End effector and open linear stapler equipped with same

Abstract

The end effector includes a distally disposed substantially U-shaped fixed jaw and a movable jaw movable relative to the fixed jaw for clamping tissue therebetween. The fixed jaw includes an anvil on a surface opposite the movable jaw. The fixed jaw is configured to receive a staple cartridge. The surface of the anvil opposite the movable jaw defines a tissue engaging surface defining a longitudinal axis and includes a first pair of staple forming pockets and a second pair of staple forming pockets located on two sides of the longitudinal axis. The first pair of staple forming pockets and the second pair of staple forming pockets are each configured as a central symmetric structure formed by two staple forming pockets disposed along the longitudinal axis, the staple forming pockets having an asymmetric shape. Corresponding staple forming pockets in the first pair of staple forming pockets and the second pair of staple forming pockets are opposite each other in a shape orientation along a lateral direction perpendicular to the longitudinal axis. The end effector can achieve better lateral alignment of the staple cartridge and the anvil during staple firing and provide a better sealing effect.

Description

[Technical field]

[0001] The present disclosure relates to an open linear stapler, and more particularly to an end effector and an open linear end effector having the same. [Background technology]

[0002] Today, in the medical field, staplers are medical instruments commonly used in surgical procedures. Staplers can clamp onto one or more tissue layers of a patient during surgery, and staples fired from the stapler can seal the tissue layer(s) adjacent to the staples. A typical stapler includes an end effector that can be inserted into the patient and positioned against the tissue to be sealed. The end effector includes a pair of elongated jaw members that cooperate with each other, one of which includes a staple cartridge that receives at least two rows of staples therein, and the other includes an anvil having staple-forming pockets aligned with the rows of staples in the staple cartridge. Generally, staplers can further include a push rod that can slide relative to the jaw members to sequentially or simultaneously fire the staples from the staple cartridge via a cam surface on a wedge slide on the push rod. The cam surface can actuate one or more staple drivers associated with the staples carried by the staple cartridge to force the staples against the anvil and form rows of staples in the tissue clamped between the jaw members. The rows of staples may be arranged in linear and / or arcuate rows to staple the patient's tissue sequentially or simultaneously in a predetermined pattern. Staplers can be classified as cavity staplers and open staplers, with cavity staplers being suitable for minimally invasive procedures such as endoscopic or laparoscopic procedures and therefore having a small end effector. In accordance with the above classification, the present disclosure relates to open staplers, i.e., open linear staplers, in which the rows of staples are arranged in a linear fashion.

[0003] However, in existing open linear staplers, during stapler firing, lateral forces are generated between the staples and the staple-forming pockets of the anvil, which possibly generate torque against the anvil and lead to failure of lateral alignment between the staple cartridge and the anvil. The staple lines formed after stapling are parallel to each other and staggered along the length direction. Two types of clearances with different widths may be generated between adjacent stitches of the staple line, which may cause poor performance in sealing after stapling and result in leakage of the sealed tissue of the patient during the stapling procedure. Summary of the Invention

[0004] Thus, a need arises for a novel open linear stapler that can balance the force applied to the anvil during staple firing, avoid the generation of torque to allow lateral alignment of the anvil and staple cartridge, and reduce the risk of leakage of the sealed tissue. [Means for solving the problem]

[0005] The present disclosure provides an end effector for a surgical instrument and an open linear stapler, the specific contents of which are as follows:

[0006] According to an aspect of the present disclosure, there is provided an end effector comprising a distally located, substantially U-shaped, fixed jaw and a movable jaw movable relative to the fixed jaw to clamp tissue therebetween, the fixed jaw comprising an anvil on a surface opposite the movable jaw, the movable jaw being configured to receive a staple cartridge, a surface of the anvil opposite the movable jaw defining a tissue engaging surface, the tissue engaging surface defining a longitudinal axis extending along a length of the anvil, with first and second pairs of staple forming pockets located on two sides of the longitudinal axis, each of the first and second pairs of staple forming pockets configured as a centrosymmetric structure formed by two staple forming pockets disposed along the longitudinal axis, the staple forming pockets having an asymmetric shape, and the first and second pairs of staple forming pockets being mirror symmetric with respect to the longitudinal axis and staggered along the longitudinal axis.

[0007] In one embodiment, the first pair of staple forming pockets and the second pair of staple forming pockets are each arranged in multiple groups along the longitudinal axis.

