WO2022009189A2

WO2022009189A2 - Surgical soft tissue stapler

Info

Publication number: WO2022009189A2
Application number: PCT/IB2021/061119
Authority: WO
Inventors: Heiko Koller; Tamás Fülöp Fekete; Dezsö János JESZENSZKY; Daniel HASCHTMANN; Tom Overes
Original assignee: Inno4Spine Ag
Priority date: 2020-12-24
Filing date: 2021-11-30
Publication date: 2022-01-13
Also published as: EP4267011A2; WO2022009189A3

Abstract

There is proposed a surgical stapler assembly for closing an incision or two layers of a target tissue. According to one example, the assembly comprises: staples comprising a back span and at least two legs extending away from the back span; front spans comprising apertures sized and shaped to receive the legs; and a surgical stapler comprising a first channel for the staples, a second channel for the front spans, and a staple driver configured to selectively engage with the respective staple to eject it out of the first channel. The stapler defines an open start state, in which the driver is in a first position allowing the staples to remain in the first channel, and in which the staples are separated from the front spans in their respective channels, and a closed end state, in which the driver is in a second position. A transition of the driver from the first position to the second position results in an ejection of the respective staple out of the first channel, and in its engagement with the respective front span to form a unity.

Description

SURGICAL SOFT TISSUE STAPLER

TECHNICAL FIELD OF THE INVENTION

One aspect of the present invention relates to a surgical soft tissue stapler. The stapler may be used after a surgical intervention to close two portions of a target soft tissue arranged at opposite sides of an incision. The stapler may be used in combination with bioabsorbable staples, suture material, and staple receiving front spans. The proposed surgical stapler provides a surgeon with a tool to close incisions in a fast and secure manner with a high resistance to forces promoting wound dehiscence. The invention also relates to a surgical soft tissue stable assembly, and to a surgical soft tissue stapler assembly.

BACKGROUND OF THE INVENTION

After invasive surgical intervention, often a longer incision needs to be closed.

Most commonly sutures are used to close the muscle and the fascial layer, and sutures or metal staples are used to close the skin. Depending on the type of tissue layer to be closed, bioresorbable or permanent materials may be preferred. Longer skin incisions are frequently closed with staples. These staples are made of metal and clamp the skin together. These metal staples are removed after healing. These staples, which are placed in the outer tissue layer of the body, can generally be easily removed. To do this, the staple is bent back using a special tool, and then pulled away.

Metal staples are rarely used for deeper tissue layers, for instance because the removal would be too difficult, and a new incision would be needed. Furthermore, the staples are not configured to stay long in the body. For example, the staples can break due to stress. Therefore, in these body parts most often sutures are used. Sutures are strong and can be chosen out of resorbable and non-resorbable materials. The disadvantage of sutures is that they are very time consuming to place.

Recently bio-resorbable staples have been introduced for the purpose of closing skin incisions. These staples have the advantage that there is no longer a need to remove these kinds of staples, but they have the disadvantage of being less strong or rigid. Furthermore, these staples cannot be used for tissue layers that are under greater stress.

Thus, in view of the above, there is a need for an improved tissue staple assembly and a stapler tool that provides a surgeon with a fast and secure application or deployment technique to close longer and short incisions in high-stress or deeper tissue layers. In other words, there is a need for a staple assembly and stapler that provide higher security, reproducibility, and reduced surgery time. SUMMARY OF THE INVENTION

It is an object of the present invention to overcome at least some of the problems associated with the closure of incisions in deeper soft tissue layers, such as the myofascial tissue layers as well as the muscles and the fascia itself. There is a need for a stapler and a staple assembly that provide the ability to quickly place staples that may be made of a bioresorbable material or alternatively of a non-resorbable material. The staples should be able to withstand higher stresses and safely close the target tissue.

According to a first aspect of the invention, there is provided a surgical stapler as recited in claim 1.

According to a third aspect of the invention, there is provided a surgical stapler assembly as recited in claim 22.

The proposed stapler will improve the fixation strength when suturing myofascial material, the muscles and/or the fascia compared to simply placing multiple single resorbable sutures. The stapler according to the present invention will shorten the suturing process because pressing a device in proximity or in contact with wound tissue layers side by side is quicker than suturing the materials with a needle holder and with forceps in the hand of a surgeon.

Other aspects of the invention are recited in the dependent claims attached hereto.

