The present invention relates to surgical clips, and more particularly to a non-snag polymer ligating clip which is easier to introduce into tight spaces during coronary artery bypass graft surgery and which is less prone to catch a suture when attaching a graft IMA (internal mammary artery) to the coronary artery during the coronary artery bypass graft procedure. More particularly, the present disclosure relates to an improved surgical ligating clip that can be used in coronary artery bypass graft surgical procedures without catching a suture during attachment of a graft IMA to the coronary artery and which subsequently allows for CT (computer tomography) to check patency in the coronary artery bypass graft juncture since the clip is translucent and not visible on CT.
Many surgical procedures require vessels or other tissues of the human body to be ligated during the surgical process. For example, many surgical procedures require cutting blood vessels (e.g., veins or arteries), and these blood vessels may require ligation to reduce bleeding. In some instances, a surgeon may wish to ligate the vessel temporarily to reduce blood flow to the surgical site during the surgical procedure. In other instances a surgeon may wish to permanently ligate a vessel. Ligation of vessels or other tissues can be performed by closing the vessel with a ligating clip, or by suturing the vessel with surgical thread. The use of surgical thread for ligation requires complex manipulations of the needle and suture material to form the knots required to secure the vessel. Such complex manipulations are time-consuming and difficult to perform, particularly in endoscopic surgical procedures, which are characterized by limited space and visibility. By contrast, ligating clips are relatively easy and quick to apply. Typically, a clip is applied to the vessel or other tissue by using a dedicated mechanical instrument commonly referred to as a surgical clip applier, ligating clip applier, or hemostatic clip applier. Accordingly, the use of ligating clips in endoscopic as well as open surgical procedures has grown dramatically.
Ligating clips can be classified according to their geometric configuration (e.g., symmetric clips or asymmetric clips), and according to the material from which they are manufactured (e.g., metal clips or polymeric clips). Symmetric clips are generally “U” or “V” shaped and thus are substantially symmetrical about a central, longitudinal axis extending between the legs of the clip. Symmetric clips are usually constructed from metals such as stainless steel, titanium, tantalum, or alloys thereof. By means of a dedicated clip applier, the metal clip is permanently deformed over the vessel. An example of one such clip is disclosed in U.S. Pat. No. 5,509,920 to Phillips et al. An example of a metallic clip applier is disclosed in U.S. Pat. No. 3,326,216 to Wood in which a forceps-type applier having conformal jaws is used to grip and maintain alignment of the clip during deformation. Such appliers may additionally dispense a plurality of clips for sequential application, as disclosed in U.S. Pat. No. 4,509,518 to McGarry et al.
With the advent of high technology diagnostic techniques using computer tomography (CATSCAN or CT) and magnetic resonance imaging (MRI), metallic clips have been found to interfere with the imaging techniques. To overcome such interference limitations, biocompatible polymers have been increasingly used for surgical clips. Unlike metallic clips, which are usually symmetric, polymeric clips are usually asymmetric in design and hence lack an axis of symmetry. Inasmuch as the plastic clip cannot be permanently deformed for secure closure around a vessel or other tissue, latching mechanisms have been incorporated into the clip design to establish closure conditions and to secure against re-opening of the vessel. For example, well known polymeric clips are disclosed in U.S. Pat. No. 4,834,096 to Oh et al. and U.S. Pat. No. 5,062,846 to Oh et al., both of which are assigned to the assignee of the presently disclosed subject matter. These plastic clips generally comprise a pair of curved legs joined at their proximal ends with an integral hinge or heel. The distal ends of the curved legs include interlocking latching members. For example, the distal end of one leg terminates in a lip or hook structure into which the distal end of the other leg securely fits to lock the clip in place.
The distal ends of the clips taught in U.S. Pat. No. 5,062,846 to Oh et al. also include lateral bosses that are engaged by the jaws of a clip applier. A clip applier specifically designed for asymmetric plastic clips is used to close the clip around the tissue to be ligated, and to latch or lock the clip in the closed condition. In operation, the jaws of this clip applier are actuated into compressing contact with the legs of the clip. This causes the legs to pivot inwardly about the hinge, thereby deflecting the hook of the one leg to allow reception therein of the distal end of the other leg. A clip applier designed for use with asymmetric plastic clips in an open (i.e., non-endoscopic) surgical procedure is disclosed in U.S. Pat. No. 5,100,416 to Oh et al., also assigned to the assignee of the presently disclosed subject matter.
In addition to compatibility with sophisticated diagnostic techniques, asymmetric clips have other advantages over symmetric clips. For example, because asymmetric clips are formed from polymeric materials, the mouths of asymmetric clips can generally be opened wider than the mouths of symmetric clips. This allows a surgeon to position the clip about the desired vessel with greater accuracy. In addition, a clip of the type described in the aforementioned U.S. Pat. Nos. 4,834,096 and 5,062,846 can be repositioned before locking the clip on the vessel or before removing the clip from the vessel, in a process referred to as “approximating” the clip.
