Catheters, especially balloon catheters, and methods for manufacturing the catheter

Description

[0001] The present invention relates to a catheter, in particular a balloon catheter, and to a method for manufacturing such a catheter.

[0002] Such a catheter is a tubular structure that can be inserted into a patient's body lumen, particularly a blood vessel, for therapeutic purposes. A specific application is that of PCTA catheters, which are used in percutaneous transluminal coronary angioplasty (PTCA) to widen or reopen a narrowed or blocked coronary artery. For this purpose, the catheter is designed as a balloon catheter and has an inflatable balloon (especially compressed air) at its distal end, which is inflated within the narrowed vessel. Such a catheter can be guided or advanced to the narrowed vessel, particularly with the aid of a guidewire.

[0003] However, the present invention can in principle also be applied to other catheters, e.g. balloon catheters used for the deployment of stents or heart valve prostheses.

[0004] Catheters are known from the prior art which have a two-part shaft structure, in which, for example, a proximal shaft segment, which is usually formed by a metallic tubular element (e.g. hypotube) and is equipped with a coaxial section at a joint, wherein the proximal shaft segment is connected to a distal shaft segment via the joint, at which a guide wire exit point or opening is also provided, which in turn is connected to the balloon.

[0005] Furthermore, three-part shaft designs are known from the prior art, in which the proximal shaft segment (e.g. hypotube) first transitions into a support tube and then, via a connection point where the guide wire exit point or the side port is provided, into a distal and coaxial shaft segment.

[0006] For example, EP1084728A1 describes a catheter in which a comparatively stiff and beveled hypotube is connected via a transition area to a comparatively soft distal assembly.

[0007] Furthermore, US2010 / 0168669A1 describes a catheter in which a relatively rigid proximal shaft section is connected to a distal shaft section via a flexible transition element, the distal shaft section having a guidewire lumen. US2010217234A1 and EP1199082A1 describe catheter systems with a mandrel attached to the outer shaft.

[0008] Starting from this, the present invention aims to provide a catheter that has a relatively easy-to-produce guide wire opening for leading a guide wire out of the catheter, while simultaneously ensuring low kinking sensitivity in the area of ​​the guide wire opening.

[0009] This problem is solved by a catheter having the features of claim 1. Advantageous embodiments of the invention are specified in the corresponding dependent claims and are described below.

[0010] Another aspect of the present invention relates to a method for manufacturing a catheter according to the invention with the features of claim 14.

[0011] According to claim 1, a catheter is disclosed comprising an outer shaft surrounding a lumen, wherein the outer shaft has a proximal outer shaft section and an associated distal outer shaft section, wherein an inner shaft is arranged in a distal section of the lumen surrounded by the distal outer shaft section, the inner shaft having a guide wire lumen for receiving a guide wire, and wherein the inner shaft has an opening at a proximal end section of the inner shaft through which the guide wire can be led out of the outer shaft or catheter.

[0012] According to the invention, a metallic tube element is arranged in the lumen of the outer shaft, through which the distal section of the lumen communicates with a proximal section of the lumen surrounded by the proximal outer shaft section, wherein the proximal end section of the inner shaft engages with the tube element, and wherein a separate, longitudinally extended metallic stiffening element is arranged in the lumen, which is connected to the tube element and projects from the tube element into the distal section of the lumen and into the proximal section of the lumen for the section-wise stiffening of the outer shaft.

[0013] According to one embodiment of the catheter according to the invention, the proximal outer shaft section is connected to the distal outer shaft section via a material-bonded connection, in particular a welded connection, wherein the connection extends in a circumferential direction of the tube element along an outer surface of a wall of the tube element. Furthermore, according to one embodiment, the two outer shaft sections are also connected to the outer surface of the wall of the tube element, in particular via a material-bonded, form-fit, and / or force-fit connection.

[0014] According to one embodiment of the catheter according to the invention, the inner shaft extends at least partially coaxially in the lumen of the distal outer shaft section.

