AU2006213928B2

AU2006213928B2 - Surgical instrument

Info

Publication number: AU2006213928B2
Application number: AU2006213928A
Authority: AU
Inventors: Santi Corsaro
Original assignee: Ethicon Endo Surgery Europe GmbH
Current assignee: Ethicon Endo Surgery Europe GmbH
Priority date: 2001-05-02
Filing date: 2006-09-12
Publication date: 2009-10-01
Anticipated expiration: 2022-04-16
Also published as: AU2006213928A1

Description

P/00/01I1 Regulation 3.2 AUSTRALIA Patents Act 1990 COMPLETE SPECIFICATION STANDARD PATENT Invention Title: Surgical instrument The following statement is a full description of this invention, including the best method of performing it known to us: 1 A Surgical Instrument The present application is a divisional application of our earlier application no 34361/02 and the reader is directed to that earlier application for inventions described herein but not claimed. 5 The invention relates to a surgical instrument having a jaw assembly with a generally straight first tissue interface, a generally straight second tissue interface and a tissue effector. This instrument can be designed as a stapling instrument and/or a cutting instrument. Instruments of this kind are widely used in surgery. Generally, the surgical instrument 10 comprises a frame having a body portion and a handle and, in the distal region of the instrument, a jaw assembly. The jaw assembly has a generally straight design with a generally straight first tissue interface and a generally straight second tissue interface, the jaw assembly being adapted to grip tissue of a patient between the first tissue interface and the second tissue interface. Moreover, a tissue effector for penetrating the 15 gripped tissue is provided. An example of a tissue effector is a set of staples which are arranged in the jaw assembly and, upon actuation of the instrument, exit from -2 the first tissue interface and penetrate the tissue, until their ends are formed or bent by the second tissue interface. Another example is a knife for cutting the tissue when the instrument is actuated. The knife can be used in combination with the staples, 5 but it can also be arranged in a pure cutting instrument. U.S. patent 4 527 724 discloses a linear surgical stapling instrument in which a straight jaw assembly is located at the distal end of a shaft. The longitudinal axis of the jaw assembly 10 extends transversely with respect to the longitudinal axis of the shaft. U.S. Patent 4 633 874 describes a surgical stapling instrument in which the longitudinal axis of the jaw assembly coincides 15 with the longitudinal axis of the rest of the instrument. A pusher bar and knife blade assembly is slidable longitudinally relative to the jaw members to sequentially drive staples from a cartridge and form the staples against one of the tissue in terfaces (which is designed as an anvil) to produce a pair of 20 laterally spaces rows of formed staples in tissue gripped between the jaw members (i.e. between the first tissue interface and the second tissue interface) and to cut the tissue along a line between the staple rows. 25 Another straight or linear stapling instrument in which the longitudinal axis of the jaw assembly runs along the longitudi nal axis of the whole instrument is disclosed in U.S. patent 5 307 976. This document also describes details of the actuating components and safety means of the instrument. 30 In all these surgical instruments, the tissue interfaces, i.e. those parts of the jaw assembly which contact the patient's tissue to be effected (e.g., stapled and/or cut), are designed as generally flat surfaces. This holds for instruments used in 35 open surgery and in endoscopic surgery. In straight (linear) cutters for open or endoscopic surgery, the tissue interfaces 3 usually extend along the longitudinal axis of the instrument. For linear staplers applied in open surgery, the tissue interfaces usually are arranged transversally with respect to the longitudinal axis of the instrument. In the current designs of these kinds of surgical instruments, the jaw assembly is generally longer than the length of tissue which can be 5 gripped between the first tissue interface and the second tissue interface. This can make it difficult to manipulate and utilize the instrument in certain situations, in particular in space limited anatomical regions. Reference to any prior art in the specification is not, and should not be taken as, an acknowledgment or any form of suggestion that this prior art forms part of the common 0 general knowledge in Australia or any other jurisdiction or that this prior art could reasonably be expected to be ascertained, understood and regarded as relevant by a person skilled in the art. It is the object of the invention to provide a surgical instrument or jaw assembly which is able to affect tissue in a more space-saving manner. 5 In accordance with a first aspect of the present invention, there is provided a surgical instrument, comprising a jaw assembly which is removably mounted in the distal region of the instrument, the jaw assembly having a generally straight first jaw with a first tissue interface, a generally straight second jaw with a second tissue interface and a tissue effector, and the jaw assembly being adapted in a gripping configuration to grip tissue of 20 a patient between the first tissue interface and the second tissue interface and to penetrate the gripped tissue by the tissue effector, wherein the first tissue interface and the second tissue interface have a generally wavy shape, the crests and valleys of the first tissue interface generally matching the valleys and crests, respectively, of the second tissue interface, such that in the gripping configuration, the first and second 25 tissue interfaces are substantially evenly spaced apart along their lengths with the tissue gripped therebetween following the generally wavy shape of the tissue interfaces to create a wavy cutting line for the tissue effector.

