Penetration element

Abstract

A penetration element for penetrating a vessel wall (7) of a blood vessel comprises a pin (20), a first locking piece (23) and a second locking piece (24), at least the first locking piece (23) being designed as a pin securing means.

Description

The invention relates to a penetration element for penetrating a vessel wall of a blood vessel and an implant. Dissection of the ascending aorta (Type A dissection) is a life-threatening condition that requires immediate surgery. In the case of an acute Type A dissection, the primary goal of surgical treatment is to restore blood circulation and to avoid or eliminate life-threatening complications such as aortic rupture, pericardial tamponade, and myocardial ischemia. The further goal of surgical therapy is, if possible, the resection of the tear in the tunica intima (the entry point into the false lumen) in the proximal aorta to ensure perfusion of the true lumen and thus of the organs. The classic surgical treatment of acute Type A dissection involves replacing the ascending aorta with a vascular prosthesis in the form of a tubular prosthesis, with the distal anastomosis performed using the "open" technique and under hypothermic circulatory arrest at a core body temperature of approximately 25 °C. Surgical access is achieved via a median sternotomy. With the use of the heart-lung machine and cooling of the patient, circulatory arrest is initiated in the Trendelenburg position, and the ascending aorta can be opened. The true lumen is identified, and the ascending aorta is resected down to its distal portion, so that the distal ascending aorta is visible like an open tube. Now, in the currently standard surgical procedure, the dissected or delaminated parts of the aortic wall (tunica intima, tunica media and tunica adventitia) are sutured together using the so-called "sandwich" technique. This is done by inserting an inner implant part, for example a felt strip, i.e., a strip of textile material, circularly or radially inside the aorta and placing it against the aortic wall, and by placing an outer implant part, for example a felt strip, around the outside of the aorta, also circularly or radially, against the vessel. Then, by hand, a continuous meandering suture is made using polypropylene suture material, or individual sutures are placed to suture these two felt strips together with the aortic wall between them (sandwich). This step of the operation takes about 25 minutes, but depending on the surgeon's experience, it can also be ten minutes faster or slower. Subsequently, in a second step, a tubular prosthesis is now manually sutured end-to-end to this sandwich stump, the fixation site, using a polypropylene suture. After an appropriate deflation maneuver, an aortic clamp can now be placed on the now sutured prosthesis, and the circulatory arrest is considered to have been reversed. The most critical phase of the operation is thus usually completed. A sandwich of the native aorta is then also performed supracoronarily at the proximal end near the heart using the same technique described above. The proximal end of the prosthesis is then sutured end-to-end to this sandwich (fixation site), as described above. It is obvious that in such a major operation, in which the normal blood circulation is interrupted and the body and brain are greatly cooled, the time factor is of immense importance in order to optimize the patient's chances of survival and recovery. Above all, the procedure described above for treating the dissection by applying the sandwich suture is highly dependent on the individual circumstances of the patient in question, the extent of the dissection of the vessel wall and, last but not least, to a significant extent on the skill of the surgeon. Therefore, devices have already been developed to simplify and accelerate the attachment of the implant, in particular by replacing the time-consuming step of placing the polypropylene suture in the form of a continuous, meandering suture with the mechanical insertion of penetration elements, such as staples. For this purpose, devices or applicators have been created that push the penetration elements out of a carrier element and thereby drive them through the implant and the vessel wall, with the implant generally consisting of an inner and an outer implant part, for example in the form of felt strips or in the form of tubes made of textile material with a relatively short longitudinal extension. For example, WO 2022 / 130274 A1 discloses a device in which a plurality of penetration elements are mounted in radially outwardly directed guides and are drivable radially outward on supports for the penetration elements. Theoretically, this device or applicator for the penetration element offers the possibility of placing all the penetration elements necessary for securing the implant in a single step. However, when using this applicator, there is a concern that, when such a large number of penetration elements are placed simultaneously, one or more of the penetration elements may not be placed properly. In view of the extremely critical situation when treating the severed aorta, this represents a risk that is hardly acceptable, since in this case the inadequately placed penetration elements would have to be at least partially removed, and it is practically inconceivable that the operation could still be brought to a positive conclusion in time in this case. This is further complicated by the fact that the penetration elements are basically designed like staples and therefore, after penetration, two ends protruding from the