Tissue spreading vascular clips with locking mechanism and non-slip clamping surfaces

[0001] This non-provisional US patent application is related to U.S. Provisional Application No. 61/713,597 filed on Oct. 14, 2012, and claims the benefit of that filing date.

[0002] The present invention relates to surgical clips, and, more particularly, to a biocompatible surgical clip with grooved clamping surfaces to prevent slipping, a tissue penetrating head lock mechanism, and a locking hinge portion to provide greater tension and security when clamping tissue between the two arms of the clip.

[0003] A wide number of surgical procedures employ surgical clips (i.e., ligation clips). Such surgical procedures may require vessels, organs or other tissues of the human body to be ligated. Surgical clips ligate, clamp, close off or otherwise occlude the engaged portion of the clamped vessels, organs or other tissues in a surgical site. Such clips may also be used to secure the ends of a suture, as in place of a conventional suture knot.

[0004] Ligation can be performed with a ligating clip (i.e., a surgical clip) or by suturing with surgical thread. Suturing 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. So long as the clips and applicator are designed with endoscopic procedures in mind, they are a preferred choice.

[0005] The clips are often in the form of thin, narrow, metal or polymeric U-shaped or V-shaped members that are placed over the vessel, tissue or suture material and then forced into a closed position using a clip applicator. Clips constructed of metal, may be initially open and then permanently deformed into a closed or clamped configuration around the desired blood vessel or other tissue structure using an appropriate clip applicator. However, metal clips, which are radio-opaque, interfere with x-ray imaging. Plastic clips include a latch feature to ensure that the clip remains closed with sufficient force to provide full and complete hemostasis or occlusion and to ensure that the clip will not loosen or open over time.

[0006] While ligating clips are an improvement over suturing in many procedures, they suffer shortcomings. First the clips typically require a surgical plane or window to be made prior to attachment. Conventional clips are not configured to penetrate tissue. Accurate planing and windowing manipulations are time-consuming and difficult to perform, particularly in endoscopic surgical procedures, which are characterized by limited space and visibility. Furthermore, creating windows can cause extensive bleeding, leading to decreased visibility.

[0007] Second, the clips tend to slip as they are applied. Slipping makes accurate placement extremely difficult. Additionally, forces applied during slipping may cause the contact surfaces of the clamping arms to deviate from parallel. In a worst case scenario, slipping may result in catastrophic dislodgment of the clip, resulting in excessive bleeding and increased mortality and morbidity.

[0008] Third, the clips are extremely difficult to remove. Conventional clips include relatively thick hinge and arm sections that abut and occlude a clamped vessel or tissue. The latch is not releasable. Cutting through such a clip without damaging the clamped vessel or tissue is extremely difficult.

[0009] U.S. Patent Publication No. 2012/0083803 is incorporated by reference in this specification. That application describes a penetrating lock and various clamping features, hinge configurations, and boss configurations.

[0010] The invention is directed to overcoming one or more of the problems and solving one or more of the needs as set forth above.

[0011] To solve one or more of the problems set forth above, in an exemplary implementation of the invention, a surgical clip includes a pair of opposed arms joined at one end by an integrally formed flexible hinge. Each arm has a free end. One arm includes a male head element near the free end. The opposite arm includes a head mating element near the free end. The male head element is configured to penetrate tissue in the path of the male head element when the male head element is urged towards the head mating element. The male head element includes a tissue penetrating head which may be a tissue spreading head. The head mating element engages the male head element and resists withdrawal of the head when the tissue spreading head of the male head element has been urged through the head mating element. The clip may be comprised of a biocompatible metal or plastic or a bioabsorbable plastic. The clip may be comprised of hybrid material with various components of metal and polymer or carbon fiber material. Each of the pair of arms includes a clamping side.

[0012] In one embodiment, the clamping side of one arm includes a wedge-shaped feature. The clamping side of the second arm includes a V-shaped trough that conforms to the shape of the wedge shaped feature. Each clamping side includes non-slip protrusions such as non-slip protruding ribs, cones, teeth, or needles. The integrally formed flexible hinge has a reduced thickness and protrudes outwardly from the clamping surfaces of the arms. The hinge may be cut to release the clip without cutting the clamped tissue or vessel.

[0013] In an exemplary surgical clip, a pair of opposed arms are joined at a hinged proximal end by an integrally formed flexible hinge. Each arm has a free distal end. One arm includes a male head element near the free distal end. The opposite arm includes a head mating element near the free end. The male head element includes a tissue piercing head configured to penetrate tissue in the path of the male head element when the male head element is urged towards the head mating element. The male head element acts as a penetrating trocar via spreading the tissue fibers so it pierces the tissue in an atraumatic fashion. As the male head element punctures the tissue, it perforates and tunnels (or bores) through the tissue to create a tissue channel/opening atraumatically. The head mating element includes a shape that engages the male head element and resists withdrawal of the head when the head of the male head element has been urged through the head mating element.