3a In accordance with a second aspect of the present invention, there is provided a jaw assembly for a surgical instrument, the jaw assembly having a generally straight first jaw with a first tissue interface, a generally straight second jaw with a second tissue interface and a tissue effector, and the jaw assembly being adapted in a gripping 5 configuration to grip tissue of a patient between the first tissue interface and the second tissue interface and to penetrate the gripped tissue by the tissue effector, wherein both the first tissue interface and the second tissue interface, have a generally wavy shape, the crests and valleys of the first tissue interface generally matching the valleys and crests, respectively, of the second tissue interface, such that in the gripping 0 configuration, the first and second tissue interfaces are substantially evenly spaced apart along their lengths with the tissue gripped therebetween following the generally wavy shape of the tissue interfaces to create a wavy cutting line for the tissue effector, and wherein the jaw assembly includes an anvil having the second tissue interface, wherein the anvil is removable. 5 In accordance with a third aspect of the present invention, there is provided a jaw assembly for a surgical instrument, the jaw assembly having a generally straight first jaw with a first tissue interface, a generally straight second jaw with a second tissue interface and a tissue effector, and the jaw assembly being adapted in a gripping configuration to grip tissue of a patient between the first tissue interface and the second 20 tissue interface and to penetrate the gripped tissue by the tissue effector, wherein the first tissue interface and the second tissue interface, have a generally wavy shape, the crests and valleys of the first tissue interface generally matching the valleys and crests, respectively, of the second tissue interface such that in the gripping configuration, the first and second tissue interfaces are substantially evenly spaced apart along their 25 lengths with the tissue gripped therebetween following the generally wavy shape of the tissue interfaces to create a wavy cutting line for the tissue effector and/or a wavy stapling line for the staples, and wherein the jaw assembly includes a cartridge device having the first tissue interface, the cartridge device containing stapes and being removable from the jaw assembly. 30 Also described, but not claimed herein, is the invention of a surgical instrument which comprises a frame having a body portion and a handle, as well as a jaw assembly in the 3b distal region of the instrument. The jaw assembly has a generally straight first tissue interface, a generally straight second tissue interface and a tissue effector, and the jaw assembly is adapted to grip tissue of a patient between the first tissue interface and the second tissue interface and to penetrate the gripped tissue by the tissue effector. A 5 moving device is adapted to move the first tissue interface relative to the second tissue interface. An actuating device is adapted to actuate the tissue effector. According to the invention, the first tissue interface and the second tissue interface have, locally and superimposed to their general straightness, a generally wavy shape, the crests and valleys of the first tissue interface generally matching the valleys and crests, respectively, of the 0 second tissue interface. As used herein, the term "comprise" and variations of the term, such as comprisingng, "comprises" and "comprised", are not intended to exclude other additives, components, integers or steps.