aortic wall and the outer implant part of the implant must be properly bent over. The susceptibility to error is therefore also increased with regard to the penetration elements, and the applicator, with its many individual parts and delicate structures, is also to be regarded as critical if an absolutely perfect result must be achieved and a correction of the initial result does not seem feasible. It is therefore the object of the present invention to provide a penetration element that can be placed more reliably than those of the prior art. To achieve this object, the penetration element according to the invention comprises a pin, a first locking piece and a second locking piece, and is characterized according to the invention in that at least the first locking piece is designed as a shaft retaining element. A "shaft retaining element" in the sense of the present invention is understood to be a mechanical element that is designed to prevent or limit axial movement of the pin relative to the locking piece in a direction opposite the direction of penetration. The shaft retaining element may comprise, for example, protrusions, elastically deformable elements, or other mechanical structures that prevent the pin from sliding back after penetrating the vessel wall and / or the implant, thus ensuring secure fixation. In particular, the shaft retaining element may have one or more radially protruding structures that form an abutment for the pin. Preferably, the locking member has at least one element that can be deflected in the penetration direction when the pin is inserted. In the event of an attempt to retract the pin in the opposite direction, the element interacts with the pin in a form-fitting and / or friction-fitting manner, thereby preventing the pin from being retracted. The second locking piece is also preferably designed as a shaft retaining element. The penetration element according to the invention thus consists of three separate parts. These are the pin and the two locking pieces, which allows tissue and implant to be connected largely independently of their thickness, since the pin can be selected independently of the locking pieces with a length corresponding to the required thickness. The first and second locking pieces are penetratable by the pin, and at least the first locking piece is designed to secure the position of the pin in the penetrated state in the radial direction and, if necessary, in the axial direction. The penetration element according to the invention is used to penetrate a vessel wall of a blood vessel and an implant to attach the implant as a fixation site for a vascular prosthesis to the vessel wall or to penetrate a vessel wall and a vascular prosthesis to directly fix the vascular prosthesis to the vessel wall. Because the pin is a separate part and thus a part of the penetration element according to the invention that is designed separately from the two locking pieces, the pin can be hidden in its full length in a corresponding applicator before placement, which brings with it a number of advantages. On the one hand, the complete containment of the pin in the applicator eliminates the risk of injury when the penetration element approaches the surgical site, since the pin only extends with its tip out of the corresponding applicator when the penetration element is placed. In addition, the pin cannot be lost in the surgical field. When the penetration element is placed, the pin is driven through the two locking pieces, so that the pin is initially optimally guided by the second locking piece when penetrating the vessel wall and the implant and therefore does not tend to bend. In this way, the pin penetrates the vessel wall and the implant in an extremely straight line and can subsequently be reliably received and secured by the first locking piece. The invention may preferably be further developed in such a way that the pin forms a support for an expulsion element at a proximal end. The support is designed with a larger diameter than the rest of the pin and provides a secure support for an expulsion element of a corresponding applicator for piercing the pin through the implant and the vessel in order to drive the pin distally. In order to optimize the entry of the pin of the penetration element according to the invention into the second locking piece, the invention may, according to a preferred embodiment, be further developed such that the second locking piece is designed as a disc with a, preferably central, hole for the passage of the pin, wherein the hole has a frustoconical chamfer for the entry of the pin into the hole. The frustoconical chamfer guides the tip of the pin into the hole even with minor radial deviations from the ideal position. For the same reason and with the same effect, according to a further preferred embodiment of the present invention, the first locking piece is designed as a disc with a, preferably central, hole for the passage of the pin, and the hole has a frustoconical chamfer for the entry of the pin into the hole. In the context of the present description, the first locking piece is the locking piece that secures the pin distally and thus near its tip, and the second locking piece is the locking piece that secures the pin proximally and thus near its base. According to a preferred embodiment of the present invention, the support may preferably be further developed in such a way that the support is designed for the pin to enter the hole in accordance with the frustoconical chamfer. In this way, the support and thus the proximal end can enter the disc as the second locking piece in a