BRIEF DESCRIPTION OF THE DRAWINGS

Other features and advantages of the invention will become apparent from the following description of non-limiting example embodiments, with reference to the appended drawings, in which:

• Figures 1 A to 1 F depict an example staple assembly according to a first embodiment of the present invention;

• Figures 2A to 2H depict the stapler components of an example tissue stapler and its operation in perspective, cross-sectional and exploded views;

• Figures 3A to 3M depict the operation principle of the tissue stapler in perspective and cross-sectional views; and

• Figures 4A and 4B depict a variant of the tissue stapler having tissue grasping spikes.

DETAILED DESCRIPTION OF THE INVENTION

The embodiments of the present invention will now be described in detail with reference to the attached figures. The embodiments are described in the context of a stapler and two portions of a target soft tissue arranged at the opposite sides of an incision, which is to be closed after a surgical intervention. Although the invention is specifically described in this context, the teachings of the invention are not limited to this environment. When the words first and second are used to refer to different elements, it is to be understood that this does not necessarily imply or mean that the first and second elements are somehow structurally substantially different elements or that their dimensions are substantially different unless implicitly or explicitly stated. Moreover, the word “end” is understood not only to mean the actual end point of an element but to also cover an end region in the proximity of the actual end point of the respective element. Identical or corresponding functional and structural elements which appear in the different drawings are assigned the same reference numerals.

Figures 1A to 1F show a first example staple assembly 10 according to the first embodiment in perspective views, in a first or separated state and in a second or engaged state. The staple assembly comprises a staple portion or staple 11 and a front span portion or front span 12, which is in this example configured as a front plate. The staple 11 comprises a plurality of legs 13 extending from a back span 14 or crown 15, which can be understood as a base portion or simply base and forms in this example a back plate. In this example, the staple comprises four legs, namely first, second, third and fourth legs. The legs comprise teeth 16 (i.e. in this example sharp portions) at the leg ends 26, in this example one tooth per leg. The legs 13 are intended to penetrate through the target soft tissue 1 and the crown 15 is intended to sit against the target soft tissue and to withstand tensile forces applied to the staple assembly 10 by the target soft tissue 1 when implanted. In this example, the teeth 16 comprise a hook-shaped end 17 with a base 18 and a tip 19 wherein the base 18 extends over the leg 13 and therefore forms a retention means or retention or locking surface, such as a barb. The retention means or surface is configured to be locked against or be engaged with the front span 12. Furthermore, the retention means 20 is directed inwardly, and thus it does not extend beyond the outer periphery of the crown 15. In this example, the respective retention surface extends orthogonally or substantially orthogonally from a respective leg main body portion, or its longitudinal axis. In the depicted example, at least four legs 13 are arranged in a substantially regularly spaced manner. Moreover, in this example, the legs extend orthogonally or substantially orthogonally from a surface defined by the back span 14. However, according to a variant of the staple, the legs would extend non-orthogonally from the back span.

As depicted in Figures 1A to 1C, the front span 12 is intended to engage with or over the staple legs 13 in an inseparable manner. In the configuration of Figures 1A to 1C, the front span is formed as a plate 23 comprising through holes or openings, which form retention means receiving apertures 24. These apertures are sized and shaped to allow the legs 13 to pass through them, one leg per aperture, and to allow the retention means 20 to engage with these apertures by means of the retention surface. Thus, the circumference in shape and length inscribed by the outer circumference of the respective retention means may substantially equal the shape and length of the circumference of the respective aperture. Alternatively, the circumference inscribed by the retention means may be slightly smaller or greater than the respective circumference of the respective aperture. In this case the retention means would slightly deflect when passing through the respective aperture, and resile once passed through the aperture. Alternatively, as shown in Figure 1D, the front span 12 may be configured as a target mesh 22, sized and shaped to be penetrated by the legs 13, and configured to hold the legs in such a manner that the retention means 20 hook through or into the mesh 22. The target mesh 22 may be formed by connected or interwoven individual tissue layers 25 which provide an open structure for the retention means to engage with the mesh, as shown in Figure 1 D.

Figures 1E and 1F show an alternative staple design. In this variant, the staple comprises micro-hooks 27 or micro-legs 28 configured to penetrate the soft tissue. An average cross-sectional diameter is in this example between 0.1 mm and 0.3 mm. An exemplary material for a resorbable version is magnesium or Vicryl resorbable mesh. Unresorbable versions can be made of materials, such as stainless steel, nitinol, cobalt chromium, titanium, PEEK, etc. The staple legs and the barbs extending therefrom may form a micro or nano roughness and enable a self-stabilising fit with the target mesh.

