Device for connecting body tissues

Description

[0001] The present invention relates to a device for connecting body tissues, comprising a head part which can be inserted into a body opening and has a longitudinal axis, wherein a plurality of tissue clamps are accommodated in a storage position in the head part, which consist of a linear main section and two engagement sections projecting perpendicularly therefrom and which are each aligned in a first plane which is substantially perpendicular to the longitudinal axis.

[0002] It is known in medicine to close wounds using tissue staples that are inserted into the skin near the wound edges and then deformed to hold the wound edges together. Devices generally called staplers have been developed to perform this process. Such devices are described, for example, in US Pat. No. 5,170,926 A, EP 1 695 668 A, or EP 0 354 724 B. Typically, several tissue staples are stacked in a magazine, similar to paper clips. Before use, the foremost tissue staple is rotated into a position where it can be advanced and inserted into the skin. Other devices of this type are known from WO2009 / 135005 A1, US Pat. No. 5,564,615 A, DE 36 89 806 T2, and EP 0 085 931 A2.

[0003] The present invention relates to devices suitable for connecting sections of body tissue in the manner described above, with the difference that the device is sufficiently small and compact to be inserted into artificial or natural body openings in order to connect body tissue inside the body. It is therefore intended for use in endoscopic or laparoscopic procedures. The particular requirement is therefore to design the device with the smallest possible cross-section, to reliably apply the required actuating forces, and to ensure high reliability, since direct visual and tactile control is not possible with this type of application.

[0004] Various devices for connecting body tissues inside the body have become known. However, these devices are complex to use and often only suitable for specific applications.

[0005] The object of the present invention is to provide a simple and easily applicable device with which it is possible to connect body tissue inside the body.

[0006] According to the invention, it is provided that a hydraulic cylinder and / or a piston rod are arranged at least partially inside the space which lies between the engagement sections of the tissue clamps in the storage position, and that the piston rod is firmly connected to the slide.

[0007] The key feature is the hydraulic drive via a hydraulic cylinder, which allows the required force to be applied regardless of the distance to an operating element. Since the fabric clamps partially surround the hydraulic cylinder or piston rod in the storage position, significant space savings are achieved.

[0008] In particular, the device can be designed to be particularly compact because the hydraulic cylinder is double-acting.

[0009] According to the invention, two rotor elements are provided which are pivotable about an axis parallel to the main sections of the tissue clamps and which each have a support surface for an engagement section of a tissue clamp in order to rotate the latter from the storage position into a working position in which the tissue clamp is arranged in a further plane which is oriented substantially perpendicular to the first plane, and a slider is provided in order to advance the tissue clamp in the working position in the further plane and to deform it into a clamping position.

[0010] It is an important aspect of the present invention that the individual tissue staples are actively rotated by rotor elements from the plane in which they are stacked in the magazine (storage position) to the plane in which they are advanced to penetrate the body tissue (working position).

[0011] The rotation takes place around an axis that is perpendicular to the longitudinal axis of the device and to the feed direction of the tissue staples.

[0012] Another important aspect of the present invention is that a slider performs both the task of advancing a tissue staple and the task of deforming it after it has penetrated the body tissue to create a secure connection. This allows the number of required components to be kept to a minimum, allowing the device to be designed to be particularly compact.

[0013] It is advantageous if a rotor spring engages each rotor element to lock its movement into two rotational positions, and preferably if the rotor elements are connected to a shaft. This makes it possible to design the drive of the rotor elements simply and with sufficient tolerances, since the precise angular position of the rotor elements in the critical positions, namely the pick-up and release of the tissue staples, is ensured by the locking mechanism.

[0014] A particularly elegant way of ensuring the advancement of the tissue staples in the magazine and the necessary contact force on the rotor elements is that the tissue staples are pre-tensioned against the rotor element in the storage position by at least one storage spring via a storage carriage, whereby the storage spring is preferably attached to the shaft of the rotor elements. The storage spring is a leaf spring that is pre-tensioned in the wound position. It always strives to shorten the linear section parallel to the magazine and to wind itself around the shaft. The particular advantage of this solution is that the force applied to the storage carriage is independent of the position of the storage carriage, i.e. it remains essentially the same from the first to the last tissue staple.