sealing manner and thus form the smoothest possible proximal end of the penetration element according to the invention. For reliable securing of the pin, the pin for engagement of the first locking piece may have at least one circumferential locking groove acting in the axial direction, which is formed by a preferably abrupt reduction in the diameter of the pin, as corresponds to a preferred embodiment of the present invention. The reduction in diameter here is relative to the true diameter of the pin beside the locking groove. The locking groove here is a circumferential depression along the circumference of the pin, which the shaft retaining element can engage in order to be optimally secured against sliding distally. The pin preferably has a plurality of circumferential locking grooves acting in the axial direction, so that the pin can pass further and further through the locking piece when penetrating the implant and the vessel and, when the second locking piece is optimally positioned against the outer part of the implant, can find support at one of the plurality of locking grooves. For an optimized securing of the second locking piece in an applicator before and during placement of the penetration element according to the invention, it is provided, according to a preferred embodiment of the present invention, that the second locking piece is designed as a disc with a circumferential groove, wherein the groove is preferably designed with a continuously extending longitudinal section. This design of the second locking piece enables the engagement of a holding structure shaped to match the groove on a suitable applicator, so that the second locking element is held on the applicator. The preferred continuously extending design of the longitudinal section of the groove allows the groove to easily engage and disengage from the holding structure on the applicator, since no discontinuities have to be overcome and the holding structure may therefore be designed, for example, as a simple spring element or as a springy wire. In a preferred manner, the invention may be further developed in such a way that the first and / or the second locking piece is at least partially encased by a plastic sleeve that is penetratable by the pin. Such a sleeve may be suitably designed to shield the support or the tip of the pin. The plastic sleeve can easily be penetrated by the pin when the implant is attached, i.e. when the penetration element is placed, and subsequently covers the tip of the penetration element. For particularly effective shielding of the tip of the pin, the invention may, according to a preferred embodiment, be further developed in such a way that the first locking piece is fitted on one side with a plastic cap that is penetratable by the pin. The plastic cap can be appropriately dimensioned to reliably enclose the tip of the pin when it is fully inserted through the implant and the vessel. An alternative or addition to securing the tip of the pin by means of the plastic cap just described may, according to a preferred embodiment of the present invention, consist in the first locking piece having a hollow metal cap on one side for the pin to enter the metal cap. The hollow metal cap can likewise serve to shield the tip of the penetration element and can also be suitable for bending the tip of the pin if the pin itself is too long. An applicator for placing the penetration element according to the invention for attaching an implant as a fixation site for a vascular prosthesis to a vessel wall of a blood vessel by penetrating the vessel wall and the implant with at least one penetration element according to the invention, preferably with a plurality of penetration elements according to the invention, has a channel for receiving and expelling the at least one pin from the channel, and a displaceable first jaw for releasably receiving a first locking piece for the penetration element, wherein the channel has an exit region directed toward the first jaw and defining an exit direction, with an exit opening for the pin, and the first jaw is displaceable in the exit direction from an initial position to a contact position which, compared to the initial position, is closer to the exit opening. The channel preferably has a circular cross-section. The applicator thus holds a single pin, which, in contrast to the prior art, interacts with at least one locking piece as a counterpart in order to be locked after penetrating the implant and the vessel wall. The locking piece allows the pin to be secured without the pin having to be bent for securing, as is the case with the prior art penetration elements. The counterpart or locking piece is designed accordingly to enable reliable securing of the pin of the penetration element. Because only a single penetration element is placed with the applicator, the applicator according to the invention can be designed more simply in terms of construction. The applicator has only a single channel for expelling the pin of the penetration element, so that the channel can be optimally designed to enable a favorable flow of force from an actuating element of the applicator to the exit region. When the implant is attached, the movable first jaw with the first locking piece held therein moves in the exit direction from an initial position to a contact position that is closer to the exit opening than the initial position, thereby securing the previously inserted parts of the implant to the vessel wall. In the contact position, the first jaw rests against the outer part of the implant and therefore provides resistance to the piercing of