In one embodiment of the invention, the staples and/or the front spans 12 are made of a biocompatible bio-resorbable material. Bioresorbable materials may be synthetic materials, such as polyglycolic acid, polylactic acid, polydioxanone, and caprolactone-based materials. An example bio-resorbable metal is magnesium or a magnesium-based alloy.

The staple 11 and/or the front span 12 may also be made of hybrid combinations of these materials.

Figures 2A to 2H illustrate a surgical stapling device or stapler 30 to implant the staple assembly 10. The stapler 30 comprises a handling section or portion 31 to manually apply the necessary forces to place the staple assembly 10, and it further comprises a staple assembly deployment section or portion 32 where a staple 11 is driven through the target tissue into a front span 12. In this example, the stapler 30 has an L-shaped overall shape or side profile consisting of an L-shaped base portion or base 33, an L-shaped ejection portion 34 and an L-shaped actuator portion 35. The ejection portion 34, the actuator portion 35 and the base portion 33 are connected by a joint or a pivot point 36, which is arranged substantially in the middle or central region of the L-shaped portions. The joint defines a defines a pivot axis. The L-shaped design allows the operator to staple the target tissue while having a full visibility of the target site. The handling portion 31 and the deployment portion 32 are arranged at opposite sides of the joint 36.

With reference to the deployment portion 32 of the stapler 30, the ejection portion 34 comprises a first or ejection arm 37, which holds the staples 11. Furthermore, the base portion 33 comprises a second or reception arm 38 containing the front spans 12, and the actuator portion 35 comprises a third arm or an actuator lever 39. The first and second arms 37, 38, respectively, comprise a first jaw 40 and second jaw 41. The first jaw 40 is arranged at an ejecting end 42, and the second jaw 41 is arranged at a reception end 43. The jaws are configured to hold the tissue at the intended location while placing the staple assembly 10, as described later. The third arm 39 is connected to a staple driver 45 shown in Figure 2C. At least two of the first, second and third arms are pivotable arms, but in this example, they are all pivotable arms. Furthermore, the first, second and third arms are in this example arranged to pivot about the same pivot axis.

In the handling portion 31 , the L-shaped base portion 33 comprises a handle 46. Moreover, the L-shaped ejection portion 34 comprises a follower lever 47, and the actuator portion 35 comprises an actuator lever 48.

As depicted in the cross-sectional view of Figure 2B, the stapler 30 comprises two spring elements 49 and 50, namely a first spring element 49, and a second spring element 50. In this example, the first spring element 49 requires a first amount of energy or force to be compressed, and the second spring element 50 requires a second amount of energy or force to be compressed. The springs serve the purpose of controlling the moment of penetration of the target tissue and the moment of deployment of the staple. Therefore, in this example, the first force level is greater than the second force level. The first spring 49 is arranged between the actuator portion 35 and the ejection portion 34, and in particular between the follower lever 47 and the actuator lever 48, while the second spring 50 is arranged between the base portion 33 and the ejection portion 34, and in particular between the handle 46 and the follower lever 47. It is to be noted that in different configurations, the purpose of the spring elements can be achieved by using tensional springs or other elastic elements when for example arranged at the opposite sides of the joint 36.

A first or staple receiving staple channel 51 (or simply a staple channel) extends through the first arm 37 and ends at the ejection end 42 into a first seat 52. The staple channel 51 is sized and shaped to hold a stack of staples 11 , and keep the staples aligned in relation to each other. Alternatively, the staple channel 51 may be sized and shaped to receive a reload cartridge (not shown) which comprises the staples. The staple channel 51 encompasses the staples in such a way that the staples can slide along the staple channel length direction SL upon operation of the stapler 30. The sliding motion is stopped by the first seat 52 that forms a stop limit for the staples. At the ejecting end 42 at the level of the first seat 52, the staple channel 51 ends in an ejection window 54 which provides an opening for the staple bodies to be ejected from the staple channel 51. As depicted, the legs 13 of the staple which is arranged in front of the ejection window 54 are directed towards the window. Hence the crown or back span 14 is directed oppositely. For the purpose of ejecting the staple 11 which is aligned with the ejection window 54 and seats at the end of the staple channel 51 , the first arm 37 comprises a staple driver 45 at a distal end of the staple channel. In this example, the staple driver 45 is a block-shaped body slidingly arranged in a pocket 56 opposite the ejection window 54. The staple driver 45 is sized and shaped to press or eject the staple 11 out of the staple channel 51 through the ejection window 54. The staple driver 45 has a staple ejection or engagement face or surface 57 and a staple blocking or support face or surface 58. As described in greater detail later, the staple blocking face 58 keeps the stack of staples in position whilst the ejection face 57 is ejecting the first staple 11a (of the stack of staples 11 a-11 j) through the ejection window 54 by pressing against the staple 11. The staple driver 45 is operated by the actuator portion 35, and more specifically by the third arm 39. The driver is coupled to the third arm 39 by a pin-in-slot connection 44.

