Catheter

Abstract

A catheter comprising an elongated catheter shaft with a distal shaft section, a middle shaft section and a proximal shaft section, a guide wire lumen which is configured to receive a guide wire and which is elongated at least in sections through the distal shaft section between a distal wire outlet and a proximal wire inlet, which opens laterally into the catheter shaft in the region of a proximal end of the distal shaft section and a distal end of the middle shaft section, is known. According to the invention, the proximal shaft section has a proximal hollow tube section which merges in the distal direction into a radially open groove section which has a convex groove outer side and a concave groove inner side, wherein the groove section is pushed in the distal direction through a lumen of the middle shaft section into a lumen of the distal shaft section, and wherein the convex groove outer side is opposite the guide wire lumen in the radial direction and the concave groove inner side is facing away from the guide wire lumen in the radial direction. Use with a catheter, especially a balloon catheter

Description

[0001] The invention relates to a catheter according to the preamble of claim 1.

[0002] Catheters are used for different therapeutic and diagnostic procedures and are therefore available on the market in different designs.

[0003] Single-operator exchange catheters (SOE catheters) or monorail catheters typically have an elongated catheter shaft with a distal shaft section, a mid-shaft section, and a proximal shaft section, as well as a guidewire lumen for receiving a guidewire. The guidewire lumen in such catheters extends only through the distal shaft section between a proximal wire inlet and a distal wire outlet. The mid-shaft section and the proximal shaft section of such catheters generally do not have a guidewire lumen. In the area of the mid-shaft and proximal shaft sections, the guidewire runs outside the catheter shaft when the catheter is in use.Compared to catheters with a so-called over-the-wire catheter design, in which the guidewire lumen extends through the entire catheter shaft, the catheter shaft of SOE catheters can be moved relatively smoothly over the guidewire. This simplifies catheter insertion and catheter exchange. A disadvantage of SOE catheters is their kink resistance, as the catheter shaft is reduced in cross-section in the area of the proximal wire inlet and is open laterally.

[0004] From EP 2 398 541 A1 a catheter according to the preamble of claim 1 is known. To improve the kink resistance, the known catheter has a central shaft section with a proximal hollow tube section which, in the distal direction, merges into a radially open groove section with a radially outwardly located convex groove outer side and a radially inwardly located concave groove inner side, wherein the concave groove inner side is opposite the guide wire lumen in the radial direction and the convex groove outer side is facing away from the guide wire lumen in the radial direction.

[0005] Furthermore, EP 2 934 311 B1 discloses a catheter having a body which has a distal portion and a proximal portion, wherein the distal portion defines a guidewire lumen and includes a guidewire exit opening which is open in a proximal direction and leads to the guidewire lumen, and wherein a proximal portion of the guidewire lumen is straight.

[0006] The object of the invention is to provide a catheter of the type mentioned above that has improved properties. In particular, simplified catheter manufacturing, improved kink resistance, and improved force transmission between the individual sections of the catheter shaft are to be achieved.

[0007] This object is achieved in that the proximal shaft section has a proximal hollow tube section which merges in the distal direction into a radially open groove section which has a convex groove outer side and a concave groove inner side, wherein the groove section is pushed in the distal direction through a lumen of the middle shaft section into a lumen of the distal shaft section, and wherein the convex groove outer side lies opposite the guide wire lumen in the radial direction and the concave groove inner side faces away from the guide wire lumen in the radial direction. Various advantages are achieved by the opposite arrangement of the convex groove outer side and the guide wire lumen according to the invention. Firstly, an improved force transmission is achieved between the proximal shaft section, in particular: its groove section, and the distal shaft section.In this context, it can also be said that the convex outer surface of the groove wedges with or against the guide wire lumen, in particular in the radial and / or axial direction. In the area of the proximal wire inlet, this increases the kink resistance of the catheter shaft. The invention also has the effect of making the catheter easier to advance axially. This is because the aforementioned wedging not only improves bending stiffness, but also improves shear stiffness. Secondly, the radially opposite arrangement of the convex outer surface of the groove and the guide wire lumen according to the invention counteracts unwanted lumen closure during catheter manufacture. Such a lumen closure can in principle occur with solutions known from the prior art with a radially opposite arrangement of the guide wire lumen and a concave outer surface of the groove.The "reversed" orientation of the groove section counteracts this disadvantage in a simple and unexpectedly effective way. During manufacture of the catheter, the proximal shaft section is pushed from a proximal end of the middle shaft section through its lumen into the lumen of the distal shaft section. In one embodiment, the lumen of the middle shaft section and the hollow tube section of the proximal shaft section are dimensionally matched to one another in such a way that a press connection is created between the middle shaft section and the proximal shaft section. The distal shaft section and the middle shaft section are joined together in a manner known to those skilled in the art, for example, glued and / or welded together. The proximal shaft section can also be referred to as a hypotube or skive.The proximal wire inlet of the guide wire lumen is located in the region of the proximal end of the distal shaft section and the distal end of the middle shaft section and opens laterally, i.e. laterally and / or radially, into the catheter shaft.