the implant and the vessel wall with the pin of the penetration element. After the pin has penetrated or pierced the implant and the vessel wall, it engages with the first locking piece and is effectively locked in the movable first jaw. The applicator is then relieved, releasing the locking piece. This also allows visual verification that the penetration element has been correctly placed before another penetration element is placed. In this way, the implant can be attached to the vessel wall quickly and extremely reliably. The first jaw preferably has a depression for releasably receiving the first locking piece, into which the first locking piece is inserted. The exit opening for the pin is formed in a fixed, second jaw of the applicator, wherein the second jaw is designed to releasably receive a second locking piece for the penetration element. The second jaw preferably has a depression for releasably receiving the second locking piece, into which the second locking piece is inserted, for example, as a disc with a circumferential groove, and is preferably secured by means of the groove. When the applicator is used, the implant and the vessel wall in between are consequently clamped between the movable, first jaw and the fixed, second jaw, the two jaws providing two locking pieces for the pin of the penetration element according to the invention. The pin is guided in a channel of the applicator with a circular cross-section. Due to the clamping effect, the locking pieces lie close to the implant, and the penetration element therefore subsequently secures the implant in reliable contact with the vessel wall. In order to reliably expel the pin from the channel and to achieve the expulsion of the pin from the channel in a simple and cost-effective manner in terms of equipment, the applicator may be further developed in such a way that a shear-resistant, and preferably flexible, expulsion element is guided in the channel for expelling the pin from the channel, wherein the expulsion element is drivable by a push rod in the direction of the exit opening. For this purpose, the expulsion element may be designed, for example, as a fully compressed tension spring. Such a tension spring has a very small pitch of the individual coils, so that the coils touch each other when the spring is in its normal state. As a result, the spring is indeed completely flexible so that it can also follow curved paths of the channel, but it is more or less completely shear-resistant when it is guided against lateral deflection. This is the case in a channel such as that of the present invention. However, the channel and the expulsion element could also be designed as a Bowden cable, for example. The drive of the expulsion element in the direction of the exit opening may also be implemented by means of a push rod. Such a push rod may be driven in a conventional manner by simple mechanical means and by manual force. The push rod may also be designed to be flexible in order to allow the applicator according to the invention to bend, depending on the requirements of the surgical field. This may make it possible to provide even rather inaccessible areas with a corresponding suture. If the expulsion element is drivable in the direction of the exit opening against the action of a first spring element, the expulsion element is automatically reset when the user has placed the penetration element. The first jaw is drivable by means of a gear mechanism to perform a linear displacement from the starting position to the contact position. This serves to allow an actuating movement by the user, for example on a handle of the applicator according to the invention, to be converted into the desired direction of displacement of the first jaw in order to displace the first jaw accordingly. The gear mechanism may additionally be designed to suitably select both the displacement path of the first jaw and its driving force as a function of a desired force that must be applied by the surgeon. The gear mechanism is driven by a drive rod, wherein the drive rod is driven against the action of a second spring element. The drive rod may run at any angle to the direction of displacement of the first jaw and thus allows a deflection of the drive direction, which is determined by the actuating movement of the surgeon or user of the applicator according to the invention and other mechanical components of the applicator, in the direction of displacement of the first jaw. As already discussed in connection with the expulsion element, a spring-loaded mounting of the drive rod may be used to return the drive rod to the initial position while returning the first jaw to the initial position. According to one variant, the drive rod is driven by a push rod, wherein preferably the expulsion element and the drive rod are driven by the same push rod. The concept of driving the movable parts of the applicator according to the invention by means of push rods is to be regarded as favorable in order to be able to implement limited drive paths in a controlled manner, wherein the application of force to the movable parts by a push rod takes up only a small amount of space, which is naturally to be regarded as advantageous in the case of a surgical instrument. When a single push rod is used to drive both the expulsion element and the first jaw by means of one and the same push rod, a desirable reduction in the number of parts of the applicator is achieved, and the movements of the first jaw and the expulsion element can be synchronized with one another via the common drive element of the common push rod. As already mentioned, the