[0015] According to one embodiment, the stiffening element is preferably a wire made of a metal. This metal can be, for example, stainless steel such as AISI 304 / 302 / 316, or nickel alloys such as Inconel or Nimonic 90. Other suitable materials include titanium, aluminum, copper, or alloys thereof.

[0016] In particular, copper alloys such as CuBe 2 are advantageous because of their elasticity and corrosion resistance, as a stiffening element made of such a material is less susceptible to connection defects when subsequently crimping a stent onto a balloon.

[0017] Furthermore, according to one embodiment, the pipe element also consists of a metal, in particular a stainless steel such as AISI 304 / 302 / 316.

[0018] Furthermore, according to one embodiment of the catheter according to the invention, the tube element has a proximal end section, a distal end section and, in particular, a wall circumferentially surrounding the tube element, which surrounds a lumen of the tube element.

[0019] Furthermore, according to one embodiment of the catheter according to the invention, the tube element is curved or shaped such that the distal end section of the tube element is offset from the proximal end section of the tube element. Preferably, this curvature is produced by forming the tube element.

[0020] Furthermore, according to the invention, the stiffening element extends through the lumen of the tube element and is clamped in the lumen of the tube element by forming the tube element, and, according to one embodiment, is connected to the tube element via a welded connection.

[0021] Furthermore, according to the invention, the opening of the proximal end section of the inner shaft is arranged on an outer surface of the outer shaft laterally to the tube element, wherein, in particular, the opening is formed on an end face of the proximal end section, i.e., at a proximal end of the inner shaft. Such an opening is therefore also referred to as a side port.

[0022] Furthermore, according to one embodiment of the catheter according to the invention, the distal end section of the tube element has a concave recess on an outer side of the wall in which at least a part of the proximal end section of the inner shaft engages or is arranged, thereby producing said engagement.

[0023] Furthermore, according to one embodiment of the catheter according to the invention, the trough is provided for in the wall of the tube element by forming the wall of the tube element.

[0024] Furthermore, according to one embodiment of the catheter according to the invention, the stiffening element is clamped by the recess in the lumen of the tube element.

[0025] Furthermore, according to one embodiment of the catheter according to the invention, it is provided that the proximal end section of the inner shaft engages with the tube element by the proximal end section of the inner shaft extending into the distal end section of the tube element and through the distal end section of the tube element in the lumen of the tube element.

[0026] Furthermore, according to one embodiment of the catheter according to the invention, the wall of the tube element has a through-opening in a connecting section or in a middle section of the tube element, which connects the proximal end section of the tube element with the distal end section of the tube element, through which a part of the proximal end section of the inner shaft is led out of the lumen of the tube element.

[0027] Furthermore, according to one embodiment of the catheter according to the invention, the through-opening (with a linearly arranged outer shaft) extends along a direction normal to a longitudinal axis of the outer shaft, so that the inner shaft extends parallel to the longitudinal axis in the area of ​​the through-opening and the guide wire can be led out linearly, i.e., without significant curvature, through the opening of the inner shaft from the guide wire lumen or from the outer and inner shaft.

[0028] Furthermore, according to one embodiment of the catheter according to the invention, the stiffening element is clamped in the proximal end section of the tube element within the lumen of the tube element. In this regard, it can be provided that the stiffening element is clamped in the lumen of the tube element, in particular by forming, especially by flattening or denting, the proximal end section of the tube element.

[0029] Furthermore, according to one embodiment of the catheter according to the invention, the proximal outer shaft section has a metallic tube structure (hypotube) which is connected to the tube element or to the distal outer shaft section via a flexible hose element of the proximal outer shaft section, wherein in particular the stiffening element extends with a proximal end section (starting from the tube element) into a section of the lumen of the outer shaft which is surrounded by the metallic tube structure.

