Nerve Conduit System

Abstract

The present invention relates to a nerve conduit system for connecting two nerve ends end-to-end. In particular, the present invention relates to a nerve conduit system that supports the repair of nerve injuries by facilitating proper placement and orientation of the nerve ends and allowing the connection of nerve ends having the same or different diameters. Accordingly, a nerve conduit system (10) for connecting two nerve ends end-to-end is provided. The nerve conduction system (10) comprises a first portion (12) and a second portion (14), each portion (12, 14) having an insertion portion (16, 26) adapted to receive one of two nerve ends and a connection portion (22, 24), each portion (12, 14) including through holes (20, 30) defined by at least the respective insertion portion (16, 26) and extending between the longitudinally opposing ends of the respective portion (12, 14), the connection portions (22, 24) configured to engage with each other and arranged such that in a connected state, i.e., when the connection portions (22, 24) of the first portion (12) and the second portion (14) are engaged, the through holes (20, 30) are in fluid communication with each other.

Description

Detailed Description of the Invention

[0001] [Technical field] The present invention relates to a nerve conduit system for connecting two nerve ends end-to-end. In particular, the present invention relates to a nerve conduit system that supports the repair of nerve injuries by facilitating proper placement and orientation of the nerve ends and enabling the connection of nerve ends, preferably nerve ends having different diameters. [Background technology] When injured, tissue damage may be accompanied by one or more nerve damage in the peripheral nervous system, resulting in partial loss of sensation and / or impaired motor skills.This type of injury accompanied by nerve damage occurs particularly in the upper extremities, such as the hand or finger, and if nerve damage is not properly treated, the individual may experience, for example, a loss of tactile or haptic feedback, and / or have difficulty controlling the fine motor skills of the injured area.

[0002] Current treatments for nerve injuries include joining nerve ends using various joining techniques to provide a substantially tension-free connection between the respective nerve ends. In more severe cases where the nerve ends are not directly adjacent to each other, reconstruction may be required to overcome the corresponding gap. For example, reconstruction can be provided by an autologous or allogeneic nerve graft. Alternatively, reconstruction can be performed by providing a tubular structure to provide a nerve guide. For example, such a tubular structure can be provided by an autologous or allogeneic venous structure or an artificial nerve conduit made from a biocompatible material. The use of a tubular structure can further facilitate injury repair, regardless of the presence of a gap, by, for example, providing additional mechanical support and structural stability, providing tension-free repair, reducing inflammatory responses to the injury site, and / or limiting the spread of fibrous tissue growth.

[0003] Tubular structures, particularly nerve conduits, are generally formed as substantially cylindrical shapes extending longitudinally and defining an internal lumen or through-hole from one end to the opposite end. The dimensions and shape are selected to match the microstructure of the damaged nerve tissue and the affected surrounding tissue. Thus, to treat nerve injury, a nerve end is inserted into the nerve conduit through one end of the nerve conduit, and the corresponding other nerve end is inserted into the nerve conduit through the opposite end of the nerve conduit. The two ends can then be fixed or bonded to the nerve conduit, for example, by a bonding technique or by applying or depositing a medical adhesive. Alternatively, a system combining a movable contact member and a pressing member can be used, where the pressing member applies a mechanical force to the contact member, pushing the contact member in the radial direction of the nerve, thereby fixing or bonding the two ends of the nerve to the nerve conduit (WO201213019). Thus, when implanted, the nerve conduit forms a nerve guide, and the continuous cylindrical shape and lumen of the nerve conduit provide a directional pathway for neurogenesis.

[0004] Another potential complication resulting from nerve injury is the increased risk of neuromas, which can develop at the ends of severed nerves. Such neuromas can arise from uncontrolled axonal growth beyond the severed epineurium at the ends of severed nerves, for example, after severe injury or surgery. The axonal sprouts can form a disorganized, hyperexcitable bundle of nerve tissue that lacks the original nerve structure. Neuromas are typically accompanied by neuropathic pain, numbness, and tingling, which can interfere with rehabilitation, functional recovery, and sensory impairment. Neuroma treatment or prevention can be based on connecting the proximal end of an injured nerve to an intact, newly degenerated motor nerve of a muscle. Such treatments are particularly applicable when there is a large gap between the proximal and distal nerve ends or when the distal nerve end has been lost due to amputation or tissue removal. Connecting techniques can at least partially restore muscle control while reducing the risk of neuroma development. Summary of the Invention Departing from the known prior art, there is a need to further facilitate the repair of nerve injuries. According to the present invention, it is recognized that inserting and attaching nerve ends into each end of a nerve conduit can be difficult, especially in situations where the nerve conduit needs to bridge a large gap between the nerve ends. This has been found to be due, on the one hand, to the in situ flexibility of the nerve conduit. Once one nerve end is introduced into and secured at each end of the nerve conduit, the insertion and alignment of the other nerve end may be particularly impaired, limiting further manipulation of the nerve conduit. On the other hand, the continuous structure of the nerve conduit and the lack of visual feedback make it difficult for the surgeon to assess whether each nerve end has been properly inserted and correctly held in place after installation, for example by the application of a medical adhesive. Therefore, potentially necessary corrections are generally impossible to make.

[0005] Furthermore, it has been found that, particularly when the gap is large and / or when connecting a proximal nerve end to a distal nerve end, such as a distal motor nerve, there may be differences in the diameter of the respective nerve ends being connected, with the latter having significantly smaller or larger diameters. To provide a connection for nerve ends exhibiting such differences in diameter, the dimensions of the nerve conduit must be correspondingly increased, which is not advantageous for the proper insertion and fixation of nerve ends with smaller diameters. In particular, in this case, a larger volume of medical adhesive may be required to properly fix at least the nerve ends with smaller diameters, further complicating the implementation and handling of the nerve conduit. Larger diameters and larger amounts of medical adhesive may further lead to inappropriate axonal growth, impairing recovery, and potentially inducing the development of neuromas.

[0006] It is therefore an object of the present invention to further improve and / or facilitate repair of nerve injuries. In particular, it is an object of the present invention to facilitate proper fixation and alignment of nerve ends relative to nerve conduits. A particular object of the present invention is to facilitate such repair for nerve ends having different diameters. This object is achieved by the independent claims. Preferred embodiments are shown in the dependent claims, the description and the figures.

[0007] Thus, there is provided a nerve conduit system for connecting two nerve ends end-to-end, comprising first and second sections, each section having an insert section adapted to receive one of the two nerve ends and a connecting section, each section including at least a through-hole defined by the respective insert section and extending between longitudinally opposed ends of each section, the connecting sections configured to engage with each other and arranged such that in a connected state, i.e., when the connecting sections of the first and second sections are engaged, the through-holes are in fluid communication with each other.

[0008] It should be noted that when the first and second portions are engaged, the connecting portion preferably does not act as a pressing member that applies a radial force to the nerve end. More specifically, the connecting portion of the first portion does not act as a pressing member against the connecting portion of the second portion that applies a radial force to the nerve end, and the connecting portion of the second portion does not act as a pressing member against the connecting portion of the first portion that applies a radial force to the nerve end. In other words, the nerve conduit system of the present invention comprises or consists of two separate (individual) portions (first and second portions) that can be connected to each other (by their connecting portion) to bring two nerve ends closer together or, in extreme cases, to connect two nerve ends. Thus, each portion and its respective insert is received in one of the two nerve ends to be connected, so that the nerve ends are accommodated in the through-holes of the respective portions. Fluid communication between the connecting portion and the through-holes allows the nerve ends to face each other end-to-end.

[0009] As used herein, connecting nerve ends in an "end-to-end manner" includes connecting (two) nerve ends directly, i.e., connecting without a gap between the nerve ends. It also includes connecting (two) nerve ends with a gap or longitudinal distance of up to about 20 mm, preferably up to about 15 mm, more preferably up to about 10 mm, and particularly preferably up to about 5 mm. In some embodiments, the (two) nerve ends are therefore connected directly, i.e., connected without a gap between the nerve ends. In other embodiments, the (two) nerve ends are connected with a gap or longitudinal distance of up to about 20 mm, preferably up to about 15 mm, more preferably up to about 10 mm, and particularly preferably up to about 5 mm between the (two) nerve ends.

[0010] The provision of two separate sections has the advantage of making handling of the nerve conduit system particularly easy, since each nerve end can be individually secured or attached to its respective (first or second) section before connecting the sections with the corresponding connector. This provides the surgeon with greater flexibility in handling. This further facilitates insertion of each nerve end into its corresponding insertion section, while ensuring that the medical adhesive or other means used to secure the corresponding nerve end to its respective (first or second) section is properly applied. Thus, the nerve ends can be optionally secured or attached to their respective sections before being connected to each other.

[0011] Furthermore, two separate sections advantageously allow each section to be selected based on the specific dimensions (diameters) of each nerve end. This is particularly advantageous for connecting nerve ends with different diameters, because each section of the nerve conduit system can be selected based on the distinct dimensions of the nerve end. In particular, each section may include an insert section that defines a portion of a through-hole and has an inner diameter corresponding to the nerve end inserted and housed within the through-hole. In contrast, conventional single-section nerve conduits are typically selected based on nerve ends with larger diameters, and the selected nerve conduit is usually too large for nerve ends with smaller diameters and requires special fixation.

[0012] The first part may comprise an insert and a corresponding through-hole with an inner diameter adapted to a nerve end with a larger diameter (compared to the (other) nerve end to be connected thereto). Based on this, the second part may comprise an insert and a corresponding through-hole with an inner diameter adapted to a nerve end with a smaller diameter (compared to the (other) nerve end to be connected thereto). Thus, the configuration of the first and second parts may be optimized for the diameter of a specific nerve end. The nerve ends can be connected to each other end-to-end by the connecting parts and the fluidically connected through-holes. The connecting parts are preferably standardized for various sizes of the inserts of the respective parts.

[0013] Thus, a nerve conduit system having two separate, yet combinable, first and second sections allows the inserts of each section to have internal through-holes with different diameters and / or cross-sectional areas. For example, a 1.1- to 10-fold, particularly 2-fold or greater, mismatch in nerve end diameters can be bridged by corresponding matching of the first and second sections of the nerve conduit system. For example, the inserts of at least one section can be configured to accept nerve ends with diameters between 1 mm and 12 mm (e.g., 1 mm, 1.5 mm, 2 mm, 2.5 mm, 3 mm, 3.5 mm, 4 mm, 4.5 mm, 5 mm, 5.5 mm, 6 mm, or 6.5 mm, 7 mm, 7.5 mm, 8 mm, 8.5 mm, 9 mm, 9.5 mm, 10 mm, 10.5 mm, 11 mm, 11.5 mm, or 12 mm). However, the insertion portion of the other portion may be configured to receive a nerve end having a diameter between 1 mm and 12 mm (e.g., 1 mm, 1.5 mm, 2 mm, 2.5 mm, 3 mm, 3.5 mm, 4 mm, 4.5 mm, 5 mm, 5.5 mm, 6 mm, or 6.5 mm, 7 mm, 7.5 mm, 8 mm, 8.5 mm, 9 mm, 9.5 mm, 10 mm, 10.5 mm, 11 mm, 11.5 mm, 12 mm).

[0014] However, it should be understood that the two nerve ends to be connected may have the same diameter, and the first and second inserts and the corresponding portions of the through-holes will be adapted accordingly.

[0015] Another advantage of having individual sections for each nerve end is that the nerve end can be observed or inspected after insertion into the respective insertion section (through-hole). In particular, each nerve end can be received within the through-hole via a corresponding insertion section. It may extend through the through-hole from one longitudinal end toward the opposing longitudinal end (of the insertion section). The nerve end may be inserted so that it does not typically extend beyond the insertion section, but terminates within the through-hole at and / or in the region of the junction between the insertion section and the adjacent section. This allows the nerve end to be observed through the opposing longitudinal ends of the through-hole. Therefore, proper insertion can be monitored prior to application of medical adhesive and / or connection of sections.