push rod may also be designed to be flexible and thus bendable to a certain extent, in order to also allow the applicator to bend, depending on the requirements of the surgical field. In order to transmit the force applied to the push rod to the drive rod for driving the first jaw, it may be provided that the drive rod is coupled to the push rod via a drive sleeve coupled for joint displacement with the push rod, wherein the drive sleeve is driven by the push rod against the action of a spring sleeve. The drive sleeve enables the decoupling of driving force from the axis of the push rod to the drive rod, which is particularly advantageous when the push rod drives both the drive rod and the expulsion element. In this embodiment, the push rod can thus act axially on the expulsion element and create a further force path to the drive rod via the drive sleeve. If a spring sleeve, which is in particular firmly connected to the push rod, acts resiliently on the drive sleeve, offset drive movements with different drive path lengths of the first jaw and the expulsion element can be realized with simultaneous actuation of the expulsion element and the first jaw by a common push rod. Thus, with a single movement of the push rod, the first jaw can be brought into contact with a retaining ring for the implant or with the implant itself, and the expulsion element can then be moved further in order to expel the pin and place the penetration element according to the invention. In this case, there is no further movement of the first jaw, since when the first jaw, and thus the first locking piece, is fully in contact with the outer implant part, the spring sleeve compresses and the drive sleeve is therefore not positively guided with the push rod. It may be provided that the push rod is driven by an actuating element that interacts with the push rod via a further gear mechanism. The actuating element may be designed, for example, as an actuating lever on a handle element of the applicator, so that the user only has to press the lever to actuate the applicator in order to set the penetration element. Preferably, the push rod, the spring sleeve, and the drive sleeve are arranged in a distal housing region of the applicator and may thus be designed as a drive unit, and preferably, the first and second jaws, the gear mechanism, and the drive rod, as well as the channel and the expulsion element, are arranged in a head of the applicator that can be detachably connected to the distal housing region. Overall, this results in a modular design of the applicator, which may allow parts of the applicator to be designed as disposable items and other parts as reusable. Thus, the head could be a disposable item and the rest of the applicator could be reusable. If the push rod is designed to be flexible in order to allow the applicator to bend, then at least the distal housing region of the applicator is also designed to be flexible. According to one variant, the penetration element is arranged as a straight pin, preferably a metal pin, in the exit region of the channel distal to the expulsion element, wherein the pin forms a support for the expulsion element at a proximal end facing the expulsion element. The penetration element can thus be expelled from the exit region of the channel along a defined axis and driven through the locking piece or locking pieces. The first locking piece, and preferably the second locking piece, are designed as clamping discs according to a preferred embodiment of the present invention. Clamping discs are known in the prior art as shaft retaining elements and allow the pin to penetrate once, whereby it is no longer possible to retract it without a great deal of force, since a frictional connection and possibly also a positive connection between the clamping disc and the pin occurs in the extraction direction. After the pin has been expelled, the penetration element according to the invention is therefore immediately secured. The present application discloses an applicator for the penetration element according to the invention in accordance with the following aspects: 1. An applicator (10) for attaching an implant (6) as a fixation site for a vascular prosthesis to a vessel wall of a blood vessel (7) by penetrating the vessel wall and the implant (6) with at least one penetration element (20), preferably with a plurality of penetration elements (20), wherein the applicator (1) has a channel (19) for receiving and for expelling the at least one penetration element (20) from the channel (19), and a displaceable first jaw (9) for releasably receiving a first locking piece (23) for the penetration element (20), wherein the channel (19) has an exit region directed toward the first jaw (9) and defining an exit direction (A), with an exit opening (19a) for the penetration element (20), and the first jaw (9) is displaceable in the exit direction (A) from an initial position to a contact position which, compared to the initial position, is closer to the exit opening (19a). 2. The applicator according to aspect 1, wherein the exit opening (19a) is formed in a fixed, second jaw (25), wherein the second jaw (25) is designed to releasably receive a second locking piece (24) for the penetration element (20). 3. The applicator according to aspect 1 or 2, wherein a shear-resistant, and preferably flexible, expulsion element (18) is guided in the channel (19) for expelling the penetration element (20) from the channel (19), wherein the expulsion element (18) is preferably drivable by a push rod (15) in the direction of the exit opening (19a). 