US 20070027461 A1
A tissue connector assembly having a flexible member and a surgical clip releasably coupled to the flexible member. A needle may be secured to one end portion of the flexible member with the surgical clip coupled to the other end portion of the flexible member. A locking device may be used to couple the flexible member to the surgical clip. A method for connecting tissues is also disclosed. The method includes drawing tissue portions together with a clip assembly and securing the tissue portions together with the clip assembly.
39. A method for connecting a graft vessel to a target vessel in an anastomosis comprising:
inserting a tissue connector assembly through said graft and target vessels with said graft vessel being spaced from said target vessel and said tissue connector assembly having a first end extending from an exterior surface of said graft vessel and a second end extending from an exterior surface of said target vessel; and
pulling at least a portion of said tissue connector assembly to draw said graft vessel into contact with said target vessel.
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The present invention relates to instruments and methods for connecting body tissues, or body tissue to prostheses.
Minimally invasive surgery has allowed physicians to carry out many surgical procedures with less pain and disability than conventional, open surgery. In performing minimally invasive surgery, the surgeon makes a number of small incisions through the body wall to obtain access to the tissues requiring treatment. Typically, a trocar, which is a pointed, piercing device, is delivered into the body with a cannula. After the trocar pierces the abdominal or thoracic wall, it is removed and the cannula is left with one end in the body cavity, where the operation is to take place, and the other end opening to the outside. A cannula has a small inside diameter, typically 5-10 millimeters, and sometimes up to as much as 20 millimeters. A number of such cannulas are inserted for any given operation.
A viewing instrument, typically including a miniature video camera or optical telescope, is inserted through one of these cannulas and a variety of surgical instruments and refractors are inserted through others. The image provided by the viewing device may be displayed on a video screen or television monitor, affording the surgeon enhanced visual control over the instruments. Because a commonly used viewing instrument is called an “endoscope,” this type of surgery is often referred to as “endoscopic surgery.” In the abdomen, endoscopic procedures are commonly referred to as laparoscopic surgery, and in the chest, as thoracoscopic surgery. Abdominal procedures may take place either inside the abdominal cavity (in the intraperitoneal space) or in a space created behind the abdominal cavity (in the retroperitoneal space). The retroperitoneal space is particularly useful for operations on the aorta and spine, or abdominal wall hernia.
Minimally invasive surgery has virtually replaced open surgical techniques for operations such as cholecystectomy and anti-reflux surgery of the esophagus and stomach. This has not occurred in either peripheral vascular surgery or cardiovascular surgery. An important type of vascular surgery is to replace or bypass a diseased, occluded or injured artery. Arterial replacement or bypass grafting has been performed for many years using open surgical techniques and a variety of prosthetic grafts. These grafts are manufactured as fabrics (often from DACRON® (polyester fibers) or TEFLON® (fluorocarbon fibers)) or are prepared as autografts (from the patient's own tissues) or heterografts (from the tissues of animals) or a combination of tissues, semi-synthetic tissues and or alloplastic materials. A graft can be joined to the involved artery in a number of different positions, including end-to-end, end-to-side, and side-to-side. This attachment between artery and graft is known as an anastomosis. Constructing an arterial anastomosis is technically challenging for a surgeon in open surgical procedures, and is almost a technical impossibility using minimally invasive techniques.
Many factors contribute to the difficulty of performing arterial replacement or bypass grafting. See generally, Wylie, Edwin J. et al., Manual of Vascular Surgery, (Springer-Verlag New York), 1980. One such factor is that the tissues to be joined must be precisely aligned with respect to each other to ensure the integrity and patency of the anastomosis. If one of the tissues is affixed too close to its edge, the suture can rip through the tissue and impair both the tissue and the anastomosis. Another factor is that, even after the tissues are properly aligned, it is difficult and time consuming to pass the needle through the tissues, form the knot in the suture material, and ensure that the suture material does not become tangled. These difficulties are exacerbated by the small size of the artery and graft. The arteries subject to peripheral vascular and cardiovascular surgery typically range in diameter from several millimeters to several centimeters. A graft is typically about the same size as the artery to which it is being attached. Another factor contributing to the difficulty of such procedures is the limited time available to complete the procedure. The time the surgeon has to complete an arterial replacement or bypass graft is limited because there is no blood flowing through the artery while the procedure is being done. If blood flow is not promptly restored, sometimes in as little as thirty minutes, the tissue the artery supplies may experience significant damage, or even death (tissue necrosis). In addition, arterial replacement or bypass grafting is made more difficult by the need to accurately place and space many sutures to achieve a permanent hemostatic seal. Precise placement and spacing of sutures is also required to achieve an anastomosis with long-term patency.