[0008] In one embodiment, the first pair of staple forming pockets and the second pair of staple forming pockets at least partially overlap along a lateral direction perpendicular to the longitudinal axis.

[0009] In one embodiment, the staple forming pocket has a straight edge and a curved edge opposite the straight edge formed on the tissue engaging surface, the straight edge being parallel to the longitudinal axis, and the two staple forming pockets form a centrally symmetrical structure with their respective curved edges facing each other.

[0010] In one embodiment, the straight edge has a first end and a second end opposite each other, and the distance between the straight edge and the curved edge gradually decreases along a direction from the first end to the second end.

[0011] In one embodiment, the staple forming pocket has a bottom, and the distance from the bottom to the tissue engaging surface defines a depth of the staple forming pocket, the depth gradually decreasing along a direction from a middle portion of the staple forming pocket to each of the first and second ends.

[0012] In one embodiment, the staple forming pocket comprises a first sidewall and a second sidewall extending between the tissue engaging surface and a base, the first sidewall forming a straight edge and the second sidewall forming a curved edge, and at least one of the first sidewall and the second sidewall is configured to slope outwardly along a direction from the base to the tissue engaging surface.

[0013] In one embodiment, two staple forming pockets forming a centrally symmetric structure at least partially overlap along a lateral direction perpendicular to the longitudinal axis.

[0014] In one embodiment, the movable jaw is provided with a tissue lock pin and the anvil of the fixed jaw is provided with a tissue lock pin hole corresponding to the location of the tissue lock pin, the tissue lock pin hole being located at the top end of the anvil along the longitudinal axis and offset laterally perpendicular to the longitudinal axis.

[0015] In one embodiment, the tissue engaging surface is provided with at least two rows of staple forming pocket pairs along a lateral direction perpendicular to the longitudinal axis, with two adjacent rows of staple forming pocket pairs defining a longitudinal axis therebetween and spaced apart by the longitudinal axis.

[0016] In one embodiment, the two rows of staple forming pocket pairs located on two sides of the longitudinal axis have the same or different numbers of staple forming pockets.

[0017] According to another aspect of the present disclosure, there is provided an open linear stapler comprising an end effector as described above.

[0018] The end effector and open linear stapler of the present disclosure can solve the above-mentioned problems existing in the prior art, achieve better lateral alignment of the staple cartridge and the anvil during firing of the stapler, and provide a better sealing effect. [Brief description of the drawings]

[0019] [Figure 1] FIG. 1 is a schematic diagram of an end effector of an existing open linear stapler. [Diagram 2] FIG. 1 is a schematic diagram of an anvil of an end effector of an existing open linear stapler. [Diagram 3] 1 is a schematic diagram of a basic configuration of a stapler according to the present disclosure; [Figure 4] 1 is a schematic diagram of a fixed jaw of an end effector of a stapler according to a first embodiment of the present disclosure; FIG. [Diagram 5] 11 is a schematic diagram of an end effector of a stapler according to a second embodiment of the present disclosure. FIG. [Figure 6] 13 is a schematic view of an anvil of a stapler according to a third embodiment of the present disclosure. [Figure 7A] 13 is a schematic diagram of an anvil of a stapler according to another embodiment of the present disclosure; FIG. [Figure 7B] 13 is a schematic diagram of an anvil of a stapler according to another embodiment of the present disclosure; FIG. [Figure 7C] 13 is a schematic diagram of an anvil of a stapler according to another embodiment of the present disclosure; FIG. [Figure 8A] 1 is a schematic diagram of a prior art staple forming pocket arrangement; [Figure 8B] 13 is a schematic diagram of a staple forming pocket arrangement of a stapler according to a further embodiment of the present disclosure; FIG. [Figure 9A] 13 is a schematic diagram of a fixed jaw of a stapler according to yet another embodiment of the present disclosure. [Figure 9B] 13 is a schematic diagram of a fixed jaw of a stapler according to yet another embodiment of the present disclosure. [Figure 10A]13 is a schematic diagram of a fixed jaw of a stapler according to yet another embodiment of the present disclosure. [Figure 10B] 13 is a schematic diagram of a fixed jaw of a stapler according to yet another embodiment of the present disclosure.