4. The applicator according to aspect 3, wherein the expulsion element (18) is drivable in the direction of the exit opening (19a) against the action of a first spring element (17). 5.   The applicator according to any one of aspects 1 to 4, wherein the first jaw (9) is drivable by means of a gear mechanism (10) to perform a linear displacement from the initial position to the contact position. 6. The applicator according mechanism (10) is driven by a preferably the drive rod (11) a second spring element (22). to aspect 5, wherein the gear drive rod (11), wherein is driven against the action of 7. The applicator according to aspect 6, wherein the drive rod (11) is driven by a push rod (15), wherein preferably the expulsion element (18) and the drive rod (11) are driven by the same push rod (15). 8. The applicator according to aspect 6 or 7, wherein the drive rod (11) is coupled to the push rod (15) via a drive sleeve (13) coupled for joint displacement with the push rod (15), wherein preferably the drive sleeve (13) is driven by the push rod (15) against the action of a spring sleeve (14). 9. The applicator according to aspect 6, 7 or 8, wherein the push rod (15) is driven by an actuating element (4) that interacts with the push rod (15) via a further gear mechanism. 10.  The applicator according to aspect 8 or 9, wherein the push rod (15), the spring sleeve (14), and the drive sleeve (13) are arranged in a distal housing region (2a) of the applicator (1). 11. The applicator according to aspect 10, wherein the first and second jaws (9, 25), the gear mechanism (10) and the drive rod (11), as well as the channel (19) and the expulsion element (18), are arranged in a head (3) of the applicator (1) that is detachably connectable to the distal housing region (2a). 12. The applicator according to any one of aspects 3 to 11, wherein the penetration element (20) is arranged as a straight pin (20), preferably a metal pin (20), in the exit region of the channel (19) distal to the expulsion element (18), wherein the pin (20) forms a support (20a) for the expulsion element (18) at a proximal end facing the expulsion element (18). 13.  The applicator according to any one of aspects 2 to 12, wherein the first locking piece (23), and preferably the second locking piece (24), are designed as clamping discs. 14.  The applicator according to any one of aspects 1 to 13, wherein a locking piece (23) is encased by a plastic sleeve (27) that is penetratable by the penetration element. 15. The applicator according to any one of aspects 1 to 14, wherein a locking element (23) has a hollow metal cap (28) for the penetration of the penetration element (20). 16. A set for attaching an implant (6) as a fixation site for a vascular prosthesis to a vessel wall of a blood vessel (7), comprising at least one applicator (1) according to any one of claims 11 to 15, the head (3) of said applicator being connected to or separated from the distal housing region (2a) of the applicator (1), a first retaining ring (5a) for holding an inner implant part (6a), and a second retaining ring (5b) for holding an outer implant part (6b). 17. The set according to aspect 16, comprising the implant (6) in the form of a first implant part (6a) arranged on the outside of the first retaining ring (5a) and a second implant part (6b) arranged on the inside of the second retaining ring (5b), wherein the first and second implant parts (6a, 6b) are preferably designed as a tube made of textile material. 18. The set according to aspect 16 or 17, comprising at least one further head (3) for attachment to the distal housing region (2a) of the applicator (1). The invention is explained in more detail below with reference to an exemplary embodiment illustrated in the drawing. In the drawing, Figures 1 and 2 show perspective views of the applicator, Figures 3 to 5 show an overall sectional view of the applicator at various stages of placement of a penetration element, Figures 6 to 9 show detailed sectional views of the applicator at various stages of placement of a penetration element according to the invention, Figures 10a and 10b show detailed views of a penetration element according to the invention, Figure 11 shows a perspective view of the individual parts of the penetration element according to the invention in an unsecured state, Figure 12 shows a perspective view of the penetration element according to the invention in a secured state, and Figure 13 shows a side view of the pin of the penetration element according to the invention. In Figure 1, a handle of the applicator 1 is designated by the reference numeral 2. The handle 2 has a distal housing region 2a, and a head 3 is placed on the distal housing region 2a, wherein the head 3 can be secured to the distal housing region 2a or the handle 2, for example, by means of a bayonet lock. The handle 2, with the lever 4, also has an actuating element that can be actuated by a user. A second, outer retaining ring is designated by the reference numeral 5b, and it can be seen that an outer, second implant part 6b made of a textile material is inserted inside the retaining ring 5b and is brought to rest against the vessel wall 7 by means of the second or outer retaining ring 5b. In Figure 2 and the other figures, identical or corresponding elements are provided with the same reference numerals. It can be seen that the lever 4 has been actuated in the direction of the arrow 8 and that, accordingly, a displaceable first jaw 9 has been displaced in the direction of the arrow 12 toward the outer retaining ring 5b. The first jaw 9 is in contact with the second retaining ring 5b and