[0030] According to one embodiment of the invention, the flexible hose element of the proximal outer shaft section has a wall formed by one or more of the following materials: a polymer, polyamide, polyurethane, polyester such as polyethylene terephthalate, polyester copolymers such as Hytrel (brand name), or polyether block amides such as PEBAX (brand name). The aforementioned materials are preferred because they allow for welding or melting to a wide range of materials.

[0031] Furthermore, according to one embodiment of the catheter according to the invention, the distal outer shaft section has a tube element that is connected to the tube element or to the proximal outer shaft section, wherein in particular the stiffening element extends with a distal end section (starting from the tube element) into a section of the lumen of the outer shaft that is surrounded by the tube element of the distal outer shaft section.

[0032] According to one embodiment of the invention, the flexible hose element of the distal outer shaft section has a wall formed by one or more of the following materials: a polymer, polyamide, polyurethane, polyester such as polyethylene terephthalate, polyester copolymers such as Hytrel (brand name), or polyether block amides such as PEBAX (brand name). The aforementioned materials are preferred because they allow for welding or melting to a wide range of plastics with varying mechanical properties.

[0033] According to a further embodiment of the invention, it is provided that the distal outer shaft section, in particular the hose element of the distal outer shaft section, is connected at a distal end of the distal outer shaft section to an unfoldable, in particular inflatable, balloon.

[0034] Another aspect of the present invention relates to a method for manufacturing the catheter (in particular a balloon catheter).

[0035] In this regard, a method for manufacturing a catheter (in particular a catheter according to the invention) is disclosed, wherein a proximal outer shaft section and a distal outer shaft section of the catheter to be manufactured areAn outer shaft is provided, wherein an inner shaft is arranged in a section of a lumen of the catheter to be manufactured surrounded by the distal shaft section, the inner shaft having a guide wire lumen for receiving a guide wire, and wherein a metallic tube element is provided, wherein a longitudinally extended metallic stiffening element is fixed in a lumen of the tube element by forming the tube element on the tube element, wherein a proximal end section of the inner shaft is engaged with the tube element, and wherein the proximal outer shaft section and the distal outer shaft section are connected to the tube element such that the stiffening element is guided from the tube element into a proximal section of the lumen of the outer shaft surrounded by the proximal outer shaft section and into the distal section of the lumen of the outer shaft.

[0036] According to one embodiment of the inventive method, the said forming is carried out by means of a die and a punch.

[0037] According to one embodiment of the method according to the invention, the pipe element is curved before being connected to the distal and proximal outer shaft sections, preferably by forming the pipe element, preferably by means of the die and by means of the punch, such that the distal end section of the pipe element is offset from the proximal end section of the pipe element.

[0038] Furthermore, according to one embodiment of the method according to the invention, an opening of the proximal end section of the inner shaft, through which a guide wire can be led out of the guide wire lumen or the catheter, is arranged laterally to the tube element, wherein in particular the opening is formed on an end face of the proximal end section, i.e., at a proximal end of the inner shaft (see also above).

[0039] Furthermore, according to one embodiment of the method according to the invention, it is provided that a distal end section of the pipe element is formed, preferably by means of said die and said punch, such that the distal end section of the pipe element receives a concave recess on an outside of a wall of the pipe element, wherein in particular the said engagement between inner shaft and pipe element is produced by arranging at least a part of the proximal end section of the inner shaft in the recess.

[0040] Furthermore, according to one embodiment of the method according to the invention, it is provided that the stiffening element is clamped by the recess in the lumen of the tube element (see also above).

[0041] Furthermore, according to an alternative embodiment of the method according to the invention, it is provided that the proximal end section of the inner shaft is brought into engagement with the pipe element by inserting the proximal end section of the inner shaft into the distal end section of the pipe element, so that it extends through the distal end section of the pipe element in the lumen of the pipe element.

[0042] Furthermore, according to one embodiment of the method according to the invention, a through-opening is provided in the wall of the pipe element in a connecting section or in a middle section of the pipe element, which connects a proximal end section of the pipe element with the distal end section of the pipe element, through which a part of the proximal end section of the inner shaft is led out of the lumen of the pipe element.