-4 In other words, the tissue interfaces are not flat, as in con ventional instruments, but have a three-dimensional, wavy shape along the length of the jaw assembly, e.g. a sinusoidal shape. Thus, the path length following the valleys and crests of the 5 wavy shape is greater than the linear extension of the tissue interfaces. Generally, this allows the instrument to effect a length of tissue greater than the length of the jaw assembly. If the surgical instrument is a stapling instrument and/or a cut ting instrument, a staple line and/or cutting line can be cre 0 ated which follows the shape of the tissue gripped between the first tissue interface and the second tissue interface, i.e. the generally wavy shape of the tissue interfaces, and which is effectively longer than the staple line or the cutting line of a conventional instrument. The greater length of the staple line 15 or cutting line has advantages, e.g., for a given length of a staple line or cutting line, the jaw assembly of the surgical instrument according to the invention can be smaller than the jaw assembly of a conventional instrument. Thus, the invention allows for the design of smaller or shorter and less bulky jaw 20 assembly components that will facilitate easier access to ana tomic sites. As already mentioned, the surgical instrument can be a stapling instrument. In this case, the jaw assembly includes a cartridge 25 device having the first tissue interface and an anvil having the second tissue interface. The tissue effector comprises, associa ted to the cartridge device, at least one generally straight row of staples which, upon actuation of the actuating device, exit from the first tissue interface, the second tissue interface 30 being adapted to form the ends of the staples. Preferably, the line defining the row of staples follows the wavy shape of the first tissue interface. Alternatively, e.g., the staples could be arranged at the top of the crests and/or at the bottom of the valleys of the first tissue interface. 35 In an advantageous version of a stapling instrument, the tissue effector comprises a knife, which is contained in the cartridge device, runs generally in parallel to the row of staples and, upon actuation of the actuating device, moves towards the anvil. 5 The knife can have a wavy cutting edge, which, preferably, gene rally runs in parallel to the wavy shape of the first tissue interface. In another advantageous version of a stapling instrument, the 10 tissue effector comprises a knife, which is adapted to move, upon actuation of the actuating device, from one end region of the cartridge device to the opposite-end region of the cartridge device, generally in parallel to and along the row of staples, in order to sequentially cut the tissue gripped between the 15 first tissue interface and the second tissue interface. Preferably, in a stapling instrument comprising a knife, there is at least one row of staples on each side of the knife. This allows opposing layers of tissue to be connected at both sides 20 of the knife, i.e. to create two closed tissue parts which are separated when the knife is actuated. In advantageous versions of a stapling instrument, the anvil is removable, and the cartridge device comprises a removable car 25 tridge containing the staples. The surgical instrument according to the invention can also be designed as a cutting instrument (without stapling function) . In this case, the jaw assembly includes a first gripping jaw having 30 the first tissue interface and a second gripping jaw having the second tissue interface. The tissue effector comprises a knife, which is adapted to cut, upon actuation of the actuating device, the tissue gripped between the first tissue interface and the second tissue interface. 35 -6 In a preferred version of a cutting instrument, the knife is generally straight, generally extends along the jaw assembly, and, upon actuation of the actuating device, moves from the first tissue interface towards the second tissue interface. In 5 this case, the knife can have a wavy cutting edge, which, pre ferably, generally runs in parallel to the wavy shape of the first tissue interface. In another design of a cutting instrument, the knife is adapted 10 to move, upon actuation of the actuating device, from one end region of the gripping jaws to the opposite end region of the gripping jaws, generally along the gripping jaws, in order to sequentially cut the tissue gripped between the first tissue interface and the second tissue interface. 15 r In advantageous versions of a stapling instrument and/or a cut ting instrument, the moving device is adapted to move the first tissue interface relative to the second tissue. interface in a generally parallel relationship. This design facilitates inser 20 tion of the tissue into the space between the first tissue interface and the second tissue interface when these interfaces are in the spaced apart state. Preferably, the body portion of the frame of the surgical in 25 strument includes a shaft. This allows for two basic geometries of the instrument. In one of these geometries, the longitudinal axes of the first tissue interface and the second tissue inter face run transversally with respect to the longitudinal axis of the shaft. This design is advantageous for applications in open 30 surgery. When, the instrument includes a knife, a generally straight knife 'which generally extends along the jaw assembly - allows for a mechanically simple actuating device. In the other basic geometry, the longitudinal axes of the first tissue inter face and the second tissue interface run generally in parallel 35 with respect to the longitudinal axis of the shaft. This geome try is advantageous for endoscopic applications,- and a sequenti- -7 ally cutting knife generally involves a simple design of the actuating device. The jaw assembly can be removably mounted in the distal end S region of the body portion. This allows for a design of the surgical instrument in which the jaw assembly is disposable, whereas the rest of the instrument, which is not contaminated or only slightly contaminated in the surgical procedure and which includes many components of the moving device and the actuating 10 device, can be re-used after sterilization. Apart from the three-dimensional shape of the tissue interfaces and any adaptions caused thereby, the surgical instrument accor ding to the invention is generally designed as a conventional 15 instrument. That means, it includes components like a handle, a shaft, gripping jaws or an anvil and a cartridge device, mecha nical members of the moving device and the actuating device, safety elements like locking means against unintentional opera tion, and so on, which are generally known from the prior art, 20 e.g., U.S. patents 4 527 724, 4 633 874, or 5 307 976. Moreover, the surgical instrument according to the invention can be used in a similar way as the prior art instruments. In the following, the surgical instrument according to the in 25 vention is further explained by means of embodiments. The dra wings show in Figure 1 a side view of a first embodiment of the surgical in strument according to the invention, 30 Figure 2 a magnified side view of the jaw assembly of the in strument of Figure 1, Figure 3 a side view of a second embodiment of the surgical 35 instrument according to the invention, -8 Figure 4 a side view of a third embodiment of the surgical in strument according to the invention, and Figure 5 a magnified side view of the jaw assembly of the in 5 strument of Figure 4. Figure 1 illustrates a surgical instrument 100 which is designed as a linear stapler and can be used in endoscopic applications. This general type of instrument is known, e.g. from U.S. patent 10 5 307 976. The instrument 100 comprises a handle section 110 and a shaft 112, which is rotatably connected to the handle section 110 via rotating means 114. The handle section 110 and the shaft 112 15 form a body portion. At the distal end 116 of the shaft 112, a jaw assembly 120 is mounted in a removable manner. Figure 2 is a magnified view of the jaw assembly 120. The jaw assembly 120 includes a cartridge 20 device 122 (lower jaw in Figures 1 and 2) and an anvil 126 (up per jaw in Figures 1 and 2). The anvil 126 is swivellably moun ted in the jaw assembly 120, but when the anvil 126 is close to the cartridge device 122, it moves in a parallel relationship with respect to the cartridge device 122. 25 The cartridge device 122 comprises a removable cartridge 124, which essentially extends along the length of the cartridge device 122. Figure 2 shows the distal end region of the cartrid ge 124 which protrudes from a mounting base provided in the 30 cartridge device 122. In the embodiment, the cartridge 124 con tains six parallel straight rows of staples in which staples of adjacent rows are staggered with respect to each other. The ends of the staples point towards the anvil 126. The surface of the cartridge device 122 including the cartridge 124 opposite to the 35 anvil 126 is called first tissue interface 130.

