Catheters having a tube and a functional element
Patent Information
- Application Number
- EP2023715816
- Authority / Receiving Office
- EP · EP
- Patent Type
- Applications
- Current Assignee / Owner
- Filing Date
- 2023-03-28
- Publication Date
- 2026-02-11
AI Technical Summary
Catheters with a tube and a functional element often experience kinking and failure at the connection between the tube and the functional element, particularly when navigating tortuous anatomy.
The catheter design incorporates a connecting section with arc-shaped through holes that reduce lateral stiffness, allowing for increased flexibility and stability at the overlap region, which can be achieved through material differences or geometric modifications such as through holes in the connecting section, enabling the catheter to conform better to anatomical shapes without abrupt changes in stiffness.
This design enhances the reliability and stability of the connection between the tube and the functional element, reducing the likelihood of kinking and failure, especially in tortuous anatomical paths, by providing a gradual change in bending stiffness along the catheter's length.
Smart Images
Figure EP2023057954_03102024_PF_FP_ABST
Abstract
Description
[0001] CATHETERS HAVING A TUBE AND A FUNCTIONAL ELEMENT
[0002] Technical Field
[0003] The present disclosure is directed to catheters having a tube and a functional element , and thrombectomy or atherectomy systems comprising a catheter .
[0004] Background
[0005] A catheter may have a tube and a functional element at the distal end of the tube . The functional element may be attached to the tube . However, such catheters are often prone to kinks in the tube adj acent the connection between the functional element and the tube and / or to failure at the connection . This may particularly occur when traversing tortuous anatomy .
[0006] Therefore , new catheters including a functional element are desirable that reduce kinking and or failure between the tube and the functional element are desirable .
[0007] Summary
[0008] The present disclosure is directed to providing improved catheters by reducing failure related to the connection between the tube and the functional element , in particular in tortuous anatomy .
[0009] According to one embodiment , the present disclosure provides a catheter having a distal tip, wherein the catheter comprises a tube having a proximal end, a distal end and a central part between the proximal end and the distal end . The catheter further comprises a functional element having a substantially tubular proximal end representing a connecting section . The connecting section is connected to the distal end of the tube , wherein the distal end of the tube and the connecting section overlap each other in an overlap region . The proximal end of the tube and the central part of the tube are proximal to the overlap region . The connecting section comprises at least one through hole ( optionally a plurality of through holes , each) in the form of a circular / circumf erential arc .
[0010] A through hole (void) is in the form of a circular arc, along the circumference of the connecting section, when viewed in a cross-sectional view perpendicular to the longitudinal direction . A through hole of the disclosure may be regarded as a slotted through hole . The through hole may be provided in the tubular wall of the connecting section .
[0011] The circular arc may be regarded as a void which is almost annular, except for a material part . As such, the through hole may be regarded as ring-shaped in part . A through hole is not closed in itsel f so that no complete 360 ° -through hole is formed .
[0012] By way of the arc-shaped through hole , the (bending) sti f fness of the connecting section perpendicular to the longitudinal direction may be reduced . Put di f ferently, the lateral bending sti f fness / strength of the connecting section may be reduced . This may mean that compared to a connecting section having no through hole ( s ) in the form of a circular arc, the bending flexibility of the connecting section and, thus , of the overlap region is increased; the bending sti f fness is reduced accordingly .
[0013] Bending occurs in the direction perpendicular to the longitudinal direction and is a lateral deformation . In contrast, axial deformation or compression may occur along the longitudinal direction.
[0014] Even if a catheter of the present disclosure is bent at the overlap region, in particular in tortuous anatomy, the connecting section can give in in that it is deformed laterally so that the catheter can better conform to the anatomy, e.g. of a blood vessel. Also, when the connecting section allows for lateral deformation, the tube may, outside the overlap region, less abruptly change the direction. In conventional catheters, an abrupt change may entail a kink in the tube or may lead to loosening of the tube from the functional element. As such, by way of the increased flexibility / reduced stiffness of the proximal part of the functional element, the connection between the tube and the functional element may be more reliable and more stable.
[0015] Through holes of the disclosure may help to at least partially compensate a reduced flexibility and higher stiffness in the overlap section. The reason is that the stiffness of the functional element, in particular of the proximal part thereof, may be higher than the stiffness of the tube. Also, since the distal end of the tube may be regarded as reinforced by the connecting section (due to the overlap) , the overall stiffness in the overlap region may be increased. Vice versa, this inversely / indirectly applies to the flexibility of the entities.