[0008] In an embodiment of the invention, the catheter has an expandable balloon section which is attached to a distal end of the distal shaft section and has an expansion volume which is fluidically connected to the hollow tube section of the proximal shaft section via the lumen of the distal shaft section and the lumen of the middle shaft section, whereby the balloon section can be expanded by pressurizing the expansion volume. In this embodiment of the invention, the catheter is a balloon catheter. Preferably, it is a vascular balloon catheter for treating stenoses, i.e., narrowing of the blood vessels. For this purpose, the balloon section of the catheter is placed in the region of the narrowing of the blood vessel and expanded by pressurizing the expansion volume. As a result, the narrowed vessel is widened under the action of the expanding balloon section in order to eliminate the stenosis.The expansion volume is pressurized via a liquid pressure medium, which is directed from a proximal end of the proximal shaft section through its hollow tube section and its groove section into the lumen of the distal shaft section and from there into the expansion volume. The inventive arrangement of the convex groove outer surface prevents the lumen of the distal shaft section from being unintentionally closed or its cross-section reduced during manufacture of the catheter as a result of the groove section being pushed in too deeply axially. Such a reduction in the cross-section can lead to a reduction in the maximum volume flow of the pressure medium. This limits the functionality of the balloon catheter.In particular, the solution according to the invention also prevents (too) rapid deflation of the expansion volume from leading to lumen closure, as is fundamentally conceivable and possible with solutions known from the prior art. Such a lumen closure can lead to the balloon section not being fully evacuated after the vascular constriction has been eliminated and consequently not being able to be easily removed from the vessel. In such a case, the balloon section still in the vessel must be burst, which entails significant risks for the patient. The inventive arrangement of the convex outer surface of the groove radially in the direction of the guide wire lumen counteracts all of this.

[0009] In a further embodiment of the invention, the groove section is formed by continuously grinding a distal region of the proximal shaft section. In other words: To form the groove section, the proximal hollow tube section is ground radially at an angle or ground down. The groove section is formed by the grinding. Due to the inclination of the grinding, the groove section tapers in the distal direction. A circumferential length of the groove section consequently decreases in the distal direction and is maximum at a proximal beginning of the grinding (a distal end of the tube section) and minimum at a distal end of the groove section.

[0010] In a further embodiment of the invention, the groove section is formed by a gradual taper of a distal region of the proximal shaft section. In contrast to the previous embodiment, the proximal shaft section is not inclined, but rather ground down in stages. As a result, the groove section tapers gradually or even in steps in the distal direction. In contrast to this, the groove section in the previous embodiment tapers continuously in the distal direction. In a further embodiment, the distal region of the proximal shaft section is alternatively or additionally provided with bores to enable direct force transmission on the one hand and high flow during expansion (inflation) and contraction (deflation) of the balloon section on the other.

[0011] In a further embodiment of the invention, the channel section is configured in two parts in the circumferential direction and has a first channel section, a second channel section, and a longitudinal gap that extends proximally from a distal end of the channel section and separates the first channel section and the second channel section from one another, forming the two-part design. The longitudinal gap splits or separates the channel section into the first channel section and the second channel section. In this embodiment, the channel section can also be said to be designed in the manner of a snake's tongue. This embodiment of the invention offers particular advantages.

[0012] In a further embodiment of the invention, the distal shaft section and the middle shaft section are each made of a plastic material, and the proximal shaft section is made of a metal material. Both the plastic material and the metal material can be provided with a coating. Preferably, the plastic material is provided with a hydrophilic coating. The metal material is preferably provided with a Teflon coating.

[0013] Further advantages and features of the invention emerge from the claims and from the following description of preferred embodiments of the invention, which are illustrated with reference to the drawings. Fig. 1 shows in a schematically simplified longitudinal section an embodiment of a catheter according to the invention with additional schematic cross sections at different axial positions of the catheter, Fig. 2 the catheter Fig. 1 in the area of a proximal wire inlet in one of the Fig. 1 corresponding representation, Fig. 3 a distal end of a proximal shaft section of the catheter according to the Fig. 1 and Fig. 2 in a schematically simplified and partially cut-out side view, Fig. 4 in one of the Fig. 3 corresponding representation a variant of the proximal shaft section and Fig. 5 in a schematic plan view a further variant of the proximal shaft section in a distal area with a two-part groove section.