-9 Similarly, the surface of the anvil 126 opposite to the cartrid ge device 122 is called second tissue interface 132. The second tissue interface comprises six parallel rows of depressions, which match to the positions of the staples in the cartridge 124 5 and are designed to form the pointed ends of the staples when they are expelled from the cartridge 124 upon actuation of the instrument 100. The features of the instrument 100 described so far are those of 10 a conventional stapler, and further details of the embodiment can be found in U.S. patent 5 307 976. Whereas in a conventional stapler the first tissue interface and the second tissue interface are essentially flat or planar, the 15 first tissue interface 130 of the instrument 100 has a generally wavy shape with crests 134 and valleys 135, see Figure 2. The second tissue interface 132 has a generally wavy shape as well, and its valleys 136 and crests 137 match to the crests 134 and valleys 135, respectively, of the first tissue interface 130, 20 see Figure 2. The proximal area of the instrument 100 is designed in a conven tional manner, see U.S. patent 5 307 976 for more details on the embodiment. In summary, a handle 150 emerging from the handle 25 section 110 serves for holding the instrument 100. A lever 152 is a component of a moving device for moving the first tissue interface 130 relative to the second tissue interface 132. That means, when the lever 152 is swivelled towards the handle 150, the anvil 126 moves towards the cartridge device 122 (i.e., the 30 jaws of the jaw assembly 120 close), the force being transmitted by further components in the handle section 110, the shaft 112 and the jaw assembly 120, as explained, e.g., in*U.S. patent 5 307 976. 35 A firing trigger 154 is actuated in order to expel the staples from the cartridge 124 towards the anvil 126 and, at the same - 10 time, to move a knife (not shown in the figures) from the proxi mal end region 128 to the distal end region 140 of the cartridge device 122. This knife is contained in the cartridge device 122 and runs in parallel to the rows of staples, wherein, in the 5 embodiment, there are three rows of staples on each side of the knife. Again, further details of the knife and the actuating mechanism are given in U.S. patent 5 307 976. The instrument 100 is used in a similar way as a conventional 10 stapler. Tissue parts to be stapled (and cut) are introduced between the first tissue interface 130 and the second tissue interface 132 when the anvil 126 is moved away from the car tridge device 122. Then the anvil 126 is closed by moving it towards the cartridge device 122 via the lever 152, thus grip 15 ping and clamping the tissue between the first tissue interface 130 and the second tissue interface 132. In contrast to a con ventional stapler, the tissue does not remain flat, but adapts to the wavy shape of the first tissue interface 130 and the second tissue interface 132. In this way, the tissue length 20 effected by the jaw assembly 120 can be longer than the linear length of the tissue interfaces 130, 132. This allows the mani pulation of a given length of tissue by an effectively smaller jaw assembly 120. 25 When the firing trigger 154 is actuated, the staples are expel led from the cartridge 124, penetrate the tissue and are formed by means of the anvil 126. Almost simultaneously the knife moves from the proximal end region 128 to the distal end region 140 of the cartridge device 122 and sequentially cuts the tissue along 30 a line in-between the rows of staples. The staple expelling mechanism disclosed in U.S. patent 5 307 976 drives the staples in a direction which is essentially perpendicular with respect to the longitudinal axis of the jaw 35 assembly. The same type of mechanism could be used in the in strument 100. If it is preferred, however, that the staples are - 11 driven perpendicularly with respect to the local slope of the wavy shape of the first tissue interface 130, the mechanism has to be modified somewhat. 5 Figure 3 shows an embodiment of another surgical stapling in strument 200. The design of the instrument 200 is similar to that of the stapling instrument disclosed in U.S. patent 4 633 874. 