holds it and the outer implant part 6b in place. In the sectional view according to Figure 3, a corresponding first or inner retaining ring 5a and a first, inner implant part 6a can now be seen, which are placed against the wall of the vessel 7. Furthermore, Figure 3 shows the displaceable first jaw 9 in an initial position and thus spaced from the vessel 7 or from the outer retaining ring 5b. The first jaw 9 can be displaced by means of a gear mechanism 10, which in turn is driven by a drive rod 11, by actuating the lever 4 in the direction of the arrow 12, whereby the first jaw 9 is lowered onto the outer, second implant part 6b. The drive rod 11 is coupled to a push rod 15 via a drive sleeve 13 and a spring sleeve 14. The spring sleeve 14 contains a spring 16. The push rod 15 acts axially and via a first spring element 17 on an expulsion element 18, which can be driven through the channel 19 by the push rod. A pin 20 of the penetration element according to the invention is mounted in the channel 19 and is expelled from the channel 19 by the expulsion element 18. It can be seen in Figure 4 that when the lever 4 is actuated, the push rod 15 is displaced in the direction of the arrow 21, so that the push rod 15 drives the first spring element 17 and thus the expulsion element 18 through the channel 19. At the same time, the drive rod 11 was also displaced in the direction of the arrow 21 by the action of the spring sleeve 14 and the drive sleeve 13, so that the first jaw 9 was displaced into the contact position in contact with the second retaining ring 5b by the action of the gear mechanism 10. The movement phases of the expulsion element 18 and the displaceable first jaw 9 are decoupled from one another by the action of the spring sleeve 14, so that the expulsion element 18 can be moved further by the action of the push rod 15 when the first jaw 9 is already in the contact position. In Figure 5, it can be seen that, upon further actuation of the lever 4 in the direction of the arrow 8, the pin 20 is pushed out of the channel 19 and through the vessel 7 and the implant parts 6a and 6b, whereby the implant parts 6a and 6b are secured to the vessel 7. Due to the action of the first spring element 17 and the second spring element 22, the applicator 1 according to the invention is reset when the lever 4 is released. In Figure 6, the initial position of the first jaw 9 can be seen more clearly, and it can be seen that a first locking piece 23 for the pin 20 is releasably received in a depression of the first, displaceable jaw 9. A second locking piece 24 for the pin 20 is releasably received in a depression of the second, fixed jaw 25. A plastic cap for the locking piece 23 is designated by the reference numeral 27. In Figure 7, the first jaw 9 is in the contact position, with the first locking piece 23 for the pin 20 also being in contact with the outer implant part 6b. Figure 8 shows a state in which the pin 20 has penetrated the implant parts 6a and 6b and the vessel 7, with the second locking piece 24 for the pin 20 having been lifted out of the second, fixed jaw 25. The pin 20 also penetrates the first locking piece 23, whereby the pin 20 is irreversibly anchored in the locking pieces 23 and 24. A support on the pin 20 for the expulsion element 18 is designated by the reference numeral 20a. In the state shown in Figure 9, the first jaw 9 has been raised against the direction of the arrow 12 by the action of the second spring element 22, and the expulsion element has been retracted back into the channel 19 by the action of the first spring element 14. The head 3 can thus be retracted in the direction of the arrow 26 and replaced in order to place another penetration element. The exit opening of the channel is designated by the reference numeral 19a, and an exit direction parallel to the exit region 19b is defined by the axis A. In Figure 10a, the pin 20 of the penetration element according to the invention can be clearly seen. The pin 20 has a support 20a for an expulsion element 18 at its proximal end facing away from the tip 20b. The first locking piece is designated by 23 and is designed as a shaft retaining element. A plastic cap 27 occupies one side of the locking piece 23 and, as shown in Figure 10b, is penetrated by the pin 20 so that the tip 20b of the pin 20 is enclosed. The plastic sleeve 27 may have a cap 28, or the cap 28 may completely replace the plastic sleeve 27 to shield the tip of the pin 20. The second locking piece 24 is designated by reference numeral 24 and has a recess on its underside in the form of a frustoconical chamfer 29 for the support 20a. Figure 10b shows the penetration element in the locked state, with the pin 20 being firmly clamped by the shaft retaining element in the first penetration element 23. The support 20a is received in the recess 29. Figure 11 shows the parts of the penetration element according to the invention just described in a perspective view from obliquely below, and it can be seen that the second locking piece 24 may have a groove 30 with a rising profile. A corresponding holding structure, for example a springy wire, can engage in the groove. In Figure 12, it can be seen that in the secured state of the penetration element according to the invention, the base 20c of the pin 20 is received in a depression 31 of the second locking piece 24, resulting in an overall smoother silhouette of the penetration element. Figure 13 shows the pin 20 in a preferred variant, where several circumferential locking grooves 32 acting in the axial direction are provided for engagement of the first locking piece 23.

