CA1162453A - Ligating clip applying instrument - Google Patents

Abstract

ABSTRACT

The invention is concerned with an instrument for applying a ligating clip having first and second leg members joined at their proximal ends by a resilient hinge means and terminating at their distal ends in latch means.
The clip applying instrument of the invention comprises a pair of handles pivoted about a hinge point, which handles cross at the hinge point and extend beyond the hinge point to form a pair of clip closing jaws having opposing inner faces, each jaw having a recessed clip receiving channel in the inner face thereof. The channel has a base and a pair of vertically extending side walls, and extends from the tip of the jaw furthest from the hinge point rearwardly towards the hinge point. The channel also has a length at least equal to the length of the clip to be applied by the instrument, each channel having a cylindrical recess disposed in the base of the channel and extending between the side walls and being spaced from the tip of the jaw. The depth of the channel from the tip of the jaw to the recess is greater than the depth of the channel from the recess towards the hinge point such that the jaws do not interfere with the closing and latching of the clip.

Description

~62~53 This application is a division of Canadian application No 354,029 filed June 16, 1980, which relates to hemostatic clips and clip appliers, and, more particu-larly, to hemostatic clips fabricated from absorbable or non-absorbable polymeric materials and to instruments for applying such clips to blood vessels and the like.
Hemostatic clips are utilized in surgical procedures to close severed blood vessels and other small fluid ducts. In the past, hemostatic clips have been narrow U-shaped or V-shaped strips formed of tantalum or stainless steel which are capable of being deformed and possess sufficient strength to retain the deformation when clamped about a blood vessel. The clips are generally applied using a forceps-type device having jaws channeled or otherwise adapted to hold the open clip. Representative hemostatic clips and appliers of the prior art are best illustrated in U.S. Patents Nos 3,867,944; 3,631,707:
3,439,523; 3,439,522, 3,363,628; 3,312,216 and 3,270,745.
It has been suggested in the prior art, as in U~S. Patent No 3,439,523, for example, that hemostatic clips might be formed of inexponsive plastics or materials which are slowly absorbable in the body. Unfortunately, conventional U- and V-shaped hemostatic clips do not possess the required strength or deformability when constructed of known plastic materials to be successfully clamped about a blood vessel. Thus, although the need and desirability of providing inexpensive plastic ligating clips of both absorbable and non-absorbable materials has been recognized for over ten years, there has been no practical way to satisfy this need.
U.S. No 3,926,195 describes a small, plastic clip designed for the temporary or permanent close of the oviduct 1 3~2~53 and vas deferens in humans. These clips preferably have a clamping surface of from 6 to 10 mm in length and 3 to 6 mm in width. The size of such clips are accordingly considerably larger than is desirable for hemostatic clips.
Additionally, clips of U.S. 3,926,195 require the use of several complex tools to apply the clips which are accept-able for the purposes described in the reference but would be unacceptable in a surgical procedure requiring the rapid placement of a large number of hemostatic clips to stem the flow of blood from severed vessels.
Accordingly, the parent application proposed to provide plastic ligating clips which are effective for clamping off small blood vessels and other fluid ducts in the body and which are quickly and easily applied to severed blood vessels and other fluid ducts with a single fvrceps-type instrument used in applying metallic clips.
me clip with which the invention of the parent application is concerned is a sterile, hemostatic ligating clip made from absorbable or non-absorbable polymeric materials for application using a clip appl~ing instrument having a pair of jaws for holding the clip, placing the clip about the vessel to be ligated and closing the clip to ligate the vessel~ The clip comprises first and second leg members joined at their proximal ends by xesilient hinge means and terminating at their distal ends in latch means, each leg member having an outer surface and a vessel clamping inner-face. The vessel clamping innerface is in opposition to a vessel clamping innerface of the other leg member. The first leg member terminates at the distal end thereof in a portion of the latch means, which portion comprises a deflectable hook member extending frorn the innerface of the leg member, the hook member having an innerface spaced from the innerface of the hook member and substantially parallel 11 B~53 thereto, the end face of the hook member being beveled so as to form an acute angle with the innerface of the hook member. The first leg member also has a boss disposed on a portion of its outer surface opposite the vessel clamping innerface, the boss having a cylindrical shape with the axis of the cylinder extending across the width of the leg member. The boss is adapted to fit into a first jaw of the clip applying instrument and is spaced from the opposite side of the leg mem~er. The second leg member terminates at the distal end thereof in a complementary portion of the latch means, which portion comprises an end face of the leg member having a bevel complementary on the bevel to the end face of the hook member, the complementary bevel forming an obtuse angle with the innerface of the second leg member and adapted to enter the space~between the innerface of the hook member and the innerface of the first leg member with the end face of the leg member being enclosed ~y the hook member. The second leg member has a boss disposed on a portion of its outer surface opposite the vessel clamp-ing innerface, the boss having a cylindrical shape withthe axis of the cylinder extending across the width of the leg member. The boss is adapted to fit into the second jaw of the clip applying instrument and is spaced from the proximal end of the leg member. When the pair of jaws of the clip applying instrument having the clip therein are closed, the bosses of the clip rotate with the jaws of the instrument and allow the first and second leg members to pivot about the hinge means and the dlstal end of the second leg member to deflect and engage the hook member of the first leg member to lock the clip in a closed position.
The clips may be formed of plastic by injection molding or other suitable technique, and may be composed of a non-absorbable material such as polypropylene or an 1 3~2~53 absorbable material such as a homopolymer or copolymer of lactide and glycolide. The clips are formed in a normally open position and constructed with a small amount of material to minimize tissue reaction. The clips are readily applied with a forceps-type applier using conven-tional surgical techniques.
The present divisional application is directed to an instrument for applying a ligating clip as described above, which has first and second leg members joined at their proximal ends by a resilient hinge means and terminat-ing at their distal ends in latch means. m is clip apply-ing instrument comprises a pair of handles pivoted about a hinge point, which handles cross at the hinge point and extend beyond the hinge point to form a pair of clip closing jaws having opposing inner faces, each jaw having a recessed clip receiving channel in the inner face thereof.
The channel has a base and a pair of vertically extending side walls, and extends from the tip of the jaw furthest from the hinge point rearwardly towards the hinge point.
The channel also has a length at least equal to the length of the clip to be applied by the instrument, each channel having a cylindrical recess disposed in the base of the channel and extending between the side walls and being spaced from the tip of the jaw. The depth of the channel from the tip of the jaw to the recess is greater than the depth of the channel from the recess towards the hinge point such that the jaws do not interfere with the closing and latching of the clip.
According to a preferred embodiment, the cylin-drical recesses in each channel are in alignment relativeto the inner faces of the jaws when the jaws are in a closed position.

