WO2002058607A2

WO2002058607A2 - Infusion cannula

Info

Publication number: WO2002058607A2
Application number: PCT/US2002/001777
Authority: WO
Inventors: Philip J. Ferrone
Original assignee: Ferrone Philip J
Priority date: 2001-01-25
Filing date: 2002-01-22
Publication date: 2002-08-01
Also published as: WO2002058607A3; AU2002240004A1

Abstract

The present disclosure relates to an infusion cannula for use in connection with vitreo-retinal surgical procedures. The infusions cannula comprises a hollow body portion defining a first direction for an infusate flow. The hollow body portion includes a proximal end and a distal end, which distal end includes a tapered distal tip integrally formed therewith. The infusion cannula further includes a pair of diametrically opposed delivery holes formed radially through the body portion near the tapered distal tip, wherein a first of the pair of delivery holes is oriented to direct the infusate flow in a second direction which is orthogonal to the first direction and wherein a second of the pair of delivery holes is oriented to direct the infusate flow in a third direction which is orthogonal to the first direction and parallel to the second direction. The first and second delivery holes dividing the infusate flow such that the infusate flow is equally divided in opposite directions and directed tangentially along the equator of a lens.

Description

INFUSION CANNULA AND METHOD FOR VITREOUS SURGICAL PROCEDURES

BACKGROUND

1. Technical Field The present disclosure relates to infusion cannulas and more particularly, to infusion

cannulas for use in connection with vitreo-retinal surgical procedures.

2. Description of Related Art

In retinal surgical procedures involving the eye, it is often desirable to use a cannula to penetrate the eye and supply an infusate in order to maintain the fluid pressure of the eye. For example, a number of ophthalmic surgical procedures involve the penetration of the chambers of the eye with a variety of surgical instruments.

The penetration of the chambers of the eye and, more particularly the removal of ocular tissue from the eye by aspiration and the like, results in a loss of fluid and pressure in the respective ocular chamber. The loss of fluid pressure in the vitreous cavity during ophthalmic

surgical procedures can cause at least a partial collapse of the chamber making it difficult to

manipulate an instrument in the eye without risking damage to ocular structures such as the retina and the lens. Accordingly, it is desirable to maintain the integrity and internal pressure of the

vitreous cavity. A commonly accepted technique for maintaining pressure in the ocular chambers is to

introduce a fluid, such as air, saline solution or other liquid or gas, into the chamber of the eye during the ophthalmic surgical procedure. The infusion of fluid helps to maintain a positive pressure within the eye and a normal configuration of the ocular chamber during surgery. Furthermore, control of intraocular pressure during surgery helps to minimize danger to the eye

both during and after surgery. A positive pressure stretches open the pupil permitting better visualization of posterior ocular structures and ensures that any flow across a wound is outward, not inward, thereby reducing the risk of entry of foreign matter or bacteria into the ocular

chamber. Fluid-air exchange is also a standard and widely used technique in modern vitreous

surgery. In a conventional three-part vitrectomy, an infusion cannula is placed inferotemporally so that the infused air is directed toward the supernasal mid-peripheral retina. Alternatively, the

infusion cannula is placed inferonasally so that the infused air is directed at the supertemporal retina. A complication observed which may arise following a fluid-air exchange in ophthalmic surgical procedures (i.e., macular hole, diabetic retinopathy and subretinal surgery) is the development of visual field defects. It has been discovered that the location of the visual field defect is correlated to the location of the mfusion cannula and that the incidence of this visual

field defect was influenced by the pressure at which the infusion air is introduced into the ocular

chamber. FIGS. 1A and IB illustrate schematically the relationship of the position of the infusion cannula and the corresponding retinal damage leading to the visual field defects. As illustrated in FIG. 1A, the directional flow of infusate from an infusion cannula placed inferotemporally (as indicated by flow arrow "A") can cause nasal retinal damage resulting in a temporal visual field

defect. Concomitantly, as illustrated in FIG. IB, the directional flow of infusate from an inferonasally (as indicated by arrow "B") placed cannula can cause temporal retinal damage resulting in a nasal visual field defect. Recently, silicone oil and perfluorocarbon liquids (PFCL's) have been used as vitreous substitutes during vitreo-retinal surgery. Among the physical characteristics of PFCL's, it is important to note that the specific gravity of PFCL is between 1.8 and 1.9. Thus, when PFCL is injected into the eye, since the PFCL is heavier than the fluid in the eye, the vitreous cavity will

tend to be filled from a posterior pole of the eye forward. In addition, since the PFCL has a

greater specific gravity than the fluid in the eye, the surface tension of the PFCL results in the formation of a PFCL bubble within the vitreous cavity of the eye.