[0014] In an exemplary surgical clip, the flexible hinge is a U-shaped segment that extends from the hinged end of each arm of the pair of opposed arms. The hinged ends of the arms are configured to abut each other when the surgical clip is closed. A curved hinge guard prevents tissue from invading the flexible hinge, while ensuring that the clamping arms maintain intimate contact with the clamped tissue. A clamped object (e.g., tissue) does not contact the flexible hinge when the surgical clip is closed and the hinge may be cut to release the clamp, without contacting the clamped object. An empty space is maintained between the hinged ends of the arms of the pair of opposed arms and the flexible hinge. The flexible hinge has a hinge thickness and width, and each arm of the pair of opposed arms has an average thickness and width. In one embodiment, the width and/or thickness of the flexible hinge is less than the average width of each arm of the pair of opposed arms to facilitate cutting. In one embodiment as depicted in FIG. 8E, the clip includes a locking hinge portion that locks the clip in the closed position when the male head element is engaged into the head mating element.

[0015] Therefore, when the clip is closed/engaged around tissue (blood vessels, etc.), there are two irreversible locking features that allow the clip to maintain tension on the tissue—one at the distal end of the clip where the male head element engages the head mating element, and one at the proximal end with the ratchet feature at the hinge. The ratchet feature provides improved clamping force, and accommodates a wide range of tissue thickness within the clamped arms without comprising the integrity of the hinge strength.

[0016] In one embodiment, to facilitate the male head element piercing the tissue via a spreading fashion, tissue anchor features are provided in proximity to the head mating element. In one example, the tissue anchor features are a pair of pillars that serve as anchors to keep the tissue in-place, under tension, and in a stretched orientation while the male head element enters tissue.

[0017] This mechanism allows the male head element to spread tissue apart laterally via shearing forces in opposite direction. This tissue spreading depicted in FIGS. 20A and 20B.

[0018] Optionally, the surgical clip may be comprised of a bioabsorbable plastic. Other materials include biocompatible metals, plastics and composites. Examples of suitable plastics include acetal polyoxymethylene (POM), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polyoxymethylene, polyetheretherketone (PEEK), polypropylene, and polyethylene or other thermoplastic materials having similar properties that can be injection-molded. The clip may be comprised of polymer material in combination with radiolucent metal alloys.

[0019] Each of the pair of arms includes a clamping side. In one embodiment, the clamping side of one arm includes a wedge-shaped feature, and the clamping side of the second arm includes a V-shaped trough that conforms to the shape of the wedge shaped feature. Each clamping side includes non-slip protrusions, such as non-slip protruding ribs.

[0020] An alternative clip design includes one arm (either a female arm or a male arm) having a pair of elongated arms or spars separated by a space or gap. The gap between the spars receives an elongated wedge-shaped ridge projecting from the clamping surface of the opposite arm, when the arms are in a closed position. The gap is wide enough to allow at least a portion of the ridge and clamped tissue or vessel to fit within the gap, thus preventing dislodgment of the clip during extreme pressure circumstances. In another embodiment, one arm includes a central window.

[0021] An exemplary clip includes a plurality of bosses, including a hinge boss, for gripping by an applicator and stabilizing during use. As used herein, a boss is a projection or protuberance that can be engaged by an applicator. The hinge boss is a grippable boss (i.e., a protrusion suitable for gripping) at or near the hinge. Gripping the hinge boss during use prevents undesirable angulation (angular disorientation) of the clip during use with an applicator. An alternative design to prevent undesired angulation of the clip during use with the applicator is to have rectangular-shaped bosses near the free end of each arm. Rectangular-shaped bosses maintain the alignment of the clip within the arms of the applicator while it is applied onto tissue, preventing the proximal end of the clip (the hinge region) from angulating out of the jaws of the applicator.

[0022] In one embodiment, the clip has a width of about 3.2 mm or more, as compared to about 1.6 mm for prior art polymer ligation clips. This extra width provides several advantages—it provides a greater clamping surface area between the clamp arms; it permits a relatively large, wide, and strong male head element feature to penetrate tissue; and it permits a relatively large diameter head mating element cross section with a larger aperture and retention area to secure the male feature.

[0064] Those skilled in the art will appreciate that the figures are not intended to be drawn to any particular scale; nor are the figures intended to illustrate every embodiment of the invention. The invention is not limited to the exemplary embodiments depicted in the figures or the configuration, shapes, relative sizes, ornamental aspects or proportions shown in the figures.

[0065] In this embodiment, a ligating clip has a head locking capability and a hinge portion locking capability.

