WO2020195581A1

WO2020195581A1 - Steerable catheter

Info

Publication number: WO2020195581A1
Application number: PCT/JP2020/008718
Authority: WO
Inventors: 徹谷; 篤史山田; 辰也嶋; 渉米道
Original assignee: 国立大学法人滋賀医科大学; 日本ゼオン株式会社
Priority date: 2019-03-22
Filing date: 2020-03-02
Publication date: 2020-10-01
Also published as: JPWO2020195581A1

Abstract

[Problem] To provide a steerable catheter with which both operability and insertability can be improved. [Solution] In a steerable catheter 1, a tube 2 comprises: a first tube section 20 the flexibility of which does not substantially change even upon receiving compression force in the axial direction; and a second tube section 21 that serves as a deflection section constituted by a porous tube which is joined so as to be continuous with a distal end of the first tube section 20, and which hardens upon being compressed according to the degree of compression force acting in the axial direction and returns to being soft when the compression force is released. A hardness adjustment means 6, which adjusts the hardness of the second tube section by releasably pushing the first tube section to a distal end side relative to an operation part 3 provided to the proximal end of the first tube section, is interposed between the proximal end of the first tube section and the operation part.

Description

Movable catheter

The present invention relates to a catheter, which is a medical treatment tool used for performing various treatments, examinations, etc., and particularly to a movable catheter (steerable catheter) capable of freely deflecting the tip portion and the like.

Includes medical treatment tools (eg, contrast medium injection catheters, electrode catheters, ablation catheters, catheter sheaths) that are inserted into target tissues such as various organs (eg, bile ducts, hearts) through body cavities, cavities, blood vessels, etc. ), The tip (distal end) of the catheter inserted into the body is oriented to the base end (proximal end) of the catheter placed outside the body in order to facilitate its insertion and access to the target tissue. A movable catheter that can be deflected by operating an operation unit provided on the side is known (see, for example, Patent Document 1 and Patent Document 2).

The catheter described in Patent Document 1 is a catheter for an endoscope used for injecting an X-ray contrast medium into the bile duct for examination in the bile duct, and extends to the duodenum via the endoscope. After being inserted, the tip is deflected (curved) by operating (pushing or pulling) the operation wire from outside the body so that the tip can be easily inserted into the duodenal papilla from the duodenal side to reach the inside of the bile duct. It is a catheter that can be used. The catheter described in Patent Document 1 has a lumen into which an operation wire for deflecting the tip portion is inserted, in addition to a large-diameter lumen used for injecting a contrast medium or the like. Since the wire is joined to the tip tip provided at the tip of the catheter by means such as plasma welding, the tip of the catheter can be deflected by pulling the operation wire on the outside of the body.

The tip movable catheter described in Patent Document 2 is a catheter used for guiding an ablation catheter to a site to be treated in the heart in order to perform catheter ablation treatment on the heart, and the tip of the ablation catheter is the heart. This is a catheter in which the tip portion can be deflected (curved) by operating the operating portion from the outside of the body so that the catheter can be easily guided to a desired position. The catheter tube constituting the catheter described in Patent Document 2 has a pair of wire lumens at positions in the tube wall facing each other 180 ° in addition to the main lumen into which various treatment tools are inserted. are doing. The rigidity of the tip of the catheter tube to be deflected is set to be gradually lowered toward the tip, and the ring (pull ring) integrally attached to the tip is used for a wire. The tips of the pair of wires inserted into each of the lumens are connected by means such as laser welding, and the base ends of the pair of wires are connected to the operating portion. Then, by operating the operation unit, one wire is pulled and the other wire is loosened so that the direction of the tube tip can be controlled.

By the way, in this type of movable catheter, the movable part (deflection part) needs to have flexibility enough to be easily and freely deflected (curved) by operating a wire. However, if the configuration is flexible (soft) in consideration of operability, bending or buckling will occur when the stenosis in the lumen such as the bile duct is breached (penetrated), and the insertability is reduced. There is a risk of On the contrary, if the configuration is rigid in consideration of operability, operability may be sacrificed.