_ ~ _ - 1316~53 According to another preferred embodiment, the clip closing jaws are of the same length and the cylin-drical recesses in each channel are equidistantly spaced from the tips of the jaws.
Further features and advantages of the inventions in the parent and divisional applications will become more readily apparent from the follawing description of preferred embodiments thereof as illustrated in the accompanying drawings, wherein:
Figure 1 is a greatly enlarged view in perspec-tive of a surgical clip according to the invention, Figure 2 illustrates the clip of Figure 1 clamped about a blood vessel, Figure 3 illustrates a forceps-type applier use-ful with the clips of the invention, Figure 4 illustrates the open clip of Figure 1 retained in the jaws of a forcep~-type clip applier; and Figure 5 illustrates the clip of Figure 4 closed and locked over a blood vessel in the jaws of the applier.
Referring now to Figure 1, there is illustrated hemostatic clip 10 constructed of two leg segments 11 and 12 connected at the proximal ends thereof by hinge section 13. Leg 11 terminates at the distal end thereof in hook member 14 having inner face 15 substantially parallel to inner face 16 of leg 11 and forming an acute angle with end face 17. Leg member 12 terminates at the distal end in end face 19 which forms an obtuse angle with inner face 18 o leg 12. End face 19 is offset at 23 to form a notch approximately midway between surfaces 18 and 20, and additionalLy is squared off at face 25 to form a substan tially right angle with surface 20.
The length and width of faces 16 and 18 are substantially equal, and face 15 of hook 14 is spaced from I ~ ~2453 face 16 of leg 11 by a distance corresponding to the thickness of leg 12 between the plane of face 18 and sur-face 20. When legs 11 and 12 are pivoted about hinge 13 to bring faces 18 and 16 into opposition, hook 14 is deflected by surface 19 of leg 12 until the distal end of leg 12 snaps under hook 14 and is thereby locked in place.
End face 17 of hook 14 and end face 19 of leg 12 are angled as illustrated to facilitate the passage of leg 12 past hook 14 during clip closure.
When the clip is closed over a tubular vessel as illustrated in Figure 2, surfaces 16 and 18 engage and compress vessel 27 to close the lumen thereof. Surfaces 16 and 18 may be smooth as illustrated in Figure 1, or may be provided with ridges or grooves to increase vessel holding po~er. Leg 11 may also be undercut at the junc-ture of hook member 14 and surface 16 as illustrated at 26 in Figure 1 to increase the deflectability of hook member 14 and increase the space between the hook member 14 and leg 11, thereby compensating for any inward deflection of hook 14 during closure which might reduce the clearance between surfaces 15 and 16 and otherwise interfere with the latching of the clip.
Referring again to Figure 1, leg 12 of clip 10 includes an outside cylindrical boss 21 extending across the width of the leg near the distal end thereof~ Boss 21 is spaced from surface 25 a distance sufficient to permit full engagement of hook member 14 by leg 12 when the clip is in a closed and latched position. Cylindrical bosses 21 and 22 are equidistant from hinge means 13 so that when the clip is closed, bosses 21 and 22 define a line perpendi~
cular to the major axis along the length of the clip as best illustrated in Figure 5.