[0016] The nerve conduit sections may generally have a substantially tubular shape with longitudinally opposing through-holes and one or more side walls. This provides each individual section with a continuous channel or through-hole, particularly when the connecting section of the first section and the connecting section of the second section are engaged, i.e., in a connected state (by connecting the through-holes of the individual sections to form a continuous through-hole in the connected state). The nerve conduit sections may have a substantially tubular shape, but the diameter of the tubular shape may vary along the longitudinal direction. In the connected state, i.e., when the connecting section of the first section and the connecting section of the second section are engaged, the sections may thus form a longitudinally extending elongated body, with the respective through-holes fluidly coupled to each other, for example, by being directly adjacent to each other or by receiving the end of the through-hole of one section and not being used for insertion of the respective nerve end into the through-hole of the other section.

[0017] According to another embodiment, the tubular shape may include a structure on the outer surface, more preferably the outer surface of the insert, having a specific geometry or surface irregularities shaped to form a retention surface, such as protrusions, slits, striations, grooves, or holes. In particular, such an outer structure may advantageously (i) increase contact between the surface of the insert and the medical adhesive, and (ii) form anchoring points for the medical adhesive. Such an outer structure is disclosed, for example, in patent application WO2022229207, the contents of which are incorporated by reference in their entirety.

[0018] The cross section of the through-hole is preferably circular or ellipsoidal. A tubular or cylindrical structure can substantially correspond to the shape of the through-hole, without undesirable bias, so that a continuous guide structure for tissue repair or support (protection), such as neurogenesis or nerve growth, is generally provided. It can provide sufficient structural stability and prevent sharp bending or twisting during tissue movement, i.e., contraction or extension or nerve growth. The tubular shape also provides a homogeneous structure, which responds in a predetermined manner along the entire longitudinal extension, particularly when a force is applied to a portion of the nerve conduit system, for example, during impact.

[0019] Thus, the through-holes in each section may be continuous or may be defined by the end faces of the openings at the longitudinally opposing ends. In some embodiments, for one or both sections of the system, preferably the second section (but not the first section), the through-holes may be defined only by the inserts. In other embodiments, for one or both sections of the system, preferably the first section (but not the second section), the through-holes may be defined by the inserts and may also be defined by portions of the respective sections that connect to and / or extend from the respective inserts, such as connecting sections and / or transition sections.

[0020] The insertion portion may define a proximal end and a distal end that is longitudinally opposed to the corresponding portion of the through-hole. That is, the proximal end (or proximal opening) can be used to insert the respective nerve ends into the insertion portion and the corresponding portion of the through-hole. The distal end may preferably be positioned so that the respective nerve ends do not protrude beyond the end. The distal ends of the insertion portions of the first and second portions may face each other when connected, i.e., when the connecting portion of the first portion and the connecting portion of the second portion are engaged. A further portion of each portion may extend from the distal end, for example, to facilitate connection and / or to facilitate guiding axonal growth of one nerve end toward the other connected nerve end. This limits the risk of neuromas while supporting nerve regeneration and recovery.

[0021] Preferably, at least one of the parts, more preferably the first and second parts, further comprises a transition section disposed or extending between the respective insert section and the respective connecting section of the part. The transition section may extend from the insert section to the connecting section, or from the connecting section to the insert section, so as to form a bridging section. An extension in this respect is understood as a longitudinal and / or radial extension. The provision of such a transition section is particularly advantageous when the diameters of the insert section and the connecting section of the same part are different from each other. Preferably, the diameter of the insert section of one part, e.g., the first part, may be larger than the diameter of the respective connecting section of the part. Additionally or alternatively, the other part, e.g., the second part, preferably comprises a connecting section having a diameter larger than the diameter of the respective insert section. In particular, the transition section "bridges" the different diameters of the insert section and the connecting section of the same part, so that the (first and / or second) parts can be integrally formed, preferably without abrupt or sharp steps (in their outer shape).

[0022] The transition section therefore preferably has, for example, a substantially tapered or conical shape when viewed in longitudinal section, such that a gradual transition from the diameter of the insertion section to the diameter of the connection section can be provided, preferably in a continuous manner, such that the transition section preferably has a substantially circular cross section.

[0023] In some embodiments, the outer surfaces of the transition and / or connecting portion can further facilitate handling of the respective portions, for example, by forming an outward gripping and / or support surface toward the connecting portion, which can be particularly true when the transition portion comprises a substantially tapered or other gradual change in shape.

[0024] The transition portions of the second portion may preferably be provided to connect and position the respective connecting portion on the outside of the insert, for example, to attach the insert to a connecting portion having a larger diameter, preferably surrounding and concentrically. The transition portions of the first portion may preferably be provided to attach the insert to the connecting portion in an adjacent radially inward or outward extending manner.

[0025] In (at least) one part, preferably the first part, the connecting portion and optionally the transition portion may further define a respective portion of the through hole (in addition to the insert portion defining another portion of the (same) through hole). This can be achieved in a configuration in which the insert portion and the connecting portion of (at least) one part, preferably the first part, are arranged adjacent to each other in the longitudinal direction, either directly or with a transition portion in between. In such a configuration, the shape of the through hole defined by the transition portion preferably has a shape that generally corresponds to the transition portion, such that the outer diameter and the inner diameter extend substantially parallel. The shape of the transition portion not only provides a transition between the different diameters of the through hole, but can also facilitate handling of the respective parts, for example by forming external gripping and / or support surfaces (even if a transition between the different diameters of the insert portion and the connecting portion is not required, particularly if said diameters are the same).

[0026] In (at least) one portion, preferably the second portion, the transition portion and connecting portion may be arranged so as not to define a respective portion of the through hole. For example, the transition portion and / or connecting portion may at least partially surround the insert portion, as described below.

[0027] At least one section, and preferably each section's insertion and / or connection section, may further comprise a substantially cylindrical (or tubular) shape. As described above, this may improve overall structural stability and ease of handling. Furthermore, such a shape provides that the radial dimensions may be optimized based on the diameter of the respective nerve conduit. The cylindrical shape also reduces or avoids the occurrence of sharp edges and / or inadvertent pinching or constriction of surrounding tissue during implantation of the nerve conduit system.

[0028] As described above, the inserts of the first and / or second parts may have a substantially tubular shape. Accordingly, the inserts of the first and / or second parts may extend along a longitudinal axis. Furthermore, the connecting parts of the first and / or second parts may have a substantially tubular shape. Accordingly, the connecting parts of the first and / or second parts may extend along a longitudinal axis. Preferably, the longitudinal axes of the inserts and the connecting parts of the same parts correspond to each other (e.g., they may be the same or the longitudinal axis of the inserts may be a longitudinal extension of the longitudinal axis of the connecting part of the same part). In other words, for each part, the inserts, the connecting parts, and, optionally, the transition parts, may preferably extend along the same longitudinal axis.

[0029] In the connected state, i.e., when the connecting portion of the first part and the connecting portion of the second part are engaged, the insert portion of the first part and the insert portion of the second part preferably extend along the same longitudinal axis. Similarly, it is preferred that the connecting portion of the first part and the connecting portion of the second part extend along the same longitudinal axis. More preferably, the insert portion, the connecting portion, and optionally the transition portion of the first part and the second part extend along the same longitudinal axis when the connecting portions of the first part and the second part are engaged, i.e., in the connected state.

[0030] The connecting portion of (at least) one part, preferably the second part, can at least partially surround the insert portion of that part. This can be directly, or preferably with a transition portion disposed between the insert portion and the connecting portion. The transition portion preferably provides a gap between the insert portion and the connecting portion (the latter at least partially, and preferably completely, surrounding the insert portion). The transition portion is preferably disposed so that it can at least partially surround (also) the insert portion. This "surrounding" configuration can be particularly advantageous when the insert portion of one part, preferably the second part, is configured for a nerve end having a smaller diameter compared to the nerve end inserted into (and accommodated by) the insert portion of the other part. This allows the longitudinal dimension of the entire part to be reduced while maintaining the connectivity of the respective connecting portions. In particular, the insert portion and the connecting portion of at least one part can be concentrically disposed. In a configuration in which the connecting portion partially or completely surrounds the respective insert portion, the connecting portion preferably does not define a corresponding portion of the through-hole.

[0031] The insert and connecting portion of at least one part, preferably the first part, may be arranged adjacent to each other in the longitudinal direction. This may be directly or with a transition portion disposed between the insert and connecting portion. Such a subsequent longitudinal arrangement, as opposed to a concentric arrangement, may be particularly advantageous when the insert of each part has substantially the same or a larger diameter than the connecting portion. In such an arrangement, the connecting portion preferably defines a corresponding portion of the through hole. Therefore, it may be of similar or smaller dimensions than the portion of the through hole defined by the insert. To bridge the difference in diameter between the insert and connecting portion, a transition portion accommodating said difference may be disposed between the connecting portion and the insert, and the transition portion preferably also defines a corresponding portion of the through hole.

[0032] According to one embodiment, both parts, i.e., the first part and the second part, may have the same (surrounding or trailing) configuration regarding the arrangement of the connecting part and the insert part relative to each other, i.e. (i) in both parts, the connecting part may at least partially surround the insert part of said part ("surrounding configuration"), or (ii) in both parts, the insert part and the connecting part may be arranged adjacent to each other in the longitudinal direction ("trailing configuration"). According to a preferred embodiment, in only one of the parts, preferably the first part, the insert part and the connecting part may be arranged adjacent to each other in the longitudinal direction ("trailing" configuration), and in the other part, preferably the second part, the connecting part may at least partially surround the insert part of said part ("surrounding configuration").

[0033] To facilitate end-to-end connection of the nerve ends, the connection sections can be configured such that when the first and second connection sections are engaged, i.e., in the connected state, the insertion sections are positioned at longitudinally opposing ends of the nerve conduit system. Depending on the required configuration, an optional additional portion, such as a transition section, defining the through-hole can therefore be positioned between the insertion sections when the first and second connection sections are engaged, i.e., in the connected state. The longitudinally opposing end positioning can be such that when the first and second connection sections are engaged, the openings of the through-holes defined by the respective insertion sections (configured to receive and insert the respective nerve ends into the respective insertion sections, i.e., configured as nerve end inlets into the insertion sections) are spaced apart from each other.

[0034] Preferably, the (single) through-holes of the first and second sections define a single longitudinal axis of the nerve conduit system when the connecting portions of the first and second sections are engaged, i.e., in the connected state. By inserting nerve ends into the respective insertion sections, the terminating end faces of the nerve ends can therefore directly oppose each other, and radial offsets or angles in the end-to-end connections provided by the nerve conduit system can be avoided to facilitate more efficient and direct repair of damaged nerves. Preferably, the through-holes are arranged and aligned in a concentric or adjacent configuration in the connected state so that the connected nerve ends are connected accordingly in an efficient manner.

[0035] The through holes of the two parts may be arranged adjacent to each other in the longitudinal direction. Preferably, the connecting part is configured such that when the connecting part of the first part and the connecting part of the second part are engaged, i.e., in the connected state, the through hole of one part, in particular the second part, is at least partially received within or adjacent to the through hole of the other part, for example the first part.

[0036] For example, by accommodating a portion of the through-hole of the second portion within the through-hole of the first portion, the overall longitudinal dimension of the nerve conduit system can be reduced. Furthermore, such a configuration can improve the structural stability of the nerve conduit system and / or the sealing of the nerve ends connected toward the exterior of the nerve conduit system, for example, by corresponding configurations of at least the respective connecting portions. In particular, the connecting portion of the first portion can define a corresponding portion of the through-hole of the first portion. Preferably, the connecting portion of the first portion is adapted to accommodate the corresponding portion of the insertion portion and through-hole of the second portion.

[0037] Receiving the nerve ends within or adjacent to the through-holes of the first portion can also promote regeneration of damaged nerve ends by ensuring that the connected nerve ends are adjacent to each other, thus supporting axonal growth from the nerve ends received within the through-holes of the first portion toward the nerve ends received within the through-holes of the second portion, for example.