Various types of hemostatic and aneurysm asymmetric clips are used in surgery for ligating blood vessels or other tissues to stop the flow of blood. Such clips have also been used for interrupting or occluding ducts and vessels in particular surgeries such as sterilization procedures.
As is well known to those skilled in the art, metal ligating clips are traditionally used to tie off the branches of an IMA being used for the graft in a coronary artery bypass graft procedure. However, metal clips are not viable when there is a desire to use a CT scan to study the patency of a graft after bypass surgery. The use of the CT scan is desirable since it eliminates the need for re-catheterization in order to verify graft patency.
Thus, there is a long-felt need in coronary artery bypass surgery to find an alternative to the metal ligating clip used to tie off branches of the IMA being used for a coronary artery bypass graft since the metal ligating clips do not readily lend themselves to CT scans to study the patency of a graft after a bypass. Thus, a re-catheterization is many times necessary in order to verify the patency. The radiolucent polymeric ligating clip such as the HEM-O-LOK® available from Pilling Weck would be ideal except for the side bosses which facilitate engagement and application of the clip by a clip applier. The applicant has now discovered a novel modification to the polymeric ligating clip such that the clip will provide all of the advantages of a traditional polymeric clip including radiolucency but will not possess the disadvantages of the suture-snagging bosses provided on prior art polymeric ligating clips such as the HEM-O-LOK® clip. The new and improved non-snag polymeric ligating clip provides a low profile clip that is ideal for coronary artery bypass graft surgery.
In accordance with the present disclosure, a polymeric surgical clip is provided of the type comprising first and second legs joined at their proximal ends by a flexible hinge section. Each leg has a vessel clamping inner surface, an opposite outer surface, and a pair of opposing side surfaces. The vessel clamping inner surface is in opposition to the vessel clamping inner surface of the other leg. Further, a female locking member is positioned on the distal end of the first leg and a male locking member is positioned on the distal end of the second leg. The female and male locking members are formed such that when the first and second leg members are moved from an open position to a closed position about the hinge section, the male locking member is lockingly engaged in the female locking member so as to removably lock the clip in the closed position.
Further in the preferred embodiment, the inner vessel-clamping surface of the first leg has a concave radius of curvature and the outer surface has a convex radius of curvature between the hinge section and the distal end. In the same embodiment, the inner vessel-clamping surface of the second leg has a convex radius of curvature and the outer surface has a concave radius of curvature between the hinge section and the distal end.
Still further in the preferred embodiment, a first pair of recesses are formed in opposite sides of the first leg between the hinge section and the distal end of the first leg, and a second pair of recesses are formed in opposite sides of the second leg adjacent the distal end of the second leg, such that the first and second pair of recesses serve to allow for engagement and application of the surgical clip by a clip applier apparatus.
In another embodiment of the non-snag polymer ligating clip, a first recess is located on the outer surface of the first leg between the hinge section and the distal end of the first leg, and a second recess is located in the outer surface of the second leg adjacent the distal end of the second leg such that the first and second recesses serve to allow for engagement and application of the surgical clip by a clip applier apparatus.
In another embodiment of the non-snag polymer ligating clip, a first protuberance is located on the outer surface of the first leg between the hinge section and the distal end of the first leg, and a second protuberance is located on the outer surface of the second leg adjacent the distal end of the second leg such that the first and second protuberances serve to allow for engagement and application of the surgical clip by a clip applier apparatus.
In still another embodiment of the non-snag polymer ligating clip of the discovery, a first pair of arcuate protuberances are joined to opposite sides of the first leg between the hinge section and the distal end of the first leg, and a second pair of arcuate protuberances are joined to opposite sides of the second leg adjacent the distal end of the second leg such that the first and second pair of arcuate protuberances serve to allow for engagement and application of the surgical clip by a clip applier apparatus.
The non-snag polymeric surgical clip disclosed herein is most suitably made of polymeric material and accordingly minimizes interference with high technology diagnostic modalities such as CATSCAN, MRI and MRS. At the same time, the clip is nearly as small as comparable metal clips while maintaining sufficient strength and possessing a high degree of security in the clip's latching mechanism. The ligating clip of the discovery is further configured with low profile bosses used for engagement and application by a clip applier apparatus, and wherein the low profile bosses will facilitate introduction into tight spaces during coronary artery bypass graft procedures and very importantly is less prone to snag a suture during coronary artery bypass graft surgical procedures than a conventional polymeric ligating clip having conventional bosses at the end of both the first and second leg that extend outwardly from the side surfaces thereof.
It is therefore an object of the presently disclosed non-snag surgical ligating clip to provide a non-snag polymeric surgical clip that is particularly well suited for coronary artery bypass graft surgical procedures.