According to the present example, the staples are made of a biocompatible bioresorbable material. However, objects of biodegradable materials are often significantly less rigid than objects made of other biocompatible materials, such as stainless steel or titanium. The intended function of the staple assembly is to connect together two layers of soft tissue 1 , such as skin or myofascial tissue layers, tendons, or parenchymal organs or mucosal structures. The concept of the stapler is suitable to improve suturing process not only in muscles and fascia as well as skin, but also it is a valuable invention to improve suturing process of tendons, parenchymal tissue (e.g. gut) and mucosal structures.

The surgical stapler may be made of long-term durable materials that withstand multiple reprocessing and cleaning steps, such as washing and sterilisation. In this case the stapler may be reloaded with staple and back span cartridges, and it may be used on different patients. According to another embodiment, the stapler including staples is delivered sterile, and it can only be used once, therefore being a single-use or disposable instrument. In this case, after usage on a patient, the stapler is to be disposed of.

In order to pre-penetrate the soft tissue layers before the staple 11 is ejected, and inhibit unwanted deformation of the staple 11 during this operation process, the first arm 37 comprises a set of penetration aids 59 or spikes 60 which are arranged around the ejection window 54. The spikes 60 and their spike tips 61 are oriented towards the second arm 38.

In the present example, the spikes 60 are partially encompassing the legs 13 of the staple

11 , and in this manner provide extra stability when the staples 11 are forced through the tissue. The spikes’ inner walls 62 form a guide throughout at least a part of the trajectory, which the staple travels when penetrating through the target soft tissue 1. In this example, the spikes have an L-profile (in a frontal view) to encompass the staple legs 13. However, alternative shapes may provide the same functionality. For example, the spikes may instead be shaped as a partial tube, having a C-profile, etc.

As described above, the staple channel 51 is intended to receive multiple staples 11 a-11j which are transferred towards the ejection window 54 for deployment one after another. For this purpose the first arm 37 comprises a first feed mechanism 63. The first feed mechanism 63 is at least partly arranged in the staple channel 51 and directly or indirectly engages with at least one of the staples 11 to transfer the staple(s) towards the ejection window 54. In this example, the first feed mechanism 63 is configured as a third spring or a first spring arrangement 64 that presses onto the top of the stack of staples. However, it is to be noted that the same effect may be achieved by pulling at the top of the staples using a feed mechanism based on an elastic band or a tensional spring.

The second arm 38 comprises a second or front span channel 65 for receiving front spans 12, and which extends through or at least partially through the second arm 38, and which ends at the reception end 43 into a second seat 66. The front span channel 65 is sized and shaped to hold a stack of front spans 12a-12j, and to keep the front spans aligned in relation to each other. Alternatively, the front span channel 65 may be sized and shaped to receive a reload cartridge (not shown) which comprises the front spans. The front span channel 65 encompasses the front spans in such a way that the front spans can slide along the front span channel 65 in the length direction FL upon operating the stapler 30.

The sliding motion is stopped by the second seat 66 that forms a stop limit for the front spans. At the reception end 43 at the level of the second seat 66, the front span channel 65 ends in a reception window 67, which forms an opening for the front spans 12 to be pierced and pulled out of the front span channel 65. As depicted, the apertures 24 of the front span

12, which are arranged in front of the reception window 67 are substantially aligned with the legs 13 of the staple 11. For the purpose of allowing the legs of the staple to penetrate through the apertures 24, the second arm 38 comprises a recess 68 opposite the reception window. The recess 68 forms a clearance for the staple legs 13. In order to withstand the penetration forces, the recess borders 69 intersect with a side seat 70 which holds the front span 12 in place. The staple channel 51 defines a first channel axis, and the front span channel 65 defines a second channel axis, and wherein in a first, open state of the stapler, the first and second channel axes have a first angle with respect to each other, while in a second, closed state of the stapler, the first and second channel axes have a second, different angle with respect to each other. More specifically, in the second state, the first and second channel axes are parallel or substantially parallel to each other.