[0038] Preferably, such accommodation in the through-hole of a respective part, e.g., the first part, can be particularly advantageous if said part is configured to accommodate a respective nerve end having a larger diameter compared to the nerve end to be accommodated in the through-hole of the other part. Thus, it is particularly advantageous if the connection part of said part, e.g., the first part, is arranged subsequent to or adjacent to the respective insertion part, e.g., via a respective transition part, and the connection part and the corresponding part of the through-hole of said part can be of larger dimensions than the insertion part of the other part, e.g., the second part.

[0039] However, the connections of each section can have predetermined dimensions that are independent of the dimensions of the inserts of each section, and thus the connections can be configured as standardized connections for various sizes of inserts, for example in a modular kit of sections.

[0040] It should be understood that the above-described embodiments are equally applicable to configurations in which, for example, the second portion is configured to receive a nerve end having substantially the same or a larger diameter than the nerve end received by the first portion, and in either configuration, at least one connection portion of said portion is preferably positioned subsequent to or adjacent to the respective insertion portion, for example, via a respective transition portion, and the connection portion of said portion and the corresponding portion of the through-hole are sized larger than the insertion portion of the other portion, for example, the second portion.

[0041] In the connected state, i.e., when the connecting portion of the first part and the connecting portion of the second part are engaged, the nerve end is preferably received (only) within the respective insert portion. This allows the nerve end to be connected in an end-to-end manner without extending into the respective insert portion of the other part. The connecting portion, e.g., the corresponding insert portion of the other part, defining a through-hole that receives the corresponding through-hole of the other part may be configured to receive only a portion of the insert portion of the other part. A predetermined gap between the end faces of the respective nerve end may be provided in the received state and the connected state, i.e., when the connecting portion of the first part and the connecting portion of the second part are engaged.

[0042] The connecting portion may extend from each transition portion, which extends between the insert portion and the connecting portion to provide a bridge between the different diameters. In such a configuration, the transition portion may alternatively or additionally provide, at least in part, the predetermined gap.

[0043] Thus, the overall dimensions of the nerve conduit system can be tailored to the corresponding requirements of each nerve end to be connected, substantially eliminating the need for oversized conduits.

[0044] In some embodiments, the through-hole of the first portion may further comprise a longitudinal end portion disposed opposite the longitudinal end portion configured to receive the respective nerve end portion, the through-hole comprising a cross-sectional area that gradually increases in the longitudinal direction away from the insertion portion. For example, a local increase in the diameter of the through-hole may be provided at a distal longitudinal end portion of the first portion defined by the respective connection portion and / or the respective free longitudinal end portion.

[0045] Thus, the increased diameter is not intended to facilitate insertion of the respective nerve ends, but may, for example, facilitate connection of the first and second parts, particularly when a corresponding connecting portion of the first part extends from the distal end of the insertion part and is adapted to receive the connecting portion of the second part therein.

[0046] In such a configuration, the connecting portion of the second part preferably engages with the connecting portion of the first part at an outer surface of the connecting portion of the first part. In other words, the connecting portion of the first part is preferably formed by a peripheral wall, and for example, the peripheral wall of the second part can engage with the outer peripheral surface of the connecting portion of the first part.

[0047] If the first portion includes a transition portion, the transition portion of the first portion is preferably configured to at least partially receive and accommodate the radially enlarged end of the insert portion of the second portion when the connecting portions of the first and second portions are engaged, i.e., in a connected state. Thus, the second portion may include at least one radially enlarged end of the insert portion. In some embodiments, the radially enlarged end of the insert portion is (only) at the end that receives the nerve end (the nerve end "entrance" into the insert portion). In some embodiments, the radially enlarged end of the insert portion is (only) at the end that is (longitudinally) opposite the end that receives the nerve end. Thus, the radially enlarged end may extend, for example, from the distal end of the insert portion, i.e., the end that is not configured to insert the respective nerve end. Preferably, both ends of the insert portion of the second portion may have a radially enlarged end.

[0048] The radially enlarged end (the end of the insert opposite the nerve entry end) is preferably configured so that the nerve end received in the through-hole does not extend through or beyond that end. Thus, the radially enlarged end can define the end face of each nerve end. This can provide a spacing or gap for the nerve end received in the portion of the through-hole defined by the corresponding insert. This prevents the nerve end from unintentionally extending into the other portion of the insert, and allows the nerve end to be received in a substantially tension-free manner.

[0049] Furthermore, the radially enlarged end of the end portion, e.g., having a conical shape, can provide a guide for axonal nerve growth or regeneration from the nerve end portion received in the through-hole of the first portion toward the nerve end portion received in the through-hole of the second portion, i.e., the target nerve end portion. The radially enlarged end portion can, for example, be adjacent to or have a predetermined spacing relative to adjacent nerve ends and / or can be sized to avoid growing along the outer periphery of the insertion portion of the second portion, e.g., when the second portion is sized for a nerve end portion having a smaller diameter.

[0050] Alternatively, the radially enlarged end portion can be received within a portion of the through-hole defined by the connecting portion of the first portion when the connecting portion of the first portion and the connecting portion of the second portion are engaged, i.e., in a connected state. Depending on the configuration of the first portion, the longitudinal end face of the radially enlarged end portion can be located, for example, at the junction of the connecting portion and the adjacent transition or insertion portion. The radially enlarged end face can be, for example, radially adjacent to the through-hole of the first portion in a frictionless manner or can be dimensioned to define a predetermined gap between the through-hole and the radially enlarged end face portion. This can provide a guide surface and / or longitudinal definition for the nerve end portion received in the through-hole of the first portion. Such a guide surface provided by the radially enlarged end face can be, for example, substantially continuous and / or flush with the adjacent transition or insertion portion of the first portion.

[0051] The insert portion of the second part and / or its optional radially enlarged end portion preferably extend longitudinally, particularly distally, beyond their respective connection portions. Such a configuration facilitates the distal end of the insert portion extending into the through-hole of the first part, typically beyond the connection portion of the first part. Furthermore, such extension into the through-hole of the first part and toward the nerve ends received in the insert portion of the first part can minimize the gap between the respective nerve ends connected in an end-to-end manner. Thus, the extension from the insert portion can provide a large portion of the insert portion and the corresponding through-hole of the second part that can be received and accommodated by the first part, i.e., within the respective through-holes, thereby advantageously bringing the terminations of the nerve ends closer together.

[0052] At least a portion of the through-hole defined by (at least a portion of) the insert of the first and / or second part may be defined by a tubular-shaped wall defining a substantially constant inner diameter. A constant inner diameter may be advantageous in view of the diameter and / or morphology of the nerve end to be accommodated therein. Furthermore, this may facilitate insertion of the respective nerve end by avoiding potentially undesirable narrowing of the through-hole. The through-hole of the second part may be substantially (only) defined by the respective insert. Thus, in the second part, the insert (only) preferably substantially defines the longitudinal extension of the through-hole (while the connecting portion and, optionally, the transition portion of the second part may not define the through-hole when disposed in a "surrounding" configuration, i.e., the portion surrounding the insert). In some embodiments, the connecting portion of the second part may therefore preferably be configured and arranged so as not to define a portion of the through-hole, e.g., provided in a configuration in which the connecting portion is disposed around the insert.

[0053] The through-hole of the first part may be substantially defined by the respective inserts, but preferably also by the respective connecting parts and, optionally, the transition parts. When the nerve conduit system is in a connected state, i.e., when the connecting part of the first part and the connecting part of the second part are engaged, the through-hole of the system, i.e., a (single) continuous through-hole extending between the first and second parts, may be substantially formed (only) by the respective inserts of the two parts. This causes the nerve ends housed in the respective inserts to be connected to, or at least brought close to, each other via said through-hole.

[0054] The connecting portions of the second portion may extend from the longitudinal ends of the respective insert portions configured to receive and / or insert the respective nerve ends, e.g., from the inlets of the respective insert portions. Alternatively, the connecting portions of the second portion may extend from longitudinally offset insert portions to the longitudinal ends of the respective insert portions configured to receive and / or insert the respective nerve ends. For example, the connecting portions may extend from the proximal ends of the insert portions or from a position between the proximal and distal ends of the insert portions. Generally, the connecting portions of the second portion may extend directly or indirectly from the insert portions, and preferably, a transition portion may be disposed between the connecting portions of the second portion and the insert portions.

[0055] In the surrounding configuration described above, the connecting portion preferably extends longitudinally along the outer surface of the insert toward the distal end of the insert. Preferably, the walls of the connecting portion surround the walls of the insert, thereby preferably providing substantially equal distances (longitudinally and / or radially) between the walls of the connecting portion and the walls of the insert. Preferably, the radial spacing between the connecting portion and the insert is provided by a transition portion, which may be configured to attach a connecting portion having a larger diameter to an insert having a smaller diameter.

[0056] Thus, the connecting portion may be formed, for example, as a peripheral wall. The connecting portion may be connected at one end to the wall defining the corresponding portion of the insertion portion and the through-hole, in particular via a transition portion as described above. The connecting portion of the second portion may have a "free" end or a protrusion (in the longitudinal direction) configured to initiate connection with the first portion. That is, said free end or protrusion may provide an initial contact with the connecting portion of the other (first) portion during connection of the two portions.

[0057] In particular, an offset of the second portion connection portion relative to, for example, the proximal end of the second portion insertion portion can be advantageous when, for example, the overall longitudinal extension of the second portion is greater to bridge a gap in a correspondingly larger nerve end. In such cases, a longitudinal offset relative to the insertion portion can be advantageous to improve the structural stability and / or handling of the second portion connection portion.

[0058] The connecting portions of the first portion are preferably positioned adjacent to the respective transition portions or adjacent to the longitudinal ends of the respective insertion portions opposite the longitudinal ends of the respective insertion portions configured to receive and / or insert the respective nerve ends.

[0059] In some embodiments, the connecting portion of the first portion may be formed by a single peripheral wall that defines a counterpart of the through hole. The wall may be further configured to receive and engage the connecting portion of the second portion. The connecting portion of the second portion may be formed as a peripheral wall.

[0060] The connecting portion of the first part may thus be formed by a single peripheral wall, which accommodates the connecting portion of the second part on its inner or outer surface. The connecting portion of the second part may therefore be received in the first part or on its outer surface, for example by a slidable arrangement, with the wall of the first part forming a guide surface and engaging with the connecting portion of the second part, which is also preferably formed as a peripheral wall. In such an embodiment, the connecting portion of the first part preferably defines a counterpart of the through-hole, which may in particular accommodate at least a portion of the through-hole of the second part.

[0061] The provision of a single peripheral wall facilitates connection because correct relative orientation of the two portions both radially and longitudinally is simplified. Furthermore, the wall of the connecting portion of the second portion may be received in or along the through-hole defined by the wall of the connecting portion of the first portion, e.g., by a sliding arrangement, to provide tactile feedback to the surgeon regarding the coupling and to provide progressive engagement depending on the length of insertion.

[0062] In some embodiments, the connecting portion of the first part is formed as a double-walled portion, e.g., two peripheral walls radially spaced apart to define a gap therebetween. Preferably, the two peripheral walls of the connecting portion are substantially concentrically arranged. The two peripheral walls may be connected to one another at one (longitudinal) end, which is adjacent to the transition or insertion portion of the first part. The opposite (longitudinal) end is preferably a "free" end, which is configured to receive and engage the connecting portion of the second part. Thus, the connecting portion of the second part, preferably a single (peripheral) wall, can be received in the gap provided between the two walls of the connecting portion of the first part. It is understood that the gap between the two walls of the connecting portion of the first part is typically dimensioned to receive / accommodate the connecting portion of the second part, preferably a single (peripheral) wall.

[0063] In other words, the connection portion of the first portion may be formed by circumferential inner and outer walls that define a longitudinally extending groove (also referred to herein above as a "gap") between said walls. In particular, this groove is configured to accommodate the connection portion of the second portion when the connection portion of the first portion and the connection portion of the second portion are engaged, i.e., connected. The inner and outer walls of the connection portion are therefore radially spaced apart from one another. In some embodiments, the groove may also be formed in a single (thicker) wall portion (instead of each wall portion), thus defining an inner wall element or portion and an outer wall element or portion.