Some of the objects of the subject matter disclosed herein having been stated hereinabove, other objects will become evident as the description proceeds when taken in connection with the accompanying drawings as best described hereinbelow.
Referring first to
Now turning to
Hinge section 26 has a continuous concave inner surface 36 and a continuous convex outer surface 38. Concave inner surface 36 of hinge section 26 joins concave inner surface 28 of first leg 22 and convex inner surface 32 of second leg 24. Convex outer surface 38 of hinge section 26 joins convex outer surface 30 of first leg 22 and concave outer surface 34 of second leg 24.
First leg 22 terminates in a female locking member 40 at its distal end. Female locking member 40 comprises a resilient inwardly turned hook 41. Second leg 24 terminates in a male locking member 50. Male locking member 50 comprises a pointed tip section 42 at its distal end. Hook 41 is distally curved inwardly toward hinge section 26, and has a transverse beveled surface 44. Beveled surface 44 and concave inner surface 28 define a latching recess 46, which is adapted for conformally engaging tip section 42 of male locking member 50 in the course of compressing clip 12 into a latched or locked position around a vessel or other tissue.
As best shown in
As best shown in
Referring again to the distal end of second or inner leg 24, another pair of cylindrical bosses 62 and 64 is formed coaxially on the opposed lateral surfaces of inner leg 24 at tip section 42. As evident in
Also, as best shown in
Both first and second legs 22 and 24 have a plurality of optional protrusions or teeth 76 extending from their respective inner surfaces 28 and 32. These features are designed to engage the tissue of the vessel being clamped and assist in preventing the vessel from sliding laterally or longitudinally during or following clip closure. It will be noted, however, that other clips equally suitable for use in conjunction with the presently disclosed subject matter may not contain such features.
In the practice of ligating and cutting a vessel or other tissue, as understood by persons skilled in the art, clip 12 is designed to be compressed into a latched or locked closed position around the vessel through the use of an appropriate clip applicator instrument. The clip applicator instrument engages protruding bosses 56, 58, 62 and 64 of clip 12 and pivots bosses 56, 58, 62 and 64 inwardly about hinge section 26. This causes first and second legs 22 and 24 to close around the vessel, with convex inner surface 32 of second leg 24 and complementary concave inner surface 28 of first leg 22 contacting the outer wall of the vessel.
However, before any contact is made between first and second legs 22 and 24, sharp tissue penetrating teeth 72 and 74 on bosses 62 and 64 of second leg 24 start to indent and penetrate any connective tissue surrounding the vessel therebetween and pull the tissue down. Simultaneously, sharp tip 68 and hook 41 on first leg 22, while sliding between teeth 72 and 74, also begin to penetrate the tissue and force the tissue up. Sharp tip 68 and cutting edge 49 on hook 41 enter a groove 43 of pointed tip section 42 on second leg 24, thereby beginning puncturing and cutting of the connective tissue.
As cutting edge 49 and sharp tip 68 of hook 41 continue to move through groove 43 between teeth 72 and 74, shear forces contribute to further puncturing and cutting of the connective tissue surrounding the vessel. If all the tissue is still not cut between the distal portion of second leg 24 and hook 41, it will stretch and become thinner until it is easily punctured by sharp tip 68 and cut by cutting edge 49 of hook 41 as it passes through groove 43 of second leg 24. Once the connective tissue is cut, female and male locking members 40 and 50 are able to lockingly engage without interference.
It should be understood that while cutting edge 49 is a desired feature of the preferred embodiment of clip 12, other embodiments of clip 12 that do not include cutting edge 49 are contemplated to be part of the prior art and clip 12. Thus, clip 12 may or may not include cutting edge 49 as described above.
Tip section 42 of second leg 24 then begins to contact female locking member 40 at hook 41. Further pivotal movement by the jaws of the applicator instrument longitudinally elongates first leg 22 and deflects hook 41, allowing tip section 42 of male locking member 50 to align with latching recess 46 of female locking member 40. Upon release of the applicator instrument, tip section 42 snaps into and is conformably seated in latching recess 46 of female locking member 40, at which point clip 12 is in its latched and closed position. In the latched condition, tip section 42 is engaged between concave inner surface 28 and beveled surface 44, thereby securely clamping a designated vessel or other tissue between concave inner surface 28 and convex inner surface 32. After clip 12 is secured in its closed position and a vessel is ligated, most likely with two clips 12 on either side of the cutting site, the physician can safely cut the vessel.
It would be desirable to use polymeric-type ligating clips similar to clip 12 shown in
Referring now to
It will be appreciated that the recesses R1, R2 and R3, R4 in both clips 100 and 200 shown in
Referring now to
Referring now to
Finally,
It will be understood that various details of the presently disclosed subject matter can be changed without departing from the scope of the disclosure. Furthermore, the foregoing description is for the purpose of illustration only, and not for the purpose of limitation—the invention being defined by the claims.