[0015] A particularly high degree of compactness can be achieved by driving the rotor elements by at least one connecting rod that is hinged to them and is preferably connected to the slide via a connecting slide. This makes it possible to drive both the slide and the rotor elements with a single drive element, thus eliminating the additional effort required for any synchronization of different drive elements.

[0016] In this context, it is particularly advantageous if the rotor elements are each driven by a connecting rod and are preferably connected to the slide via a connecting slide. This ensures symmetrical force transmission.

[0017] An optimal sequence of the individual movements is achieved in particular by the fact that the connecting slide(s) are firmly connected to the slide and that an elongated hole is arranged on each connecting slide into which a pin of the connecting rod engages.

[0018] The elongated hole ensures that, in the first phase of the forward movement, only the slide is advanced, while the connecting rod pin slides backward in the elongated hole of the connecting slide, so that the connecting rod and thus the rotor elements are not moved. This phase ends when the pin reaches the rear end of the elongated hole. In a second phase of the forward movement, the connecting slide now carries the connecting rod with it, thus causing the rotor elements to rotate.

[0019] During the reverse movement, similarly, only the slider initially moves, while the pin of the connecting slider slides forward in the slotted hole, so that the connecting rod and rotor elements do not move. Only when the pin rests against the front end of the slotted hole is the connecting rod driven along, and the rotor elements are rotated backward.

[0020] A particularly preferred embodiment of the present invention provides that a slider is arranged on the side of the main sections of the tissue staples facing away from the engagement sections so as to be movable in the direction of the longitudinal axis, which slider has two lateral advance areas on its front end face, between which an essentially rectangular recess is provided, and that a retaining element is provided which engages in the recess of the slider in order to deform the linear main section of an intermediate tissue staple when the slider is advanced.

[0021] An important aspect of the present invention is that the slider accomplishes both the advancement of the tissue staples and their deformation in a single movement. Advantageously, the force exerted on the respective tissue staple during advancement is exerted directly in the area of ​​the engagement elements, so that these can be advanced against the resistance of the body tissue without initially causing deformation of the tissue staple. Only when the tissue staple has penetrated sufficiently deeply into the body tissue does the central portion of the main section of the tissue staple come into contact with the retaining element, so that the tissue staple is bent around the edges of the retaining element.

[0022] After the tissue staple has been properly inserted into the body tissue, safe removal from the device according to the invention must be ensured. According to a preferred embodiment of the present invention, this is achieved by arranging an ejection spring to strip a deformed tissue staple from the retaining element. A particular advantage of this solution is that the stripping of the tissue staple occurs fully automatically, without requiring any special control effort.

[0023] Stripping is achieved particularly easily by the ejection spring extending into the slider's range of motion when force is not applied. By advancing the slider, the ejection spring is preloaded, and by retracting the slider, the spring is released, allowing the tissue staple to be stripped away.

[0024] A particularly secure guidance of the tissue staple can be achieved by providing a nose on the slider, which supports the tissue staple to be advanced against the pretension of the ejection spring.

[0025] An optimal configuration of the tissue staple in the applied state is achieved by the recess being essentially rectangular.

[0026] A particularly compact and space-saving design of the device according to the invention can be achieved by having a plate-shaped slider and a plane of movement that lies in the region of the tips of the engaging portions of the tissue staples in the storage position, and particularly preferably substantially parallel to and at a constant distance from the main portions of the tissue staples in the storage position. This allows the slider and other components that drive the slider to utilize the space created by the tissue staples present in the magazine in the storage position.

[0027] A particularly efficient operation of the device is achieved in that the slider has a front position and a rear position, wherein in the front position a deformed tissue clamp is clamped between the slider and the retaining element, and in the rear position a tissue clamp rotated from the storage position into a working position perpendicular to it can be received.

[0028] A particularly advantageous embodiment of the invention provides at least one channel for receiving a holding instrument. Such known holding instruments can be advantageously used to hold tissue in place or to manipulate its position in order to optimally insert the tissue clamps.

[0029] Preferably, two channels are provided, which preferably diverge slightly toward the front, with the angle between the channels particularly preferably being controllable. This allows for appropriately approaching distant tissue.

[0030] In particular, the manipulation of body tissue can be made particularly flexible if the holding instruments can be controlled independently of each other.

[0031] A particularly compact construction of the device according to the invention can be achieved in particular in that the channel is preferably arranged adjacent to the hydraulic cylinder and / or in that the channel is arranged between the side parts.