[0064] The inner and outer walls are preferably formed to extend from the longitudinal end of the connecting part adjacent to the transition part (or the insertion part, if no transition part is present). At the other (longitudinal) end of the connecting part, free ends of the inner and outer walls are provided, which are configured to receive the connecting part of the second part. The free ends usually face away from the respective insertion parts and / or away from the corresponding openings of the through-holes configured as entrances for receiving the nerve ends. In particular, the inner and outer walls are connected to each other at the (longitudinal) end of the connecting part adjacent to the transition part (or adjacent to the insertion part). The other longitudinal end of the wall is preferably free and forms respective protrusions and corresponding seats (or grooves / gaps) for receiving the connecting part of the second part. The connecting part of the second part, which may be formed by a groove or double wall, preferably also as a peripheral wall, can be inserted into the connecting part or groove of the first part to engage with the outer and / or inner wall, for example by snap-fitting.

[0065] The outer wall may further include a radial flare or extension at its free end, for example in the form of a funnel, chamfer, or bevel. This may increase the radius of the outer wall of the connecting portion of the first part at its free end compared to the other end (and compared to the main portion of the connecting portion, so that the inner and outer walls preferably extend substantially concentrically around the same longitudinal axis as the connecting portion of the second part and / or the through-hole, respectively). This radial flare may facilitate insertion of the connecting portion of the second part. Such a flare may further be used to release the intermittent coupling of the two parts, for example, by facilitating spacing between the outer wall and the receiving portion of the connecting portion of the second part.

[0066] As mentioned above, each connection portion may include at least one peripheral wall to facilitate connection of the two portions via the corresponding connection portion. Preferably, the peripheral walls are configured to engage with each other, be radially biased, and / or be dimensioned and configured to be mated with each other when the connection portion of the first portion and the connection portion of the second portion are engaged, i.e., in a connected state.

[0067] According to one embodiment, the outer diameter of the peripheral wall of the connecting portion of the second part can be preferably adapted to (e.g., substantially corresponding to or slightly smaller than) the inner diameter of the (outer) peripheral wall of the connecting portion of the first part, so as to enable a press-fit engagement of the peripheral walls. According to a preferred embodiment, the inner diameter of the peripheral wall of the connecting portion of the second part can be preferably adapted to (e.g., substantially corresponding to or slightly larger than) the outer diameter of the (inner) peripheral wall of the connecting portion of the first part, so as to enable a press-fit engagement of the peripheral walls. Typically, a certain tolerance and / or flexibility is provided with respect to the diameters to enable a press-fit engagement of the peripheral walls. For example, the difference in the diameters of the peripheral walls can correspond to between about 30 and 90 percent of the wall thickness, preferably between 40 and 60 percent of the wall thickness. One of the peripheral walls can further have a greater thickness so that the radial biasing force towards the peripheral wall having a smaller thickness can be increased, for example to facilitate a radially outward biasing force.

[0068] Additionally, the peripheral wall can be dimensioned such that a wall of the connecting portion of the second part is slidably received by at least one wall of the connecting portion of the first part. Thus, the peripheral wall of the first part can provide a guide surface that facilitates connection and engagement of the two parts. This allows the peripheral wall of the second part to be received on an outer or inner surface of the peripheral wall of the first part.

[0069] The slidable arrangement can further provide that when the connecting portion of the first portion and the connecting portion of the second portion are engaged, i.e., connected, initial retention is provided prior to potential fixation of the two portions, for example, by application of a medical adhesive or mechanical fixation. The guide surface and slidable arrangement further facilitate proper orientation and alignment of the nerve conduit portion and the nerve end portion received therein.

[0070] Alternatively, or in addition to a press-fit engagement, the portions can be secured or fixed together by positive locking, which may reduce the need for medical adhesives and / or facilitate attachment of the portions and nerve ends to one another, potentially reducing the occurrence of loose engagement.

[0071] Thus, one of the connecting portions can include at least one radial protrusion, and the other connecting portion can include at least one slit or groove configured to receive the protrusion and secure the second portion to the first portion at least longitudinally when the connecting portion of the first portion and the connecting portion of the second portion are engaged, i.e., in a connected state. Preferably, the at least one radial protrusion and the at least one slit are configured for a snap-fit ​​engagement when the connecting portion of the first portion and the connecting portion of the second portion are engaged. It should be understood that "at least one protrusion or slit" can therefore refer to one or more protrusions, slits, or grooves, i.e., two, three, four, five, six, or more protrusions, slits, or grooves, but can also refer to a single protrusion, slit, or groove. In general, the number of protrusions and the number of slits or grooves can be the same or different.

[0072] By providing positive locking, a predetermined connection state can be provided to ensure a required or predetermined distance or proximity between the nerve ends in a contained state. Furthermore, such positive locking mechanisms, and particularly snap-fit ​​engagements, provide tactile feedback to the surgeon to confirm that the parts are properly connected to one another. For example, even when medical adhesive is applied for redundancy or specific treatment requirements, the positive locking ensures that the parts are maintained in a predetermined connection state, i.e., when the connecting portion of the first part and the connecting portion of the second part are engaged, eliminating the need to manually hold the parts together during application and / or curing of the medical adhesive.

[0073] Preferably, at least one protrusion or slit of the connecting portion of the first part is disposed on the inner or outer surface of the peripheral wall of the connecting portion. Alternatively, or in addition, at least one protrusion or at least one slit of the connecting portion of the second part may be disposed on the opposite surface (i.e., the outer or inner surface) of the peripheral wall of the connecting portion. At least one protrusion or at least one slit of the connecting portion of the first part may, for example, be present in a connecting portion defined by a single peripheral wall, or may be disposed in a groove defined by the double peripheral walls that define the connecting portion of the first part.

[0074] In particular, the peripheral wall of the connecting portion of the second part can therefore be received or housed within the peripheral wall of the connecting portion of the first part, i.e., inserted within a single peripheral wall or into a groove defined by the connecting portion of the first part. In the connected state, i.e., when the connecting portion of the first part and the connecting portion of the second part are engaged, interfaces at the connecting portion of the second part can engage with corresponding interfaces at the connecting portion of the first part.

[0075] At least one slit may have a circumferential extension greater than at least one protrusion. This allows for some flexibility in the orientation of the segments relative to one another in the circumferential direction. Thus, the greater extension of the slit allows for corresponding movement or rotation of the segments corresponding to the difference in circumferential extension. This may be particularly advantageous in situations where, after initially securing the segments together, the surgeon determines that relative rotation would be beneficial to treatment. Furthermore, this may provide some natural movement at the implantation site, absorbing torque forces that could otherwise impair nerve regeneration, for example. After proper alignment, additional medical adhesive may be applied to prevent such further rotation. As discussed above, positive locking provides that the segments are secured together at least longitudinally during application and / or curing of the medical adhesive.

[0076] Preferably, the nerve conduit system comprises a plurality of protrusions and a plurality of slits. Preferably, the number of slits and protrusions is equal. The protrusions and slits may be equally spaced apart in the circumferential direction.

[0077] Preferably, the nerve conduit segments include at least two slits and / or at least two protrusions. Multiple protrusions and slits provide improved fixation of the nerve conduit segments relative to one another and may facilitate proper orientation and alignment by the surgeon during attachment of the segments. For example, the nerve conduit system may include 2 to 12 protrusions and slits, preferably 6 to 10 protrusions and slits. Furthermore, the slits may be provided in two rows, where the rows are longitudinally spaced apart from one another and the slits in each row are circumferentially aligned along a single straight line. This allows the surgeon to choose between two different predetermined gaps between adjacent nerve ends upon attachment, selecting the required gap based on the clinical condition of the nerve ends and / or the required or preferred treatment.

[0078] Instead of one or more slits, the nerve conduit system may include one or more recesses configured to receive corresponding protrusions, in which case the protrusions do not extend through or beyond the receiving recesses, as would be the case with a slit, but are instead received, seated, or retained by the recesses, e.g., in a form-fitting manner.

[0079] To facilitate insertion of the nerve end into each insertion section, the cross-sectional area of ​​the through-hole of the insertion section of the first and / or second part may gradually increase at the longitudinal end that receives the nerve end in an opposing direction toward the end that receives the nerve end (nerve entrance).

[0080] This may be particularly advantageous for nerve conduit sections sized to accommodate nerve ends with smaller diameters, where inserting the corresponding nerve ends into the openings may be difficult. Nerve ends with larger diameters may be less difficult to insert into correspondingly sized inserts. However, even in such cases, the increased diameter or opening may facilitate insertion and / or application of a medical adhesive to secure the nerve ends to their respective inserts.

[0081] Preferably, the insert, especially the counterpart of the through-hole with an increased cross-sectional area, has a rotationally symmetrical shape along the longitudinal axis defined by the wall. In particular, the shape can be substantially U-shaped, sigmoidal, conical, concave, funnel-shaped, or parabolic. This avoids sharp edges that could impair insertion and provides gradually extending guide surfaces that facilitate insertion. Preferred shapes are understood as shapes that extend substantially from the insert defining the counterpart of the through-hole, especially from a portion with a substantially continuous diameter, as seen in a longitudinal cross-section of the respective portion. These are usually continuous in the circumferential direction, i.e., without gaps, due to the rotational symmetry.

[0082] According to some embodiments, the insert, particularly the counterpart with an increased cross-sectional area of ​​the through-hole, may include structures on its outer surface with specific geometric shapes or irregular surfaces or surface irregularities shaped to form a holding surface, such as protrusions, slits, striations, grooves, or holes. In particular, such external structures may advantageously (i) increase contact between the surface of the insert and the adhesive, and (ii) create anchoring points for the adhesive. Such external structures are disclosed, for example, in patent application WO2022229207, the contents of which are incorporated by reference in their entirety.

[0083] Therefore, providing a larger cross-sectional area at at least one end of the nerve conduit system significantly facilitates insertion of each nerve end of the nerve to be repaired. In particular, the larger cross-sectional area can provide tolerance for (unintentional) offsets in the insertion height of the nerve end relative to the cross-sectional area of ​​the through-hole of the insertion section during the repair procedure. This ensures that even if such offsets are provided, the nerve end will be received within the nerve conduit and (minor) adjustments can be made without the need for reinsertion of the nerve end or specific manipulation of the nerve conduit. Furthermore, the larger cross-sectional area serves as an optical guide surface for the surgeon, further facilitating proper insertion of each nerve end. This allows proper insertion and placement of nerve ends into the nerve conduit system, for example, into through-holes that may be specifically sized to accommodate the nerve ends to be connected, to be achieved more easily and in a time-efficient manner without adversely affecting the respective nerve ends.

[0084] Preferably, a guide surface may be provided toward the second diameter and / or the insertion portion of the other (second) portion to facilitate or direct appropriate axonal growth from, for example, a nerve end having a larger diameter received and accommodated in the first portion to, for example, a nerve end having a smaller diameter received in the through-hole of the second portion. Such a configuration may also be advantageous for surrounding tissue by providing smooth or no edges at the interface with adjacent portions. Furthermore, a conical shape may facilitate gripping and handling of the first portion during surgery. Furthermore, a conical shape may improve the structural stability of the first portion and the entire nerve conduit system in the connected state, i.e., when the connecting portion of the first portion and the connecting portion of the second portion are engaged.

[0085] In some embodiments, the first diameter of the through-hole of the insertion portion of the first part may be smaller than the second diameter of the corresponding connecting portion. This allows the transition portion to define a radially outwardly expanding through-hole portion. The connecting portion may be disposed as a longitudinal extension of the insertion portion. For example, the through-hole of the first part may be substantially formed by the insertion portion, the transition portion, and the connecting portion. The through-hole expands radially outward at the transition portion. Such a configuration may be provided, for example, when the diameter of the nerve end of the first part is smaller than or equal to the nerve end to be received in the second part. Similarly, such a configuration may be provided when the nerve end to be connected has a relatively small diameter, i.e., smaller than the connecting portion of the first part. Thus, as long as the diameter of the nerve end received in the first part is smaller than the corresponding connecting portion, nerve ends having substantially the same dimensions or a larger diameter than the nerve end of the second part may also be connected using such a configuration.