Hinge Lock

[0066] In FIG. 8F-8H, the hinge portion 115 of a surgical clip is constructed with a hinge lock 812 comprising a first hinge locking element 810 and a second hinge locking element 820, thus providing an irreversible locking mechanism at the proximal hinge end 115 of the clip 100. As the clip arms 105, 110 are re-approximated together to clamp tissue between the arms, a prong 815 of first hinge locking element 810 will fit irreversibly into a slot or groove 825 of the second hinge locking element 820. Once the prong 815 and slot 825 are united, the hinge 115 is said to be in the locked and closed position. By having a hinge lock apparatus at the hinge area, there will be constant pressure applied to the tissue being clamped at the hinge region as well as the male-female locking interface region—a parallel tension mechanism from both ends of the clip. This hinge lock, or an alternative hinge lock can be provided in combination with various head designs and arm clamping surfaces, such as illustrated in the example figures.

Side Hinge Lock

[0067] FIG. 21A is a side view of a surgical clip 103 in an open configuration, with a first side hinge lock 750 in an open configuration with latch element 751 provided on arm 110 and catch element 752 formed as a recess on arm 105. FIG. 21B is a side perspective view of a surgical clip of FIG. 21A showing a latch element 761 of second hinge lock 760 on the opposite side of arm 105 from the first side hinge lock.

[0068] FIG. 21C is a side view of the surgical clip of FIG. 21A with the first side hinge lock in an engaged (locked) configuration. In this example, a first lock is provided between the male head element 800 and the head mating element 900; and a second set of locks is provided by hinge locks 750 and 760.

[0069] FIG. 21D is a side view of the surgical clip of FIG. 21A positioned in a clip applicator.

Ratcheting Hinge Lock

[0070] FIG. 22A is a side view of a surgical clip in an open configuration, with an a ratcheting hinge lock 850. FIG. 22B is a rear view of the hinge lock. In this example, the ratcheting hinge lock 850 comprises a first hinge portion 860 integral to arm 105, and a second hinge portion 870 integral to arm 115. A pin 852 may be provided on either hinge portion. As arm 105 is moved toward arm 115, teeth 862 in the first hinge portion 860 rotate past teeth 872 in the second hinge portion 870. Each tooth 862 comprises a latch element 864 which engages a corresponding catch element 874 on teeth 872. The engagement of the latch element 864 by the catch element 874 prevents the arms from opening. In this example, a first lock is provided between the male head element and the head mating element; and a second lock is provided by hinge locks 850.

Clip Arms

[0071] With reference to FIGS. 1A through 3, in one embodiment, a clip 100 according to principles of the invention generally includes a pair of clamping arms 105 and 110, adjoined at an integral flexible hinged joint 115 (the “hinge”) located at the hinge end or proximal end of the clip. Each arm has a free end or distal end 155, 160 with an opening 101 therebetween, such as an opening having a generally u- or v-shaped space. The opening 101 is preferably sufficiently wide to engage a vessel, organ or tissue to be ligated. In the exemplary embodiment shown in FIGS. 1A, 1B, 1C, the clamping arms 105, 110 are generally rigid. However, the hinged end 115 is sufficiently flexible so that the arms, 105, 110 can be angularly deflected bringing their free ends or distal ends 155, 160 towards each other to decrease the space between the arms 105, 110, until a locking engagement is achieved. In the exemplary clip 100 of FIGS. 1A through 1C, one or more cutouts 119, 120 formed in the hinge 115 facilitates bending at the hinge 115. Alternatively, other configurations with a reduced cross-sectional area at the hinge 115 (e.g., an integrally formed living hinge) may be utilized to facilitate such bending while maintaining structural integrity. Because a clip 100 according to the invention is inserted into a body cavity in a fully opened configuration, the hinge is not required to facilitate expansion.

[0072] A first clamping arm 105 extends from the hinge 115. The first clamping arm 105 includes an outer side 125 and a clamping side 130.

Clamping Features

[0073] In one embodiment, first arm 105 has a convex stepdown-like clamping side 130 and a concave or flat outer side 125. In one example, the clamping side 130 includes a configuration resembling “downward” steps to create a V-shaped trough portion 200 with an opening 201 as depicted in FIG. 3. In this example, converging downward staircase surfaces form the trough 200 in the arm of the first clamping arm 105. As shown in FIG. 3, a plurality of step-like intrusions such as downward steps or ribs 185 are spaced longitudinally apart along a portion of the length of the clamping side 130 of clamping arm 105. In this example, a tissue slippage prevention feature is comprised of a zig-zag pattern that interlocks into the adjacent arm. This zig-zag pattern on cross-section resembles the steps of a pyramid; consisting of acute, orthogonal or obtuse angles creating a step-like staircase feature. The zig-zag pattern itself can also have acute, orthogonal or obtuse angles or a combination there of. A boss 145 is provided to facilitate handling and manipulation. A male head element 800 extends from the clamping surface of the first clamping arm 105.