[0020] In the drawings, the reference numbers are listed below: 1-handle;2-connecting rod;3' / 3-end effector;4-firing trigger;6-fixed jaw;7-movable jaw;8' / 8-anvil;81' / 81-tissue locking pin hole;82-tissue engaging surface;83-first staple forming pocket pair;84-second staple forming pocket pair;85' / 85-staple forming pocket;851-straight edge;852-curved edge;853-first end;854-second end;855-convex curved segment;856-concave curved segment;857-bottom;858-first side wall;859-second side wall;9-staple cartridge;10' / 10-tissue locking pin;11-inner anvil clamping plate;12' / 12-outer anvil clamping plate;121 / 122-flexed portion;F-lateral force;T-torque;C-center of symmetry. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0021] Hereinafter, the technical solutions of the present disclosure will be further described through specific embodiments with reference to the drawings, but the present disclosure is not limited to these embodiments. The following description of some examples of the present disclosure should not be used to limit the scope of the present disclosure. It is assumed that other examples, features, aspects, implementation solutions and advantages will become more apparent to those skilled in the art through the following description, which is provided in an exemplary manner, and the most suitable method for implementing the present disclosure is adopted. It will be understood that the present disclosure includes other distinct and obvious aspects, which do not depart from the present disclosure. Therefore, the drawings and examples should be considered as substantial examples, not as limitations.

[0022] In addition, any one or more of the teachings, expressions, implementation solutions, examples, etc. described herein may be combined with any one or more of the other therein. Thus, the teachings, expressions, implementation solutions, and embodiments provided below should not be interpreted as being independent of each other. Various suitable ways of combining according to the present teachings will be apparent to those skilled in the art. Such modifications and variations are intended to be included within the scope defined by the appended claims.

[0023] For clarity, the terms "proximal" and "distal" are used herein with respect to an operator manipulating a surgical instrument or robot. The term "proximal" refers to an element location closer to an operator manipulating a surgical instrument or robot and further from a surgical end effector 3 of the surgical instrument. The term "distal" refers to an element location closer to a surgical end effector 3 of the surgical instrument and further from an operator manipulating a surgical instrument or robot. It will be further understood that for convenience and clarity, spatial terms such as "vertical," "horizontal," "up," "down," "front," and "back" may be used herein with respect to the drawings. However, surgical instruments are used in many orientations and positions, and these terms are not intended to be limiting and / or absolute.

[0024] The open linear stapler according to the present disclosure will be described in detail below with reference to FIGS.

[0025] First, a basic structure of the stapler according to the present disclosure will be described with reference to FIG. 3. The stapler according to the present disclosure is mainly composed of a main body and a firing member. The main body includes, from the proximal side to the distal side, a handle 1, a connecting rod 2, and an end effector 3. The firing member includes a firing trigger 4 and a push rod (not shown), which may be designed as a conventional long push rod or a short push rod. The end effector 3 mainly includes two jaws including a substantially U-shaped fixed jaw 6 and a movable jaw 7 movable relative to the fixed jaw, the fixed jaw 6 including an anvil 8, the movable jaw 7 including a staple cartridge 9, a tissue locking pin 10 provided on the movable jaw 7, and a tissue locking pin hole 81 provided on the anvil 8 of the fixed jaw 6 at a position corresponding to the position of the tissue locking pin 10. The connecting rod 2 is configured to connect the handle 1 and the end effector 3. Although the present disclosure is described with the fixed jaw 6 positioned distally and the movable jaw 7 positioned proximally, it should be understood by those skilled in the art that the present disclosure is also applicable to situations where the fixed jaw 6 is positioned proximally and the movable jaw 7 is positioned distally.

[0026] For ease of explanation, a three-dimensional coordinate system is shown in Figure 3, where the X direction represents the horizontal direction, the Y direction represents the vertical direction, and the Z direction is the lateral direction. The coordinate system and the three directions as described above may also be applied to other figures in this disclosure.