[0032] It is particularly advantageous if the channel is located in the proximal area of ​​the head. This leaves space below the tissue staples in their storage position, allowing the holding instruments to be advanced laterally from the divergent channels, even outside the cross-section of the device, in order to grasp lateral areas of the body tissue and pull them into the area of ​​the tissue staples.

[0033] In the following, exemplary embodiments of the present invention are explained in more detail with reference to the accompanying figures. They show: Fig. 1 shows a first embodiment of a device according to the invention in a view from below; Fig. 2 shows the device of Fig. 1 in a side view; Fig. 3 the device of Fig. 1 and Fig. 2 in a view from above; Fig. 4 the device of Fig. 1 to Fig. 3 in a front view; Fig. 5 the device of Fig. 1 to Fig. 4 in an exploded view; Fig. 6bis Fig. 9Longitudinal sections at different stages of movement to explain the function of the device; Fig. 10 and Fig. 11 different oblique views of a first embodiment of the rotor element; Fig. 12 and Fig. 13 different oblique views of a second embodiment of the rotor element; Fig. 14 a further embodiment of a device according to the invention in a longitudinal section; Fig. 15 and Fig. 16 two alternative applications of the device, each in an oblique view; Fig. 17 and Fig. 18 each a longitudinal section of a further embodiment of the invention in two different positions; and Fig. 19 a cross section through the embodiment of Fig. 17 and Fig. 18 , Fig. 20a view of the variant of Fig. 17 to Fig. 19 from underneath.

[0034] The Fig. 1 to Fig. 5show the head part 100 of a device according to the invention, which comprises a tissue clamp 1 with a linear main section 2 and two parallel engagement sections 3 projecting vertically therefrom (visible in Fig. 5 ) and deform.

[0035] The device comprises a support element 4, on which two side parts 5, a hydraulic cylinder 6 with a piston rod 10 and a retaining element 22 are arranged. Tissue clamps 1 with their engagement sections 3 are located on the support element 4 in a storage position 7, which in Fig. 2 is partially shown.

[0036] The side parts 5 each have a recess 39, the main part of which is rectangular and is intended to accommodate the engaging sections 3 of the tissue clips 1 in the storage position 7 and to guide them at the top and bottom. Furthermore, the respective rotor element 9 is accommodated in the recess 39.

[0037] In the storage position 7, the tissue clamps 1 lie essentially in a stack, with the planes 7a, in which the main section 2 and the engagement sections 3 are located, being parallel to one another. Furthermore, the planes 7a lie essentially perpendicular to the axis 6a of the hydraulic cylinder 6, which simultaneously also represents the longitudinal axis of the device. This allows the tissue clamps 1 to be arranged in the storage position 7 such that the hydraulic cylinder 6 or the piston rod 10 can be located at least partially in the space formed between the engagement sections 3 of the tissue clamps 1 in the storage position 7. This enables a very compact and space-saving design.

[0038] The tissue clamps 1 in the storage position 7 are pressed by a storage carriage 8 against two rotor elements 9, which are connected to a shaft 12. The necessary preload is generated by two storage springs 11. These are designed as unwound spiral springs, with one end attached to the shaft 12 and the other end to the storage carriage 8.

[0039] Each of the two rotor elements 9 is rotatably mounted and has a support surface 13 with a support lug 16 for an engagement portion 3 of a tissue clamp 1 and a recess 14. A rotor spring 15 can engage in the recess 14 to enable locking and to define the positions of the rotor elements 9. The rotor spring 15 is designed as an extension of the side part 5.

[0040] A slide 17 is attached to the piston rod 10 and has two feed areas 19 with lugs 18. Between the feed areas 19 is a central, rectangular recess 20. The slide 17 can be moved along the longitudinal axis 6a via the hydraulic cylinder 6.

[0041] In a first orientation of the rotor elements 9, the support surfaces 13 point in the direction of the tissue clamps 1 in the storage position 7. The storage carriage 8 presses a first tissue clamp 1 against the support surfaces 13. The rotor elements 9 can now be rotated by approximately 90°. The supported tissue clamp 1 is rotated by the support lugs 16 to reach a working position 29, in which it is arranged in a further plane 29a that is parallel to the longitudinal axis 6a. During the first part of the rotation, the first tissue clamp 1 is pressed against the support surfaces 13 by the storage carriage 8; during the second part of the rotation, the surface pressure is maintained by the rotor spring 15 to hold the first tissue clamp 1 in a defined position. The hydraulic cylinder 6 is in a retracted position at this time, and the slide 17 is therefore located behind the main section 2 of the first tissue clamp 1.