[0016] For some embodiments, catheters according to the present disclosure may compensate at least partially for differences in bending stif fness / strength between the tube and the functional element, in particular in the overlap region. The overlap region may, hence, be regarded as providing an intermediate stiffness (e.g. higher bending stiffness than the tube, but lower bending stiffness than the functional element distal to the overlap region) . Hence, the connecting section may provide, in the overlap region, for a gradual change of the bending strength / stiffness along the longitudinal direction. In general, an abrupt change or transition is considered as less preferable and more prone to failure .
[0017] By providing a through hole, such as in the form of a circular (e.g., semi-circular) arc, in the connecting section, the functional element and the connecting section may be formed of the same material. Though it is contemplated the connecting section and the functional element may be formed of different materials. In any case, wherein the functional element and the connecting section are formed of the same material (e.g., having the same elasticity (as to the material, e.g. Young's modulus) ) , by way of the though hole, the stiffness of the connecting section has been reduced (due to its geometry) . For example, the functional element and the connecting section may, in its entirety, be made of metal or of one or more of the materials listed below .
[0018] There may be other measures to avoid an abrupt transition in terms of f lexibility / strength / stif fness between the tube and the functional element. For example, the functional element may comprise different materials, such as a more elastic (resilient) material at its proximal end, i.e. in the connecting section, and a less elastic (resilient) material at the distal part of the functional element. As such, a catheter tip comprising two materials, e.g., a two-part functional element, is considered. For example, the distal end of the functional element may be made of metal, whilst the proximal part, i.e. the connecting section, is made of a polymer. This may represent an embodiment of the disclosure, wherein no through hole in the form of a circular arc is needed in the connecting section.
[0019] However, a combination of a functional element having two different materials, in particular where the material at the proximal end of the functional element is more elastic than the material of the distal part of the functional element, and of through holes according to the disclosure is contemplated .
[0020] In general, elasticity (as an intensive property of the material) is defined by the elastic modulus of the material (Young's modulus) . The stiffness (e.g. bending stiffness; as an extensive property) not only depends on the material, but also on the geometry of the entity. The flexibility is considered as the "opposite" to stiffness.
[0021] The proximal end of the tube and the central part of the tube are proximal to the overlap region, which means that the proximal end of the tube and the central part of the tube are outside the overlap region. Put differently, the overlap region does not include the proximal end of the tube nor the central part of the tube.
[0022] The tube and the tubular connecting section may be concentric in the overlap region. This may mean that the tube wall and the wall of the connecting section have a common center (e.g., in axial alignment) .
[0023] Optionally, at least two through holes, more optionally at least five through holes, may be formed in the connecting section. A plurality of through holes may be provided. If more than one through hole is present, each of the through holes may individually have the characteristics as described for the at least one through hole in this disclosure.
[0024] Optionally, the connecting section is bonded to the distal end of the tube in the overlap region at one or more bonding sections. Optionally, the one or more bonding sections are outside the through holes. If a bonding section is outside the at least one through hole, the flexibility offered by the through hole is not impaired. The bonding may be achieved by way of glue, heat bonding, laser welding, or the like.
[0025] Optionally, the at least one through hole is annular excluding a connection or connecting remainder or node or apex. This means that material of the functional element remains as a connection / remainder / node / apex .
[0026] Optionally, at least two through holes are arranged one after the other along the longitudinal direction, i.e. the proximal / distal direction. This increases the flexibility of the connecting section along the longitudinal direction.
[0027] Optionally, the at least two through holes are staggered relative to each other. This means that the circular arcs of the through holes are shifted as to the angular position.
[0028] A remainder or node of a through hole is angularly offset relative to a remainder or node of another through hole, optionally the adjacent through hole. This may support the desired lateral stiffness uniformly in radial directions and may help to provide for unidirectional stiffness perpendicular to the longitudinal direction. For example, every second through hole may have the same annular position of the circular arc. Arcs may, however, have different lengths along the circumference, i.e. different angular dimension .
[0029] Optionally, the through holes are regularly and / or uniformly distributed along the connecting section (i.e. the overlap section) . Put differently, the through holes may be equally distanced relative to each other in the longitudinal direction .