[0027] First embodiment The first embodiment will be described below. Figure 4 is a schematic diagram of a substantially U-shaped fixed jaw 6 of the end effector 3 of the stapler according to the first embodiment of the present disclosure. As shown in Figure 4, the fixed jaw 6 according to the present disclosure includes a hook member that looks like a hook because it extends from the bottom of the stapler body (i.e., the bottom in the Y direction in Figure 3) to the most distal end of the end effector 3 along a horizontal direction to the distal left direction and then extends upward along a vertical direction. The hook member includes an inner anvil clamping plate 11 located in the center and two outer anvil clamping plates 12 arranged respectively on the outside of the inner anvil clamping plate 11 in the lateral direction. The inner anvil clamping plate 11 is preferably made of a plastic approved for use in medical instruments, specifically nylon, more specifically medical material nylon 66. Of course, the inner anvil clamping plate 11 can also be made of a metal approved for use in medical instruments, such as medical stainless steel. The anvil 8 and outer anvil clamping plate 12 are made from a metal approved for use in medical instruments, preferably medical grade stainless steel.

[0028] At the proximal end of the fixed jaw 6, the anvil 8 is fixedly connected by welding to a proximal surface of the distal end of a substantially U-shaped outer anvil clamping plate 12. Because a large amount of heat is generated during welding, the anvil 8 is not in direct contact with the inner anvil clamping plate 11. Instead, as can be clearly seen in Figure 4, a small clearance is provided between the anvil 8 and the inner anvil clamping plate 11, so that the heat generated during welding is not directly transferred from this clearance to the inner anvil clamping plate 11.

[0029] For the welding applied between the anvil 8 and the outer anvil clamping plate 12, laser welding is preferred, but gas shield welding or friction stir welding may also be employed.

[0030] In addition to welding, the anvil 8 and outer anvil clamping plate 12 may be fixedly connected by other methods, such as adhesively bonding, where the adhesive material for bonding should be approved for use in medical devices.

[0031] In terms of shape, the anvil 8 is aligned laterally and vertically with the inner anvil clamping plate 11 and the outer anvil clamping plate 12. In other words, as viewed from both lateral sides of the end effector 3 and from top to bottom, the surfaces formed by the anvil 8 together with the inner anvil clamping plate 11 and the outer anvil clamping plate 12 are smooth rather than irregular in shape. This arrangement allows the hook members to be hidden under the anvil 8 and inconspicuous when viewed from a horizontal firing orientation as shown in FIG.

[0032] In contrast, the anvil 8' in the prior art as shown in FIG. 1 has a U-shape, covers the outside of the hook member, and is fixedly connected to the hook member via a rivet. In this connection method, the U-shaped anvil 8' and the hook member cannot form a substantially rigid integral member. Therefore, during use of the stapler, after the firing trigger 4 is triggered, the firing force is first transferred from the anvil 8' to the rivet pin between the anvil 8' and the outer anvil clamping plate 12', and then to the outer anvil clamping plate 12'. During this process, the firing force is transferred over a long distance.

[0033] In the first embodiment of the present disclosure, the anvil 8 is directly welded onto the two outer anvil clamping plates 12 such that the anvil 8 and the hook members form a substantially rigid integral member. In this way, when the stapler is in use and after the firing trigger 4 is triggered, the firing force is directly transmitted from the anvil 8 to the outer anvil clamping plates 12 as an effect of the push rod force, thus resulting in a short distance transmission of force. The outer anvil clamping plates 12 configured as above according to the present disclosure have a high load capacity.

[0034] Second embodiment The second embodiment of the present disclosure will be described below. FIG. 5 is a schematic diagram of the end effector 3 of the stapler according to the second embodiment of the present disclosure. As can be clearly seen from FIG. 5, two bent portions are provided on the outer surface of the outer anvil clamping plate 12, which bends the two outer anvil clamping plates 12 toward each other, thus reducing the distance between the two outer anvil clamping plates 12. Here, the vertical bent portion 121 is located close to the distal end, and the horizontal bent portion 122 is located on the proximal side. Although not shown, a person skilled in the art will understand that the other outer anvil clamping plate 12 located on the other side, which cannot be seen in FIG. 5, is also provided with the same bent portion. By arranging the two bent portions, the distance between the two outer anvil clamping plates 12 is shortened, and the lateral dimension of the end effector 3 is further reduced, thereby realizing a compact stapler. Therefore, the stapler according to the present disclosure can be easily inserted into some important parts of the patient's body, such as deep abdominal area. Although the above embodiment in which the outer anvil clamping plate 12 includes two bent portions is used and described herein, it should be understood by those skilled in the art that only one bent portion can also achieve the purpose of reducing the size of the end effector 3.