[0042] The hydraulic cylinder 6 can now be extended. The slide 17 carries the first tissue clamp 1 with it. The position on the slide 17 is secured by an ejector spring 21 pressing the first tissue clamp 1 against the nose 18. At the same time, the ejector springs 21 are increasingly pretensioned by the advance.

[0043] The first tissue clamp 1 is now pressed against the retaining element 22, which is centrally positioned and adapted to the width of the recess 20 of the slider 17. This deforms the first tissue clamp 1 into a rectangle at the main section 2.

[0044] When the hydraulic cylinder 6 is subsequently retracted, the preload of the ejection spring 21 is transferred to the first fabric clamp 1 and thus stripped off the retaining element 22.

[0045] The rotation of the rotor elements 9 is achieved via a connecting rod 23 connected to each of them, which has a first pin 30 that engages in an eccentric bore 31 of the respective rotor element 9. Each connecting slide 24 connected to the slide 17 has an elongated hole 25 into which a second pin 26 of the connecting rod 23 engages. The connection in an elongated hole 25 ensures that the rotation of the rotor elements 9 occurs in a second phase of the movement of the slide 17.

[0046] The other components of the device according to the invention are briefly explained below: Cover plates 32 are mounted laterally outside the side parts 5 to cover their recesses 33. The piston rod 10 is sealed by seals 34 from the hydraulic cylinder 6, which is attached to the support element 4 via mounting elements 35. Hydraulic connections 36 and 37 serve to supply the hydraulic medium to control the device. 38 denotes a mounting clamp.

[0047] To illustrate the working process of the device, the Fig. 6 to 9 the same longitudinal section is shown in different positions of the hydraulic cylinder 6.

[0048] Fig. 6shows the initial state with hydraulic cylinder 6 and fully extended piston rod 10. The pin 26 is located in the extension-side stop 27 of the elongated hole 25, and the support surface 13 of the rotor elements 9 is parallel to the longitudinal axis 6a. The slide 17 is in the fully extended position, in which a tissue staple 1 (not shown here) has just been ejected.

[0049] Starting from this position, the piston rod 10 is retracted, the slide 17 moves to the right in the illustration, and the connecting slide 24 connected to it also moves with it. In the first part of the extension process, no movement is transmitted to the connecting rod 23, since the pin 26 moves in the direction of the retraction-side stop 28 of the elongated hole 25 of the connecting slide 24. After approximately half the stroke, the retraction-side stop 28 is reached, and the connecting rod 23 is now moved along with the slide 17 and the connecting slide 24. As a result, the rotor elements 9 are rotated by approximately a right angle, so that a first tissue staple 1, which rests on the support surface 13 in the storage position, is moved from a Fig. 6vertical position into a horizontal position in which it lies in the plane of the slider 17. The tissue clamp 1 resting on the support surfaces 13 is carried along by the support lugs 16 of the rotor elements 9. Since the slider 17 has already retracted behind the rotor elements 9 at this time, the movement path for the tissue clamp 1 is free.

[0050] The position thus achieved with the piston rod 10 fully retracted is in Fig. 7 Now the piston rod 10 can be extended again from the hydraulic cylinder 6. The slide 17 with the connecting slides 24 move again towards the position of the Fig. 6 . Initially, no movement is transferred to the connecting rods 23, since the pin 26 in the slot 25 is pushed in the direction of the extension-side stop 27. Once the extension-side stop 27 is reached, which is Fig. 8As shown, the connecting rods 23 move with the piston rod 10, whereby the rotor elements 9 return to the position of Fig. 6 be turned back, which is the one in the Fig. 10 During the extension movement of the piston rod 10, which is Fig. 7 goes out and in Fig. 9 ends, the slider 17 is advanced to finally reach the phase between Fig. 6 and Fig. 7 to deform and eject the inserted tissue staple 1. The rotor elements 9 are arranged in the Fig. 9 shown position again to accommodate another tissue staple 1.

[0051] When the slider 17 is advanced, the ejector springs 21 are pretensioned via the tissue clamp 1 in the working position 29, with the lugs 18 on the slider 17 supporting the tissue clamp 1 at the bottom in the working position 29, so that the tissue clamp 1 is guided on both sides. When the slider 17 is retracted, the support of the tissue clamp 1 from below is removed, so that the ejector springs 21 press it downward and strip it from the retaining element 22.