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The distal end of leg 12 forward ~f lug 21 is of reduces thickness relative to the thickness immediately to the rear of lug 21, thereby forming step 24 between lug 21 and surface 20. The significance of this clip confi-guration will be appreciated in connection with the instrument used to apply and close the clip as illustrated in Figures 3 through 5.
Figure 3 illustrates a forceps-type ligating clip applier 30 comprising two handle members 31 and 32 crossing at hinge point 33 and maintained in a normally open position by spring 38. -Handle 31 extends beyond hinge 33 forming jaw member 34 while the extension of handle 32 forms jaw member 35.
Figure 4 illustrates the detail of the construc-tion of jaws 34 and 35 and the interaction of the jaws with the clip of Figure 1. Jaws 34 and 35 are of identical design and are provided respectively with channels 36 and 37 extending rearwardly from the tips of,the jaws. Each channel is provided with a cylindrical recess 38 and 39 respectively across the width of the channel and near the distal end thereof. ~ecesses 38 and 39 are in alignment when the jaws of the applier are closed and are sized to receive the cylindrical lugs 21 and 22 of the clip.
Channels 36 and 37 forward of recesses 38 and 39 are deeper than to the rear of the recesses as illustrated in Figure 4. When the open clip is held in the applier, the cylindrical lugs on the clip extend into the cylindrical recesses in each jaw. Due to the angle of the clip in the applier, the distal ends of legs 11 and 12 extend into the deeper forward channel section of each jaw. The reduced thickness of leg 12 at the distal tip prevents interference between the tip and the channel of the applier when the clip is held in the open position as illustrated in Figure 4.
Clip 10 is initially loaded in applier 30 in the open position as illustrated in Figure 4. After moving the jaws of the applier and the clip into position over the vessel to be ligated, the jaws of the applier are closed and the clip is locked in position over the vessel as illustated in Figure 5. As the clip is closed, the cylindrical lugs of legs 11 and 12 rotate in the cylindrical recesses of jaws 37 and 36 until the outer surface of leg 12 rests on the base of channel 36 as illustrated in Figure 5. At this point, the distal end of leg 12 has rotated away from the base of the channel and sufficient space exists for hook 14 to bypass leg 12 and latch over the outer surface thereof. After the clip has been securely latched over the vessel to be ligated, the jaws of the applier are opened to release the clip and vessel and a new clip is loaded in the applier. Since the jaws of the applier are identical, it is not necessary to orient the applier to the clip when loading the applier.
Man~ variations in the clip design other than the embodiments disclosed herein will be apparent to those skilled in the art and are contemplated within the scope of the invention. For example, the undercut at the juncture of hook 14 and surface 16 of leg 11 may be omitted, and the inner surface of leg 12 may be beveled at the distal end as indicated by broken line _ in Figure 1 to compensate for downward deflection of hook 14 during closure which might reduce the clearance under face 15 and interfere with the 30 latching of leg 12. Offset 23 in end face 19 of leg 12 provides an intermediate latching position and effectively increases the length of face 18 at the distal end of leg 12, but may be omitted if desired. These and other modifications in the configuration of the clip may be employed without departing from the spirit and scope of the invention~