Highly trained and experienced surgeons are able to perform arterial replacement and bypass grafting in open surgery using conventional sutures and suturing techniques. A suture has a suture needle that is attached or “swedged on” to a long, trailing suture material. The needle must be precisely controlled and accurately placed through both the graft and artery. The trailing suture material must be held with proper tension to keep the graft and artery together, and must be carefully manipulated to prevent the suture material from tangling. In open surgery, these maneuvers can usually be accomplished within the necessary time frame, thus avoiding the subsequent tissue damage (or tissue death) that can result from prolonged occlusion of arterial blood flow.
A parachuting technique may be used to align the graft with the artery in an end-to-side anastomosis procedure. One or multiple sutures are attached to the graft and artery and are used to pull or “parachute” the graft vessel into alignment with an opening formed in a sidewall of the artery. A drawback to this procedure is the difficulty in preventing the suture from tangling and the time and surgical skill required to tie individual knots when using multiple sutures. Due to space requirements, this procedure is generally limited to open surgery techniques.
The difficulty of suturing a graft to an artery using minimally invasive surgical techniques has effectively prevented the safe use of this technology in both peripheral vascular and cardiovascular surgical procedures. When a minimally invasive procedure is done in the abdominal cavity, the retroperitoneal space, or chest, the space in which the operation is performed is more limited, and the exposure to the involved organs is more restricted, than with open surgery. Moreover, in a minimally invasive procedure, the instruments used to assist with the operation are passed into the surgical field through cannulas. When manipulating instruments through cannulas, it is extremely difficult to position tissues in their proper alignment with respect to each other, pass a needle through the tissues, form a knot in the suture material once the tissues are aligned, and prevent the suture material from becoming tangled. Therefore, although there have been isolated reports of vascular anastomoses being formed by minimally invasive surgery, no system has been provided for wide-spread surgical use which would allow such procedures to be performed safely within the prescribed time limits.
As explained above, anastomoses are commonly formed in open surgery by suturing together the tissues to be joined. However, one known system for applying a clip around tissues to be joined in an anastomosis is disclosed in a brochure entitled, “VCS Clip Applier System”, published in 1995 by Auto Suture Company, a Division of U.S. Surgical Corporation. A clip is applied by applying an instrument about the tissue in a nonpenetrating manner, i.e., the clip does not penetrate through the tissues, but rather is clamped down around the tissues. As previously explained, it is imperative in forming an anastomosis that tissues to be joined are properly aligned with respect to each other. The disclosed VCS clip applier has no means for positioning tissues. Before the clip can be applied, the tissues must first be properly positioned with respect to each other, for example by skewering the tissues with a needle as discussed above in common suturing techniques or with forceps to bring the tissues together. It is extremely difficult to perform such positioning techniques in minimally invasive procedures.
Therefore, there is currently a need for other tissue connecting systems.
The present invention involves apparatus and methods for connecting material, at least one of which is tissue. The invention may, for example, be used to secure one vessel to another, such as in a vascular anastomosis.
According to one aspect of the invention, a tissue connector assembly is provided and comprises a flexible member and a surgical clip which may be releasably coupled to the flexible member. With this construction, a needle may be coupled to the flexible member, which may be in the form of a suture, to facilitate, for example, parachuting suture tissue connecting procedures. The surgical clip may eliminate the need for tying sutures, which requires significant skill, space, and time.
According to another aspect of the invention a tissue connector assembly comprises a needle, a flexible member coupled to the needle, and a locking device coupled to the flexible member. The locking device is adapted for receiving a surgical fastener. Thus, a surgical fastener may be selected based on a desired procedure and coupled to the locking device to facilitate, for example, parachuting suture tissue connecting procedures as discussed above.
According to another aspect of the invention, a method for connecting tissues includes drawing portions of tissue together with a clip assembly and securing the tissue portions together with the clip assembly.
According to another aspect of the invention, multiple portions of material are drawn together with a tissue connector assembly having a clip in an open position. At least one of the portions of material is tissue. The clip is closed to secure the material portions therein. The materials may be drawn together by pulling the tissue connector assembly with at least a portion of the clip positioned in the materials. A needle may be used to insert the tissue connector assembly into the material. A portion of the tissue connector assembly may be manipulated to simultaneously actuate closure of the clip and release the needle from the clip.
According to another aspect of the invention, a tissue connector assembly is inserted through graft and target vessels with the graft vessel being spaced from the target vessel. The tissue connector assembly has a first end extending from an exterior surface of the graft vessel and a second end extending from an exterior surface of the target vessel. At least one end of the tissue connector assembly is pulled to draw the graft vessel into contact with the target vessel.
According to another aspect of the invention, a tissue connector assembly is inserted through the graft and target vessels with the graft vessel being spaced from the target vessel and the tissue connector assembly having a first end extending from an exterior surface of the graft vessel and a second end extending from an exterior surface of the target vessel. At least a portion of the tissue connector assembly is pulled to draw the graft vessel into contact with the target vessel.