[0086] When the through-hole of the insertion portion of the first portion has a first diameter greater than the second diameter of the corresponding connecting portion, the transition portion can define a radially inwardly narrowing through-hole portion, such that the first portion can accommodate a nerve end having a larger diameter than a nerve end accommodated in the second portion.

[0087] In some embodiments, the connector can have a predetermined diameter. Such predetermined dimensions of the connector can be particularly advantageous in a kit of parts, for example, to accommodate connectors corresponding to various second parts having different through-hole and / or insert dimensions.

[0088] Thus, the connecting portion of the first part (and the second part) can be provided with a standardized predetermined radial dimension, e.g., in a kit of parts, whereby the dimensions of at least the insert and the through-hole may be variable. The transition portion of the first part and / or the second part can ensure a gradual transition of the termination of the nerve end contained in the respective insert towards the respective connecting portion and / or the adjacent insert of each other part.

[0089] Preferably, the connecting portions are configured to connect the respective through-holes to the entire through-hole toward the outside of the system when the connecting portions of the first and second portions are engaged. This can further promote axonal growth from one nerve end to the other through the nerve conduit system by preventing axonal deviation and allowing the concentration of nutrients and growth factors. Therefore, for example, the risk of axonal growth around the insertion portion of the first or second portion can be reduced or effectively avoided.

[0090] At least a portion of the transition section adjacent to the insert (preferably the entire transition section) may be provided by or formed by a wall, said wall being disposed at a predetermined angle relative to the wall of the insert, the predetermined angle being based on the difference and distance between the first diameter (of the through hole) of the insert and the second diameter of the corresponding connecting section. The wall of the transition section preferably defines a portion of the through hole. It may also define a bridge between the insert and the connecting section, for example, concentrically disposed along the outside of the insert.

[0091] Thus, the length or extension of the longitudinal transition may increase with a corresponding increase in the difference between the first and second diameters. The longitudinal extensions of the first and / or second sections and / or the angled insertion section may be adapted accordingly to reduce the overall length of the nerve conduit system.

[0092] Preferably, in arrangements where the transition portion surrounds or extends over the respective insert, the predetermined angle is between 10 and 60 degrees, preferably between 30 and 60 degrees, more preferably between 30 and 50 degrees. In arrangements where the transition portion is located adjacent to the insert, the predetermined angle may be between 120 and 240 degrees, more preferably between 130 and 230 degrees.

[0093] Such an angle may define, in longitudinal cross section as a whole, a conical shape of the transition portion and a funnel shape of the first portion (and / or second portion). The predetermined angle provides a predetermined gradual slope, with angles between 120 and 240 degrees being found to be particularly advantageous.

[0094] Alternatively, the transition section (of the first section) may be formed by a wall defining a predetermined longitudinal extension, with the angle between said wall and the wall defining the insert section and / or its through-hole based on the difference between the first and second diameters. The predetermined longitudinal extension or axial length may provide a standardized overall length of the first section for various dimensions of the insert section and the connection section. Such a standardized length may also define a predetermined gap or spacing between the terminations of the nerve ends connected via the nerve conduit system. For example, nerve ends housed in the first section may be inserted up to or near the interface with the transition section, while nerve ends housed in the second section may be inserted up to the end face of the respective insert section or to the interface with the optionally radially enlarged end of the insert section.

[0095] Additionally, the predetermined length may facilitate handling by the surgeon during implantation of the nerve conduit system, for example, during insertion of each nerve end and / or connection of the first and second portions.

[0096] To facilitate connection and provide tactile feedback to the surgeon, the connecting portion of the first part may define a stop configured to abut the connecting portion of the second part when the connecting portions of the first and second parts are engaged, i.e., in a connected state. Thus, the stop can prevent the connecting portion of the second part from being inserted or advanced longitudinally beyond the stop, i.e., preventing the second part from being inserted beyond its intended position. Preferably, the stop defines a predetermined relative position between the first and second stops. For example, the stop can provide a predetermined spacing or gap between the accommodated nerve ends, the spacing or gap being optimized for end-to-end connection and nerve regeneration. The stop can further provide a predetermined connection, for example, by a corresponding interference fit and / or by ensuring a positive locking or snap fit, where one or more protrusions and corresponding recesses or slits of the first and second parts engage with each other. The stop may be formed, for example, by a wall of the connection section and / or a wall of an adjacent transition section, if such a transition section exists.

[0097] Preferably, the stop comprises a longitudinally extending locking portion configured to at least partially receive the connecting portion of the second part and / or to radially secure the connecting portion of the second part when the connecting portion of the first part and the connecting portion of the second part are engaged, i.e., in the connected state. Thus, the abutment may be provided, for example, by a radially extending ridge on the wall of the connecting portion and / or the adjacent transition part, but the stop is preferably formed so as to at least partially surround the immediately adjacent end, e.g., wall, of the connecting portion of the second part as well. The stop may be formed, for example, as a semicircular or parabolic groove or undercut, and preferably comprises a peripheral wall extending radially along the adjacent end face of the connecting portion of the second part.

[0098] As mentioned above, the connecting portion may be formed substantially as a longitudinally extending peripheral wall and configured to engage a corresponding peripheral wall portion of the connecting portion of the second part. The stop may thus form a wall or stop parallel to the peripheral wall such that the end faces of the connecting portion are secured radially inward and outward and received within the undercut.

[0099] In some embodiments, in addition to or instead of the stop of the first part described above, the second part may also define a stop. The above description regarding the stop of the first part equally applies to the stop of the second part. It is understood that the stop of the second part is configured to be adjacent to the connecting part of the first part when the connecting part of the first part and the connecting part of the second part are engaged, i.e., in a connected state. Thus, the stop can prevent the connecting part of the first part from being inserted or advanced longitudinally beyond the stop, i.e., can prevent the second part from being inserted beyond its intended position. In some embodiments, the first part and the second part each include a stop, e.g., in a complementary manner. For example, the stop of the first part may be located on an inner surface of a peripheral wall of the connecting part of the first part, while the stop of the second part may be located on an outer surface of a peripheral wall of the connecting part of the second part. Preferably, the stop of the first part may be located on the outer surface of the (circumferential) wall of the connecting part of the first part, while the stop of the second part may be located on the inner surface of the (circumferential) wall of the connecting part of the second part.

[0100] During insertion of the nerve ends into the respective nerve conduit sections and subsequent fixation of the nerve ends, for example with a medical adhesive, undesirable compression of the respective nerve conduit sections and nerve ends may occur, which may be detrimental to the integrity and repair of the nerve ends. To facilitate handling during connection of the first and second sections, at least one connection section and / or transition section and / or insertion section may include one or more gripping ribs that protrude radially outward from the outer surface of the wall of the connection section, preferably extending longitudinally at or along the outer surface of the connection section. The radially outward extension facilitates gripping and handling of the respective sections without directly interfering with the integrity of the insertion section, through-hole, and connection section, and may absorb or at least attenuate undesirable effects on the respective sections.

[0101] The connection portion may include two or more gripping ribs. Thus, the connection portion may include a single gripping rib or may include more than one gripping rib, for example, two, three, four, five, six, seven, eight, nine, or more gripping ribs. Preferably, when two or more gripping ribs are present, the two or more gripping ribs may be equally spaced apart from one another around the circumference of the connection portion. For example, the gripping ribs may be arranged in two or more sets of ribs, with the gripping ribs in each set having the same predetermined circumferential spacing, and the sets of ribs may be configured with different predetermined circumferential spacings.

[0102] The predetermined placement of the gripping ribs can facilitate orientation between the orientations of the respective portions, for example, providing rotational symmetry and / or a level of redundancy. Furthermore, when both portions include one or more ribs, the ribs may be provided in predetermined locations, for example, relative to one or more protrusions or slits in the connecting portion. This allows the ribs to indicate the intended predetermined placement of the portions relative to each other. In other words, such rib placement can facilitate correct alignment of the portions.

[0103] The ribs can have various shapes that are advantageous for handling and gripping the respective segments. Because the ribs can increase the radial dimension of the respective segments and / or the entire nerve conduit system, the ribs may protrude into the surrounding tissue during implantation. Therefore, to avoid or reduce potential tissue damage, each gripping rib can have at least one rounded end in the longitudinal cross section of the respective connection portion. This can avoid sharp edges.

[0104] At least one wall of the first section connection portion may further include a transparent window or opening, e.g., a radial opening, which may be positioned at a predetermined longitudinal offset relative to the free end of the first section connection portion. The window or opening allows the surgeon to monitor the insertion length or depth of the second section connection portion. This allows the surgeon to provide visual feedback regarding the connection status, i.e., when the first section connection portion and the second section connection portion are engaged, and to insert the second section connection portion, for example, to provide a predetermined gap relative to the nerve ends to be connected and / or based on therapeutic needs. According to particular embodiments, the first and / or second sections of the nerve conduit system are made of a transparent material.

[0105] The window or opening may provide an alternative to the tactile feedback provided by, for example, protrusions and slots on the connector or stops on the first section, however, the window or opening may also provide additional feedback to confirm correct positioning and attachment of the nerve conduit section.

[0106] Preferably, the window or opening is formed in a wall defining the connection portion, such as a longitudinal peripheral wall. To improve structural stability, a transparent window may be provided, eliminating the need for sealing with, for example, a medical adhesive. By enabling such monitoring into the connection portion and / or toward the through-hole, the surgeon can be provided with direct visual feedback regarding the distance of the nerve end received by the second portion relative to the nerve end received by the insertion portion of the first portion.

[0107] In some embodiments, at least one of the portions, and in particular its respective lumen or through-hole, may contain a drug, e.g., by a coating or integrated into the material of the respective portion, e.g., the wall, which may be released over time, e.g., to promote nerve growth.

[0108] The first and / or second portions, preferably each portion, are preferably formed of a biocompatible, inert, bioimplantable, and / or biodegradable material. The material may be selected to provide a predetermined structural stability while substantially avoiding or at least reducing an inflammatory response in the treated patient. For example, a biocompatible material may be selected. This material may gradually degrade over time after implantation, but may initially provide sufficient structural support to properly repair nerve damage, ensuring that the respective nerve ends are properly and sufficiently stably connected, for example, during tissue movement.

[0109] Certain materials may further be selected to promote or support neural growth, for example, by comprising, incorporating, or including a corresponding coating containing a bioactive agent and / or one or more neurotrophic factors. Other examples of such bioactive surface functionalities include, but are not limited to, anti-inflammatory agents, immunosuppressants, and neuroprotective agents. Bioactive agents may be surface-bound and / or entrapped in structures defining the elongate body, such as the walls described above.

[0110] Preferably, the first and / or second portions, more preferably each portion, are made of a polymeric material, preferably an elastomer. This has the advantage that multiple manufacturing methods can be applied and / or specific properties can often be provided, for example, based on the polymer unit. In particular, the polymeric material may be biocompatible and have elastic properties so that, when implanted, the nerve conduit can adapt to the movements of the tissue surrounding the repaired nerve injury.

[0111] The first and / or second portions, preferably each portion, may be formed of polymerized and / or crosslinked polymer units comprising an ester group component and an acidic ester group component, the ester group component preferably being a polyol and the acidic ester group component preferably being a polyacid.

[0112] The materials used for each section may be the same, which may facilitate easier manufacturing and may allow the structural properties of each section to be substantially uniform along the length of the nerve conduit system, allowing biodegradation (and / or bioresorption) to occur in a predetermined or predictable manner when the nerve conduit system is properly constructed.