[0035] Third embodiment A third embodiment of the present disclosure will now be described. Please refer to FIG. 6, which is a schematic diagram of an anvil 8 of a stapler according to a third embodiment of the present disclosure. At the top vertical end of the anvil 8, a tissue locking pin hole 81 is laterally off-centered (i.e., offset from the lateral center) and configured to cooperate with a tissue locking pin 10 such that the movable jaw 7 and the fixed jaw 6 are positioned during stapling. In other words, the staple cartridge 9 and the anvil 8 are precisely positioned during stapling to ensure that the staples fired from the staple cartridge 9 are aligned one by one with the staple forming pockets on the anvil 8.

[0036] Corresponding to the third embodiment of the present disclosure, Figs. 1 and 2 show an anvil 8' of an end effector 3' of an existing open linear stapler, in which a tissue locking pin hole 81' is vertically disposed at the top end of the anvil 8', but laterally positioned at the center of the anvil. In this situation, a staple forming pocket cannot be disposed at this location, and a corresponding staple cannot be provided. Thus, a staple is missing at that location when stapling the patient's tissue. Through experimentation, the inventors have realized that sparse stapling may occur against the patient's tissue at the distal end of the anvil 8' close to the tissue locking pin 10', which may lead to leakage.

[0037] According to the present disclosure, the tissue locking pin hole 81 is located off-center, thereby allowing an additional staple forming pocket to be provided adjacent to the tissue locking pin hole 81 at the top end of the anvil 8 in the vertical direction. Although only one additional staple forming pocket is provided, the inventors have found through experiments that compared to the prior art in which the tissue locking pin hole 81 is located at the center, the present disclosure in which the anvil 8 has a tissue locking pin hole 81 located off-center can reduce the possibility of sparse stapling at the end by 20% to 30%, and achieve a good stapling effect, e.g., a good hemostatic effect.

[0038] In the third embodiment of the present disclosure, considering the fact that the tissue locking pin hole 81 is located off-center on the anvil 8, the clearance between the edge of the tissue locking pin hole 81 and the edge of the pocket on the anvil must be greater than 0.010 inches, and the width of the anvil must be set to ensure sufficient distance between the edge of the tissue locking pin hole 81 and the edge of the anvil. In this case, if the U-shaped anvil 8 is left to house the outside of the hook members as in the conventional case, the lateral dimension of the fixed jaw 6 of the end effector 3 will be significantly large, which will in turn hinder the insertion of the stapler into the patient's body. In contrast, if the anvil 8 is fixedly connected to the proximal end of the outer anvil clamping plate 12 by welding as described in the first embodiment of the present disclosure, the lateral dimension of the stapler end effector 3 will be thin. For example, the thickness of the distal end of the anvil system is 0.251 inches.

[0039] Additionally, to prevent the substantially U-shaped outer anvil clamping plate from entangling with tissue, a coating may be applied to the outer surface of the substantially U-shaped anvil, thereby improving the smoothness of the anvil.

[0040] From the above description, those skilled in the art will have a clear idea of ​​the inventive concept and the specific technical means of the present disclosure. The open linear stapler according to the present disclosure can reduce the lateral thickness of the hook member system, thereby allowing easier insertion into the patient's body during surgery and allowing a simpler anvil manufacturing process. During firing, the outer anvil clamping plate has a better load-bearing capacity. There is no clearance between the anvil and the outer anvil clamping plate, making the anvil unable to move relative to the outer anvil clamping plate during use. Furthermore, the additional staples provided beside the off-centered tissue locking pin hole can reduce the risk of leakage of tissue to be sealed around the tissue locking pin.

[0041] Those skilled in the art will understand that the three embodiments of the present disclosure described above can be implemented alone or in combination.

[0042] The present disclosure also encompasses the following improved embodiments.

[0043] 7A-7C show an anvil in the first improved embodiment of the present disclosure. The anvil body is U-shaped, the anvil face is provided with staple forming pockets, and the anvil top has a different shape from the main body, which is not U-shaped but a flat sheet-like shape, as clearly shown in the drawings. The purpose of such a configuration is to obtain a minimum width of the anvil. In this situation, the anvil body is designed in a U-shape, and the upper end of the anvil is a sheet placed on the outer anvil clamping plate and protrudes in the Z direction (i.e., laterally) from the outer anvil clamping plate to ensure sufficient space for the placement of the eccentric tissue locking pin hole on the sheet. The anvil according to the improved embodiment provides a large space for the eccentric tissue locking pin hole, thereby facilitating processing. The outer anvil clamping plate covered by the anvil has a support function in use. The body of the anvil is designed in a U-shape which contributes to the good stress behavior of the anvil, and the end seat of the anvil can provide more space for the anvil end, which is particularly suitable for the placement of an eccentric tissue locking pin hole.