10 The instrument 200 comprises a body portion 210 with integrated handle and a jaw assembly 220. Similar to the instrument 100 described above, the jaw assembly 220 includes a cartridge devi ce 222, which comprises a first tissue interface 230, and an anvil 226, which comprises a second tissue interface 232. In the 15 embodiment, the cartridge device 222 contains four parallel straight rows of staples and a knife running along the center line' of the staple arrangement for sequentially cutting tissue gripped between the cartridge device 222 and the anvil 226. 20 The first tissue interface 230 and the second tissue interface 232 have a wavy shape, like in the instrument 100. To operate the instrument 200, the anvil 226 is moved towards the cartridge device 222 in a parallel relationship by means of 25 a lever 252 in order to grip or clamp tissue between the car tridge device 222 and the anvil 226. In the state shown in Figu re 3, the lever 252 is swivelled in a position parallel to the body portion 210. Then an actuator 254 is pushed along the body portion 210 in distal direction, which causes the staples to be 30 expelled from the cartridge device 222 for penetrating the tis sue, the pointed ends of the staples being bent by the anvil 226, and to move the knife from the proximal end region 228 to the distal end region 240 of the cartridge device 222 for se quentially cutting the tissue. 35 - 12 Figure 4 is an overall view of a surgical instrument 300 accor ding to a third embodiment. The instrument 300 includes a handle section 310, a shaft 312 and a jaw assembly 320 at the distal end of the shaft 312. Figure 5 is a magnified view of the jaw 5 assembly 320. The jaw assembly 320 comprises a cartridge device 322 and an anvil 326. Whereas in the instruments 100 and 200, the respecti ve cartridge device and anvil are aligned in parallel to the 10 longitudinal axis of the instrument, the anvil 326 and the car tridge device 322 extend transversally with respect to the shaft 312. The instrument 300 is designed for open surgery. The anvil 326 is rigidly connected to an extension of shaft 312, and the cartridge device 322 can be moved towards and away from the 15 anvil 326, while a parallel relationship between a first tissue interface 330 provided at the cartridge device 322 and a second tissue interface 332.provided at the anvil 326 is maintained. As in the previous embodiments, the first tissue interface 330 20 and the second tissue interface 332 have a wavy shape, in con trast to comparable instruments of the prior art. An example of such prior art instrument is described in U.S. patent 4 527 724 which also discloses details on the actuating elements of the instrument. 25 As before, the cartridge device 322 includes one or more par allel straight rows of staples, and the anvil 326 is adapted to form the ends of the staples when they are driven out of the cartridge device, here essentially simultaneously in the distal 30 direction. Moreover, the cartridge device 322 contains a knife which ex tends over the width of the cartridge device 322 and is guided between two rows of staples. The knife can be moved towards the 35 anvil 326 in order to cut the tissue gripped or clamped between the anvil 326 and the cartridge device 322 essentially in one - 13 instant. In the embodiment, the knife has a wavy cutting edge which runs in parallel to the wavy shape of the first tissue interface 330. 5 In its proximal end region, the instrument 300 comprises a hand le 350, a lever 352, a firing trigger 354, and a safety button 356. When the lever 352 is pulled towards the handle 350, the cartridge device 322 moves towards the anvil 326. In order to actuate the instrument 300, the firing trigger 354 is pulled 10 towards the handle 350. This causes the staples and the knife to be driven towards the anvil 326 and to penetrate the tissue gripped in-between the first tissue interface 330 and the second tissue interface 332 in order to staple and cut the tissue. 15 Each of the instruments 100, 200, and 300 is designed as a stap ler/cutter for stapling and cutting tissue. The invention, howe ver, also includes pure stapling instruments (without a knife or cutter) and pure cutting instruments (without stapling means). In a pure cutting instrument, the jaw assembly includes gripping 20 jaws having wavy-shaped tissue interfaces and a knife.