[0030] Optionally, the connecting section is received inside the distal end of the tube. This means that the tube surrounds the functional element along the overlap section. This may help to improve the reliability as to the connection between the connecting section and the tube , as the tube may protect the connecting section from the environment , namely the vasculature .
[0031] Optionally, the functional element has an annular protrusion between the distal part of the functional element and the connecting section of the functional element . Hence , the annular protrusion may separate the distal part from the connecting section . The annular protrusion may form a complete ring protruding from the distal part and the connecting section of the functional element .
[0032] Optionally, the distal end of the tube abuts a proximal side of the annular protrusion . By way of the abutment , the distal end of the tube may be sealed to the functional element .
[0033] The distal part of the functional element may represent or comprise a stator, i . e . an entity which is stationary relative to the remaining functional element and / or to the tube . Optionally, the stator comprises an opening for aspiration of clot and / or calci fications . The opening may be referred to as a stator opening .
[0034] The functional element may, optionally, further comprise a rotor which is rotatable relative to the stator . The rotor may have a rotor opening for aspiration of clot and / or calci fications . The rotor is configured to remove clot and / or calci fications from the vessel by way of drilling . The rotor may comprise a drill tip . I f the rotor opening and the stator opening overlap intermittently during rotation, clot and / or calci fications can be aspirated .
[0035] In another aspect of the disclosure ( as explained above ) , the catheter has a distal tip and substantially extends in a longitudinal direction . The catheter comprises a tube having a proximal end, a distal end and a central part between the proximal end and the distal end. The catheter further comprises a functional element having a substantially tubular proximal part representing a connecting section and a distal part, wherein the connecting section is connected to the distal end of the tube, the distal end of the tube and the connecting section overlapping each other in an overlap region, wherein the proximal end of the tube and the central part of the tube are proximal to the overlap region. The connecting section may be configured to provide a (bending) stiffness such that the (bending) stiffness of the tube outside (proximal to) the overlap region is smaller than the (bending) stiffness of the overlap region (tube plus connection section of functional element) , and the stiffness of the overlap region is smaller than the (bending) stiffness of the distal part of the functional element. For example, the stiffness of the connecting section may be smaller than the stiffness of the distal part of the functional element. For example, the material of the connecting section may be more elastic than the material of the distal part.
[0036] For example, the stiffness of the tube at its proximal end and the central part of the tube is lower than the stiffness of the overlap region (including the functional element and the tube) . At the same time, the stiffness of the distal part of the functional element may be higher than the stiffness in the overlap region. Put differently, the stiffness of the proximal part of the functional element may be between the stiffness of the tube and of the distal part of the functional element. (This may in particular apply to the material of the respective entity, i.e. the elasticity of the material respective entity.) As such, a gradual change of the (bending) stiffness in connection with the transition from the tube to the functional element may be obtained.
[0037] As an example, materials for the connecting section, i.e. the proximal part of the functional element, and also for the distal part may be as follows: Medical grade hard polymers such as HDPE, PEEK, Nylon (young's modulus 1-5 GPa) , fibre- reinforced polymers (young's modulus 5-200 GPa) and metals such as Stainless Steel, Titanium, Nitinol (young's modulus 50 - 250 GPa) , or the like.
[0038] Example materials for the tube may be as follows: Vestamid, Nylon, PE, Silicone, Pebax (young's modulus 0.1-1 GPa) , or the like and may include additional layers or braiding for reinforcement .
[0039] The dimensions (in particular thicknesses) of the entities may be as follows: Wall thickness (in particular of tubular features of the entities) ranges from 30 pm (0.03 mm) to 0.3 mm. Different stiffnesses of the connecting section and of the distal part of the functional element may be obtained by providing, e.g. in the functional element, the same materials (i.e. materials having the same elasticity) , but different geometry (e.g. different wall thicknesses) .
[0040] A through hole of the disclosure may not be necessary, if a gradual change of the stiffness is achieved e.g. by way of the materials. However, through holes may be present, and in particular the disclosure herein in connection with the through holes may define this aspect further.