JP-A-2002-272675 Japanese Unexamined Patent Publication No. 2014-188039

The present invention has been made in view of such an actual situation, and an object of the present invention is to provide a movable catheter capable of improving both operability and insertability in a compatible manner.

In order to achieve the above object, the movable catheter according to the present invention is
It has a flexible tube having a distal end inserted into the body and a proximal end located outside the body, and an operating portion provided at the proximal end of the tube, by operation in the operating portion. , A movable catheter designed to deflect the deflection part on the distal end side of the tube.
The tube is joined to the first tube portion whose flexibility does not substantially change even when a compressive force is applied in the axial direction, and is continuously connected to the distal end of the first tube portion, and acts in the axial direction. It is provided with a second tube portion as the deflection portion, which is composed of a porous tube that is compressed and hardened according to the degree of the compressive force to be applied, and then returns to the original state and becomes soft when the compressive force is released.
The hardness adjusting means for adjusting the hardness of the second tube portion by leaching the first tube portion toward the distal end side with respect to the operation portion is provided with the proximal end portion of the first tube portion and the said. It is a movable catheter interposed between the operation unit.

According to the movable catheter according to the present invention, the hardness adjusting means is appropriately operated so that the first tube portion is not extruded (the extruded state is released), and the operating portion is appropriately operated. The second tube portion as a deflecting portion can be deflected, and since the first tube portion is not extruded at this time, no compressive force acts on the second tube portion, and the second tube portion is soft. It is in a state. Therefore, good operability can be realized. On the other hand, in the case of breaking through (penetrating) a narrowed portion in the lumen of the body such as a bile duct, the hardness adjusting means is appropriately operated to push the first tube portion toward the distal end side. A compressive force can be applied to the two tube portions to make the second tube portion in a rigid state. As a result, it is possible to suppress the occurrence of bending and buckling, and it is possible to improve the insertability. Therefore, it is possible to provide a movable catheter that can improve both operability and insertability in a compatible manner.

In the movable catheter according to the present invention, the hardness adjusting means has a first male threaded portion having a base end portion fixed to one of a proximal end portion of the first tube portion and the operating portion and a right-hand thread on the outer surface. It has a substantially cylindrical first male threaded member having a base end portion fixed to the proximal end portion of the first tube portion and the other of the operating portion, and has a second male threaded portion which is a left-handed screw on the outer surface. A connecting female screw having a cylindrical second male thread member, a first female thread portion that is arranged substantially coaxially with each other and into which the first male thread portion is screwed, and a second female thread portion into which the second male thread portion is screwed. It can be provided with a member. By rotating the connecting female thread member in one direction with respect to the first male thread member and the second male thread member, the first male thread member and the second male thread member can be separated from each other, and by rotating in the opposite direction, the first male thread member can be separated from each other. The 1 male screw member and the 2nd male screw member can be brought close to each other. Therefore, the first tube portion can be extruded toward the distal end side with respect to the operation portion, or the first tube portion can be pulled back toward the proximal end side with respect to the operation portion (extrusion is released), and the extrusion amount can be increased. Since it can be adjusted arbitrarily, the hardness (hardness or softness) of the second tube portion can be arbitrarily adjusted as needed.

In this case, the hardness adjusting means does not hinder the contact and separation of the first male screw member and the second male screw member screwed into the connecting female screw member as the connecting female screw member rotates. , Rotation regulating means for regulating each other's rotation can be provided. The rotation regulating means includes a fitting convex portion provided on one of the first male screw member and the second male screw member so as to project along the axial direction, and the first male screw member and the second male screw. It is possible to adopt a member provided on the other side of the member and provided with a fitting recess in which the fitting protrusion is slidably fitted. Relative of the first male thread member and the second male thread member when the connecting female thread member is rotated with respect to the first male thread member and the second male thread member in order to separate or approach the first male thread member and the second male thread member. Rotation can be prevented.