[0044] 8A-8B show a second modified embodiment of the present disclosure, which relates to a pattern arrangement of 3D staple forming pockets on the anvil.

[0045] The 3D staple forming pocket present on the anvil is composed of two small pockets 85', i.e., for every two small staple forming pockets 85', a large 3D staple forming pocket pair is formed. As shown in FIG. 8A, two staple forming pocket pairs are arranged in a lateral direction (Z direction). Then, a plurality of such features, each consisting of two staple forming pocket pairs, are arranged along a vertical direction (Y direction) in a manner as shown in FIG. 6 and FIG. 7A, so that two staple fastening lines are formed. The two staple fastening lines are identical in formation, except that the corresponding staple forming pockets are vertically staggered. During firing, due to the shape of the small pocket 85', the staple exerts a lateral force F on the small pocket 85' perpendicular to the straight long side of the small pocket 85'. In the existing configuration, the lateral force F exerted on the corresponding staple forming pocket pairs of the two staple fastening lines cannot be balanced, thus generating a torque T. As the staple line extends vertically, the torque T increases, leading to misalignment of the staple cartridge with the anvil during staple firing. Also, the vertical staggering of the two staple lines creates two types of clearances of different widths between adjacent stitches of the staple line, resulting in poor sealing and leak-proofing after stapling.

[0046] In accordance with the present disclosure, an improved pattern arrangement of staple forming pockets is provided. As shown in Figures 3 and 4, it will be appreciated that a surface of the anvil 8 opposite the movable jaw 7 is clamped onto one or more tissue layers of a patient during stapling, and thus defines a tissue engaging surface 82. With further reference to Figure 8B, the tissue engaging surface 82 defines a longitudinal axis AX extending along the length of the anvil 8 (i.e., the vertical or Y direction), and a first pair of staple forming pockets 83 and a second pair of staple forming pockets 84, each formed by two staple forming pockets 85, are disposed on two sides of the longitudinal axis AX, respectively.

[0047] The staple forming pockets 85 are asymmetrically shaped. Taking the first staple forming pocket pair 83 as an example, two identical staple forming pockets 85 are arranged along the longitudinal axis AX and are symmetrical about a point C therebetween, thus forming the first staple forming pocket pair 83. Here, the point C is also referred to as the center of symmetry C of the first staple forming pocket pair 83. The second staple forming pocket pair 84 is arranged in a substantially similar manner to the first staple forming pocket pair 83. The two are arranged in a substantially mirror symmetric manner about the longitudinal axis AX, rather than in a duplicate manner as shown in FIG. 8A.

[0048] In the illustrated embodiment, the staple forming pocket 85 includes a straight edge 851 and an opposite curved edge 852 formed on the tissue engaging surface 82. The straight edge 851 is parallel to the longitudinal axis AX. The two staple forming pockets 85 form a centrally symmetrical structure, and their corresponding curved edges 852 face each other. The straight edge 851 of the staple forming pocket 85 has a first end 853 and a second edge 854 opposite each other. Preferably, along the direction from the first end 853 to the second end 854, the distance between the straight edge 851 and the curved edge 852 gradually decreases. The center of symmetry C is farther away from the first end 853 than from the second end 854. In other words, the first end 853 faces the outside of the centrally symmetrical structure, while the second end 854 faces the inside of the centrally symmetrical structure.

[0049] Furthermore, curved edge 852 has a convex curve segment 855 and a concave curve segment 856, where convex curve segment 855 is closer to first end 853 than concave curve segment 856. Due to the convex and concave curve segments of the curve, the distance between straight edge 851 and curved edge 852 changes accordingly.