[0113] The first and / or second portions, preferably each portion, are preferably integrally formed (i.e., each formed as a single piece). Thus, the connection portion preferably does not require a specific connection, for example, with the transition portion or the insertion portion. Instead, a material bond can be provided by the materials used for each portion and their corresponding structural integrity. By providing each portion as a single piece, separate connections between the portions are effectively avoided, which can further improve the robustness of the nerve conduit system.

[0114] Preferably, the first and / or second portions, more preferably each portion, are formed by a 3D printing process. This is particularly advantageous when the nerve conduit material is polymeric, and material hardening can be achieved virtually instantly, for example, using (UV) light. It offers a level of precision that cannot be easily achieved by extrusion and / or immersion processes. In particular, the 3D printing process allows for the specific shape of each nerve conduit portion to be obtained. For example, the printing process may provide for specific bioactive agents to be incorporated into the 3D structure according to a predetermined pattern, for example, within the mesh structure and / or within specific pockets or cavities formed by the 3D structure. This may further improve coordination and support for nerve repair and / or achieve biodegradation in a more controllable manner.

[0115] The above-mentioned objects are further achieved by the use of the nerve conduit described above for repairing, supporting, and / or guiding nerve tissue, particularly for repairing peripheral nerve injuries and / or for connecting two nerve ends. Furthermore, the nerve conduit can be used in combination with a medical adhesive. According to a preferred embodiment, the medical adhesive is based on a polymer unit containing an ester group component and an acidic ester group component, the ester group component being preferably a polyol, and the acidic ester group component being preferably a polyacid. According to one embodiment, the medical adhesive is based on a photocurable elastomer from poly(glycerol-co-sebacate), preferably poly(glycerol-co-sebacate) acrylate (PGSA).

[0116] In a further aspect, a kit of parts is provided, comprising a nerve conduit system according to the invention as described herein, the kit comprising two or more first parts adapted to different nerve end diameters and / or two or more second parts adapted to different nerve end diameters, the connections of said parts being adapted such that each first part of the kit is connectable to each second part of the kit.

[0117] In some embodiments, the kit comprises two or more (different) first parts and at least one second part adapted to different nerve end diameters. In some embodiments, the kit comprises at least one first part and two or more (different) second parts adapted to different nerve end diameters. Preferably, the kit comprises two or more (different) first parts adapted to different nerve end diameters and two or more (different) second parts adapted to different nerve end diameters. The two or more (different) first parts and / or second parts typically differ in (their) inserts. In particular, to accommodate nerve end portions of different diameters, the two or more (different) first parts may have different (inner) diameters of the inserts (through holes). Similarly, to accommodate nerve end portions of different diameters, the two or more (different) second parts may have different (inner) diameters of the inserts (through holes). This allows the selection of an appropriate size that best fits the nerve end from among the different sized (insertion parts) of the (different) first parts and / or second parts.

[0118] The inner diameter of the nerve end is preferably selected from 1.5 mm to 12 mm, more particularly 1.5 mm to 12 mm for nerves above the wrist, 1.5 mm to 3 mm for nerves between the wrist and hand, and 1.5 mm to 2 mm for nerves in the hand.

[0119] On the other hand, as mentioned above, the connecting parts of each part comprising the kit are designed so that each first part of the kit can be connected to each second part of the kit. For this purpose, the connecting parts are preferably equally dimensioned. In other words, the connecting parts of the (different) first parts are preferably identical, at least for the part of the connecting part involved in the connection with the second part. Furthermore, the connecting parts of the (different) second parts are preferably identical, at least for the part of the connecting part involved in the connection with the first part. In this context, it is understood that the connecting parts of the first and second parts of the kit are configured to engage with each other.

[0120] Due to the specific configuration of the differently sized inserts, nerve ends of different diameters can be easily connected by selecting a first and / or second portion with an appropriately sized insert, while the connections still fit together. Thus, the appropriate first and second portions can be selected on the spot, for example, during surgery. This avoids incompatible conduits, which can cause difficulties during and after surgery.

[0121] In a further aspect, a kit of parts is provided, comprising the nerve conduit system according to the present invention described herein, further comprising a medical adhesive. According to a preferred embodiment, the medical adhesive is based on a prepolymer unit comprising an ester group component and an acidic ester group component, the ester group component preferably being a polyol, and the acidic ester group component preferably being a polyacid. According to one embodiment, the medical adhesive is based on a photocurable elastomer from poly(glycerol-co-sebacate), preferably poly(glycerol-co-sebacate) acrylate (PGSA). According to a preferred embodiment, the medical adhesive is a photocurable adhesive, i.e., it polymerizes or otherwise hardens upon exposure to appropriate radiant energy, more particularly in the form of light from a light source. Preferably, the photocurable adhesive comprises a prepolymer and a photoinitiator, which is capable of inducing polymerization of the prepolymer when exposed to light of a specific wavelength, e.g., ultraviolet (UV) light.

[0122] According to another aspect of the present invention, there is provided a method of connecting two nerve ends, comprising the steps of providing a first portion and a second portion of the nerve conduit system as described above; inserting one of the connected nerve ends into an insertion portion of the first portion and the other of the connected nerve ends into an insertion portion of the second portion; optionally, fixing the nerve ends to the respective portions; and connecting the first portion and the second portion in an end-to-end manner by connecting the connection portion of the first portion to the connection portion of the second portion, preferably by receiving at least a portion of the insertion portion of the second portion into the through-hole of the first portion.

[0123] Fixation of the injured nerve end can be achieved by applying a medical adhesive to the outside of each insertion portion. The connection between the first and second portions is preferably achieved by inserting and / or receiving the connecting portion of the second portion into or around the connecting portion of the first portion until the connecting portions engage with each other, preferably by an interference fit and / or positive locking. BRIEF DESCRIPTION OF THE DRAWINGS The present disclosure will be more readily understood by reference to the following detailed description considered in conjunction with the accompanying drawings, in which:

[0124] FIG. 1 shows a schematic diagram of an exemplary nerve conduit system according to the present invention in a connected state, i.e., a schematic diagram of the first and second parts in a longitudinal cross section with the connection between the first and second parts engaged.

[0125] FIG. 2 shows a schematic view of the second part according to FIG. 1 in a longitudinal section according to FIG.

[0126] FIG. 3 shows a schematic diagram of the nerve conduit according to FIG. 2 with an alternative insertion section.

[0127] FIG. 4 shows a schematic diagram of the nerve conduit according to FIG. 2 with an alternative insertion section.

[0128] FIG. 5 shows a schematic view of a first portion of a nerve conduit system in longitudinal section, according to another embodiment.

[0129] FIG. 6 shows a schematic view of the first part in longitudinal section according to another embodiment.

[0130] 7 and 8 show schematic views of the first part according to FIG. 6 with alternative connections and / or transitions.

[0131] 9 and 10 show schematic views of the second part according to FIG. 4 with additional ribs according to an alternative embodiment.

[0132] 11 and 12 show schematic views of a first portion of a nerve conduit system in longitudinal cross section according to another embodiment having an alternative rib arrangement.

[0133] FIG. 13 shows a schematic diagram of the first and second portions of a nerve conduit system according to an embodiment with positive locking (A), (A) is a top view showing both portions separated and connected (dashed lines), and (B) is a longitudinal cross section along AA as shown in (A).

[0134] Detailed Description The present invention will now be described in more detail with reference to the accompanying drawings showing exemplary embodiments of the present invention. However, the present invention is not limited in scope by the specific embodiments described herein. The following embodiments are provided to enable those skilled in the art to more clearly understand and implement the present invention. In the drawings, similar elements are designated by the same reference numerals, and repeated descriptions may be omitted to avoid redundancy.

[0135] FIG. 1 shows a schematic longitudinal cross-sectional view of a nerve conduit system 10 according to the present invention. The nerve conduit system 10 includes a first portion 12 and a second portion 14, shown here in a connected state, i.e., with the connecting portion of the first portion engaged with the connecting portion of the second portion. Both the first portion 12 and the second portion 14 are configured to receive respective nerve ends (not shown), with one nerve end constituting a proximal nerve end and the other nerve end constituting a distal or target nerve end. In this example, the first portion 12 is sized for the nerve end to have a larger diameter than the nerve end received by the second portion 14, so that axonal growth can be promoted from the first portion 12 to the second portion 14, or vice versa.

[0136] Both first and second portions 12 and 13 are substantially tubular and formed by walls defining lumens for receiving and housing the respective nerve ends. Accordingly, first portion 12 includes an insert portion 16 and a connecting portion 22, both of which are defined by walls. Insert portion 16 and connecting portion 22 are connected via a transition portion 18 to form a continuous, homogenous structure.

[0137] As shown, insert 16, or a wall of insert 16, defines an open throughbore 20, shown here extending between longitudinally opposed ends of first portion 12, and defined by insert 16, transition portion 18, and connecting portion 22. Thus, throughbore 20 is formed as a continuous channel from one end of first portion 12 to the opposing end.

[0138] The connecting portion 22 has two radially spaced peripheral walls 23 configured to engage with the corresponding connecting portion 24 of the second portion 14 in the connected state of the nerve conduit system 10, i.e., when the connecting portions 22, 24 of the first and second portions 12, 14 are engaged as shown in the embodiment. The outer wall 23 of the connecting portion 22 is connected to the transition portion 18 and defines a longitudinal groove together with the inner wall 23 for receiving the corresponding peripheral wall of the connecting portion 24 of the second portion 14. To facilitate insertion of the connecting portion 24 into the groove and thus facilitate connection or engagement of the connecting portions 22, 24, the wall of the connecting portion 22 is configured with a radial flare at its free end to provide an enlarged opening of the groove.

[0139] At the junction between the transition section 18 and the connecting section 22, a stop 32 is defined by the wall of the transition section 18 and / or the wall 23 of the connecting section 22, and this stop 32 provides an abutment for the connecting section 24 of the second section 14, ensuring that the connection between the first section 12 and the second section 14 can be provided in a predetermined, defined connection state, i.e., when the connecting sections 22, 24 of the first section 12 and the second section 14 are engaged. The thus provided double-walled feature formed by the connecting section 22 radially fixes the second section 14 to the first section 12, ensuring that the first section 12 and the second section 14 are in a predetermined relative position, as determined by the stop 32, when the connecting sections 22, 24 of the first section 12 and the second section 14 are engaged.

[0140] Nerve ends having smaller diameters can be received within the second portion 14, facilitated by corresponding inserts 26 defining openings into through-holes 30 of the second portion 14. The longitudinal ends of the inserts 26 are also provided with radially enlarged ends 29 opposite the longitudinal ends configured as entrances for the respective nerve ends. The radially enlarged ends 29 are configured to direct nerve growth from the first portion 12, i.e., the inserts 16 and / or the transition portion 18, into the through-holes 30. Preferably, nerve ends received within the second portion 14 are inserted substantially into the through-holes 30 defined by the inserts 26 up to the radially enlarged ends 29. Similarly, nerve ends received in the through-holes 20 of the first portion 12 are inserted such that they do not extend beyond the respective inserts 16, i.e., the transition portion 18. Thus, the nerve ends are brought close together in an end-to-end manner, with the transition portion 18 of the first portion 12 and the radially expanding end 29 of the second portion 14 providing a predetermined spacing or gap between the nerve ends.

[0141] The connecting portions 24 of the second portion 14 shown in this embodiment extend longitudinally from the insertion portions 26 along the outer surface of the wall of each insertion portion 26 and are configured to seal the through-holes 30 at the distal end of the first portion 12. Thus, nerve regeneration is contained within the nerve conduit system 10 and is effectively guided from the insertion portion 16 of the first portion 12 to the insertion portion 26 of the second portion 14. In other words, axonal growth between the first portion 12 and the second portion 14 outside the through-holes 30 is avoided to the greatest extent possible.