As described, in order to pre-penetrate tissue layers before the staple is ejected, and to inhibit unwanted deformation of the staples during this process, the first arm 37 comprises a set of penetration aids 59 or spikes 60 which are arranged around the ejection window 54. The spikes or spike tips 61 are oriented towards the second arm 38. According to one example, in a closed configuration of the stapler 30, prior to ejecting the staples 11 , the spikes 60 engage against the front span 12 and hold the front span in place.

The front span channel 65 is intended to hold multiple front spans 12a-12j that are transferred towards the reception window 67 to be captured one after another. For this purpose, the second arm 38 comprises a second feed mechanism 71. The second feed mechanism 71 is at least partly arranged in the front span channel 65 and directly or indirectly engages with at least one of the front spans to transfer the front spans towards the reception window 67. In this example, the second feed mechanism 71 is configured as a fourth spring or a second spring arrangement 72 that presses onto the top of the stack of front spans. It is to be noted that the same effect may be achieved by pulling at the top of the front spans using a feed mechanism based on an elastic band or a tensional spring.

Figures 3A to 3M depict the operation of the stapler. Figures 3A to 3C show the stapler in a first or open configuration or state. In this example, the stapler 30 accommodates ten staples 11 a-11 j and ten front spans 12a-12j. The staple driver 45 is arranged in a first or start position, wherein the staple ejection face 57 is engaged or nearly engaged with the back span 14 of the first staple 11a. The first staple 11a is arranged at the distal end of the staple channel 51. At the same time, the first front span 12a is arranged at the distal end of the front span channel 65. The staple driver 45 is connected to the third arm 39, which is configured to translate the staple driver 45 towards the ejection window 54. The first spring element 49 is arranged between the actuator lever 48 and the follower lever 47, and the second spring element 50 is arranged between the follower lever 47 and the handle 46, and these spring elements press the follower lever 47, actuator lever 48 and handle 46 in a spaced or spread orientation. Hence, the first arm 37 and the second arm 38 are spaced apart, and the first and second jaws 40, 41 are open. Moreover, the staple driver 45 is forced in its start position. Figure 3C shows a situation where the jaws are being placed over the target soft tissue 1. Figures 3D and 3E show how the actuator lever 48 is being pressed towards the handle 46. The first spring element 49 maintains the distance between the actuator lever 48 and the follower lever 47. Therefore the follower lever 47 and the actuator lever 48 are urged to swivel synchronously around the joint 36. Simultaneously, the spikes 60 are urged to penetrate through the target soft tissue 1. The second spring element 50 is now being compressed. The combined tissue penetration resistance and the spring compression resistance of the second spring element 50 is smaller than the spring compression resistance of the first spring element 49.

Figures 3F and 3G show how the follower lever 47 engages with a stop face or surface 73 of the handle and/or how the spikes 60 engage with the front span 12. Upon engagement, the follower lever 47 and the actuator lever 48 form a blocked unity. Now all operation forces are transferred to the first spring element 49, and the first spring element is caused to shorten. Figures 3F and 3G show that upon shortening of the first spring element 49, the actuator lever 48 is urged to swivel further around the joint and consequently translates the staple driver 45. The translation axis is substantially orthogonal to the longitudinal axis of the first arm and/or the second arm in the second state of the stapler. The staple driver is now pressing the staple 11 forwards through the ejection window 54, and forces the staple legs 13 through the target soft tissue 1. The staple blocking face 58 forms a stop for the staple stack, and keeps the remaining staples in place. In the present example, the staple driver 45 is configured to individually come in contact with the staple 11 to be ejected, and to eject the staples one-by-one, i.e. one staple at a time, or selectively. However, the stapler may be modified so that a plurality, e.g. two staples, can be ejected simultaneously to engage with the respective front spans. For this purpose, the stapler may be able to receive two or more rows or columns of staples and front spans. Alternatively, or in addition, two or more staples may be ejected simultaneously from any given row or column of staples.