FIG. 1 is a diagram showing an external configuration of a movable catheter according to an embodiment of the present invention. FIG. 2A is a cross-sectional view taken along the line IIa-IIa of FIG. FIG. 2B is an enlarged perspective view showing a main part of the movable catheter of FIG. 1. FIG. 2C is a cross-sectional view of the distal end of the movable catheter of FIG. 2B cut along a plane passing through the respective axes of the pair of wire lumens. FIG. 3 is an enlarged view showing the distal end portion of the movable catheter of FIG. 1, and is a diagram for explaining the operation of the deflection portion. FIG. 4A is a perspective view showing a case where the number of wires inserted into the wire lumen of the movable catheter of FIG. 2B is increased. FIG. 4B is a cross-sectional view of the distal end of the movable catheter of FIG. 4A cut along a plane orthogonal to its axis. FIG. 4C is a cross-sectional view of the distal end of the movable catheter of FIG. 4A cut along a plane passing through the respective axes of the pair of wire lumens. FIG. 5A is a diagram showing a modified example of the movable catheter of FIG. 4A. FIG. 5B is a diagram showing another modification of the movable catheter of FIG. 4A. FIG. 5C is a diagram showing still another modification of the movable catheter of FIG. 4A. FIG. 6A is a front view of the hardness adjusting means of the movable catheter of FIG. 1, which shows a state in which the first male screw member and the second male screw member are brought close to each other. FIG. 6B is a diagram showing a state in which the first male screw member and the second male screw member of the hardness adjusting means of FIG. 6A are separated from each other. FIG. 7A is a front view of the first male screw member of the hardness adjusting means of FIG. 6A. FIG. 7B is a side view of the first male screw member of FIG. 7A as viewed from the tip end side. FIG. 7C is a front view of the second male screw member of the hardness adjusting means of FIG. 6A. FIG. 7D is a side view of the second male screw member of FIG. 7C as viewed from the tip end side. FIG. 7E is a cross-sectional view taken along a plane including the axial center of the connecting female screw member of the hardness adjusting means of FIG. 6A. FIG. 7F is a side view of the connecting female thread member of FIG. 7E.

Hereinafter, embodiments of the present invention will be specifically described with reference to the drawings. The catheter sheath (movable sheath) as the movable catheter of the present embodiment precedes, for example, an electrode catheter for detecting electrocardiogram, an ablation catheter for cauterizing the affected area, and the like when performing catheter ablation. It is a catheter that is inserted and guides these electrode catheters, ablation catheters, and the like. In the following, a catheter sheath will be described as an example of a movable catheter to which the present invention is applied, but it is used for an electrode catheter, an ablation catheter, an X-ray contrast agent for injecting an X-ray contrast medium for examination in the bile duct, and the like. The present invention can also be applied to a movable endoscope catheter and other movable catheters.

Catheter ablation is a treatment method for treating arrhythmia that occurs in the heart, and an ablation catheter having a high-frequency electrode at its tip is passed through a blood vessel to the myocardial tissue that causes the arrhythmia in the heart. It is a treatment method in which the myocardial tissue or its vicinity is inserted and cauterized at about 60 to 70 ° C. to cause coagulation necrosis and block the circuit of arrhythmia.

First, refer to FIGS. 1 and 2A to 2C. The catheter sheath (movable catheter) 1 is configured to substantially include a sheath (tube) 2, an operating portion 3, a grip portion 4, and a pair of wires W1 and W2.

The sheath 2 is composed of a flexible hollow tube having a distal end inserted into the body and a proximal end arranged outside the body, and the sheath body portion (first tube portion) 20 arranged on the proximal end side. It is composed of a deflection portion (second tube portion) 21 arranged on the distal end side. The sheath body 20 is configured to have relatively high rigidity so that the flexibility does not substantially change even if a compressive force is applied in the direction along the axis (axis direction). As the sheath main body 20, for example, a multilayer tube including a blade layer made of net-like stainless steel or the like and a plurality of resin layers is used.