[0052] The working cycle can be stopped after reaching the Fig. 9 start again in the position shown.

[0053] In the Fig. 10 to Fig. 13 Two different design variants of a rotor element 9 are shown. The first design variant, which is shown in the Fig. 10 and Fig. 11 shown corresponds to the version of the Fig. 1 to Fig. 9 used and illustrated rotor element 9.

[0054] This first embodiment has a support surface 13 that forms part of a circular segment with respect to the circumference 43. A nose 13a is provided at one end to entrain the tissue clamp 1, which in its storage position rests with its engagement portion 3 against the support surface 13, during the rotation of the rotor element 9. The support surface 13 does not extend over the entire thickness of the rotor element 9. A web 40 remains on one side, which laterally guides the engagement portion 3 of the adjacent tissue clamp 1. A first recess 41 is provided in the area of ​​this web 40, and a second recess 14 is formed in the circumference 43 at right angles to it, as seen from the center of the rotor element 9. The two recesses 41, 14 serve to engage the rotor spring 15 and determine the end positions for the rotation of the rotor element 9. The eccentric bore 31 is used for rotation by the connecting rod 23.The bore 42 is intended for insertion onto the shaft 12.

[0055] In the alternative design variant, which is described in the Fig. 12 and Fig. 13 As shown, the support surface 13 extends over the entire thickness of the circumference 43. The lateral guidance is provided by the cover plates 32. In addition to the support surface 13, a further contact surface 44 is provided on the circumference, preferably at right angles thereto, against which the tissue staples 1 rest in the storage position 7 when the support surface 13 is rotated into the ejection position (parallel to the longitudinal axis 6a). In this embodiment, the engagement sections 3 of the tissue staples 1 resting against the support surface 13 or the contact surface 44 and pressed against by the storage springs 11 define the end positions of the rotation of the rotor element 9. Recesses are therefore not required here.

[0056] Fig. 14shows a longitudinal section of an embodiment of the device according to the invention using the rotor elements 9 of the Fig. 12 and Fig. 13 This variant largely corresponds to the one in the Fig. 1 to Fig. 9 illustrated embodiment. It can be seen that the engagement section 3 of a first tissue staple 1 on the support surface 13 is already in the working position 29. A further tissue staple 1 rests with its engagement section 3 against the further support surface 44 and is pressed by the supply slide 8, so that the rotor element 9 is resiliently fixed in this position. After the first tissue staple 1 has been ejected, the rotor element 9 is rotated back clockwise, whereby, however, the supply slide 8 together with the tissue staples 1 located in the supply position 7 must first be pushed back against the resistance of the supply springs 11.

[0057] Out of Fig. 14It is also apparent that the engaging portions 3 of the tissue clamps 1 in the storage position 7 (a tissue clamp 1 is shown accordingly with broken lines) extend upwards significantly beyond the lower region of the piston rod 10, which means that the piston rod 10 in the extended position moves within the rectangular space which is spanned on three sides by the main portion 2 and the two engaging portions 3 of the tissue clamp 1.

[0058] In Fig. 15 A first variant of the use of a device according to the invention is shown. The head part 100 is removably mounted on a conventional endoscope 101 with a bend 102 and is controlled via hydraulic hoses 103 and 104, which are inserted into a body opening parallel to the endoscope.

[0059] Fig. 16shows an alternative variant of the use of the device according to the invention, in which the head part 100 forms the tip of an independent flexible instrument 105. According to the usual design, this has at least one channel through which an endoscope 107 can be inserted with a bend 102. The endoscope 107 is laterally extended with a separate bend 106 to allow observation of the clamping process.

[0060] The version of the Fig. 17 and Fig. 18differs from the variants described above in that two channels 50, 51 are provided below the hydraulic cylinder 6. The channels 50, 51 are directed outward toward the distal end, i.e., divergent, with the angle of divergence preferably being adjustable. When holding instruments are advanced through the channels 50 and 51, they emerge slightly outward, with the variable extent thus further increasing due to the distance to the tip, i.e., the space below the tissue staples 1 in their storage position 7.

[0061] Due to the special design of the device, it is possible to arrange the channels 50 and 51 within the circular cross-section defined by the other components.