[0043] Furthermore, according to one embodiment of the method according to the invention, the stiffening element is clamped in the proximal end section of the pipe element in the lumen of the pipe element, in particular by forming, especially by flattening or denting the proximal end section of the pipe element.

[0044] Further features and embodiments of the present invention will be described below in connection with the figures. The figures show: Fig. 1 a schematic sectional view of an embodiment of a catheter according to the invention, here in the form of a balloon catheter; Fig. 2 a schematic sectional view of an embodiment of a tube element of a catheter according to the invention; Fig. 3 a schematic sectional view of a further embodiment of a tube element of a catheter according to the invention; and Fig. 4 a perspective view of a die and a punch for forming the tube element in the manufacture of a catheter according to the invention, without tube element (A) and with tube element (B).

[0045] Fig. 1Figure 1 shows a schematic sectional view of a catheter 1 according to the invention, with a longitudinally extending outer shaft 2, wherein the outer shaft 2 surrounds a lumen 2a of the catheter 1 and further comprises a proximal outer shaft section 20 and a distal outer shaft section 21 connected to the proximal outer shaft section 20. The two outer shaft sections 20, 21 each surround a section 20a and 21a of the lumen 2a, respectively, wherein the two sections 20a, 21a of the lumen 2a communicate with each other, i.e., are fluid-connected to each other. Furthermore, an inner shaft 3 is arranged in the distal section 21a of the lumen 2a, which has a guide wire lumen 3a for receiving a guide wire 30, wherein the inner shaft 3 has an opening 3c at a proximal end section 3b of the inner shaft 3, through which the guide wire 30 can be led out of the outer shaft 2.According to one embodiment, the inner shaft 3 extends at least partially coaxially in the distal section 21a of the lumen 2a.

[0046] The catheter 1 is designed as a balloon catheter and accordingly has a balloon 7 connected to the distal outer shaft section 21, which can be inflated, for example, by means of compressed air that can be introduced into the balloon 7 via sections 20a and 21a of the lumen 2a. The inner shaft 3 extends through the balloon 7, so that the balloon 7 can be guided to a target location in a patient's vessel by means of the guide wire 30.

[0047] According to the invention, the catheter 1 has a metallic tube element 4 arranged in the lumen 2a of the outer shaft 2, such that the distal section 21a and the proximal section 20a of the lumen 2a communicate via a lumen 4a of the tube element 4, which is surrounded by a wall 43 of the tube element 4. That is, to inflate the balloon 7, compressed air or another suitable fluid can be introduced into the proximal section 20a of the lumen 2a, flows through the lumen 4a of the tube element 4, and enters the balloon 7 via the subsequent section 21a of the lumen 2a.

[0048] The distal and proximal outer shaft sections 21, 20 are further connected to each other in the region of an outer surface 43a of the pipe element 4, in particular by a material bond, e.g. by welding the two sections 20, 21 together. Furthermore, the two sections 20, 21 of the outer shaft 2 are connected to the outer surface 43a of the wall 43 of the pipe element 4 by a material bond and / or a form-fit and / or a force-fit.

[0049] The catheter 1 continues to point towards the section-by-section stiffening of the outer shaft 2 in the area of ​​the lateral opening 3c of the inner shaft 3 (in the Figure 1(designated as transition region B) a stiffening element 5, in particular in the form of a separate metal wire, which is fixed to the pipe element 4, in particular by clamping the stiffening element 5 in the pipe element 4 and / or by means of a material-bonded connection (e.g. welded connection). The stiffening element 5 is in particular arranged in the lumen 4a of the pipe element 4 such that it projects into the distal section 21a of the lumen 2a as well as into the proximal section 20a of the lumen 2a to stiffen the transition region B.

[0050] The opening 3c preferably forms a so-called side port and is arranged accordingly laterally on the catheter 1, i.e., on an outer surface 2b of the outer shaft 2. Here, the opening 3c is preferably provided at a transition between the two outer shaft sections 20, 21, which abuts the outer surface 43a of the tube element 4.