The fluid for maintaining the intraocular pressure of the eye is typically introduced into the ocular chamber via a maintainer infusion cannula inserted through an incision made in the sclera of the eye. The cannula is connected via a silicone elastomer tubing or other suitable fluid

communicating conduit to a container holding the infusion fluid. The flow of infusate through

the cannula is controlled by the surgeon or an assistant in response to a surgeon's instructions, for example by operation of a foot pedal, by fingertip control or by manually altering the height of an

infusion bottle.

Typical infusion cannulas deliver infusate from an axial opening formed at a distal end

thereof such that the infusate is permitted to flow in a direct, unobstructed, and unrestricted fluid flow path. An example of such a cannula may be found in U.S. Patent 4,781 ,675 to White which

relates to an infusion cannula for infusing fluids into various cavities of the eye, wherein the cannula includes a tube having a first end configured for permitting a flow of infusate axially out

of a distal end thereof and a second end having a hilt for connection to an infusion fluid source. Likewise, U.S. Patent 4,692,142 to Dignam, relates to an ocular infusion cannula including a first tube segment having an opening formed at a distal end along a longitudinal axis thereof and a second tube segment joined coaxially to the first tube segment at an end opposite the distal end of

the first tube, wherein an infusate is ejected from the opening formed at the distal end of the first tube segment.

One disadvantage of such infusion cannulas is that the infusate jet exiting the distal end of the cannula is directed axially out of the end of the infusion cannula and directly onto or into the PFCL bubble, which direction may lead to emulsification of the PFCL in the vitreous cavity.

The emulsification of the PFCL creates a plurality of relatively smaller PFCL bubbles, as compared to the one large liquid perfluorocarbon bubble, in the eye, which plurality of smaller PFCL bubbles are difficult and time consuming to remove from the vitreous cavity of the eye

once the surgical procedure has ended and which also make it more difficult to see the retina and perform manipulations through the smaller PFCL bubbles.

A further disadvantage of such infusion cannulas is that the high flow jet air/gas stream into the retina, emitted axially from the distal end opening of such cannulas, may cause damage resulting in visual field defects and even retinal damage in certain circumstances. An additional disadvantage of standard infusion cannulas is the possibility of crystalline lens opacification

during fluid air exchange.

In U.S. Patent 5,919,158 to Saperstein et al. (hereinafter "the ' 158 patent"), an infusion cannula is disclosed for use in clearing and preventing condensation on the posterior surface of an artificial lens during a fluid-gas exchange portion of a pars plana vitrectomy. The ' 158 patent discloses an infusion cannula configured and adapted to direct the flow of an infusion gas entering the eye in a single non-axial direction, i.e., toward the posterior surface of an artificial lens. In the ' 158 patent, the infusion cannula includes a tubular body having a face provided at a distal end thereof and a pair of co-linear infusate ports formed along one side of the tubular body for directing all of the infusate flow toward the posterior of the surface of the lens. Thus, the infusion cannula disclosed in the '158 patent directs all of the flow of the infusion gas in a single desired direction, i.e., toward the lens. As such, the infusion cannula disclosed in the ' 158 patent continues to share in the disadvantages of standard infusion cannulas.

A need still exists, however, for an improved infusion cannula for use in vitreous surgical

procedures which overcomes the above noted disadvantages of prior art infusion cannula designs. A need also exists for an improved procedure and surgical instrument which will reduce the impact of infusion air on the retinal surface thereby reducing the occurrence of visual field defects.

SUMMARY

The present disclosure relates to an infusion cannula for use in connection with vitreo-

retinal surgical procedures. The infusion cannula includes a hollow body portion including a pair of diametrically opposed delivery holes formed radially through the body portion near a tapered

distal tip thereof, wherein a first hole of the pair of delivery holes is oriented to direct the infusate flow in a second direction which is orthogonal to the first direction and wherein a second hole of

the pair of delivery holes is oriented to direct the infusate flow in a third direction which is orthogonal to the first direction and parallel to the second direction. The first and second

delivery holes being configured and oriented to divide the force of the infusate flow substantially

equally in two opposite directions and substantially tangential to the equator of the lens of the

eye. In this manner, the direction of infusate is not oriented directly towards or into the lens, or

into the PFCL bubble and the force of the jet of the infusate is substantially divided and directed

in substantially opposite directions.