[0041] Generally, the embodiments of the present disclosure may allow adjustment to the stiffness in the overlap region (transition between the tube and the functional element) so as to reduce failure of the connection between the tube and the functional element. This may be achieved by providing through holes in the form of arcs in the connection section or by reducing the stiffness of the connecting section otherwise, e.g. by providing a connecting section having a material having higher elasticity. The disclosure is also directed to an aspiration system, in particular a thrombectomy or atherectomy system, wherein, in addition to any catheter of the disclosure , a handle including a motor, and a control unit are provided . A catheter of the disclosure may be used in a bodily lumen, such as a blood vessel .
[0042] I f the catheter is for aspiration, the catheter may comprise a helix extending along the tube and the functional element . The helix extends in the longitudinal direction and is within the lumen of the tube . The helix is also within the lumen defined by the functional element .
[0043] Any catheter according to the disclosure may be manufactured including EDM, laser cutting, laser machining, or the like in particular for providing the at least one through hole in the connecting section . Also , 3D-printing is considered . Speci fically, multi-material 3D-printing may be used for manufacturing the functional element , and may be particularly useful such as two di f ferent materials are used .
[0044] Generally, the distal direction refers to the direction pointing towards the patient , from the user ( surgeon) . The opposite direction, namely the proximal direction, points , from the patient / treatment area towards the user ( surgeon) bracket . The proximal and distal directions define the longitudinal direction .
[0045] Brief Description of the Drawings
[0046] Figure 1 schematically depicts a side view of a catheter with a tube shown transparently, according to one or more embodiments of the disclosure . Figure 2 schematically depicts a view of a functional element , according to one or more embodiments of the disclosure .
[0047] Figure 3 schematically depicts a view of another embodiment of a functional element , according to one or more embodiments of the disclosure .
[0048] Figure 4 schematically depicts a cross-sectional view of a catheter including a functional element comprising a rotor and a stator, according to one or more embodiments of the disclosure .
[0049] Figure 5 schematically depicts a situation in a tortuous anatomy, wherein
[0050] Fig . 5a depicts a catheter in a vessel , Fig . 5b depicts the catheter of FIG . 5a when bent , Fig . 5c depicts an enlarged section of a proximal part of the functional element of the catheter of FIG . 5b when bent , according to one or more embodiments of the disclosure .
[0051] Figure 6 schematically depicts cross-sectional view of a catheter including a stator ( only) , according to one or more embodiments of the disclosure .
[0052] Figure 7 schematically depicts an axial cross-sectional view of the connecting section of a functional element , according to one or more embodiments of the disclosure .
[0053] Figure 8 schematically depicts a system, according to one or more embodiments of the disclosure .
[0054] Detailed Description Figure 1 depicts a catheter 1 having a distal tip la . The catheter 1 extends from a proximal direction P in a distal direction D . This is in general referred to as the longitudinal direction .
[0055] The catheter 1 comprises a tube 3 having a proximal end 3a, a distal end 3b and a central part 3c between the proximal end 3a and the distal end 3b . The catheter 1 further comprises a functional element 2 having a substantially tubular proximal part 2a and a distal part 2b . The proximal end 2a of the functional element 2 represents a connecting section . The connecting section 2a is connected to the distal end 3b of the tube . The distal end 3b of the tube 3 and the connecting section 2a of the functional element overlap each other in the overlap region 5 , i . e . thereby forming the overlap region 5 . The proximal end 3a of the tube and the central part 3c of the tube 3 are outside the overlap region 5 , namely proximal to the overlap region 5 .
[0056] The tube 3 and the functional element 2 are substantially tubular and in particular define respective tubular lumens . In particular, the connecting section 2a of the functional element 2 has a tubular shape . The distal end 3b of the tube and the connecting section 2a of the functional element 2 are concentric to each other in the overlap section 5 .
[0057] The connecting section 2a of the present embodiment defines through holes 6 to increase the flexibility / reduce the sti f fness of the connecting section 2a, i . e . of the overlap region 5 .
[0058] The connecting section 2a is bonded to the distal end 3b o f the tube 3 in the overlap region 5 at one or more bonding sections 7 . The bonding sections 7 are outside the through holes 6 so as to avoid that the flexibility due to the through holes 6 is impaired . That is , the bonding section 7 are remaining material of the connecting section 2a bordering the through hole ( s ) 6 .
[0059] Between the proximal part 2a of the functional element 2 and the distal part 2b of the functional element 2 , a protrusion 8 may be provided . In embodiments , the protrusion 8 has a ring shape and completely circumscribes the distal a diameter of the function element . However, other shapes are contemplated and possible . In embodiments , the distal end 3b of the tube abuts the proximal side 8a of the protrusion 8 .