[0074] A second clamping arm 110 includes an outer side 135 and a clamping side 140. Second arm 110 has a concave clamping side 140 and a convex or flat outer side 135. In this example, the clamping side 140 includes a triangle-shaped step-like wedge configuration resembling a pyramid 210, such as the triangle-shaped pyramid wedge conceptually illustrated in FIGS. 1A, 1B, 1C, 3 and 4. Converging step-like staircase (i.e., angled) surfaces 215 form the an apex of the pyramid 211. The surfaces 215 converge at an apex 211 (i.e., a point of intersection). Concave clamping side 140 of second arm 110 and convex clamping side 130 of first arm 105 have substantially matching radii of curvature. The trough 200 forms a female receptacle for at least partially receiving the pyramid-like wedge 210 when the arms 105, 110 are urged together. A plurality of protrusions such as protruding rows of benches or ribs 215 are spaced apart along a portion of the length of the clamping side 140 of clamping arm 110. A boss 150 is provided to facilitate handling and manipulation. A head mating element is formed in the clamping surface 140 of the second clamping arm 110.

[0075] The embodiment in FIG. 3 includes a prominent wedge or ridge 210 (e.g., an elongated ridge having a staircase-like triangle pyramid figured cross section) extending from the clamping surface of one arm 110. The surface of the prominent wedge 210 is textured with step-like protrusions 215. For example, a plurality of striations, ribs or other protuberances 215 may be provided to enhance frictional gripping force exerted by the clip 100. A corresponding trough 200 or aperture is provided on the other arm 105. The trough 200 may extend from the clamping side of the arm through the opposite side of the arm, or only partly through the arm. The trough 200 may have a shape that generally corresponds to the shape of the ridge 210. Thus, the ridge 210 mates with the trough 200 when the clip 100 is closed. End portions 202 and 203 of the clamping arm flank and define the trough 201. The tissue contacting surfaces of these portions may also be textured, e.g., feature a plurality of striations, ribs, or other protuberances to enhance frictional gripping force exerted by the clip 100. The wedge 210 and top ridge 211 mates with the trough 200 and window 201 when the clip is closed. The surface of the trough may also be textured. For example, a plurality of striations, ribs or other protuberances may be provided to enhance frictional gripping force exerted by the clip 100. The corresponding surface of one arm 105 has an open space 201 to allow bulky tissue to fill the window 201 without causing the arms 105 and 110 to bow outward when the clip is in the closed configuration around tissue.

[0076] The arrangement and configuration of the wedge and trough may vary within the scope of the invention. For example, the pyramid-like wedge 210 may be formed on the first clamping arm 105 and the step-down staircase trough 200 may be formed on the other arm 110. In this configuration, the pyramid-like wedge 210 may enhance structural integrity and stability of the first arm 105, which may facilitate closure.

Tissue Capture

[0077] The alternating staircase pattern within the inner aspect of the male and female arms acts to capture tissue into the arms of the clip as it closes rather than pushing tissue out as the clip closes. The inner teeth or jaws of the clip act as cogs or teeth where the teeth from one arm (such as the male arm of the clip) fits into a corresponding slot within the other arm (such as the female arm). Each slot is configured by the walls of two adjacent teeth or cogs. The inner teeth or the alternative staircase pattern of one clip arm (either the male or female arm) fits into a corresponding slot located on the opposite clip arm (either the female or male arm), so that the teeth from the two arms come together as a “zipper” as the clip closes. As the clip arms are re-approximated, the teeth anchor onto tissue to capture the tissue within the clip arms as it closes rather than pushing the tissue out as the clip closes.

[0078] The slot on one clip arm is a space that fits the teeth from the opposite clip arm; it is created by two adjacent teeth walls. The teeth from one arm (such as the male arm of the clip) fits into a corresponding slot or space within the other arm (such as the female arm of the clip). the teeth from one arm (such as the female arm of the clip) fits into a corresponding slot or space within the other arm (such as the male arm of the clip).

[0079] The two interacting surfaces of the clip is similar to a gear or cogwheel mechanism where the teeth or tongues (created by the alternating staircase pattern on the inner part of the clip arms) mesh together with another toothed part in order to transmit a force towards the hinge region of the clip, causing the tissue to be captured into the clip rather than outwards and away from the clip as the clip closes. There is a mechanical advantage through this gear mechanism of the alternating staircase patterned teeth on one side of the clip arm which corresponds to the slots on the opposite side of the clip arm.

Hinge

[0080] Flexible hinge 115 has a continuous concave inner surface and a continuous convex outer surface. Concave inner surface of hinge section 115 joins concave clamping side 130 of first arm 105 and convex clamping side 140 of second arm 110. Convex outer surface of the hinge 115 joins outer side 125 of first arm 105 and outer side 135 of second arm 110.