Claims

1. A surgical instrument, comprising a jaw assembly which is removably mounted in the distal region of the instrument, the jaw assembly having a generally straight first jaw with a first tissue 5 interface, a generally straight second jaw with a second tissue interface and a tissue effector, and the jaw assembly being adapted in a gripping configuration to grip tissue of a patient between the first tissue interface and the second tissue interface and to penetrate the gripped tissue by the tissue effector, wherein the first tissue interface and the second tissue interface have a generally 0 wavy shape, the crests and valleys of the first tissue interface generally matching the valleys and crests, respectively, of the second tissue interface, such that in the gripping configuration, the first and second tissue interfaces are substantially evenly spaced apart along their lengths with the tissue gripped therebetween following the generally wavy shape of the tissue interfaces to create a wavy cutting line for the tissue effector. 5

2. A jaw assembly for a surgical instrument, the jaw assembly having a generally straight first jaw with a first tissue interface, a generally straight second jaw with a second tissue interface and a tissue effector, and the jaw assembly being adapted in a gripping configuration to grip tissue of a patient between the first tissue interface and the second tissue interface and to penetrate the gripped tissue by the tissue effector, 20 wherein both the first tissue interface and the second tissue interface, have a generally wavy shape, the crests and valleys of the first tissue interface generally matching the valleys and crests, respectively, of the second tissue interface, such that in the gripping configuration, the first and second tissue interfaces are substantially evenly spaced apart along their lengths with the tissue gripped therebetween following 25 the generally wavy shape of the tissue interfaces to create a wavy cutting line for the tissue effector, and wherein the jaw assembly includes an anvil having the second tissue interface, wherein the anvil is removable. 15

3. A jaw assembly for a surgical instrument, the jaw assembly having a generally straight first jaw with a first tissue interface, a generally straight second jaw with a second tissue interface and a tissue effector, and the jaw assembly being adapted in a gripping configuration to grip tissue of a patient between the first tissue interface and the 5 second tissue interface and to penetrate the gripped tissue by the tissue effector, wherein the first tissue interface and the second tissue interface, have a generally wavy shape, the crests and valleys of the first tissue interface generally matching the valleys and crests, respectively, of the second tissue interface such that in the gripping configuration, the first and second tissue interfaces are substantially evenly 0 spaced apart along their lengths with the tissue gripped therebetween following the generally wavy shape of the tissue interfaces to create a wavy cutting line for the tissue effector and/or a wavy stapling line for the staples, and wherein the jaw assembly includes a cartridge device having the first tissue interface, the cartridge device containing staples and being removable from the jaw 5 assembly.

4. The surgical instrument as claimed in claim 1 wherein the jaw assembly is such that the first tissue interface is moveable in a generally parallel relationship relative to the second tissue interface.

5. The jaw assembly as claimed in claims 2 or 3 being such that the first tissue 20 interface is moveable in a generally parallel relationship relative to the second tissue interface.

6. The jaw assembly as claimed in claim 3 wherein the staples are drivable perpendicularly to the local slope of the wavy shape of the first tissue interface.

7. The surgical instrument as claimed in claim 1 further including a shaft wherein 25 the first and second jaws extend transversely to the shaft.

8. A surgical instrument as claimed in claim 1 or a jaw assembly as claimed in claims 2 or 3 wherein the tissue effector is a knife having a wavy cutting edge. 16

9. A jaw for a surgical instrument substantially as hereinbefore described with reference to the accompanying figures.