In one aspect, the present disclosure an infusion cannula is provided which supplies an

infusate into the vitreous cavity of an eye and which substantially divides the force of the infusate

jet and which directs the flow of the infusate jet into substantially diametrically opposed

directions.

The infusion cannula directs the flow of an infusate in at least two substantially

diametrically opposed directions and along a surface of a PFCL bubble.

One advantage of the presently disclosed infusion cannula is that it lessens the

emulsification of a PFCL bubble upon injection of an infusate into the eye.

In another aspect of the present disclosure, the infusion cannula redirects the air and

decreases the force of the infusate jet during retinal surgery in order to prevent retinal damage

and visual field defects.

Another advantage of the presently disclosed infusion cannula is that it helps reduce the

likelihood of lens opacification during fluid gas exchange.

These objects and advantages, together with other objects and advantages of the presently

disclosed infusion cannula, along with the various features of novelty which characterize the

disclosure, are pointed out with particularity in the claims annexed to and forming a part of this disclosure.

BRIEF DESCRIPTION OF THE DRAWINGS

By way of example only, preferred embodiments of the disclosure will be described with

reference to the accompanying drawings, in which:

FIG. 1A is a schematic illustration of an infusion cannula placed inferotemporally leading

to nasal retinal damage;

FIG. IB is a schematic illustration of an infusion cannula placed inferonasally leading to

temporal retinal damage;

FIG. 2 is a partial cross-section of an eye showing one illustrative embodiment of an

infusion cannula constructed in accordance with the present disclosure implanted in the eye;

FIG. 3 is a perspective view of an infusion cannula in accordance with the present

disclosure coupled to infusion tubing;

FIG. 4 is a side elevational view of the infusion cannula in accordance with the present

disclosure;

FIG. 5 is a cross-sectional view of the infusion cannula of FIG. 4 taken along a

longitudinal axis thereof;

FIG. 6 is a plan view of the infusion cannula in accordance with the present disclosure

coupled to an infusion tubing including an infusion coupling at a proximal end thereof;

FIG. 7 is a side elevational view of the infusion cannula having a diffusion tip in

accordance with the present disclosure; FIG. 8 is a cross-sectional view of the infusion cannula of FIG. 4 taken along a

longitudinal axis thereof and illustrating a baffling in accordance with the present disclosure; and

FIG. 9 is a cross-sectional view of the infusion cannula of FIG. 4 taken along a

longitudinal axis thereof and illustrating an alternative baffling in accordance with the present

disclosure.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

The present disclosure overcomes the above-noted and other disadvantages of previous

infusion cannulas by providing an improved uniquely advantageous infusion cannula with a tip

design which redirects the flow of infusate from the usual direct, unrestricted, unobstructed

infusion flow as well as divides the flow of infusate into at least two different flow paths.

Referring now to FIGS. 2-6, in which like reference numerals identify similar or identical

elements, one illustrative embodiment of the presently disclosed infusion cannula is generally

designated as cannula 10. In particular with reference to FIG. 2, a partial cross-section of the

human eye including infusion cannula 10 implanted therein is shown. As seen in FIG. 2, the

cornea is designated as "C"; the iris as "I"; the lens as "L"; the sclera and "S"; the retina as "R";

the pars plicata of the ciliary body as "PT"; the pars plana "PN"; the vitreous cavity as "V"; and

the limbus as "M". Infusion cannula 10 is shown implanted through the sclera "S" of a patient's

eye and into the vitreous cavity "V.

Infusion cannula 10 is shown more fully in FIGS. 3-5 and includes a hollow body portion

12, a proximal end portion 14, a distal end portion 16 and a tapered distal tip 18 integrally

formed with distal end portion 16 thereby defining a closed distal end. One exemplary size for infusion cannula 10 is approximately 4.5 mm in length from wings 36 and 38 (discussed in detail greater detail below) to the most distal tip of infusion cannula 10. Preferably, body portion 12 of infusion cannula 10 has an approximately 19 or 20 gauge size. It is however envisioned that the design according to the present invention can be adapted to any size cannula gauge. The dimensions of infusion cannula 10 are provided for illustrative purposes only, actual dimensions may be varied depending upon the particular performance characteristics desired for a given application. Infusion cannula 10 may be formed from any suitable medical grade material such as, for example, polymer or metal.