~ ~ ~2~53 The clips of the invention may be constructed in various sizes according to their intended function.
Hemostatic clips are typically less than 6 mm in length~
about 1.5 mm in width, and have a vessel clarnping surface about 3 mm in length. The dimensions of the clip may be reduced by about 50 percent for certain applications in microsurgery. Larger clips for special hemostatic applications and other functions such as closure of oviducts or vas deferens may have dimensions of about double those of a typical hemostatic clip. Ihe various sizes of clips are preferably matched with individual appliers having jaws tailored to the size of the clip for best performance.
The clips of the invention are most conveniently molded of biologically acceptable plastic materials which may be absorbable or non-absorbable. Preferred absorbable polymers include homopolymers and copolymers of glycolide and lactide, and poly(~-dioxanone). Preferred non-absorbable polymers include nylon and polypropylene. All these materials have been demonstrated to be biologically acceptable when used as sutures or other implantable medical devices. The clips may also be cast or machined from solid polymeric materials or from metals such as aluminum, magnesium, stainless steel, tantalum, and various alloys o~ these, some of which may also be absorbable in biological tissue.

Claims (3)

The embodiments of the invention, in which an exclusive property or privilege is claimed, are defined as follows:-

1.- An instrument for applying a ligating clip having first and second leg members joined at their proximal ends by a resilient hinge means and terminating at their distal ends in latch means, said clip applying instrument com-prising a pair of handles pivoted about a hinge point, said handles crossing at said hinge point and extending beyond the hinge point to form a pair of clip closing jaws having opposing inner faces, each of said jaws having a recessed clip receiving channel in the inner face thereof, said channel having a base and a pair of vertically extending side walls, said channel extending from the tip of said jaws furthest from said hinge point rearwardly towards said hinge point, said channel having a length at least equal to the length of the clip to be applied by said instrument, each channel having a cylindrical recess disposed in the base of the channel and extending between said side walls and being spaced from the tip of said jaw, the depth of the channel from the tip of the jaw to said recess being greater than the depth of the channel from the recess towards the hinge point whereby the jaws do not interfere with the closing and latching of the clip.

2.- A clip-applying instrument as defined in claim 1, wherein the cylindrical recesses in each channel are in alignment, relative to the inner faces of said jaws when said jaws are in a closed position.

3.- A clip-applying instrument as defined in claim 1, wherein the clip closing jaws are of the same length and the cylindrical recesses in each channel are equidistantly spaced from the tips of said jaws.