Non-Slip Features

[0081] In this embodiment, the clamping arms are configured with non-slip protrusions, such as teeth, ribs or step-like ridges. The teeth, ribs, or step-like ridges are uniquely dimensioned and configured to frictionally engage a vessel, organ or tissue. The teeth, ribs or step-like ridges protrude from the clamping-side surface of one clamping arm. The teeth, ribs or step-like ridges or protrusions increase the clamping side pressure and surface area in frictional contact with the engaged vessel, organ or tissue. In the exemplary embodiment, step-like ridges or protrusions extend along the longitudinal axis of the clamping-side surface of one arm. In one example, the height of each layer or step-like ridge of the pyramid may preferably be approximately 0.01 to 0.5 mm. A substantially greater height prevents an engaged vessel, organ or tissue from contacting the clamping side surfaces of the clamping arms between the step-like pyramid upward wedge and the step-like downward trough, thereby substantially compromising the frictionally engaging surface area. In such a case, the vessel, organ or tissue would be suspended between adjacent step-like ridges. A substantially greater height will also result in a substantially thicker clamp, which can compromise utility in endoscopic procedures.

Alternative Clamping Surfaces

[0082] Referring now to FIG. 4, portions of arms 105 and 110 featuring an alternative configuration of clamping surfaces is shown. A plurality of spaced apart step-like “staircase” pillars protruding 220 from the clamping side surface 130 of the first clamping arm 105. Spaces 230 are provided between adjacent “staircase” pillars 220. In this example, each staircase-shaped pillar protrusion 220 comprises chamfered (i.e., right-angled) surfaces 235 that converge at a vertex 225. Correspondingly, a wedge shaped a step-like pattern resembling a pyramid 210 protrude from the clamping surface 140 of the second clamping arm 110. The pyramid-shaped wedge protrusion 210 is comprised of chamfered (i.e., right-angled) surfaces 255 that converge at a vertex 250. The staircase-like pillars 220 are aligned with the pyramid-shaped wedge segments 210. Thus, when the arms 105 and 110 are urged together in locking configuration, the pyramid-shaped wedge 210 receives corresponding staircase-like pillar protrusions 220. When the arms are urged together to close the clip arms 105 and 100, the top ridge or apex 211 of the pyramid-shaped wedge will be approximated to the floor 213 of the other arm 105. This configuration increases the pressure applied to vessels, organs or tissue sandwiched between the triangle-shaped pyramid-like wedge 210 and the corresponding staircase-shaped pillar protrusions 220.

[0083] In yet another alternative embodiment, the protrusions are of a size, shape and arrangement so that the protrusions of opposing arms interdigitate with one another when the opposing arms are moved toward one another. By interdigitate it is meant that the protrusions of one arm extend into spaces between counterpart protrusions of the other arm when the arms are moved towards one another. Once the arms are brought together, vessels, organ or other tissue engaged between the arms will be forced under clamping pressure to wind around the protrusions and into the interdigital spaces. The displacement into the interdigital spaces increases the traction and gripping force of the arms upon the engaged vessel, organ or tissue and increases the force required to move the gripped vessel, organ or tissue relative to the arms. In addition, protrusions having gripping features (e.g., ribs) provide additional traction and further resist movement of the gripped vessel, organ or tissue in directions transverse to the gripping edges.

Arm Shape

[0084] The shapes of the arms may vary from straight to concave or convex. Referring now to FIG. 5, a configuration 300 with a substantially straight arm 310 and a corresponding curved (i.e., convex) arm 305 is shown. Another embodiment 400 with a pair of curved (i.e., convex) arms 405, 410 is shown. In yet another embodiment 500 a configuration with a pair of substantially straight arms 505, 510 is shown. Another embodiment 600 includes a pair of curved (i.e., convex) arms 605, 610, and a severable hinge 615. In that embodiment, the hinge 615 extends from the converging ends of the arms 605, 610. These and other arm configurations that allow clamping of vessels, organs or tissue between the arms are feasible and come within the spirit and scope of the invention. Thus, two concave surfaces may define a lens shaped space therebetween. A concave and convex surface may define a lune shaped space therebetween. Crescent, circular segment and triangular shapes may also be defined using various combinations of curved and straight arms.

Tissue Spreading Head and Head Mating Element

[0085] Referring now to FIGS. 6A, 6B, 7A and 7B, a clip according to principles of the invention includes a male and female locking mechanism, wherein the male component consists of a male head element 800 configured to penetrate an engaged tissue or organ. As shown in FIGS. 6A and 6B, the head mating element 900 comprises a resilient aperture 930 in the second arm 110, aligned with the male head element 800. A tapered ridge section 940, flexible tab or other snap fit feature in the receptacle 900 resists withdrawal of the fully inserted male head element 800. As shown in FIGS. 7A and 7B, the male head element 800 includes a base 820 which extends from the first arm 105, a shank 830 that extends from the base 820, and a head 840 that extends from the shank 830.

[0086] As shown in FIGS. 7A and 7B, an example head 800 includes a sharpened and/or pointed leading edge 840 suitable for penetrating an engaged portion of an organ or tissue. The head may be rigid biocompatible plastic, reinforced biocompatible plastic, or biocompatible metal.