Infusion cannula 10 further includes a pair of substantially diametrically opposed infusate delivery holes 20 and 22 formed radially through body portion 12 near a juncture 24 between body portion 12 and tapered distal tip 18. Preferably, infusate delivery holes 20 and 22 are disposed substantially 180 degrees apart such that they divide the infusate flow pressure and direct it radially outward in opposite directions. In FIG. 2, only infusate delivery hole 20 is illustrated, infusate delivery hole 22 being oriented substantially 180 degrees away from delivery hole 20 (i.e., behind delivery hole 20) and thus not visible in FIG. 2.

An effective location for infusate delivery holes 20 and 22 is between approximately 3.5 mm and approximately 4.2 mm from the proximal end portion 14 of infusion cannula 10. Further, an effective diameter of infusate delivery holes 20 and 22 is approximately 0.7 mm.

Upon insertion of infusion cannula 10 into the vitreous cavity, delivery holes 20 and 22 are preferably oriented substantially tangential to the equator of the lens.

The insertion of body portion 12 radially into the eye in combination with the orientation

of infusion delivery holes 20 and 22 radially through body portion 12, results in delivery holes 20 and 22 being situated substantially tangential to the equator of lens "L" upon insertion of body portion 12 into vitreous cavity "N". In this manner, the potential of damage from the pressure the infusate jet to the crystalline lens or to a posterior chamber intraocular lens ("POOL") is greatly reduced. Similarly, potential damage to the peripheral retina or vitreous base is also greatly reduced. Additionally, the likelihood of having suprachoroidal infusion is minimized due

to the positioning of infusate delivery holes 20 and 22 a distance from the proximal end 14 of infusion cannula 10 as previously noted.

In addition, the present infusion cannula design improves the ease with which PFCL can be removed from the eye by decreasing the emulsification of PFCL caused by the infusate jet. In other words, due to the configuration and orientation of infusate delivery holes 20 and 22, the infusate jet is not oriented directly into or in a direction toward the PFCL bubble, thereby preventing emulsification of the PFCL and, therefore, the formation of tiny PFCL bubbles. Specifically, the presently disclosed infusion cannula design directs the flow of saline or infusate along the surface of the PFCL bubble "B" (see FIG. 2) or very near the surface of the PFCL bubble as opposed to directly into the bubble as is the case in a distal end infusate discharge cannula design.

Further, the likelihood of damage caused by a high flow jet air stream into the retina opposite the cannula tip, which has been associated with visual field defects and retinal damage

in certain circumstances, is greatly reduced. The likelihood of lens opacification during fluid air

exchange is also reduced due to the radially oriented design of infusate delivery holes 20 and 22. Tapered distal tip 18 provides infusion cannula 10 with a solid distal end to prevent delivery of the infusate from flowing directly from the distal end in an axial direction. The tapered design facilitates easier insertion of infusion cannula 10 through the sclera "S" into the

eye after any size incision is made, for example, a 19 or 20 gauge microvitreoretinal ("MVR")

incision. Tapered distal tip 18 can be any tapered design, however, it is preferred that tapered

distal tip 18 be conical.

Infusion cannula 10 further includes a connection hub 32 extending proximally from body

portion 12, which hub 32 is in fluid communication with the hollow interior of body portion 12.

Hub 32 facilitates the connection of a length of infusion tubing 34 to infusion cannula 10.

Infusion cannula 10 also includes a pair of wings 36 and 38 are formed to extend radially from

body portion 12 adjacent to the juncture of body portion 12 and connection hub 32, which wings

36 and 38 facilitate suturing of infusion cannula 10 to sclera "S" as well as proper orientation of

infusion cannula 10 during a surgical procedure. Preferably, wings 36 and 38 are oriented in

alignment with delivery holes 20 and 22. In this manner, a surgeon can readily ascertain the orientation of delivery holes 20 and 22 after cannula 10 has been inserted into the eye.

While infusion cannula 10 may be secured to the sclera "S" using any suitable technique,

for example, by suturing it is envisioned that any other medically known technique for securing

infusion cannula 10 to the sclera "S" can be performed. Securing infusion cannula 10 to the

sclera "S" provides a fixed reference point from which infusion flow rates can be optimally

directed for the fixed position of infusate delivery holes as will be described in greater detail

herein.