Figures 3H and 3I show how finally the staple legs are pressed into the front span 12, and the staple and the front span become engaged with each other or form a unity or become interlocked. Figures 3J and 3K show that upon releasing the actuator lever 48, the first and second spring elements 49, 50 return to their normal or rest spring length, and the stapler 30 returns to the open position. The soft tissue pulls the staple assembly 10 out of the reception window 67. The staple driver 45 has now returned to its start position, and the staple blocking face 58 is not blocking the stack of staples. The first feed mechanism 63 will advance the next staple in front of the ejection window. Similarly, the second feed mechanism 71 will advance the next front span in front of the reception window. Figures 3L and 3K show the full opening of the stapler, which now has the next staple and front span ready for deployment.

Figures 4A and 4B show one further example of the stapler. In this example, the first jaw and/or the second jaw of the stapler comprise(s) additional tissue grasping protrusions 90a, 90b, 90x, 91a, 91b, 91 x to better hold the target soft tissue 1.

To summarise, a surgical stapler assembly for closing an incision or two layers of a target tissue 1 is proposed according to one aspect of the present invention. The surgical stapler assembly comprises:

- one or more staples 11 , the respective staple comprising a back span 14 and at least two legs 13 extending away from the respective back span 14,

- one or more front spans 12, the respective front span 12 comprising at least two apertures 24 sized and shaped to receive the legs 13, a surgical stapler 30 comprising a first channel 51 for receiving the one or more staples 11 , a second channel 65 for receiving the one or more front spans 12, and a staple driver 45 configured to engage with the respective staple 11 during operation of the surgical stapler 30 to eject the respective staple 11 out of the first channel 51 , wherein the surgical stapler 30 defines an open start state, in which the stapler driver 45 is in a first position allowing the one or more staples 11 to remain in the first channel 51 , and in which the staples 11 are separated from the front spans 12 in their respective channels 51 , 65, and a closed end state, in which the staple driver 45 is in a second position, and wherein the stapler driver 45 is configured such that a transition of the staple driver 45 from the first position to the second position results in an ejection of the respective staple 11 out of the first channel 51 , and in its engagement with the respective front span 12 to form a unity.

While the invention has been illustrated and described in detail in the drawings and foregoing description, such illustration and description are to be considered illustrative or exemplary and not restrictive, the invention being not limited to the disclosed embodiments. Other embodiments and variants are understood, and can be achieved by those skilled in the art when carrying out the claimed invention, based on a study of the drawings, the disclosure and the appended claims. New embodiments or variants may be obtained by combining any of the above teachings.

The described stapler is a manually powered and operated stapling device. It must be noted that alternative actuation mechanisms and methods can achieve the same purpose. These actuation mechanisms do not need to be actuated by manually applied forces, but they may instead be motor or magnet driven mechanisms. For example, the driver could be arranged over a motorised spindle, which actuates the translational movement. Equally, the stack of staples and back spans may be actuated to translate by means of a motor. An example translation mechanism may be a conveyor belt. According to a further variant of the present invention, the stapler may comprise an arm including a set of adjacently arranged or connected arms allowing multiple staples arranged parallel to each other to be to ejected at the same time to reduce surgery time. Moreover parallel ejected staples would allow a longer incision length to be closed by using similarly sized instruments.

In the claims, the word “comprising” or “including” does not exclude other elements or steps, and the indefinite article “a” or “an” does not exclude a plurality. The mere fact that different features are recited in mutually different dependent claims does not indicate that a combination of these features cannot be advantageously used. Any reference signs in the claims should not be construed as limiting the scope of the invention.

Claims

1. A surgical stapler (30) for a surgical stable assembly for closing an incision or two layers of a target tissue (1), the surgical stapler (30) comprising:

- a first arm (37) comprising a first channel (51 ) for receiving one or more staples (11 );

- a second arm (38) comprising a second channel (65) for receiving one or more staple front spans (12);

- a staple driver (45) configured to engage with the respective staple (11 ) during operation of the surgical stapler (30) to eject the respective staple (11) out of the first channel (51), wherein the surgical stapler (30) defines an open start state, in which the staple driver (45) is in a first position allowing the one or more staples (11) to remain in the first channel (51), and in which the staples (11) are separated from the front spans (12) in their respective channels (51 , 65), and a closed end state, in which the staple driver (45) is in a second position, and wherein the staple driver (45) is configured such that a transition of the staple driver (45) from the first position to the second position results in an ejection of the respective staple (11 ) out of the first channel (51 ), and in its engagement with the respective front span (12).