[0014] According to Fig. 1, a catheter 1 in the form of a balloon catheter 1' is provided for use in angioplasty and has an elongated catheter shaft with a distal shaft section 10, a middle shaft section 20, and a proximal shaft section 30. The catheter 1 also has a guide wire lumen 40 and a balloon section 60. The balloon section 60 is optional. In an embodiment not shown in the figures, the catheter does not have such a balloon section.

[0015] The guidewire lumen 40 is configured to receive a guidewire 50 and extends longitudinally between a distal wire outlet 41 and a proximal wire inlet 42. The guidewire lumen 40 extends at least partially through the distal shaft portion 10.

[0016] In the embodiment shown, the guide wire lumen 40 also extends longitudinally through the balloon portion 60. The distal wire outlet 41 is arranged in the region of a distal end 62 of the balloon portion 60.

[0017] The proximal wire inlet 42 is arranged in the region of a proximal end 12 of the distal shaft section 10 and a distal end 21 of the middle shaft section 20 and opens laterally into the catheter shaft.

[0018] In the Fig. In the exemplary usage situation shown in Figure 1, the guidewire 50 extends longitudinally through the guidewire lumen 40. In the proximal direction of the proximal wire inlet 42, the guidewire 50 thus extends outside and radially offset from the catheter shaft.

[0019] The proximal shaft section 30 has a proximal hollow tube section 31 which merges in the distal direction into a radially open groove section 32.

[0020] The groove section 32 has a convex groove outer side 321 and a concave groove inner side 322. The groove outer side 321 and the groove inner side 322 are radially opposite one another.

[0021] The groove section 32 is pushed in the distal direction through a lumen 23 of the middle shaft section 20 into a lumen 13 of the distal shaft section 10.

[0022] As shown in the cross-sectional views of the Fig. As shown in Figure 1, the convex groove outer side 321 is arranged radially opposite the guide wire lumen 40. The concave groove outer side 322 faces away from the guide wire lumen 40 in the radial direction.

[0023] Regarding the character level of the Fig. 1, the groove section 32 is thus open downwards. In other words, the concave groove inner side 322 points downwards and / or radially outwards, and the convex groove outer side 321 points upwards and / or radially inwards (toward the guide wire lumen 40).

[0024] The distal shaft section 10, the middle shaft section 20, the proximal shaft section 30 and the balloon section 60 are coaxial.

[0025] The distal shaft portion 10 has a distal end 11 and the aforementioned proximal end 12. The distal shaft portion 10 is elongated between its distal end 11 and its proximal end 12. The lumen 13 of the distal shaft portion 10 extends continuously between the distal end 11 and the proximal end 12. The guidewire lumen 40 runs in and / or parallel to the lumen 13.

[0026] The middle shaft section 20 has the aforementioned distal end 21 and a proximal end 22. The middle shaft section 20 is longitudinally extended between its distal end 21 and its proximal end 22. The lumen 23 of the middle shaft section 20 is longitudinally extended continuously between the distal end 21 and the proximal end 22.

[0027] The proximal shaft portion 30 has a distal end 35 and a proximal end not shown in detail in the figures. The proximal shaft portion 30 extends longitudinally between the distal end 35 and the proximal end. A catheter hub is preferably attached to the proximal end of the proximal shaft portion 30.

[0028] The tube section 31 extends distally from the proximal end of the proximal shaft section 30 and merges into the groove section 32. In the embodiment shown, this transition begins approximately at the axial height of the proximal end 22 of the central shaft section 20. The groove section 32 extends from there to the distal end 35 of the proximal shaft section 30.

[0029] In the area of the hollow tube section 31, the proximal shaft section 30 has a lumen 33.

[0030] In Fig. 3 shows that the groove section 32 is formed by a continuous abraded section A of a distal region of the proximal shaft section 30. This abraded or ground-down region can also be referred to as a skive. It is understood that the abraded section does not necessarily have to be formed by grinding. In principle, other machining technologies are also conceivable and possible for forming the abraded section.

[0031] In contrast to the hollow tube section 31 and / or lumen 33, the channel section 32 is open on one side (in the radial direction).

[0032] Due to the continuous grinding A, the groove section 32 tapers in the distal direction. This is also shown in the cross-sectional views of the Fig. 1. There it is shown that the groove section 32 decreases in its circumferential length in the distal direction.

[0033] The groove section 32 is pushed over the proximal end 22 into the lumen 23 of the middle shaft section 20 into the lumen 13 of the distal shaft section 10. The distal end 35 of the proximal shaft section 30 is arranged in the vicinity of the proximal wire inlet 42.