Turning now to FIG. 6, infusion cannula 10 is coupled to a distal end of infusion tubing

34 while an infusion coupling 40 is coupled to a proximal end of infusion tubing 34. Infusion

coupling 40 is configured and adapted to place infusion tubing 34 into fluid communication with a source of infusate (not shown).

Turning now to FIG. 7, an alternative embodiment of the presently disclosed infusion

cannula is illustrated as infusion cannula 100, which includes a tapered distal tip 118, is provided

with a plurality of orthogonally radiating holes 140 thereby creating a diffusion tip. Preferably, holes 140 each have a diameter which is less than approximately 0.2 mm. Holes 140 direct the

flow of the infusate jet into a plurality of different directions thereby dividing and reducing the

force of the infusate jet by an amount proportional to the size of the individual holes 140 and the

quantity of the holes 140. By dividing and redirecting the flow of the infusate jet, the effects of

the infusate jet on the retina, opposite the infusion cannula insertion site, is greatly reduced.

Holes 140 may be formed in tapered distal tip 118 by a suitable technique, for example, a laser

drilling process in which a laser burns a hole into tapered distal tip 118. While laser drilling has

been disclosed, it is envisioned that any other known techniques for forming holes having a

diameter which is less than 0.2 mm can be utilized. While holes having a diameter less than

approximately 0.2 mm are preferred, it is envisioned that holes 140 can have a diameter which is

equal to or larger than 0.2 mm. Moreover, it is envisioned that if holes having a diameter which

is larger than 0.2 mm is used, a mesh screen (not shown) made of medical grade biocompatible

materials can be optionally inlayed or overlaid over holes 140 to thereby diffuse the force of the

infusate jet.

Turning now to FIGS. 8 and 9, infusion cannula 100 is provided with baffling means

disposed within body portion 112. Referring initially to FIG. 8, infusion cannula 100 further

includes an arcuately shaped baffle, such as, a hemispherical baffling surface 142 located within

body portion 112. Hemispherical baffling surface 142 contacts the inner surface of body portion 112 distally of delivery holes 120 and 122, preferably along juncture 124. The surface of hemispherical baffling surface 142 extends proximally within body portion 112. Accordingly, hemispherical baffling surface 142 will reduce, if not eliminate, the formation of turbulence within tapered distal tip 118 resulting from a distal flow indicated by arrow "A" of infusate through body portion 112. In addition, hemispherical baffling surface 142 will tend to cause distal flow "A" of infusate jet to be at least partially redirected in a proximal direction as indicated by arrow "A," upon delivery of an infusate to the eye. While a generally hemispherical baffling surface has been disclosed, it is envisioned that a semi-cylindrical surface (not shown) having a longitudinal axis oriented orthogonally with respect to both the longitudinal axis of infusion cannula 100 and a central axis extending between the pair of delivery holes 120 and 122 is also possible.

Turning now to FIG. 9, infusion cannula 100 further includes a conical baffling surface 144 located within body portion 112. Conical baffling surface 144 contacts the inner surface of body portion 112 distally of delivery holes 120 and 122, preferably along juncture 124. The surface of conical baffling surface 144 extends proximally within body portion 112.

Accordingly, conical baffling surface 144 will reduce, if not eliminate, the formation of turbulence within tapered distal tip 118 resulting from a distal flow as indicated by arrow "B" of infusate through body portion 112. In addition, conical baffling surface 144 will tend to cause

distal flow "B" of infusate jet to be at least partially redirected in a proximal direction as

indicated by arrow "B, " upon delivery of an infusate to the eye. While a generally conical baffling surface has been disclosed, it is envisioned that other geometries, for example, a

pyramidical like surface (not shown) having a pair of planar surfaces extending transversely across the longitudinal axis of infusion cannula 100 and transversely across a central axis extending between the pair of delivery holes 120 and 122 is also possible.

Although illustrative embodiments of the presently disclosed infusion cannula have been described herein with reference to the accompanying drawing, it is to be understood that the disclosure is not limited to those precise embodiments, and that various other changes and modifications may be affected therein by one skilled in the art without departing from the scope or spirit of the invention. All such changes and modifications are intended to be included within the scope of the present disclosure.

Claims

IN THE CLAIMS:

1. An infusion cannula for use in connection with vitreo-retinal surgical procedures, comprising:

a hollow body portion including a proximal end portion and a distal end portion having a distal tip integrally formed therewith, said distal tip closing said distal end portion of said

cannula; and

a pair of diametrically opposed delivery holes formed radially through said body portion

near a juncture between said body portion and said distal tip.