[0142] The radial spacing of the connecting portion 24 from the insert portion 26 of the second portion 14 ensures that the connecting portion 24 can engage with the corresponding connecting portion 22 of the first portion 12. At the same time, the difference in diameter between the connecting portion 24 and the insert portion 26 provides that the insert portion 26 can be received and accommodated by the connecting portion 22 or a portion of the through-hole 30 defined by the connecting portion 22. The insert portion 26 can therefore extend toward or into the transition portion 18 of the first portion 12 to facilitate end-to-end connection of the respective nerve ends. Furthermore, this can improve the structural stability of the second portion 14 without significantly increasing the overall dimensions of the nerve conduit system 10 as a whole.

[0143] The connecting portion 24 of the second section 14 is connected to the insert portion 26 by a corresponding transition portion 28 that extends between the connecting portion 24 and the inlet end and / or proximal end of the insert portion 26. Thus, the transition portion 28 bridges a first diameter at the junction with the insert portion 26 and a second diameter at the junction with the connecting portion 24. The connecting portion 24 substantially concentrically surrounds the insert portion 26.

[0144] As shown, sealing of through-hole 30, i.e., the space between the inner surface of inner wall 23 of connecting portion 22 and the outer surface of insert portion 26 that was initially sealed at the distal end of first portion 12, is achieved by transition portion 28. Such space may further reduce potentially undesirable friction and / or provide a bearing for second portion 14 to dampen radial forces, for example, during surgery or movement at the implantation site.

[0145] Similarly, transition section 18 extends between insert section 16 and connecting section 22, bridging the different diameters of the respective sections 16, 22. In such adjacent arrangement, transition section 18 defines corresponding portions of through-hole 20. Additionally, transition section 18 has a substantially conical shape, providing a gentle guide surface toward radially expanding end 29 to facilitate axonal growth toward the nerve end received in insert section 26 of second section 14.

[0146] 2, the second part 14 according to FIG. 1 is shown in an uncoupled or cut state, showing the free end of the connecting portion 24 which receives and engages the connecting portion 22 of the first part 12. It is also clear from this view that a transition portion 28 extending from the insert portion 26 forms a seal between the longitudinally extending wall of the connecting portion 24 and the longitudinally extending wall of the insert portion 26 which defines the through hole 30.

[0147] 3 and 4 schematically illustrate an alternative embodiment of the second portion 14 according to FIG. 2, in which the insert 26 is substantially configured differently. Thus, as shown in FIG. 3, the insert 36 can extend longitudinally, substantially forming the elongation of the through-hole 30. Accordingly, the connecting portion 24 is positioned at a predetermined longitudinal offset from the inlet end of the insert 26. Such an embodiment may be advantageous for applications requiring a longer nerve injury gap to be bridged by the nerve conduit system 10; in this case, the connecting portion 24 is provided substantially similarly to reduce the overall (radial) dimension of the second portion 14 and ensure that the connection between the first portion 12 and the second portion 14 is not compromised by the corresponding elongation of the connecting portion 24. In other words, a predetermined flexibility or resilience can be maintained for the connecting portion 24 while the second portion 14 is adapted to bridge a longer nerve injury gap.

[0148] The embodiment according to Figure 4 substantially corresponds to the embodiment according to Figure 3. However, in this configuration, the insert 26 has an opening and a cross-sectional area that increases in the direction away from the connecting portion 24. The insert 26 is formed as a cone, thereby facilitating the insertion of the respective nerve ends into the insert 26.

[0149] FIG. 5 shows a schematic view of the first part 12 according to the present invention in longitudinal section according to another embodiment. Compared to the embodiment according to FIG. 1, an insert 16 is provided, which is accordingly adapted to receive a nerve end having a smaller diameter compared to the embodiment according to FIG. 1. The insert 16 is substantially cylindrical, with a radially outwardly expanding opening at the entrance or proximal end, which has a conical or parabolic shape. This may facilitate the insertion of a nerve end having a smaller diameter into the insert 16, as described above, for example, in view of the insert 26 of the second part 14 according to FIG. 4.

[0150] Based on the smaller sized insert 16 and through hole 20, a transition portion 18 according to the present embodiment extends radially outward and connects the smaller through hole 20 with a larger sized connecting portion 22. The connecting portion 22 according to the present embodiment is formed as a single peripheral wall extending in the longitudinal direction of the first part 12 and away from the transition portion 18.

[0151] 5 also shows stops 32 defined as semicircular wall extensions or stops of connecting portion 22 and / or transition portion 18, which form recesses for receiving and radially securing corresponding connecting elements or walls of connecting portion 24 of second portion 14. Stops 32 define longitudinal stops that are dimensioned to prevent the end face of connecting portion 24 of second portion 14 from inadvertently advancing towards transition portion 18 and thereby being inserted beyond its intended position.

[0152] The connecting portion 22 is configured to receive the connecting portion 24 on the inner surface of the (single) peripheral wall that defines the connecting portion 22, and forms a guide surface by allowing slidable engagement with the connecting portion 24 of the second part 14.

[0153] The embodiment according to Fig. 6 showing the first portion 12 is substantially similar to the embodiment shown in Fig. 1, but with a smaller diameter of the part of the through-hole 20 defined by the insert 16. In this example, the longitudinal extension of the transition portion 18 is predetermined such that the angle of the transition portion 20 is less abrupt compared to the angle shown in Fig. 1. This is because the difference in diameter between the connecting portion 22 and the insert 16 is smaller, and the height or radial extension of the connecting transition portion 18 is reduced compared to the embodiment shown in Fig. 1.

[0154] Furthermore, like the embodiment of the first portion 12 according to Figure 1, the first portion 12 according to Figure 6 is also configured to receive nerve ends having a larger diameter than the nerve ends accommodated in the second portion 14. Any enlarged opening at the entrance of the insertion portion 16, as shown for example in Figure 5, is not shown in this embodiment.

[0155] 7 and 8 show diagrammatically the first part 12 according to FIG. 6 with an alternative transition section 18 and connection section 22. In FIG.

[0156] Thus, as shown in Figure 7, the transition portion 18 and the connecting portion 22 may be configured as shown in Figure 5. However, in this embodiment, the insert portion 16 and the transition portion 18 are configured to accommodate a nerve end having a diameter larger than the diameter of the nerve end accommodated in the second portion 14. Thus, the insert portion 16 and the transition portion 18 are formed substantially as shown in the embodiment according to Figure 6. This results in the portion of the through hole 20 defined by the insert portion 16 being less pronounced compared to the embodiment according to Figure 5, although the connecting portion 22 is similarly configured to accommodate and / or engage the connecting portion 24 on the inner surface of the wall defining the connecting portion 22.

[0157] An alternative configuration, in which the connecting portion 24 is received and accommodated in the outer surface of the wall defining the connecting portion 22, is shown in Figure 8. Compared to the embodiment according to Figure 7, the free end surface of said wall is not radially enlarged, but instead forms a linear extension parallel to the longitudinal axis of the first part 12 so as to facilitate coupling at the outer surface of the connecting portion 22. According to this embodiment, the transition portion 18 comprises an increased wall thickness, which may be advantageous for improving the structural stability and / or for improving the functionality of the stop 32 preventing longitudinal displacement of the connecting portion 24 of the second part 14 beyond the transition portion 18 towards the insert 16.

[0158] 9 and 10 schematically illustrate the second portion 14 according to FIG. 4 with additional ribs 34 according to an alternative embodiment. As shown in these figures, multiple longitudinally extending ribs 34, e.g., 4-10, or, as shown, 6 or 8, may be provided on the outer surface of the connecting portion 24 of the second portion 14, with the ribs 34 evenly spaced around the circumference of the wall defining the connecting portion 24. While the ribs 34 are rounded at one longitudinal end as shown in FIG. 9, in the embodiment according to FIG. 10, the ribs 34 are rounded at both longitudinal ends. A double-rounded surface may be beneficial for the surrounding tissue of the intended implantation site and may provide a reduced overall size. However, a single rounded end may be selected to improve potential gripping and handling.

[0159] 11 and 12 show schematic views of a first portion 12 according to the invention in longitudinal section according to another embodiment having an alternative arrangement of ribs 34 on the outer surface of the connecting portion 22. The configuration of the first portion 12 substantially corresponds to a combination of the embodiments shown in Figures 5 and 8, in which the insertion portion 16, the through-hole 20 and the transition portion 18 are dimensioned to accommodate the smaller diameter of the nerve end, while a single peripheral wall also defines the connecting portion 22, but which is adapted to receive a corresponding connecting portion 24 of the second portion 14 on the outer surface of said wall.

[0160] 9 and 10, the first portion 12 may include a plurality of spaced ribs 34, e.g., 4 to 10, that are rounded at one or both longitudinal ends based on the structural and anatomical needs of the patient at the implantation site.

[0161] 13 shows a schematic diagram of the first and second sections 12, 14 of the nerve conduit system 10, illustrating both sections in a separated and connected state (dashed lines). The sections 12, 14 are designed to be secured or fixed to one another by positive locking. Such positive locking may reduce the need for medical adhesives and / or facilitate the joining of the sections 12, 14 and the connection of the nerve ends to one another, potentially reducing the occurrence of loose engagement.

[0162] Accordingly, the connecting portion 24 of the second part 14 comprises a plurality of radial protrusions 36, while the connecting portion 22 of the first part 12 comprises (corresponding) slits or grooves 38 configured to receive the protrusions 36. This allows the second part 14 to be fixed at least longitudinally to the first part 12 when the connecting portion 22 of the first part 12 and the connecting portion 24 of the second part 14 are engaged, i.e., in a connected state. In particular, the at least one radial protrusion 36 and the at least one slit or groove 38 are configured for snap-fit ​​engagement when in a connected state, i.e., when the connecting portion of the first part and the connecting portion of the second part are engaged.

[0163] The slit or groove 38 of the connecting portion 22 of the first part 12 is disposed on the inner wall (peripheral wall) of the connecting portion 22. The protrusion 36 of the connecting portion 24 of the second part 14 is disposed on the outer (peripheral) wall of the connecting portion 24. Therefore, the peripheral wall of the connecting portion 24 of the second part 14 can be received or accommodated within the peripheral wall of the connecting portion 22 of the first part 12. That is, the peripheral wall of the connecting portion 24 of the second part 14 can be inserted inside the single peripheral wall or into the groove 38 defined by the connecting portion 22 of the first part 12. Therefore, in a connected state, i.e., when the connecting portion 22 of the first part 12 and the connecting portion 24 of the second part 14 are engaged, an interface on the outer surface of the connecting portion of the second part can engage with a corresponding interface on the inner surface of the connecting portion of the first part.

[0164] 13, both the first part 12 and the second part 14 are provided with complementary stops 32, such that the stops 32 of the first part 12 can be located on the inner surface of the (circumferential) wall of the connecting part 22 of the first part 12, while the stops 32 of the second part 14 can be located on the outer surface of the (circumferential) wall of the connecting part 24 of the second part 14.

[0165] It will be apparent to those skilled in the art that these embodiments and items merely illustrate examples of multiple possibilities. Therefore, the embodiments illustrated herein should not be understood as limiting the features and configurations. Any possible combination and configuration of the described features can be selected in accordance with the scope of the present invention.