The deflection portion 21 is integrally joined so that the proximal end is continuous with the distal end of the sheath body portion 20. The lumen of the deflection portion 21 and the lumen of the sheath body portion 20 are continuously connected to each other, and the main lumen 22 is formed by these. The deflection portion 21 is composed of a porous tube that is compressed and hardened according to the degree of compressive force acting in the axial direction, and returns to its original state and becomes soft when the compressive force is released. The flexibility (hardness and softness) of the porous tube can be controlled by adjusting the compressive force acting in the axial direction.

The material of the sheath body 20 is not particularly limited as long as it has flexibility, but is preferably a thermoplastic resin or a thermoplastic elastomer, for example, a polyamide-based elastomer such as a polyether blockamide copolymer. Polyamide, polyimide, polyamideimide, polyethylene terephthalate, polyethylene, polypropylene, polyurethane, ethylene / vinyl acetate copolymer, polyvinyl chloride, polytetrafluoroethylene, tetrafluoroethylene / hexafluoropropylene copolymer, tetrafluoroethylene / perfluoro An alkyl vinyl ether copolymer or the like is used.

The material of the porous tube constituting the deflection portion 21 is not limited, but the use of PTFE (polytetrafluoroethylene) is excellent in heat resistance, chemical resistance, weather resistance, water repellency, etc. Is preferable. As the porous tube, a tube produced by extruding PTFE and stretching the tube in the axial direction can be used. By making PTFE porous, it is possible to obtain the required waterproofness while maintaining air permeability. Further, the porosity can be adjusted by appropriately adjusting the stretching ratio (degree of stretching) during the stretching process, and the change in flexibility during compression can be appropriately adjusted (controlled). Is. It is also possible to change the ventilation performance by adjusting the porosity.

An operation portion 3 and a grip portion 4 are provided on the proximal end side of the sheath 2 (sheath body portion 20), and the proximal end portion of the sheath 2 is the operation portion 3 via the hardness adjusting means 6 (details will be described later). It is attached to the distal end of. A connecting tube that penetrates through the lumens (through

holes

61d and 62d, fitting recesses 62c described later) provided in the hardness adjusting means 6 and the lumens (not shown) provided in the operation portion 3 and the grip portion 4. (Not shown) is provided, and the distal end side of the connecting tube reaches the inside of the main lumen 22 of the sheath 2. The connecting tube has an outer diameter slightly smaller than the inner diameter of the main lumen 22 so that the distal end side can slide with respect to the main lumen 22 of the sheath 2 and the lumen of the hardness adjusting means 6. It has been inserted. Therefore, the main lumen 22 of the sheath 2 communicates with the proximal end of the grip portion 4 via the lumen of the connecting tube. A sheath hub 41a is attached to the proximal end of the grip portion 4.

The sheath hub 41a has a lumen, and a connecting tube in the grip portion 4 is attached to the proximal end side of the sheath hub 41a so that the lumen of the sheath hub 41a and the lumen of the connecting tube communicate with each other. .. Further, a catheter insertion port provided with a hemostatic valve is formed on the distal end side of the sheath hub 41a. When the catheter sheath 1 is used (during treatment), the above-mentioned electrode catheter and ablation catheter are inserted from the catheter insertion port of the sheath hub 41a and guided to the main lumen 22 of the sheath 2 via the connecting tube to each distance. The ends of the catheter are guided to the myocardial tissue to be treated. A side injection tube is formed on the side of the sheath hub 41a, and a three-way stopcock 41c is attached to the side injection tube via the tube 41b. For example, a syringe or the like can be attached to the three-way stopcock 41c to suck blood in the body or send a drug solution into the body. In the present embodiment, the distal end of the connecting tube is assumed to reach a position near the distal end side of the proximal end of the sheath 2, but may reach the distal end of the sheath 2. In this case, the lumen of the connecting tube will function as the main lumen 22.