[0060] As indicated in Figure 1 , the connecting section 2a i s received within the distal end 3b of the tube 3 . Put di f ferently, the distal end 3b of the tube surrounds the connecting section 2a of the functional element 2 .
[0061] Figure 2 depicts the functional element 2 without the tube 3 . Speci fically, the connecting section 2a of the functional element 2 has one or more through holes 6 . The through holes 6 each represent a semi-circular / circumf erential arc 6 , as each arc extends around the circumference of the tubular wall forming the distal part 2b of the functional element 2 . The through holes 6 may be regarded as annular, excluding a remainder or connection or node 4 . The node 4 is a remainder of the material of the distal part 2b of the functional element 2 .
[0062] The through holes 6 may be arranged one after the other along the proximal / distal direction . In Figure 2 , the distance from one through hole 6 to the adj acent through hole 6 is the same for all through holes . As such, the through holes 6 are regularly distributed along the connecting section 2a in the longitudinal direction .
[0063] The through holes 6 may be staggered relative to each other along the longitudinal direction . This means that an arc 6 is staggered relative to the neighboured arc 6 as to the angular position of the node 4. As such, the nodes / apexes may be angularly spaced from one another along the longitudinal axis. Put differently, the nodes 4 are annularly offset from each other when looking at two neighboured arcs 6. In Figure 2, every second through hole 6 is identical, while adjacent through holes 6 differ from each other as to the angular position of the node 4. Optionally, nodes 4 are offset from one another about an angle of 180° when looking at neighboured through holes 6.
[0064] In the embodiment of Figures 1 and 2, the material of the proximal part 2a may differ from the material in the distal part 2b. Specifically, the material in the proximal part 2a may be more elastic than the material of which the distal part 2b of the functional element 2 is made.
[0065] Figure 3 depicts another embodiment of the disclosure, this embodiment having no through holes 6. The connecting section 2a is made of a material which is more elastic than the material of which the distal part 2b of the functional element 2 is made. Although Figure 3 does not show through holes 6, through holes 6 as described throughout this disclosure may additionally be provided, to reduce the stiffness of the connecting section further.
[0066] With reference to Figure 4 and the embodiments of Figures 1 to 3, the distal part 2b (as well as the proximal part 2a) of the functional element may be stationary relative to the tube 3. Therefore, the distal part 2b may be referred to as stator 9. The stator 9 comprises a stator opening 10, through which removed clot and calcifications (not shown in Fig. 4) can enter the functional element 2 before being conveyed towards the proximal end 3a of the tube 3. In addition to the stator 9, the functional element 2 may comprise a rotor 11 having a rotor opening (not shown) . The rotor may, in some embodiments, be regarded as an outer cap which is rotatable relative to the stator. Figure 4 depicts a cross-section of such functional element 2 having the stator 9 and the rotor 11 rotatable around the stator 9. (Such rotor 11 has been omitted in Fig. 1 to 3, for the sake of clarity.) If the stator opening 10 overlaps the rotor opening when the rotor 11 rotates around the stator 9, clot and / or calcifications can be aspirated when whenever the stator opening 10 and rotor opening are aligned. A helix 14 may be attached to the rotor 11, so as to impart rotation to the rotor 11.
[0067] Figure 5a depicts a vessel 13 in which any catheter 1 of the disclosure may be used. The functional element 2 is for facilitating removal of clot and / or calcifications 12 from the vessel 13. Specifically in a tortuous anatomy, the connecting section 2a of the disclosure may provide for sufficient lateral bending in the overlap region 5. As an example, the functional element 4 of Fig. 2 is shown in a bent configuration in Fig. 5b. Due to the bending, the through holes / arcs 6 are deformed. This is depicted in more detail in Fig. 5c. While the arcs 6 have and / or each of the arcs has, in the neutral or relaxed configuration, when the catheter 1 is in the straight configuration, a substantially constant thickness d in the longitudinal direction (see Fig. 2) , the thickness is different in the bent configuration: Fig. 5c shows that one side (the "outer side" of the bent) of the arc 6 is widened (thickness d2, d2' ) , i.e. the through hole is widened in the radial direction (perpendicular to the longitudinal direction) ; while the opposite side of the arc 6 (the "inner side" of the bent) is narrowed (thickness dl, dl' ) , i.e. the through hole 6 is compressed in the radial direction (perpendicular to the longitudinal direction) . This change of the thickness / breadth d of an arc 6 to the reduced thicknesses dl, dl' or to the larger thicknesses d2, d2' provides for the desired bendability / reduction in stiffness of the connecting section 2a, i.e. in the overlap region 5. As an example, the functional element 2 is a combination of a stator 9 and a rotor 11 in Fig. 1 to 5. However, the functional element 2 may be a stator 9' without a rotor, as shown in Fig. 6.