[0166] (List of reference numbers) 10 Nerve Conduit System 12 Part 1 14 Part 2 16 Insertion section 18 Transition 20 through holes 22 Connection 23 Wall 24 Connection 26 Insertion section 28 Transition 29 Radial expansion end 30 through holes 32 Stop part 34 Ribs 36 Radial protrusion 38 Slits or grooves [Brief explanation of the drawings]

[0167] [Figure 1] A schematic diagram of an exemplary nerve conduction system according to the present invention in a connected state, i.e., a schematic diagram of the first and second parts in a longitudinal cross section, with the connection between the first and second parts engaged. [Figure 2] 2 shows a schematic view of the second part according to FIG. 1 in a longitudinal section according to FIG. 1; [Figure 3] FIG. 3 shows a schematic diagram of the nerve conduit according to FIG. 2 with an alternative insertion section. [Figure 4] FIG. 3 shows a schematic diagram of the nerve conduit according to FIG. 2 with an alternative insertion section. [Figure 5] 10 shows a schematic view of a first portion of a nerve conduit system in longitudinal section, according to another embodiment. [Figure 6] 10 shows a schematic view of a first part in longitudinal cross section according to another embodiment. [Figure 7] 7 shows a schematic view of the first part according to FIG. 6 with alternative connections and / or transitions. [Figure 8] 7 shows a schematic view of the first part according to FIG. 6 with alternative connections and / or transitions. [Figure 9] 5 shows a schematic view of the second part according to FIG. 4 with additional ribs according to an alternative embodiment. [Figure 10] 5 shows a schematic view of the second part according to FIG. 4 with additional ribs according to an alternative embodiment. [Figure 11] 10 shows a schematic view of a first portion of a nerve conduit system in longitudinal cross section according to another embodiment having an alternative rib arrangement. [Figure 12] 10 shows a schematic view of a first portion of a nerve conduit system in longitudinal cross section according to another embodiment having an alternative rib arrangement. [Figure 13A]1A-1C show a schematic diagram of the first and second parts of a nerve conduit system according to an embodiment with positive locking (A), with the parts shown in a separated and connected state (dashed lines) in top view. [Figure 13B] 1A and 1B show schematic diagrams of the first and second parts of a nerve conduit system according to an embodiment with positive locking (A), and a longitudinal cross section along AA as shown in (A).

Claims

1. A nerve conduit system (10) for connecting two nerve ends end-to-end, comprising: A first portion (12) and a second portion (14), Each section (12, 14) has an insertion section (16, 26) adapted to receive one of the two nerve ends and a connection section (22, 24), each section (12, 14) including a through hole (20, 30) defined by at least the respective insert (16, 26) and extending between longitudinally opposed ends of each section (12, 14); The connecting portions (22, 24) are configured to engage with each other, and when the connecting portions (22, 24) of the first portion (12) and the second portion (14) are engaged, the through holes (20, 30) are arranged to be in fluid communication with each other, and optionally, when the first portion (12) and the second portion (14) are engaged, the connecting portions (22, 24) preferably do not act as pressing members that apply force in the radial direction of the nerve end portion.

2. 2. The nerve conduit system (10) of claim 1, wherein at least one portion (12, 14), preferably the first portion (12) and the second portion (14), further comprises a transition portion (18, 28) extending between the respective insertion portion (16, 26) and the respective connection portion (22, 24).

3. The nerve conduit system (10) of claim 2, wherein the transition section (18, 28) has an essentially tapered shape.

4. 4. A nerve conduction system (10) according to any one of claims 1 to 3, wherein the insertion portion (16, 26) and / or the connection portion (22, 24) of at least one portion (12, 14), preferably each portion (12, 14), has an essentially cylindrical shape.

5. 5. A nerve conduction system (10) according to any one of claims 1 to 4, wherein the connection portion (22, 24) of at least one portion (12, 14), preferably the second portion (14), at least partially surrounds the insertion portion (16, 26) of the portion (12, 14).

6. 6. The nerve conduit system (10) of claim 5, wherein the insertion portion (16, 26) and the connection portion (22, 24) of at least one portion (12, 14), preferably the second portion (14), are concentrically arranged.

7. 7. A nerve conduction system (10) according to any one of claims 1 to 6, wherein the insertion portion (16, 26) and the connection portion (22, 24) of at least one portion (12, 14), preferably the first portion (12), are arranged adjacent to each other in the longitudinal direction.

8. The nerve conduit system (10) of claim 7, wherein a transition section (18, 28) is disposed between the insertion section (16, 26) and the connection section (22, 24).

9. A nerve conduction system (10) as described in any one of claims 1 to 8, wherein the connection portions (22, 24) are configured so that the insertion portions (16, 26) are positioned at longitudinally opposite ends of the nerve conduction system (10) when the connection portions (22, 24) of the first portion (12) and the second portion (14) are engaged.

10. A nerve conduction system (10) as described in any one of claims 1 to 9, wherein the through holes (20, 30) of the first and second portions (12, 14) define a single longitudinal axis of the nerve conduction system (10) when the connection portions (22, 24) of the first (12) and second portions (14) are engaged.

11. A nerve conduction system (10) as described in any one of claims 1 to 10, wherein the connection portions (22, 24) are configured so that the through hole (30) of the second portion (14) is at least partially accommodated within the through hole (20) of the first portion (12) when the connection portions (22, 24) are engaged.

12. 12. A nerve conduction system (10) as described in any one of claims 1 to 11, wherein when the connection portions (22, 24) of the first portion (12) and the second portion (14) are engaged, the transition portion (18) of the first portion (12) is configured to at least partially receive and accommodate the radially expanding end (29) of the insertion portion (26) of the second portion (14).

13. A nerve conduction system (10) according to any one of claims 1 to 12, wherein the insertion portion (26) of the second part (14) and / or the radially expanding end portion (29) of the insertion portion (26) extend longitudinally beyond the respective connection portion (24).

14. 14. The nerve conduit system (10) of claim 1, wherein the connecting portion (24) of the second portion (14) extends longitudinally offset from or to the longitudinal end of each of the insertion portions (26) configured to receive and / or insert the respective nerve end portions.

15. 15. A nerve conduction system (10) according to any one of claims 1 to 14, wherein the connection portion (22) of the first portion (12) is positioned opposite and adjacent to the respective transition portion (18) or the longitudinal end of each of the insertion portions (16), and the longitudinal end of each of the insertion portions (16) is configured to receive and / or insert the respective nerve end portion.

16. A nerve conduction system (10) as described in any one of claims 1 to 15, wherein at least a portion of the through hole (20, 30) defined by the insertion portion (16, 26) of the first and / or second part (12, 14) is defined by a tubular-shaped wall defining an essentially constant inner diameter.

17. A nerve conduction system (10) as described in any one of claims 1 to 16, wherein the connection portion (22) of the first portion (12) is formed by a single peripheral wall (23), and the single wall (23) accommodates the connection portion (24) of the second portion (14) on the inner or outer surface of the wall (23).

18. 17. A nerve conduction system (10) according to any one of claims 1 to 16, wherein the connection portion (22) of the first portion (12) is formed by circumferential inner and outer walls (23) defining a longitudinally extending groove between the walls (23), the groove being configured to accommodate the connection portion (24) of the second portion (14) when the connection portions (22, 24) of the first portion (12) and the second portion (14) are engaged.

19. 19. A nerve conduction system (10) according to any one of claims 1 to 18, wherein each connection portion (22, 24) includes at least one circumferential wall (23), the circumferential walls (23) being configured to engage with each other and bias radially when the connection portions (22, 24) of the first portion (12) and the second portion (14) are engaged, and / or the circumferential walls (23) being dimensioned and configured to engage with each other by an interference fit.

20. The nerve conduction system (10) of claim 19, characterized in that the peripheral wall (23) is dimensioned so that when the connecting portions (22, 24) of the first portion (12) and the second portion (14) are engaged, the wall (23) of the connecting portion (24) of the second portion (14) is slidably received by at least one peripheral wall (23) of the connecting portion (22) of the first portion (12).

21. 21. A nerve conduction system (10) according to any one of claims 1 to 20, wherein one of the connection portions (22, 24) comprises at least one radially extending protrusion (36), and the other connection portion (22, 24) comprises at least one slit or groove (38) configured to receive the protrusion (36), preferably configured to fix the second portion (14) to the first portion (12) at least longitudinally when the connection portions (22, 24) of the first portion (12) and the second portion (14) are engaged.

22. the at least one protrusion (36) or the at least one slit or groove (38) of the connecting portion (22) of the first part (12) is arranged on the inner surface of the peripheral wall (23) of the connecting portion (22), and / or The nerve conduction system of claim 21, wherein the at least one protrusion (36) or the at least one slit or groove (38) of the connection portion (24) of the second portion (14) is arranged on the outer surface of the peripheral wall (23) of the connection portion (24).

23. 23. The nerve conduction system (10) of claim 21 or 22, wherein the at least one radially extending protrusion (36) and the at least one slit or groove (38) are configured to snap-fit ​​engage when the connecting portions (22, 24) of the first portion (12) and the second portion (14) are engaged.

24. 24. The nerve conduit system (10) of any one of claims 21 to 23, wherein the at least one slit or groove (38) includes a circumferential extension that is greater than the at least one protrusion (36).

25. 25. A nerve conduction system (10) as described in any one of claims 21 to 24, comprising a plurality of protrusions (36) and a plurality of slits or grooves (38), preferably in equal numbers, the protrusions (36) and slits or grooves (38) being preferably equally spaced apart in the circumferential direction.

26. A nerve conduction system (10) as described in any one of claims 1 to 25, wherein the cross-sectional area of ​​the through holes (20, 30) of the insertion portions (16, 26) of the first part (12) and / or the second part (14) gradually increases in the direction away from the respective connection portions (22, 24) at the longitudinal ends for receiving the nerve ends.

27. A nerve conduction system (10) as described in any one of claims 1 to 26, wherein the transition portions (18, 28) of the first portion (12) and / or the second portion (14) are configured to seamlessly connect the respective insertion portions (16, 26) having a first diameter to the respective connection portions (22, 24) having a second diameter different from the first diameter.

28. 28. The nerve conduit system (10) of claim 27, wherein at least a portion of the transition portion (18, 28) adjacent to the insertion portion (16, 26) has a conical or tapered shape in a longitudinal cross section of the first portion.

29. 29. The nerve conduit system (10) of claim 27 or 28, wherein at least a portion of the transition portion (18, 28) adjacent to the insertion portion (16, 26) includes a wall, the wall being disposed at a predetermined angle relative to the wall of the insertion portion (16, 26), the predetermined angle being based on the difference and distance between the first diameter and the second diameter.

30. 30. The nerve conduit system (10) of claim 29, wherein the predetermined angle is between 30 and 60 degrees, preferably between 40 and 50 degrees, in configuration, and the transition portion (18, 28) surrounds and / or extends over the respective insertion portion (16, 26), or wherein the predetermined angle is between 120 and 240 degrees, preferably between 130 and 230 degrees, in configuration, and the transition portion (18, 28) is adjacent to the insertion portion (16, 26).

31. 31. A nerve conduction system (10) according to any one of claims 1 to 30, wherein the connection portion (22) of the first portion (12) defines a stop portion (32), and the stop portion (32) is configured to contact the connection portion (24) of the second portion (14) when the connection portions (22, 24) of the first portion (12) and the second portion (14) are engaged.

32. The nerve conduction system (10) of claim 31, characterized in that the stop portion (32) is configured to at least partially receive the connection portion (24) of the second portion (14) and / or includes a longitudinally extending locking portion configured to radially fix the connection portion (24) of the second portion (14) when the connection portions (22, 24) of the first portion (12) and the second portion (14) are engaged.

33. A nerve conduction system (10) according to any one of claims 1 to 32, wherein at least one portion (12, 14) is provided with one or more gripping ribs (34) that protrude radially outward from the outer surface of the wall of the connection portion (22, 24) and preferably extend longitudinally at or along the outer surface of the portion (12, 14).

34. 34. The nerve conduit system (10) of claim 33, wherein the portions (12, 14) include two or more gripping ribs (34), preferably spaced equally apart from one another around the circumference of the portions (12, 14).

35. A nerve conduction system (10) as described in claim 33 or 34, characterized in that the one or more gripping ribs (34) include at least one rounded longitudinal end in a longitudinal cross section of each of the connection portions (22, 24).

36. A nerve conduction system (10) as described in any one of claims 1 to 35, wherein the wall (23) of the connection portion (22) of the first portion (12) includes a transparent window or opening positioned at a predetermined longitudinal offset relative to the free end of the connection portion (22) of the first portion (12).

37. 37. A kit of parts comprising a nerve conduit system (10) according to any one of claims 1 to 36, A kit of parts, wherein the kit comprises two or more first parts (12) adapted to different nerve end diameters and / or two or more second parts (14) adapted to different nerve end diameters, and the connecting parts (22, 24) of the parts are adapted so that each first part (12) of the kit is connectable to each second part (14) of the kit.

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