[0087] The head 800 is configured to pass through the opening in the head mating element 930, yet resist withdrawal. The head 800, the head mating element 900 or both may exhibit resiliency to allow passage of the head for locking. The bulbous portion, arrow-shape, flanged edge, detents or cone-shape of the head resist or prevent withdrawal of the head after it has been urged through the head mating element.

Clip Alignment Guides

[0088] Adjacent to the distal (free) ends of the first and second arms and adjacent to the male head element 800 and head mating element 900, a pair of cylindrical bosses 145, 150 are formed coaxially on the opposed lateral surfaces of the first and second arms 105, 110. The bosses 145, 150 project outwardly beyond the outer surfaces of the arms 105, 110. An applicator engages the clip 100 using the bosses 145, 150. An alternative design of the bosses 145, 150 to prevent undesired angulation of the clip 100 during use with the applicator 900 is depicted in FIGS. 19A and 19B. Adjacent to the circular bosses 145, 150, there are rectangular-shaped alignment guides 147, 157 located on each arm 105, 110 of the clip. These rectangular-shaped alignment guides 147, 157 provide stability of the clip. Rectangular-shaped alignment guides 147, 157 maintain the alignment of the clip 100 within the arms of the applicator 900 while it is applied onto tissue, preventing the proximal end of the clip 115 (the hinge region) from angulating out of the jaws of the applicator 900. The applicator tip may engage the front portion of alignment guides 147 and 157 to prevent lateral movement of the clip. The applicator may also include fixture elements for engaging the rear portions of alignment guides 147 and 157 to retain the rear portion of the clip in alignment with the applicator tip.

Materials

[0089] Clips according to principles of the invention may be comprised, in whole or in part of metals such as stainless steel, titanium, tantalum, or alloys thereof. Bioabsorbable and radiolucent versions may be comprised of a one-piece integral polymeric body formed from a suitable strong biocompatible engineering plastic such as the type commonly used for surgical implants. Examples of suitable plastics include acetal polyoxymethylene (POM), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polyoxymethylene, polyetheretherketone (PEEK), polypropylene, and polyethylene or other thermoplastic materials having similar properties that can be injection-molded, or other thermoplastic materials having similar properties that can be injection-molded, extruded or otherwise processed into like articles.

Clip Application

[0090] In use, the clip 100 is typically positioned and compressed into a locked position using an applicator. An applicator includes a forceps-type applier having a conformal jaw assembly used to grip and maintain alignment of the clip during placement and compressive deformation. The proximal end of the applicator includes a handle assembly with a stationary element and a movable (e.g., pivoting) element. A linkage contained within an elongated tubular shaft operably couples the movable handle element to the conformal jaw assembly. The shaft preferably fits through a 10-15 mm trocar. The distal end of applicator generally comprises the conformal jaw assembly having opposing pivotable jaws which have respective jaw recesses adapted to engage and retain bosses 145, 150 of the clip 100. Closure of the jaws of the applicator compresses the held clip 100. This causes the first and second arms 105, 110 of the clip 100 to close around a vessel, organ or tissue with clamping sides of the first and second arms 105, 110 contacting the outer surface of the engaged vessel, organ or tissue.

Head Penetration and Lock

[0091] As the clip is compressed, any portion of the engaged vessel, organ or tissue or surrounding tissue in the path of the male head element will be penetrated by spreading tissue laterally as depicted in FIGS. 20A and 20B. In one invention model of the clip in FIGS. 6A, 6B, 7A and 7B, as compression continues, the male head element 800 enters the head mating element 930 and begins to contact the female ridge 940. Further pivotal movement by the applicator urges the pin 800 into the aperture created by two parallel pillars or columns 910 and 920 until the head of the pin 840 is forced through the aperture 930 and passes adjacent to the tapered ridge section 940, flexible tab or other snap fit feature in the receptacle. Thereafter, the shank 830 of the male head element is matingly seated in the head mating element opening 930 and resting on the tapered ridge section 940, flexible tab or other snap fit feature to resist withdrawal of the fully inserted male head element 800. This is the locked position. Upon release of the applicator instrument, the clip remains in the locked position. Once in the locked position, reference to FIGS. 2A, 2B, 11A and 11B, the male head element 800 resists withdrawal from the head mating element 930 by allowing the shank 830 to engage the tapered tab 940 or other snap fit feature in a one-way forward fashion.

[0092] In this example, the tissue spreading head 840 includes a leading edge 842, a tip 841, and a latch surface 830. The latch surface 840 engages a catch surface 950 on the head mating element 900. The pillars 910 and 920 include sharp edges 914 and 916, front walls 918, and bottoms 920.