At the distal end of the sheath 2 (the tip of the deflection portion 21), a substantially cylindrical tip protection member 29 made of resin and having a hemispherical distal end side is provided. The tip protection member 29 has a lumen having substantially the same diameter as the main lumen 22 of the sheath 2, and is integrally joined (fixed) to the distal end of the sheath 2 (deflection portion 21) by heat fusion or the like. There is. However, the tip protection member 29 may be omitted.

Four wire lumens (sub-lumens) 23a to 23d substantially parallel to the main lumen 22 are formed in the pipe wall of the sheath 2 (sheath body portion 20 and deflection portion 21) so as to surround the outside of the main lumen 22. Has been done. The wire lumens 23a to 23d are formed from the proximal end of the sheath 2 (the proximal end of the sheath body 20) to the distal end (the distal end of the deflection portion 21). The wire lumens 23a to 23d are formed on the outside of the main lumen 22 with the axis of the sheath 2 as the center and separated from each other at an angular pitch (angle interval) of approximately 90 °.

A single wire W1 is inserted through the wire lumen 23a and the wire lumen 23b, and a single wire W2 is inserted through the wire lumen 23c and the wire lumen 23d. In the present embodiment, the wires W1 and W2 are formed of a metal such as stainless steel, but the wires W1 and W2 may be formed of another material such as resin.

About half of the wire W1 on one end side is inserted into the lumen 23a for wire, and the intermediate portion W1c is folded back at the distal end surface to which the tip protection member 29 of the sheath 2 is joined, and the other end side. Approximately half W1b is inserted through the wire lumen 23b, and both ends (one end and the other end) thereof are arranged so as to be located at the operation portion 3 on the proximal end side of the sheath 2. Similarly, in the wire W2, approximately half W2a on one end side thereof is inserted into the lumen 23c for the wire, and the intermediate portion W2c thereof is folded back at the distal end surface to which the tip protection member 29 of the sheath 2 is joined, and the other end. Approximately half W2b on the portion side is inserted into the lumen 23d for wire, and both end portions (one end portion and the other end portion) thereof are arranged so as to be located at the operation portion 3 on the proximal end side of the sheath 2.

Both ends of the wire W1 and both ends of the wire W2 penetrate the hardness adjusting means 6 (wire insertion holes 64a to 64d and 65a to 65d to be described later) and reach the inside of the operation unit 3, and the operation unit 3 It is connected to each of the rotation operation members 31 of. The operation unit 3 has a pair of protruding

grip portions

32, 32 integrally provided on the rotation operation member 31, and a holding portion 42 provided on the tip end (distal end) side of the grip portion 4. It is held via a screw-in type knob member 5.

Since the distal ends of the wires W1 and W2 (folded portions W1c and W2c) are folded back at the distal ends of the deflection portions 21, the proximal ends (both ends) of the wires W1 and W2 are pulled at the same time. , The distal ends of the wires W1 and W2 are engaged with the distal end of the deflection portion 21, and a force can be applied to the distal end of the deflection portion 21.

The hardness adjusting means 6 is interposed between the proximal end portion of the sheath 2 (sheath body portion 20) and the operating portion 3, and pushes the sheath main body portion 20 toward the distal end side with respect to the operating portion 3 or It is a means for adjusting the hardness (flexibility) of the deflection portion 21 by releasing the extrusion (pulling it back to the proximal end side). The hardness adjusting means 6 of the present embodiment is a so-called turnbuckle. That is, as shown in FIGS. 6A and 6B, the hardness adjusting means 6 includes a first male screw member 61, a second male screw member 62, and a connecting female screw member 63.

As shown in FIGS. 7A and 7B, the first male screw member 61 is a member having a substantially cylindrical shape as a whole, and is fitted with the operation portion side fixing portion 61a and the male screw portion 61b from the proximal end side to the distal end side. It has a convex portion (rotation regulating means) 61c.