[0068] Figure 7 shows a cross-sectional view perpendicular to the longitudinal direction through an arc 6 in the connecting section 2a. For example, Fig. 7 may represent a crosssection taken along a through hole 6 of Fig. 2. Depicted is an angle a forming the arc of the through hole 6. Also, the angle p corresponding to the angular dimension of the node 4 is indicated. (a and p add up to 360°.) The angular extension of the circumferential arc may be at least a = 180°, optionally at least 240°, optionally less than 315°. A node 4 of about at least an angle p = 20° (a = 340° at most) , optionally 35° (a = 325° at most) is considered as appropriate .
[0069] Fig. 8 depicts a thrombectomy / atherectomy system. The thrombectomy / atherectomy system may generally include any embodiment of the catheter described herein. Additionally, the thrombectomy / atherectomy system may include a guide wire 20, a collection bag 19, a foot switch 18, a control unit 17, a motor 16 and a handle 15. The thrombectomy / atherectomy system may include a greater or fewer number of components without departing from the scope of the present disclosure. The system may, for example, comprise a handle including a motor, and a control unit.
[0070] In embodiments, the motor 16 may be positioned within the handle 15 and may be configures to drive rotation of the helix, as described above, and / or the rotor 11 in embodiments including a rotor 11. In a thrombectomy system, the functional element 2 is typically a stator 9' . In an atherectomy system, the functional element 2 typically comprises a stator 9 and a rotor 11. Reference signs
[0071] 1 catheter la distal tip of catheter
[0072] 2 functional element
[0073] 2a proximal part ( connecting section) of functional element 2b distal part of functional element
[0074] 3 tube
[0075] 3a proximal end of tube
[0076] 3b distal end of tube
[0077] 3c central part of tube
[0078] 4 remainder / connection / node / apex
[0079] 5 overlap region
[0080] 6 through hole
[0081] 7 bonding section
[0082] 8 protrusion
[0083] 8a proximal side of protrusion
[0084] 9 , 9 ' stator
[0085] 10 stator opening
[0086] 11 rotor
[0087] 12 clot and / or calci fications
[0088] 13 vessel
[0089] 14 helix
[0090] 15 handle
[0091] 16 motor
[0092] 17 control unit
[0093] 18 foot switch
[0094] 19 collection bag
[0095] 20 guide wire d thickness of through hole in straight configuration dl , dl ' thickness of compressed through hole d2 , d2 ' thickness of expanded through hole
[0096] P proximal direction
[0097] D distal direction a angular dimension of arc p angular dimension of node
Claims
Claims1. A catheter (1) having a distal tip (la) , the catheter substantially extending in a longitudinal direction and comprising- a tube (3) having a proximal end (3a) , a distal end (3b) and a central part (3c) between the proximal end (3a) and the distal end ( 3b) ,- a functional element (2) having a substantially tubular proximal part (2a) representing a connecting section (2a) , wherein the connecting section (2a) is connected to the distal end (3b) of the tube, the distal end of the tube (3b) and the connecting section (2a) overlapping each other in an overlap region (5) , and the proximal part (3a) of the tube and the central part (3c) of the tube are proximal to the overlap region ( 5 ) , and the connecting section (2a) comprises at least one through hole (6) in the form of a circumferential arc.
2. The catheter of claim 1, wherein the connecting section (2a) is bonded to the distal end (3b) of the tube in the overlap region (5) at one or more bonding sections (7) , optionally wherein the one or more bonding sections (7) are outside the at least one through hole (6) .
3. The catheter of any of the preceding claims, wherein the at least one through hole (6) is annular excluding a node(4) .
4. The catheter of any of the preceding claims, wherein at least two though-holes (6) are arranged one after the other along the longitudinal direction.