The above is a brief description of some deficiencies in the prior art and advantages of the present invention. Other features, advantages, and embodiments of the invention will be apparent to those skilled in the art from the following description, accompanying drawings, and claims.
Corresponding reference characters indicate corresponding parts throughout the several views of the drawings.
Referring now to the drawings, and first to
In the embodiment shown in
The penetrating member or needle 16 has a sharp pointed tip 30 at its distal end for penetrating tissue. The needle 16 may be bent as shown in
The flexible member 18 may be in the form of a suture formed from conventional filament material, metal alloy such as nitinol, polymeric material, or any other suitable material. The material may be non-stretchable or stretchable, solid or hollow, and have various cross-sectional diameters. The suture may have a cross-sectional diameter of 0.003 inch, for example. The diameter and length of the suture will vary depending on the specific application. The suture may be attached to the needle 16 by crimping or swaging the needle onto the suture, gluing the suture to the needle, or any other suitable attachment method. The flexible member 18 may have cross-sectional shapes other than the one shown herein.
One embodiment of a fastener comprises a deformable wire 34 made of a shape memory alloy. A nickel titanium (nitinol) based alloy may be used, for example. The nitinol may include additional elements which affect the yield strength of the material or the temperature at which particular pseudoelastic or shape transformation characteristics occur. The transformation temperature may be defined as the temperature at which a shape memory alloy finishes transforming from martensite to austenite upon heating (i.e., Af temperature). The shape memory alloy preferably exhibits pseudoelastic (superelastic) behavior when deformed at a temperature slightly above its transformation temperature. At least a portion of the shape memory alloy is converted from its austenitic phase to its martensitic phase when the wire 34 is in its deformed configuration. As the stress is removed, the material undergoes a martensitic to austenitic conversion and springs back to its original undeformed configuration. When the wire 34 is positioned within the tissue in its undeformed configuration, a residual stress is present to maintain the tissue tightly together (
It is to be understood that the shape memory alloy may also be heat activated, or a combination of heat activation and pseudoelastic properties may be used, as is well known by those skilled in the art.
The cross-sectional diameter of the wire 34 and length of the wire will vary depending on the specific application. The diameter d of the wire 34 may be, for example, between 0.001 and 0.015 inch. For coronary bypass applications, the diameter is preferably between 0.001 and 0.008 inch with a diameter D of the loop being between 0.0125 and 0.0875 inch (
The proximal end of the wire 34 may include a stop 36 having a cross-sectional area greater than the cross-sectional area of the wire and coil 26 to prevent the wire and coil from passing through the tissue. The stop 36 may be attached to the end of the wire 34 by welding, gluing or other suitable attachment means or may be formed integrally with the wire by deforming the end of the wire. The stop 36 may also be eliminated to facilitate pulling the fastener completely through the tissue, if, for example, the entire fastener needs to be removed from the vessel during the insertion procedure. The distal end of the wire 34 includes an enlarged portion 38 for engagement with the restraining device 24 as further described below (
The wire 34 has an undeformed or closed configuration (position, state) (
The wire 34 may be formed in the above described shape by first wrapping the wire onto a mandrel and heat treating the wire at approximately 400-500 degrees Celsius for approximately 5 to 30 minutes. The wire 34 is then air quenched at room temperature. The mandrel may have a constant diameter or may be conical in shape.
An alternate configuration of the surgical clip 20 in its closed position is shown in
Another alternate configuration of the surgical clip 20 is shown in
A modification of the fastener 41 is shown in
It is to be understood that the fastener 20, 40, 41, 43 may have undeformed or deformed configurations different than those shown herein without departing from the scope of the invention. In addition, a locking clip (not shown) may also be attached to connect the ends of the fastener 20, 40, 41, 43 when the fastener is in its closed position to prevent possible opening of the fastener over time. The locking clip may also be integrally formed with one end of the fastener.
As shown in
When the coil 26 is in its free state (with the wire in its undeformed configuration), loops of the coil are generally spaced from one another and do not exert any significant force on the wire 34 (
The locking device 28 of the embodiment shown in
The tubular member 50 is movable between a locked position (
The proximal end 54 of the tubular member 50 includes a bore 62 having a diameter slightly greater than the outer diameter d of the wire 34, but smaller than the diameter of the enlarged portion 58 at the distal end of the wire and the outer diameter of the coil 26. The bore 62 extends into a cavity 64 sized for receiving the enlarged portion 38 of the wire 34. Member 50 may be described as having an annular flange 61 for releasably securing the enlarged portion 38. As shown in
It is to be understood that locking devices other than those described above may be used without departing from the scope of the invention. For example, a locking device (not shown) may comprise a tubular member having an opening formed in a sidewall thereof for receiving an end portion of the wire. The end of the wire may be bent so that it is biased to fit within the opening in the sidewall of the tubular member. An instrument, such as a needle holder may then be used to push the wire away from the opening in the tubular member and release the wire from the tubular member. Various other types of locking devices including a spring detent or bayonet type of device may also be used.