[0050] The staple forming pocket 85 has a bottom 857. The distance between the bottom 857 and the tissue engaging surface 82 defines a depth of the staple forming pocket 85. Here, along the longitudinal axis AX, the staple forming pocket 85 has a maximum depth at a middle position, and along a direction from the middle portion to the first end 853 and a direction from the middle portion to the second end 854, the depth of the staple forming pocket gradually decreases. In addition, the staple forming pocket 85 further includes a first sidewall 858 and a second sidewall 859 extending between the bottom 857 and the tissue engaging surface 82. The first sidewall 858 intersects with the tissue engaging surface 82 to form a straight edge 851, and the second sidewall 859 intersects with the tissue engaging surface 82 to form a curved edge 852. Preferably, at least one of the first sidewall 858 and the second sidewall 859 is configured as an inclined sidewall. As used herein, "sloped" refers to the sidewalls gradually sloping outward along a direction from the base 857 toward the tissue engaging surface 82 to form a flared configuration.

[0051] Although FIG. 8B shows only one group of corresponding first and second staple forming pocket pairs 83, 84, it will be understood by one skilled in the art that the first and second staple forming pocket pairs 83, 84 may be arranged in multiple groups along the longitudinal axis AX, respectively, to form two substantially parallel stapling lines.

[0052] Preferably, the first staple forming pocket pair 83 and the second staple forming pocket pair 84 are staggered along the longitudinal axis AX. It should be understood by those skilled in the art that the staggered arrangement should ensure that the corresponding staple forming pockets 85 of the first staple forming pocket pair 83 and the second staple forming pocket pair 84 at least partially overlap in a lateral view. In this arrangement, a balanced force is generated for each element, which allows the arrangement to achieve a better stapling effect. Furthermore, the two staple forming pockets 85 constituting the first staple forming pocket pair 83 and the second staple forming pocket pair 84, respectively, also at least partially overlap in a lateral view. The staples may be made of titanium.

[0053] As described above, in the improved pattern arrangement of the staple forming pockets, the clearance between adjacent stitches in two staple fastening lines after stapling has a uniform width, which is advantageous for maintaining good sealing performance.

[0054] In addition, although not shown in the drawings, one skilled in the art will appreciate that in some embodiments, the tissue engaging surface of the anvil may have more than two (e.g., three or more) rows of staple forming pocket pairs along a lateral direction perpendicular to the longitudinal axis. A longitudinal axis is defined between every two rows of staple forming pocket pairs, such that more than one longitudinal axis is defined on the tissue engaging surface. Furthermore, the number of staple forming pockets in the two rows on two sides of the longitudinal axis may be the same or different (e.g., an even number of staple forming pockets in one row and an odd number of staple forming pockets in the other row, etc.).

[0055] A third improved embodiment of the present disclosure will be described below. As shown in Fig. 9A and Fig. 9B, in this embodiment, the two outer anvil clamping plates are not flat members, but have a curved shape in horizontal cross section. When measured from the Z direction (i.e., the lateral direction), the clearance between the two outer anvil clamping plates formed on the proximal side is small, but the clearance formed on the distal side is large. The U-shaped anvil covers the proximal end of the two outer anvil clamping plates respectively, and the proximal surface of the two outer anvil clamping plates supports the rear surface of the anvil. At the distal end of the outer anvil clamping plate, a plastic member is disposed between the two outer anvil clamping plates to fill the clearance between them. A pin extending laterally is used to fix the anvil on the outer anvil clamping plate. In the surgical stapler according to this embodiment, the fixed jaw has a smaller thickness, the anvil has a smaller width, and the curved outer anvil clamping plate can reinforce the rigidity of the entire anvil system.

[0056] A fourth improved embodiment of the present disclosure will be described below. In Fig. 10A and Fig. 10B, as can be seen from the horizontal cross section, the body of the anvil is U-shaped and sleeve-connected on the inner anvil clamping plate. The inner anvil clamping plate has a T-shape and is mutually nestedly engaged with the body of the anvil. Two outer anvil clamping plates cover the two sides of the anvil and the inner anvil clamping plate. The top of the anvil is sheet-like and covers the outside of the outer anvil clamping plate to ensure sufficient space for the eccentric tissue locking pin hole in the upper sheet of the anvil. As shown in Fig. 10B, the anvil protrudes from the outer anvil clamping plate in the X direction (i.e., horizontal direction), thereby forming a height difference between the surface of the anvil and the surface of the outer anvil clamping plate. The height difference provides a blade cutting site for the surgeon to cut tissue.