[0034] During the manufacture of the catheter 1, the proximal shaft section 30 is axially connected to the middle shaft section 20 and the distal shaft section 10. This creates a press connection between the hollow tube section 31 and the lumen 23 of the middle shaft section 20. At the same time, the groove section 32 is pressed and / or wedged to the lumen 23 of the middle shaft section 20 and / or the lumen 13 of the distal shaft section 10.

[0035] The balloon portion 60 has an expansion volume 61, the aforementioned distal end 62, and a proximal end 63. The balloon portion 60 is elongated between its distal end 62 and its proximal end 63 and can be expanded by applying pressure to the expansion volume 61.

[0036] This pressurization by means of a liquid pressure medium, which is introduced into the expansion volume 61 starting from the proximal end of the proximal shaft section 30 via its hollow tube section 32 and / or lumen 33 as well as the lumens 23 and 13 of the middle shaft section 20 and distal shaft section 10, respectively.

[0037] The proximal end 63 of the balloon section 60 is joined, for example, welded or glued, to the distal end 11 of the distal shaft section 10. The guide wire lumen 40 is welded or glued to the balloon section 60 in the region of the distal end 62. This creates a pressure-tight expansion volume 61.

[0038] In the embodiment shown, the distal shaft section 10 and the middle shaft section 20 are provided with a hydrophilic coating S1.

[0039] The proximal shaft section 30 has a Teflon coating S2 in the area of the hollow tube section 31.

[0040] Furthermore, in the embodiment shown, the distal shaft section 10 and the middle shaft section 20 are made of a plastic material K. The proximal shaft section 30 is made of a metal material M.

[0041] In the Fig. 4 and Fig. 5 alternatively designed proximal shaft sections 30a, 30b are shown.

[0042] At the Fig. 4, the proximal shaft section 30a has several steps or gradations T1, T2, T3. The steps T1, T2, T3 form a gradual taper to form the groove section 32a. In contrast, the continuous grinding A in the variant according to Fig. 3 also a continuous tapering of the channel section 32.

[0043] At the Fig. 5, the groove section 32b has a first groove section 32b', a second groove section 32b'' and a longitudinal gap 34b. The longitudinal gap 34b extends proximally from the distal end 35b of the groove section 32b and subdivides the groove section 32b into the first groove section 32b' and the second groove section 32b''. In the variant shown in Fig.In the variant shown in Figure 5, the groove section 32b is designed in the manner of a snake's tongue.

Claims

[1] Catheter (1) having an elongated catheter shaft having a distal shaft portion (10), a middle shaft portion (20) and a proximal shaft portion (30, 30a, 30b), a guide wire lumen (40) adapted to receive a guide wire (50) and extending longitudinally at least in sections through the distal shaft portion (10) between a distal wire outlet (41) and a proximal wire inlet (42), which opens laterally into the catheter shaft in the region of a proximal end (12) of the distal shaft portion (10) and a distal end (21) of the central shaft portion (20), characterized bythat the proximal shaft section (30, 30a, 30b) has a proximal hollow tube section (31, 31a) which merges in the distal direction into a radially open groove section (32, 32a, 32b) which has a convex groove outer side (321, 321a, 321b) and a concave groove inner side (322, 322a, 322b), wherein the groove section (32, 32a, 32b) is pushed in the distal direction through a lumen (23) of the middle shaft section (20) into a lumen (13) of the distal shaft section (10), and wherein the convex groove outer side (321, 321a, 321b) is opposite the guide wire lumen (40) in the radial direction and the concave groove inner side (322, 322a, 322b) is facing away from the guide wire lumen (40) in the radial direction. [2] Catheter (1) according to claim 1, further comprising an expandable balloon portion (60) attached to a distal end (11) of the distal shaft portion (10) and having an expansion volume (61) fluidly connected to the hollow tube portion (31) of the proximal shaft portion (30) via the lumen (13) of the distal shaft portion (10) and the lumen (23) of the middle shaft portion (20), whereby the balloon portion (60) is expandable by pressurizing the expansion volume (61). [3] Catheter (1) according to claim 1 or 2, wherein the groove portion (32) is formed by a continuous grinding (A) of a distal region of the proximal shaft portion (30). [4] Catheter (1) according to claim 1 or 2, wherein the groove portion (32a) is formed by a stepwise taper of a distal region of the proximal shaft portion (30a). [5] Catheter (1) according to one of the preceding claims, wherein the channel section (32b) is designed in two parts in the circumferential direction and has a first channel section (32b'), a second channel section (32b'') and a longitudinal gap (34b) which extends proximally from a distal end (35b) of the channel section (32b) and separates the first channel section (32b') and the second channel section (32b'') from one another to form the two-part design. [6] Catheter (1) according to one of the preceding claims, wherein the distal shaft portion (10) and the middle shaft portion (20) are each made of a plastic material (K), and wherein the proximal shaft portion (30) is made of a metal material (M).

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