2. The infusion cannula according to claim 1, wherein said delivery holes divide a

supply of infusate into a pair of radially opposed directions from said distal end portion of said cannula, thereby dividing an infusate flow pressure into said two radially opposed directions.

3. The infusion cannula according to claim 1, wherein said distal tip is conical.

4. The infusion cannula according to claim 1, further comprising a connection hub

extending proximally from said proximal end portion of said body portion, wherein said hub is in

fluid communication with an interior of said hollow body portion.

5. The infusion cannula according to claim 4, further comprising a pair of wings

extending radially outward from said body portion and located adjacent a juncture between said

body portion and said connection hub.

6. The infusion cannula according to claim 5, wherein said infusion cannula measures approximately 4.5 mm in length from said wings to a distal most tip of said infusion cannula.

7. The infusion cannula according to claim 6, wherein said delivery holes are located between approximately 3.5 mm and approximately 4.2 mm from said pair of wings.

8. The infusion cannula according to claim 7, wherein an effective diameter of each

delivery hole is approximately 0.7 mm.

9. The infusion cannula according to claim 8, wherein said body portion has a size selected from the group consisting of approximately 19 gauge and approximately 20 gauge.

10. The infusion cannula according to claim 1 , further comprising a flow vectoring structure disposed within said hollow body portion, wherein said flow vectoring structure is configured and adapted to redirect said supply of infusate.

11. The infusion cannula according to claim 10, wherein said flow vectoring structure is a baffle operatively associated with at least one of said pair of delivery holes in order to

facilitate at least one of redirecting the flow and decreasing the flow force of said supply of infusate outward from said distal end portion.

12. A method for maintaining an internal fluid pressure of an eye during a vitreo- retinal surgical procedure, comprising the steps of:

providing an infusion cannula, wherein said infusion cannula includes:

a hollow body portion having a proximal end portion and a distal end portion having a distal tip integrally formed therewith, said distal tip closing said distal end portion of said cannula, and

a pair of diametrically opposed delivery holes formed radially through said body portion near a juncture between said body portion and said distal tip;

inserting said infusion cannula through the sclera of the eye;

coupling an infusion tubing to a comiection hub formed at said proximal end portion of

said body portion;

infusing a supply of infusate to an interior of said eye via said infusion tubing and via said infusion cannula; and

dividing said supply of infusate into a plurality of flow paths.

13. The method according to claim 12, further comprising the step of orienting said

infusion cannula in a direction such that said delivery holes are oriented tangential to the equator of the lens of said eye.

14. An infusion cannula for use in connection with vitreo-retinal surgical procedures, comprising:

a hollow body portion defining a first direction for an infusate flow, said hollow body portion including a proximal end and a distal end, which distal end includes a distal tip integrally formed therewith; and a pair of diametrically opposed delivery holes formed radially through said body portion of said distal tip, wherein a first hole of said pair of delivery holes is oriented to direct said infusate flow in a second direction which is orthogonal to said first direction and wherein a second hole of said pair of delivery holes is oriented to direct said infusate flow in a third direction which is orthogonal to said first direction and parallel to said second direction.

15. The infusion cannula according to claim 14, wherein said first and second delivery holes divide said infusate flow such that said infusate flow is divided in a plurality of flow paths.

16. ' The infusion cannula according to claim 14, further comprising a connection hub extending proximally from said proximal end of said infusion cannula and wherein said hub is in fluid communication with an interior of said hollow body portion.

17. The infusion cannula according to claim 16, further comprising a pair of wings extending radially outward from said body portion at a location adjacent to a juncture between said body portion and said connection hub.

18. The infusion cannula according to claim 14, further comprising a flow vectoring structure disposed within said hollow body portion, wherein said flow vectoring structure is configured and adapted to facilitate at least one of redirecting the flow and decreasing the flow force of said supply of infusate.

19. The infusion cannula according to claim 18, wherein said flow vectoring structure is a baffle operatively coupled to at least one of said pair of delivery holes in order to direct said supply of infusate outward from said distal end portion.

20. An infusion cannula for use in connection with vitreo-retinal surgical procedures, comprising: a hollow body portion including a proximal end and a distal end portion having a distal tip integrally formed therewith, said distal tip including a plurality of delivery holes formed therein.