5. The catheter of claim 4, wherein the through holes are staggered relative to each other.
6. The catheter of claim 3, wherein node of respective through holes are angularly offset from each other.
7. The catheter of any of the preceding claims, wherein the through holes (6) are regularly and / or uniformly distributed along the connecting section (2a) .
8. The catheter of any of the preceding claims, wherein the connecting section (2a) is received inside the distal end (3b) of the tube.
9. The catheter of any of the preceding claims, wherein the functional element (2) has an annular protrusion (8) between the distal part (2b) and the connecting section (2a) .
10. The catheter of any of claim 9, wherein distal end (3b) of the tube (3) abuts a proximal side (8a) of the annular protrusion ( 8 ) .
11. The catheter of any of the preceding claims, wherein the distal part (2b) of the functional element (2) comprises a stator (9, 9' ) which is stationary relative to the tube (3) and has an opening (10) for aspiration of clot and / or calcifications (13) .
12. The catheter of claim 11, wherein the functional element (2) further comprises a rotor (11) rotatable relative to the stator (9, 9' ) , the rotor (11) having a rotor opening (12) for aspiration of clot and / or calcifications (13) .
13. The catheter of claim 12, wherein the rotor (11) is configured to remove clot and / or calcifications (13) from a vessel (14) by way of drilling.
14. The catheter of any of the preceding claims, wherein the stiffness of the connecting section (2a) is less than the stiffness of the distal part (2b) .
15. A catheter (1) having a distal tip (la) , the catheter substantially extending in a longitudinal direction and comprising- a tube (3) having a proximal end (3a) , a distal end (3b) and a central part (3c) between the proximal end (3a) and the distal end ( 3b) ,- a functional element (2) having a substantially tubular proximal part (2a) representing a connecting section (2a) , and a distal part (2b) distal to the proximal part (2a) , wherein the connecting section (2a) is connected to the distal end (3b) of the tube, the distal end of the tube (3b) and the connecting section (2a) overlapping each other in an overlap region (5) , wherein the proximal part (3a) of the tube and the central part (3c) of the tube are proximal to the overlap region ( 5 ) , and the stiffness of the connecting section (2a) is less than the stiffness of the distal part (2b) .
16. The catheter of claim 15, wherein the connecting section (2a) comprises at least one through hole (6) in the form of a circumferential arc.
17. The catheter of claim 15 or 16, wherein the connecting section (2a) is bonded to the distal end (3b) of the tube in the overlap region (5) at one or more bonding sections (7) , optionally wherein the one or more bonding sections (7) are outside the at least one through hole (6) .
18. The catheter of any of the preceding claims 15 to 17, wherein the at least one through hole (6) is annular excluding a node (4) .
19. The catheter of any of the preceding claims 15 to 18, wherein at least two though-holes (6) are arranged one after the other along the longitudinal direction.
20. The catheter of claim 19, wherein the through holes are staggered relative to each other.
21. The catheter of claim 18, wherein nodes of respective through holes are angularly offset from each other.
22. The catheter of any of the preceding claims 15 to 21, wherein the through holes (6) are regularly and / or uniformly distributed along the connecting section (2a) .
23. The catheter of any of the preceding claims 15 to 22, wherein the connecting section (2a) is received inside the distal end (3b) of the tube.
24. The catheter of any of the preceding claims 15 to 24, wherein the functional element (2) has an annular protrusion (8) between the distal part (2b) and the connecting section (2a) .
25. The catheter of any of claim 24, wherein distal end (3b) of the tube (3) abuts a proximal side (8a) of the annular protrusion ( 8 ) .
26. The catheter of any of the preceding claims 15 to 25, wherein the distal part (2b) of the functional element (2) comprises a stator (9, 9' ) which is stationary relative to the tube (3) and has an opening (10) for aspiration of clot and / or calcifications (13) .
27. The catheter of claim 26, wherein the functional element(2) further comprises a rotor (11) rotatable relative to the stator (9, 9' ) , the rotor (11) having a rotor opening (12) for aspiration of clot and / or calcifications (13) .
28. The catheter of claim 12, wherein the rotor (11) is configured to remove clot and / or calcifications (13) from a vessel (14) by way of drilling.
29. An aspiration system, in particular a thrombectomy or atherectomy system, comprising a catheter of any of the preceding claims, a handle including a motor, and a control unit .