[0093] As depicted in FIGS. 20A and 20B, the clip penetrates tissue by spreading the fibers of the tissue laterally or aside to allow the male head element 840 to penetrate the tissue atraumatically and without cutting into the tissue. All endovascular tissue in the human body is made of organized collagen fibers—not random placement of cells; these fibers 970 are organized layers of cells that create cylindrical-shaped fibers. These collagen fibers 970 are assembled in organized fashion to create connective tissue 960. Connective tissue 960 is the backbone of every organ and blood vessel in the human body; it surrounds organs and vessels to give it structure, shape and substance. The male head element 840 is designed to separate these organized layers of collagen fibers 970 laterally as it penetrates tissue 960.

Alternate Hinges

[0094] With reference to FIGS. 8A through 8D, various exemplary embodiments of a clip 100 according to principles of the invention are illustrated. The hinged sections of the clips vary. In each case, the width and/or thickness of the hinge section 115 is equal to, less than, or greater than the average thickness of a clamping arm 105, 110. In each case the hinged section 115 includes one or more apertures 119, 120 to facilitate bending. The hinged section may also include a hinge boss in proximity to the hinge on each side of the clip to maintain alignment. The hinge boss is a protruding feature that can be gripped by the applicator during insertion. The shape and position of the hinge boss may vary within the scope of the invention.

[0095] An alternative design of the hinge is shown in FIG. 8D; the hinge 115 resembles a star-shaped or fan-shaped configuration with multiple finger-like projections 119 radiating outwards. The radial cut-outs 119 at the hinge area 115 allows the clip 100 to accommodate various tissue thicknesses as the clip arms 105, 110 are reapproximated to each other during the clip closure process. The star-like configuration 119 of the hinge 115 allows the hinge to act as an “accordion” to accommodate various tissue thicknesses within its arms 105, 110 while maintaining ample pressure on the clamped tissue to prevent slippage under high pressures.

Bosses

[0096] Thus, the clip may include a unique arrangement of bosses. As discussed above, there may be bosses at the free end of the arms. There may also be one or more hinge bosses. The applicator will hold the clip by its bosses until the clip is released from the applicator. Gripping the boss at the hinge until the clip is released provides enhanced control and stability of the clip while applying to tissue. Specifically, gripping the boss at the hinge may prevent unwanted angulation of the clip.

Clip Size

[0097] A clip according to principles of the invention can be sized to accommodate various vessels. In an exemplary embodiment, the clips are sized to work with laparoscopic procedures, meaning that it preferably can fit through a 10-15 mm trocar. It may pass through the trocar in a partially clamped state. After passing through the trocar, if the clip was partially compressed, then the jaws of the applicator and the clip will expand into a fully opened state. Thus, other than being sized for use with a laparoscopic procedure, the size of the clip may vary considerably to accommodate various vessels.

Tissue Piercing Head

[0098] Referring now to FIGS. 9 through 11B, alternative exemplary male and female locking mechanisms are illustrated, wherein the male head element 805 comprises an arrow-like or cone-shaped lance 815 configured to penetrate an engaged tissue or organ. The lance 800 in FIG. 9 includes a sharp tip 842 for penetrating tissue, extending outwardly from a shank 832. The shank extends from a base 820 to a sharp tip 842. The leading edges 818 of the tip may be sharp.

[0099] As shown in FIGS. 10 through 11B, the head mating element 905 comprises an aperture 932 near the free end of an arm 110, aligned with the male head element 805 and head 815. The apertures may be generally aligned with bosses 145 and 150. The receptacle in FIG. 10 includes a one-way catch 952 that engages the resilient male head element 805 when the two arms 105, 100 are urged together via an applicator. A tapered ridge section 942, flexible tab, catch or other snap fit feature in the receptacle 932 of FIG. 10 resists withdrawal of the fully inserted male head element 805 and head 810. The mated male lance and head mating element are illustrated in FIGS. 2A, 2B, 11A and 11B.

[0100] In one example, the head mating element 905 comprises two parallel pillars or columns 910 and 912 extending from the clamping arm 110 via a base 922. The two columns 910 and 912 create an opening or aperture 932 to allow the male head element 805 of one arm 105 to engage the tapered ridge 942 of the second arm 110.

[0101] In this example, the tissue piercing head 815 includes a leading edge 818, a tip 842, and a latch surface 832. The latch surface 832 engages a catch surface 952 on the head mating element 905. The pillars 910 and 912 include sharp edges 914 and 916, and front walls 918.

[0102] The two parallel pillars 910 and 912 have distinct sharp edges that provide counter-traction of the tissue being clamped as the male head element 800 penetrates the tissue. The male tissue piercing head 815 shears or scissors tissue as it passes adjacent to the sharp pillars 910 and 912, thus allowing the male head element 805 to penetrate the tissue. As the male head element 805 passes through the aperture 932, it locks into the closed position when the shank 8332 is resting on the ridge 942 within the aperture 932.