[0062] The present invention makes it possible to connect tissue inside the body with tissue staples, wherein it is particularly advantageous that a plurality of tissue staples can be applied one after the other without the need to withdraw the device from the patient's body and then reinsert it.

Claims

1. Device for connecting body tissues, having a head part (100), which can be pushed into a body opening and has a longitudinal axis (6a), wherein a plurality of tissue staples (1) are accommodated in the head part (100) in a storage position (7), which tissue staples consist of a linear main section (2) and two engagement sections (3) projecting perpendicularly therefrom and are each aligned in a first plane (7a) which is substantially perpendicular to the longitudinal axis (6a), and having a hydraulic cylinder (6) and a cylinder rod (10) which is fixedly connected to a slider (17), characterised in that the hydraulic cylinder (6) and / or the cylinder rod (10) are arranged at least partially inside the space which lies between the engagement sections (3) of the tissue staples (1) in the storage position (7), and in that two rotor elements (9) are provided, which are pivotable about an axis parallel to the main sections (2) of the tissue staples (2) and which each have a bearing surface (13) for an engagement section (3) of a tissue staple (1) in order to rotate the said tissue staple from the storage position (7) into a working position (29), in which the tissue staple (1) is arranged in a further plane (29a), which is oriented substantially perpendicularly to the first plane (7a), and in that a slider (7) is provided in order to advance the tissue staple (1) which is present in the working position (29) in the further plane (29a) and to deform it into a clamping position.

2. Device according to claim 1, characterised in that the hydraulic cylinder is of double-acting design.

3. Device according to one of claims 1 to 2, characterised in that a rotor spring (15) engages in each case on a rotor element (9) in order to carry out its movement in two rotational positions so as to be latchable, and in that the rotor elements (9) are preferably connected to one another by means of a shaft (12).

4. Device according to one of claims 1 to 3, characterised in that the rotor elements (9) are driven by at least one connecting rod (23) which is articulated to them and which is preferably connected to the slider (17) via a connecting slider (24).

5. Device according to claim 4, characterised in that the connecting slider or sliders (24) is or are firmly connected to the slider (17), and in that an elongated hole (25) is arranged on each connecting slider (24), in each of which a pin (26) of the connecting rod (23) engages.

6. Device according to one of claims 1 to 5, characterised in that the tissue staples (1) are guided, in the storage position (7), in recesses (39) of side parts (5).

7. Device according to one of claims 1 to 6, characterised in that the slider (17) is arranged on the side of the main sections (2) of the tissue staples (1) facing away from the engagement sections (3) so as to be movable in the direction of the longitudinal axis (6a), said slider having two lateral feed regions (19) on its front end face, between which a recess (20) is provided, and in that a retaining element (22) is provided which engages in the recess (20) of the slider (17) in order to deform the linear main section (2) of an interposed tissue staple (1) when the slider (17) is advanced.

8. Device according to one of the claims 1 to 7, characterised in that the slider (17) is plate-shaped and the range of movement of the slider (17) lies in a further plane (29a) which lies in the storage position (7) in the region of the tips of the engagement sections (3) of the tissue staples (1) and lies particularly preferably substantially parallel and at a constant distance from the main sections (2) of the tissue staples (1) in the storage position (7).

9. Device according to one of the claims 1 to 8, characterised in that the slider (17) has a front position and a rear position, wherein a deformed tissue staple (1) is clamped between the slider (17) and the retaining element (22) in the front position, and a tissue staple (1) turned from the storage position (7) into a working position (29) disposed perpendicular thereto is receivable in the rear position.

10. Device according to one of claims 1 to 9, characterised in that the head part (100) is designed as an attachment to an endoscope (101) or is integrally connected to a flexible instrument (105) which preferably has a channel for an endoscope (107).

11. Device according to one of claims 1 to 10, characterised in that at least one channel (50, 51) is provided for receiving a holding instrument.

12. Device according to claim 12, characterised in that two channels (50, 51) are provided which preferably diverge slightly towards the front, wherein the angle between the channels (50, 51) is particularly preferably controllable.

13. Device according to one of claims 11 or 12, characterised in that the holding instruments are controllable independently of one another.

14. Device according to one of claims 11 to 13, characterised in that the channel (50, 51) is arranged adjacent to the hydraulic cylinder (6), and / or between the side parts (5), and / or in the proximal region of the head part (100).