[0051] The proximal end section 3b of the inner shaft 3 is preferably enclosed in the outer shaft 2 in a sealing manner when connecting the two outer shaft sections 20, 21.

[0052] As in the Figure 1 As indicated, the pipe element 4 has a proximal end section 40 and a distal end section 42, which are connected to each other, in particular via a connecting section 41. The pipe element 4, especially the connecting or middle section 41, can be curved such that the distal end section 42 of the pipe element 4 is offset from the proximal end section 40 of the pipe element 4 with respect to the longitudinal axis x of the outer shaft 2.

[0053] Furthermore, the proximal outer shaft section 20 preferably comprises a metallic tube structure 201, also referred to as a hypotube, which is connected via a flexible hose element 200 of the proximal outer shaft section 20 to the tube element 4 or a flexible hose element 210 of the distal outer shaft section 42 (via the above-described, e.g., material-bonded connection). The metallic tube structure 201 is furthermore attached, in particular, to a handle 6 for handling the catheter 1. With regard to the tube structure 201, it is further provided that the stiffening element 5 extends with a proximal end section 50 into a section of the lumen 2a that is surrounded by the metallic tube structure 201.

[0054] Furthermore, it is also preferably provided that the stiffening element 5 extends with a distal end section 51 into a section of the lumen 2a which is surrounded by the tube element 210 of the distal outer shaft section 21.

[0055] This creates sufficient stiffening of the outer shaft 2 in the area of ​​the lateral opening 3c.

[0056] The Figure 2 and 3 Two different embodiments are shown in detail with regard to the further design of the pipe element 4.

[0057] After the in the Figure 2In the depicted variant, the distal end section 42 of the pipe element 4 has a concave recess 44 on an outer surface 43a of the wall 43, in which at least a part of the proximal end section 3b of the inner shaft 3 engages or is arranged. The recess 44 is preferably formed in the wall 43 of the pipe element 4 by forming it. The forming can be carried out, for example, using the tool described in the Figure 4 The tool shown comprises a die 8 and a punch 9 for forming the tube element 4.

[0058] The forming process also clamps the stiffening element 5 through the recess 44 in the distal end section 42 in the lumen 4a of the tube element 4, by forming the recess 44 so that two opposing areas 4b of the inside of the tube element 4 press against the stiffening element 5. Figure 1 shows the location of this connection along the longitudinal axis x as connection point V.

[0059] Furthermore, it is preferably provided that the proximal and distal outer shaft sections 20, 21 are in the cross-sectional plane A shown. Fig. 2 overlap and weld together, with the proximal end section 3b of the inner shaft 3 being sealed between the two sections 20, 21 of the outer shaft 2.

[0060] According to Figure 2 The pipe element 4, apart from the trough 44, is essentially cylindrical, but can also be shaped as shown in the Figure 1 exhibit the curvature shown (see above).

[0061] Fig. 3Figure 1 shows an alternative embodiment of the pipe element 4. In particular, the connecting section 41 of the pipe element 4 is shaped or curved such that the proximal end section 40 and the distal end section 42 are offset from each other. Furthermore, a through-opening 4c is formed in the wall 43 of the connecting section 41, extending along a direction R perpendicular to the longitudinal axis x. This also includes the possibility that the opening plane of the through-opening 4c is inclined to the longitudinal axis x.

[0062] According to Fig. 3It is provided that the proximal end section 3b of the inner shaft 3 engages with the tube element 4, in that the proximal end section 3b of the inner shaft 3 extends into the distal end section 42 of the tube element 4 and through the distal end section 42 of the tube element 4 in the lumen 4a of the tube element 4, and is partially led out of the tube element 4 and in particular the outer shaft 2 through the through-opening 4c.