2. The surgical stapler (30) according to claim 1 , wherein the first channel (51 ) defines a first channel axis, and the second channel (65) defines a second channel axis, and wherein in the open start state, the first and second channel axes have a first angle with respect to each other, while in the closed end state, the first and second channel axes have a second, different angle with respect to each other.

3. The surgical stapler (30) according to claim 2, wherein in the closed end state, the first and second channel axes are parallel or substantially parallel to each other.

4. The surgical stapler (30) according to any one of the preceding claims, wherein the staple driver (45) is arranged at a distal end of the first arm (37).

5. The surgical stapler (30) according to any one of the preceding claims, wherein the first and second arms (37, 38) are configured to pivot around a common pivot axis during operation of the surgical stapler (30).

6. The surgical stapler (30) according to any one of the preceding claims, wherein the first, second and third arms (37, 38, 39) are configured to pivot around a common pivot axis during operation of the surgical stapler (30).

7. The surgical stapler (30) according to any one of the preceding claims, wherein the staple driver (45) is configured to translate along a translation axis, which is substantially orthogonal to a first longitudinal axis defined by the first arm (37) and/or a second longitudinal axis defined by the second arm (38) in the closed end state of the surgical stapler (30).

8. The surgical stapler (30) according to any one of the preceding claims, wherein the staple driver (45) is configured to individually come in contact with the staple (11 ) to be ejected.

9. The surgical stapler (30) according to any one of the preceding claims, wherein the staple driver (45) comprises an ejection surface (57) configured to come in contact with the staple (11 ) to be ejected, and a support surface (58) configured to support another staple (11 ) in the first channel (51 ).

10. The surgical stapler (30) according to any one of the preceding claims, wherein at least two of the first, second and third arms (37, 38, 39) are pivotable arms.

11. The surgical stapler (30) according to any one of the preceding claims, wherein the first arm (37) is part of a first substantially L-shaped element, the second arm (38) is part of a second substantially L-shaped element, and the third arm (39) is part of a third substantially L-shaped element.

12. The surgical stapler (30) according to any one of the preceding claims, wherein a set of penetration aids (59) is provided at a distal end of the first arm (37) for tissue penetration prior to the ejection of the respective staple (11 ).

13. The surgical stapler (30) according to claim 12, wherein the penetration aids (59) are configured as spikes (60).

14. The surgical stapler (30) according to claim 12 or 13, wherein the penetration aids (59) comprise guide surfaces to guide the staples (11 ) through the target tissue (1 ) during their ejection.

15. The surgical stapler (30) according to any one of the preceding claims, wherein the staple driver (45) is configured to drive the respective staple (11), one by one, through the target tissue (1) into the apertures (24) of the respective front span (12).

16. The surgical stapler (30) according to any one of the preceding claims, wherein the surgical stapler (30) is a single-use stapler.

17. The surgical stapler (30) according to any one of the preceding claims, wherein the first arm (37) comprises an ejection window (54), and the second arm (38) comprises a reception window (67), and wherein the surgical stapler (30) comprises at least one feed mechanism (49, 50) configured to transfer the staples (11) to the ejection window (54) and/or the front spans (12) to the reception window (67).

18. The surgical stapler (30) according to claim 17, wherein the at least one feed mechanism (49, 50) is configured as a spring element (49, 50).

19. The surgical stapler (30) according to any one of the preceding claims, wherein the surgical stapler (30) comprises one or more reload cartridges holding the staples (11) and/or the front spans (12).

20. The surgical stapler (30) according to any one of the preceding claims, wherein the surgical stapler (30) further comprises a third arm (39), and wherein the staple driver (45) is coupled to the first arm (37) and/or the third arm (39).

21. The surgical stapler (30) according to any one of the preceding claims, wherein the staple driver (45) is coupled to the first and third arms (37, 39) by a pin-in-slot coupling.

22. A surgical stapler assembly comprising the surgical stapler (30) according to any one of the preceding claims, and further comprising one or more staple assemblies each comprising a staple (11 ) and a front span (12).

23. The surgical stapler assembly according to claim 21 , wherein the respective staple (11) comprises a back span (14), and at least a first leg (13) configured to be received in a first aperture (24) in the front span (12), a second leg (13) configured to be received in a second aperture (24) in the front span (12), a third leg (13) configured to be received in a third aperture (24) in the front span (12) and a fourth leg (13) configured to be received in a fourth aperture (24) in the front span (12), and wherein the first, second, third and fourth legs (13) extend away from the back span (14).