Claims

1. A penetration element for penetrating a vessel wall (7) of a blood vessel and an implant, comprising a pin (20), a first locking piece (23) and a second locking piece (24), characterized in that at least the first locking piece (23) is designed as a shaft retaining element, wherein the second locking piece (24) is preferably also designed as a shaft retaining element.

2. The penetration element according to claim 1, characterized in that the pin (20) forms a support (20a) for an expulsion element (18) at a proximal end.

3. The penetration element according to claim 1 or 2, characterized in that the second locking piece (24) isdesigned as a disc with a, preferably central, hole (24a) forthe passage of the pin (20), wherein the hole (24a) has afrustoconical chamfer (29) for the entry of the pin (20) intothe hole (24a).

4. The penetration element according to claim 1, 2 or 3,characterized in that the first locking piece (23) is designed as a disc with a, preferably central, hole (23a) for the passage of the pin, wherein the hole has a frustoconical chamfer (33) for the entry of the pin (20) into the hole (23a).

5. The penetration element according to claim 2, 3 or 4,characterized in that the support (20a) is designed according to the frustoconical chamfer (29) for the entry of the pin (20) into the hole (24a).

6. The penetration element according to any one of claims 1 to 5, characterized in that the pin (20) for the engagement of the first locking piece (23) has at least one circumferential locking groove (32) acting in the axial direction, the locking groove (32) being formed by a, preferably abrupt, reduction in the diameter of the pin (20).

7. The penetration element according to claim 6, characterized in that the pin (20) has a plurality of circumferential locking grooves (32) acting in the axial direction.

8. The penetration element according to any one of claims 1 to 7, characterized in that the second locking piece (24) is designed as a disc with a circumferential groove (30), the groove (30) preferably being designed with a continuously extending longitudinal section.

9. The penetration element according to any one of claims 1 to 8, characterized in that the first and / or the second locking piece (23, 24) is at least partially encased by aplastic sleeve (27), the sleeve (27) being penetratable by the pin (20).

10. The penetration element according to any one of claims 3 to 9, characterized in that the first locking piece (23) isfitted on one side with a plastic cap (27), the cap (27) beingpenetratable by the pin (20).

11. The penetration element according to any one of claims 3 to 10, characterized in that the first locking piece (23) has a hollow metal cap (28) on one side for the pin (20) to enterthe metal cap (28) and for the pin to bend on an inner side ofthe metal cap (28).

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