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EP-4335479-B1 - CATHETER

EP4335479B1EP 4335479 B1EP4335479 B1EP 4335479B1EP-4335479-B1

Inventors

  • KANEKO, YOSHIKI

Dates

Publication Date
20260513
Application Date
20230830

Claims (4)

  1. A catheter (10) comprising: a first tube (110) having a first lumen, and a second tube (120) having a second lumen, wherein the first tube (110) includes an inner layer corresponding to an innermost layer of the first lumen, an outer layer surrounding the inner layer, and a reinforcing layer sandwiched between the inner layer and the outer layer, characterized in that the catheter (10) further comprises a connection layer (130) covering at least a portion of the outer peripheral surfaces of the first tube (110) and the second tube (120) to connect the first tube (110) and the second tube (120), and a core wire (50) embedded in the connection layer (130), wherein the melting point of the connection layer (130) is lower than those of the inner layer and the outer layer, and wherein in a cross section of the catheter (10), the first tube (110) and the second tube (120) are exposed to outside of the connection layer (130) at both ends in a direction where the first tube (110) and the second tube (120) are aligned side by side.
  2. The catheter (10) according to claim 1, wherein an outer periphery of the catheter (10) is elliptical in a transverse section.
  3. The catheter (10) according to claim 1 or 2, wherein the reinforcing layer is a coil.
  4. The catheter (10) according to any one of claims 1 to 3, wherein the reinforcing layer is a first reinforcing layer (113), the inner layer is a first inner layer (111), the outer layer is a first outer layer (112), the second tube (120) includes a second inner layer (121) corresponding to an innermost layer of the second lumen, a second outer layer (122) surrounding the second inner layer (121), and a second reinforcing layer (123) sandwiched between the second inner layer (121) and the second outer layer (122).

Description

TECHNICAL FIELD The technology disclosed herein relates to a catheter. BACKGROUND ART A catheter is an elongated medical device to be inserted for use into a biological lumen such as a blood vessel to diagnose or treat the biological lumen. A catheter having two or more lumens is known for the purposes such as for improving the vascular selectivity of a guide wire. For example, a catheter of this type has a configuration in which a plurality of inner tubes each having a lumen are inserted into an outer tube and welded to the outer tube (for example, see JP 2015 - 213 684 A). When the tubes of the catheter are welded together, the wall thickness of the tubes may become thinner and the strength of the tubes may be decreased. Reduced strength of the tubes each having a lumen may, for example, cause a guide wire to unintentionally protrude out of a lumen. JP 2009 - 082 566 A discloses a catheter comprising a first lumen and a second lumen, wherein at least the second lumen is composed of an inner layer, a reinforcing layer, and an outer layer. EP 2 944 344 A1 discloses a catheter including an outer tube, a first inner tube, a second inner tube, and a reinforcing member. Protective films cover the outer periphery of the inner tubes. Welded parts connect the outer tube, the protective films, and the inner tubes to one another. WO 2006 / 126 642 A1 discloses a catheter having a distal shaft, a proximal shaft, a metallic core wire, and a hub. The distal shaft has a dual lumen structure having a first lumen and a second lumen. The distal shaft further comprises inner layers and an outer layer of the shaft forming the inner surfaces of the two lumens of the first lumen and the second lumen. WO 2018 / 008272 A1 discloses a catheter comprising a distal shaft having a first tube including a first lumen, a second tube including a second lumen and a reinforcing layer. Conventionally, a catheter having a protective film placed between an inner tube and an outer tube or between a plurality of inner tubes has been proposed to prevent decreased wall thickness due to inter-tube welding. SUMMARY OF INVENTION Technical Problem The invention is according to claim 1. Preferred embodiments of the invention are set forth in the dependent claims. In the aforementioned configurations of the conventional catheters, there is room for improving the strength of a tube having a lumen. Disclosed herein is a technology which can solve the above problem. This problem is solved by the subject matter of the independent claim. Further aspects are disclosed in the dependent claims. Solution to Problem The technology disclosed herein can be implemented, for example, according to the following aspects. (1) A catheter disclosed herein comprises a first tube having a first lumen, and a second tube having a second lumen. The first tube has an inner layer corresponding to the innermost layer of the first lumen, an outer layer surrounding the inner layer, and a reinforcing layer sandwiched between the inner and the outer layer. According to the present catheter, the strength of the first tube having the first lumen can be improved by means of the reinforcing layer sandwiched between the inner layer and the outer layer. This can, for example, prevent a guide wire from unintentionally protruding out of the first lumen, or can prevent a guide wire from being stuck due to a collapse of the first lumen.(2) The above catheter further comprises a connecting layer covering at least a portion of outer peripheral surfaces of the first tube and the second tube to connect the first tube and the second tube, and having a melting point lower than those of the inner layer and the outer layer. This configuration can prevent the inner layer and the outer layer for the first tube from becoming thinner due to welding, effectively increasing the strength of the first tube, and can also prevent the reinforcing layer sandwiched between the inner layer and the outer layer from being exposed. As further, a core wire is embedded in the connection layer. As further, in a cross section of the catheter, the first tube and the second tube are exposed to outside of the connection layer at both ends in a direction where the first tube and the second tube are aligned side by side.(3) In the above catheter, an outer periphery of the catheter may be elliptical in a transverse section. This configuration can improve the passability through a lesion site and the operability of a concomitantly-used device as compared to a configuration in which an outer periphery is circular in a transverse section.(4) In the above catheter, the reinforcing layer may be a coil. This configuration enables the coil as a reinforcing layer to improve the strength of the first tube while ensuring the flexibility required for the catheter.(5) In the above catheter, the reinforcing layer may be a first reinforcing layer, and the inner layer may be a first inner layer, and the outer layer may be a first outer laye