[0103] The head mating element 905 is surrounded by two pillars 910 and 912 with sharp edges that are parallel to each other, creating the aperture 932 between its columns. These two sharp pillars are arranged in parallel fashion to create a valley 932 where the male head element 805 will rest when the two clip arms 105, 110 are urged together. The top of the pillars comprise sharp edges 914 and 916, designed to provide counter-traction of the tissue as the male head element 805 advances through the tissue and into the head mating element 905. The sharp edges of the pillars enhance the tissue penetrating capability of the male head element 805 and head 815 when advancing it through thick tissue.

[0104] The head of the lance 815 includes a sharp and/or pointed leading edge 818 suitable for penetrating an engaged portion of an organ or tissue. The head 815 may be rigid biocompatible plastic, reinforced biocompatible plastic, or biocompatible metal. The head 815 is configured to pass through the opening or valley in the head mating element 932, yet resist withdrawal. The head 815, the head mating element 905, or both may exhibit resiliency to allow passage of the head for locking. The bulbous portion, arrow-shape, flanged edge, detents or cone-shape of the head resist or prevent withdrawal of the head after it has been urged through the head mating element and locked into the closed position when the shank 832 rests on the female ridge 942. The tip of the head 840 of the lance should not extend beyond the margins of the female arm 110 when the clip is closed. Thus the tissue penetrating tip will not rub against, abrade, puncture, pinch or otherwise harm adjacent structures.

Tissue Gripping

[0105] FIG. 12 provides a cross-section view from the clip in FIGS. 1A through 11B. As shown, tissue (i.e., tissue or a vessel, collectively “tissue”) 620 is folded and sandwiched between the ridge 210 of one arm 110 and the trough 185 of the other arm 105. A substantial portion of tissue is wedged into the trough 201. The surface area of tissue that contacts gripping surfaces of the clamp 100 is significantly greater than in the case of a substantially planar clamping surface. The peak of the ridges 185, 215, 225, 235, 250, 255 substantially increases the frictional gripping force resisting lateral movement of the tissue. This configuration resists dislodgement of the clip.

[0106] Referring now to FIGS. 13 through 15, various views of arms 600, 605 of an exemplary surgical clip with interdigitating teeth 610 according to principles of the invention, are conceptually illustrated. Straight arms 600, 605 are illustrated. However, the invention is not limited to straight arms. Rather, curved arms may be used within the scope of the invention. While the teeth 610 are shown with a generally rectangular shape, teeth with other shapes may be used without departing from the invention. For example, the teeth may be v-shaped, u-shaped, or some other shape, or have beveled or filleted edges. The teeth fit into corresponding gaps 615 in the opposite arm. The gaps are shaped and sized to receive the teeth as well as portions of a clamped tissue or vessel 620 urged into the gaps by the teeth. The number, size and configuration of teeth and gaps on the clamping surfaces may vary without departing from the invention. The interdigitating or interfitting teeth bend the clamped tissue or vessel and provide increased surface area for frictional engagement. Counter-intuitively, a clamping surface with teeth may damage tissue less than a smooth surface because the toothed surface can grasp with less overall pressure.

Other Gripping Features

[0107] Referring now to FIGS. 16 through 18, various views of arms 700, 705 of an exemplary surgical clip with interdigitating conical teeth 710, 715 according to principles of the invention. Straight arms 700, 705 are illustrated. However, the invention is not limited to straight arms. Rather, curved arms may be used within the scope of the invention. While the teeth 710, 715 are shown with generally pointed tips, teeth with other shapes may be used without departing from the invention. For example, the tip may be slightly dulled or rounded. The teeth fit into corresponding gaps or spaces between teeth in the opposite arm. The gaps are shaped and sized to receive the teeth. In this embodiment, the tips of the teeth may actually penetrate slightly into the surface of the gripped tissue or vessel, without penetrating so deeply as to cause puncturing and hemorrhaging. While three rows of teeth 715, 716, 717 are shown, the invention is not limited to any number of rows or teeth aligned in rows. The number, size and configuration of teeth and gaps on the clamping surfaces may vary without departing from the invention. The interdigitating or interfitting teeth penetrate into the surface of the tissue or vessel to provide enhanced resistance to dislodging.

[0108] While an exemplary embodiment of the invention has been described, it should be apparent that modifications and variations thereto are possible, all of which fall within the true spirit and scope of the invention. With respect to the above description then, it is to be realized that the optimum relationships for the components and steps of the invention, including variations in order, form, content, function and manner of operation, are deemed readily apparent and obvious to one skilled in the art, and all equivalent relationships to those illustrated in the drawings and described in the specification are intended to be encompassed by the present invention. The above description and drawings are illustrative of modifications that can be made without departing from the present invention, the scope of which is to be limited only by the following claims. Therefore, the foregoing is considered as illustrative only of the principles of the invention. Further, since numerous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation shown and described, and accordingly, all suitable modifications and equivalents are intended to fall within the scope of the invention as claimed.