An alternate embodiment of the restraining device is shown in
Another tissue connector assembly is shown in
The restraining device 108 comprises a coil 112 and the locking device 104. The locking device 104 is similar to the locking device 28 shown in
As noted above, the tissue connector assemblies 10, 100 have many uses. They may be especially useful for minimally invasive surgical procedures including creating an anastomosis between a vascular graft 12 and an artery 14 (
The patient is first prepped for standard cardiac surgery. After exposure and control of the artery 14, occlusion and reperfusion may be performed as required. After the arteriotomy of the snared graft vessel 12 has been made to the appropriate length, a tissue connector assembly 10 is attached to the free end of the graft vessel along an edge margin of the vessel. In order to attach the connector assembly 10, the surgeon grasps the needle 16 with a needle holder (e.g., surgical pliers, forceps, or any other suitable instrument) and inserts the needle 16 into the tissue of the graft vessel 12 in a direction from the exterior of the vessel to the interior of the vessel. The surgeon then releases the needle 16 and grasps a forward end of the needle which is now located inside the graft vessel 12 and pulls the needle and a portion of the suture 18 through the vessel. The needle 16 is passed through an opening 120 formed in the sidewall of the artery 14 and inserted into the tissue of the artery in a direction from the interior of the artery to the exterior of the artery. The surgeon then grasps the needle 16 located outside the artery 14 and pulls the needle and a portion of the suture 18 through the arterial wall. A second tissue connector assembly 10 may be inserted at a location generally 180 degrees from the location of the first tissue connector in a conventional “heel and toe” arrangement.
Once the tissue connector assemblies 10 are inserted, the graft vessel 12 is positioned above and aligned with the opening 120 in the sidewall of the artery 14 (
A surgical instrument (e.g., needle holder) is used to radially squeeze each locking device 28 to release the locking device from the fastener 20. Upon removal of the locking device 28, the coil 26 moves to its free uncompressed state which allows the wire 34 to return to its original undeformed closed position (
The tissue connector assemblies 100 are subsequently inserted at circumferentially spaced locations around the periphery of the graft vessel to sealingly fasten the graft vessel 12 to the artery 14. The needle 102 of the fastener 100 is inserted into the graft vessel 12 from the exterior surface of the graft vessel and pushed through the graft vessel and artery 14 tissue. The needle holder is then used to pull the needle 102 through the arterial wall. An instrument (same needle holder or other suitable instrument) is used to apply a squeezing force to the locking device 104 to release the wire and coil 112 from the needle 102. This allows the coil 112 to move to its uncompressed configuration and the wire to move to its closed position. It should be noted that the tissue connector assemblies 10 may remain in their open position while the tissue connector assemblies 100 are inserted into the tissue and moved to their closed position. The locking devices 28 of the tissue connector assemblies 10 may subsequently be removed from the fasteners 20 to allow the fasteners to move to their closed position. The number and combination of tissue connectors assemblies 10, 100 required to sealingly secure the connecting tissues together may vary. For example, only tissue connector assemblies 10 may be used to complete the entire anastomosis.
Although the coil 26 is shown remaining on the wire (
As an alternative to inserting tissue connector assemblies 10 at “heel and toe” locations described above, a number of tissue connectors 10 may be inserted generally around the location of the heel. The graft vessel may then be pulled towards the artery to determine whether the opening formed in the sidewall of the artery is large enough before completing the anastomosis.
The graft vessel 12 may also be parachuted onto the artery 14 in the method shown in
Although the suturing procedure has been described for an end-to-side anastomosis, it should be appreciated that the procedure is applicable to an end-to-end and side-to-side anastomosis, connecting various tissue structures including single and multiple tissue structures, and puncture sites, and connecting tissue to a prosthetic graft or valve, for example.
It will be observed from the foregoing that the tissue connector assemblies of the present invention have numerous advantages. Importantly, the assemblies are easier and faster to apply than conventional sutures which require tying multiple knots. The assemblies also may be used in minimally invasive procedures including endoscopic procedures.
All references cited above are incorporated herein by reference.
The above is a detailed description of a particular embodiment of the invention. It is recognized that departures from the disclosed embodiment may be made within the scope of the invention and that obvious modifications will occur to a person skilled in the art. The full scope of the invention is set out in the claims that follow and their equivalents. Accordingly, the claims and specification should not be construed to unduly narrow the full scope of protection to which the invention is entitled.