a clip assembly as defined in any one or more of the previous claims, and

a clip driver and tissue cutting device carrying the clip, the clip driver and cutting device including a clip assembly holder, a blade and actuating structure configured to move the clip assembly from the open condition to the closed condition and move the blade for severing a portion of the tissue.

13. A method of approximating a wound in tissue with a clip assembly including a first clip and a second clip, said first and second clips each including tissue penetrating structure movable between an open condition and a closed condition, the method comprising:

placing the clip assembly adjacent the tissue with the first and second clips in the open condition,

moving the first and second clips from the open condition towards the closed condition while penetrating the tissue with the tissue penetrating structure of the first and second clips, and

penetrating into the tissue more deeply with the tissue penetrating structure of the first clip than with the tissue penetrating structure of the second clip.

14. The method of claim 13, wherein the first and second clips are each annular shaped in the open condition, and moving the first and second clips comprises:

compressing each clip so as to elongate the clips and apply tension to the wound along the length thereof while penetrating into the tissue with the tissue penetrating structure of the first and second clips.

15. The method of claim 13, wherein the tissue penetrating structures of the first and second clips each comprise opposed teeth with sharpened points directed toward each other, and penetrating into the tissue further comprises:

moving the opposed teeth of each clip toward each other and into the tissue when the first and second clips are moved from the open condition to the closed condition.

16. The method of claim 15, further comprising:

interdigitating the opposed teeth of at least one of the first and second clips in the closed condition.

17. The method of claim 13, wherein the first and second clips each increase in length along a longitudinal axis upon moving from the open condition to the closed position.

18. The method of claim 13 wherein the tissue is skin tissue and further comprising:

approximating the reticular bed of the wound with the first clip and approximating the epidermis of the wound with the second clip.

19. The method of claim 15, wherein at least some of the opposed teeth of the first clip are longer than at least some teeth of the second clip.

20. A clip assembly for approximating a wound in tissue, comprising:

a first clip and a second clip, the first and second clips each including tissue approximating structure movable between an open condition for receiving the tissue adjacent to the wound and a closed condition in which the tissue approximating structure of the first and second clips engages the tissue as the clips close the wound, the first and second clips positioned generally adjacent to each other, and wherein the tissue approximating structure of the first clip is configured to engage a first portion of the tissue and the tissue approximating structure of the second clip is configured to engage a second portion of the tissue located proximal to the first portion when moving from the open condition to the closed condition, and

21 . The clip assembly of claim 20, wherein the first and second clips are movable independently of each other for at least a portion of the movement from the open to the closed condition.

22. The clip assembly of claim 20, wherein the first and second clips move together from the open to the closed condition.

23. The clip assembly of claim 20, wherein at least one of the tissue approximating structures comprises a pair of opposed, at least substantially nonpenetrating elements for compressing the tissue.

24. The clip assembly of claim 20, wherein the tissue approximating structure of the first clip comprises a pair of opposed, at least substantially nonpenetrating elements for compressing the tissue, and the second clip comprises a pair of opposed tissue penetrating elements.

25. A method of approximating a wound in tissue with a clip assembly including a first clip and a second clip, said first and second clips each including tissue approximating structure movable between an open condition and a closed condition, the method comprising:

moving the first and second clips from the open condition towards the closed condition while engaging the tissue with the tissue approximating structure of the first and second clips, and

engaging the tissue more distally with the tissue approximating structure of the first clip than with the tissue approximating structure of the second clip.