[0057] The embodiments described herein are merely provided as examples to illustrate the spirit of the present disclosure. Without departing from the spirit of the present disclosure, those skilled in the art may make various modifications, additions, or substitutions to the embodiments disclosed herein, and all such modifications, additions, or substitutions shall fall within the scope of protection defined by the appended claims.

Claims

1. An end effector for a surgical instrument, wherein the end effector (3) comprises a substantially U-shaped fixed jaw (6) located distally, and a movable jaw (7) movable relative to the fixed jaw (6) to clamp tissue between itself and the fixed jaw (6), the fixed jaw (6) having an anvil (8) on the surface opposite to the movable jaw (7), and the movable jaw (7) being configured to receive a staple cartridge (9), An end effector wherein the surface of the anvil (8) opposite to the movable jaw (7) defines a tissue engagement surface (82), the tissue engagement surface (82) defines a longitudinal axis (AX) extending along the length direction of the anvil (8), and a first pair of staple-forming pockets (83) and a second pair of staple-forming pockets (84) are provided located on two sides of the longitudinal axis (AX), each of the first pair of staple-forming pockets (83) and the second pair of staple-forming pockets (84) is configured as a centrally symmetric structure formed by two staple-forming pockets (85) arranged along the longitudinal axis (AX), the staple-forming pockets (85) have an asymmetric shape, and the first pair of staple-forming pockets (83) and the second pair of staple-forming pockets (84) are mirror-symmetric with respect to the longitudinal axis and are arranged alternately along the longitudinal axis.

2. The end effector according to claim 1, wherein the first staple-formed pocket pair (83) and the second staple-formed pocket pair (84) are each arranged in a plurality of groups along the longitudinal axis (AX).

3. The end effector according to claim 1 or 2, wherein the first pair of staple-formed pockets (83) and the second pair of staple-formed pockets (84) at least partially overlap along a transverse direction perpendicular to the longitudinal axis.

4. The end effector according to claim 1, wherein the staple-formed pocket (85) has a straight edge (851) and a curved edge (852) formed on the tissue engagement surface (82) opposite to the straight edge (851), the straight edge (851) is parallel to the longitudinal axis, and the two staple-formed pockets (85) form a centrally symmetric structure with their respective opposing curved edges (852).

5. The end effector according to claim 4, wherein the straight edge portion (851) has a first end portion (853) and a second end portion (854) opposite to each other, and the distance between the straight edge portion (851) and the curved edge portion (852) gradually decreases along the direction from the first end portion (853) to the second end portion (854).

6. The end effector according to claim 5, wherein the staple-formed pocket (85) has a bottom (857), the distance from the bottom (857) to the tissue engagement surface (82) defines the depth of the staple-formed pocket (85), and the depth gradually decreases along the direction from the middle portion of the staple-formed pocket (85) to the first end (853) and the second end (854), respectively.

7. The end effector according to claim 6, wherein the staple-formed pocket (85) comprises a first side wall (858) and a second side wall (859) extending between the tissue engagement surface (82) and the bottom (857), the first side wall (858) forming the straight edge (851), the second side wall (859) forming the curved edge (852), and at least one of the first side wall (858) and the second side wall (859) is configured to incline outward along the direction from the bottom (857) to the tissue engagement surface (82).

8. The end effector according to any one of claims 4 to 7, wherein the two staple-formed pockets (85) that form the centrally symmetrical structure overlap at least partially along a transverse direction perpendicular to the longitudinal axis.

9. The end effector according to claim 1, wherein the movable jaw (7) is provided with a tissue locking pin (10), the anvil (8) of the fixed jaw (6) is provided with a tissue locking pin hole (81) corresponding to the position of the tissue locking pin (10), the tissue locking pin hole (81) is located at the upper end of the anvil (8) along the longitudinal axis and is offset laterally perpendicular to the longitudinal axis.

10. The end effector according to claim 1, wherein the tissue engagement surface (82) is provided with at least two rows of staple-formed pocket pairs along a transverse direction perpendicular to the longitudinal axis, and two adjacent rows of the staple-formed pocket pairs are spaced apart by the longitudinal axis, with the longitudinal axis defining the space between them.

11. The end effector according to claim 1, wherein two rows of staple-forming pocket pairs located on two sides of the longitudinal axis have the same or different numbers of staple-forming pockets.

12. An open linear stapler comprising the end effector described in claim 1.

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