[0063] Due to the arrangement of the through-opening 4c or the curvature of the pipe element 4, it is possible for the inner shaft 3 to extend parallel to the longitudinal axis x of the outer shaft 2 in the area of ​​the through-opening 4c, and for the guide wire 30 to be led out of the guide wire lumen 3a or the outer and inner shaft 2, 3 in a correspondingly linear manner, i.e., without any significant curvature, via the opening 3c of the inner shaft 3.

[0064] Unlike the one in the Figure 2In the variant shown, the stiffening element 5 is clamped in the proximal end section 40 of the pipe element 4 in the lumen 4a of the pipe element 4. Figure 2 Figure 1 shows a section along plane A in this regard. The proximal end section 40 of the pipe element 4 is then reshaped to clamp the pipe element 4, e.g. by denting or flattening the wall 43, so that two opposing areas 4b of the inside of the wall 43 of the pipe element press against the stiffening element 5.

[0065] The stiffening element 5 can alternatively or additionally be connected to the pipe element 4 via a welded connection in all embodiments.

[0066] The ones related to the Figure 1 and 2 The described recess 44 can be used in particular by means of the [method / tool / etc.] described [item / tool / etc.]. Figure 4 The tool shown is formed. The tool has a die 8 and an associated punch 9.

[0067] According to Figure 4(A) The die 8 has a cylindrical through-opening 80 formed in a base 81 of the die 8, with a projection 82 extending from an edge of the opening 80 and from the base 81. The projection has an outer surface 83 that forms a positive shape for the trough 44 to be formed. To form the trough 44, and in particular to form a curvature of the connecting section 41 of the pipe element 4, the following is carried out according to Figure 4(B)A cylindrical blank 4 is inserted into the through-opening 80, such that the future proximal end section of the pipe element is positioned in the through-opening 80. The stiffening element 5 is then inserted into the lumen 4a of the blank 4 or pipe element 4. The punch 9 is then moved along a surface 81a of the base 81 towards the projection 82, whereby an end face 90 of the punch 9 engages with the blank 4 and presses it against the outer surface 83 of the projection 82 with a defined force F. In this process, the wall 43 of the blank 4, in the region of the distal end section 4 of the blank 4, folds around the outer surface 83 or the projection 82, forming the recess 44 and, in particular, the aforementioned curvature of the pipe element 4.At the same time, the distal end section 42 of the pipe element 4, which protrudes from the through-opening 80, is clamped in the lumen 4a of the pipe element 4 due to the shape of the recess 44 (see also above).

Claims

1. Catheter (1), comprising an outer shaft (2) surrounding a lumen (2a), wherein the outer shaft (2) has a proximal outer shaft portion (20) and a distal outer shaft portion (21) connected thereto, wherein an inner shaft (3) is arranged in a distal portion (20a) of the lumen (2a) surrounded by the distal outer shaft portion (21), the inner shaft (3) having a guide wire lumen (3a) for receiving a guide wire (30), and wherein the inner shaft (3) at a proximal end portion (3b) of the inner shaft (3) has an opening (3c) via which the guide wire (30) can be guided out from the outer shaft (2), wherein a metallic tube (4) is arranged in the lumen (2a) of the outer shaft (2), via which the distal portion (21a) of the lumen (2a) communicates with a proximal portion (20a) of the lumen (2a) surrounded by the proximal outer shaft portion (20), wherein the proximal end portion (3b) of the inner shaft (3) is engaged with the tube (4), and wherein a separate, elongate and metallic stiffening element (5) is arranged in the lumen (2a), which stiffening element is connected to the tube (4) and protrudes from the tube (4) into the distal portion (21a) of the lumen (2a) and into the proximal portion (20a) of the lumen (2a) for sectionwise stiffening the outer shaft (2), characterized in that the stiffening element (5) extends through the lumen (4a) of the tube (4) and is securely clamped in the lumen (4a) of the tube (4), and that the opening (3c) of the proximal end portion (3b) of the inner shaft (3) is arranged on an outer side (2b) of the outer shaft (2) laterally of the tube (4).

2. Catheter according to claim 1, characterized in that the tube (4) has a proximal end portion (40), a distal end portion (42) and a wall (43) surrounding a lumen (4a) of the tube (4).

3. Catheter according to claim 2, characterized in that the tube (4) is curved such that the distal end portion (42) of the tube (4) extends offset relative to the proximal end portion (40) of the tube (4).

4. Catheter according to claim 3, characterized in that the stiffening element (5) extends through the lumen (4a) of the tube (4) and is connected to the tube (4) via a welded connection.

5. Catheter according to any one of claims 2 to 4, characterized in that the distal end portion (42) of the tube (4) has, on an outer side (43a) of the wall (43), a concave hollow (44) in which at least part of the proximal end portion (3b) of the inner shaft (3) engages.

6. Catheter according to claim 5, characterized in that the hollow (44) is formed in the wall (43) by reshaping the wall (43) of the tube (4).

7. Catheter according to any one of claims 1, 4, 5 or 6, characterized in that the stiffening element (5) is clamped in the lumen (4a) of the tube (4) by the hollow (44).

8. Catheter according to any one of claims 2 to 4, characterized in that the proximal end portion (3b) of the inner shaft (3) is engaged with the tube (4) such that the proximal end portion (3b) of the inner shaft (3) protrudes into the distal end portion (42) of the tube (4) and extends in the lumen (4a) of the tube (4) through the distal end portion (42) of the tube (4).

9. Catheter according to any one of claims 2 to 4 or according to claim 8, characterized in that the wall (43) of the tube (4), in a connection portion (41) of the tube (4) connecting the proximal end portion (40) of the tube (4) to the distal end portion (42) of the tube (4), has a through-opening (4c) through which part of the proximal end portion (3b) of the inner shaft (3) is guided out from the lumen (4a) of the tube (4).

10. Catheter according to claim 9, characterized in that the through-opening (4c) extends along a direction (R) running perpendicular to a longitudinal axis (x) of the outer shaft (2).

11. Catheter according to any one of claims 2 to 4 or according to any one of claims 8 to 10, characterized in that the stiffening element (5) is securely clamped in the lumen (4a) of the tube (4) in the proximal end portion (40) of the tube (4).

12. Catheter according to any one of the preceding claims, characterized in that the proximal outer shaft portion (20) has a metallic tube structure (201), which is connected via a flexible hose element (200) of the proximal outer shaft portion (20) to the tube (4) and / or to a flexible hose element (210) of the distal outer shaft portion (21), wherein in particular the stiffening element (5) extends with a proximal end portion (50) into a portion of the lumen (2a) surrounded by the metallic tube structure (201).

13. Catheter according to any one of the preceding claims, characterized in that the distal outer shaft portion (21) has a hose element (210) which is connected to the tube (4) and / or to a flexible hose element (200) of the proximal outer shaft portion (20), wherein in particular the stiffening element (5) extends with a distal end portion (51) into a portion of the lumen (2a) surrounded by the hose element (210) of the distal outer shaft portion (21).

14. Method for producing a catheter (1), in particular according to any one of the preceding claims, wherein a proximal outer shaft portion (20) and a distal outer shaft portion (21) of the catheter (1) to be produced are provided, wherein an inner shaft (3) is arranged in a distal portion (21a) of a lumen (2a) of the catheter (1) to be produced, which distal portion is surrounded by the distal shaft portion (21), the inner shaft (3) having a guide wire lumen (3a) for receiving a guide wire (30), and wherein a metallic tube (4) is provided, wherein an elongate and metallic stiffening element (5) is secured in a lumen (4a) of the tube (4) by reshaping the tube (4), wherein a proximal end portion (3b) of the inner shaft (3) is brought into engagement with the tube (4), and wherein the proximal outer shaft portion (20) and the distal outer shaft portion (21) are connected to the tube (4) such that the stiffening element (5) is guided from the tube (4) into a proximal portion (20a) of the lumen (2a) surrounded by the proximal outer shaft portion (20) and into the distal portion (21a) of the lumen (2a).