The operation unit side fixing portion 61a is a portion fixed to the distal end portion of the operation portion 3, and although it is a substantially disk-shaped portion in the present embodiment, it is fixed to the distal end portion of the operation portion 3. Any shape may be used as long as it is suitable for the above.

The male screw portion 61b is erected on the surface of the operation portion side fixing portion 61a opposite to the side fixed to the operation portion 3, and a male screw which is a right-hand screw (positive screw) is formed on the outer surface thereof. ing. The fitting convex portion 61c is erected on the tip surface of the male screw portion 61b. The fitting convex portion 61c is a portion that is slidably fitted in the fitting concave portion 62c of the second male screw member 62, which will be described later, in the axial direction.

A through hole 61d penetrating along the axial direction is formed in the central portion of the first male screw member 61. Inside the side wall of the male screw portion 61b, the side fixed to the operation portion 3 of the operation portion side fixing portion 61a from the tip surface of the male screw portion 61b (the outer portion of the portion where the fitting convex portion 61c is erected). Four wire insertion holes 64a to 64d are formed at an angle pitch of approximately 90 ° so as to penetrate over the surface. The wire insertion holes 64a to 64d are provided so as to correspond to the wire lumens 23a to 23d of the sheath 2, and both ends of the wire W1 and both ends of the wire W2 are corresponding wire insertion holes, respectively. It penetrates 64a to 64d and is guided to the inside of the operation unit 3.

As shown in FIGS. 7C and 7D, the second male screw member 62 is a member having a substantially cylindrical shape as a whole, and has a sheath side fixing portion 62a and a male screw portion 62b from the proximal end side to the distal end side. There is.

The sheath-side fixing portion 62a is a portion where the proximal end portion of the sheath 2 (sheath body portion 20) is fixed, and if the shape is suitable for fixing the proximal end portion of the sheath 2, any Shape may be used. In the present embodiment, the sheath-side fixing portion 62a has a substantially disk-shaped disc portion and a sheath connecting portion 62e. The sheath connecting portion 62e is provided so as to project from the surface of the disk portion on the side where the proximal end portion of the sheath 2 is fixed. The sheath connecting portion 62e is a tubular portion in which a plurality of substantially umbrella-shaped barbs are formed around the sheath connecting portion 62e, and this portion is press-fitted into the main lumen 22 at the proximal end of the sheath 2, so that the sheath 2 is formed. Is connected and fixed.

The male thread portion 62b is erected on the surface of the disc portion of the sheath side fixing portion 62a opposite to the sheath connecting portion 62e, and a male thread which is a left-hand thread (reverse screw) is formed on the outer surface thereof. There is. A fitting convex portion 61c of the first male screw member is slidably fitted in the central portion of the male screw portion 62b of the second male screw member 62 so as to be recessed from the tip side along the axial direction. A fitting recess (rotation regulating means) 62c to be formed is formed.

The lumen (through hole 62d) of the sheath connecting portion 62e is open to the bottom surface of the fitting recess 62c. Inside the side wall of the male threaded portion 62b, and outside the fitting recess 62c, penetrates from the tip surface of the male threaded portion 62b to the surface of the disc portion of the sheath side fixing portion 62a on the side to which the sheath 2 is fixed. , Four wire insertion holes 65a to 65d are formed at an angle pitch of approximately 90 °. The wire insertion holes 65a to 65d are provided so as to correspond to the wire lumens 23a to 23d of the sheath 2, and both ends of the wire W1 and both ends of the wire W2 are corresponding wire insertion holes, respectively. It penetrates 65a to 65d and is guided to the inside of the operation unit 3.

As shown in FIGS. 7E and 7F, the connecting female screw member 63 is composed of a substantially cylindrical member as a whole, is arranged coaxially with each other on the inner surface thereof, and the male screw portion 61b of the first male screw member 61 is screwed. A second female threaded portion 63b into which the male threaded portion 63a of the first female threaded portion 63a and the male threaded portion 62b of the second male threaded member 62 are screwed is provided. That is, the first female thread portion 63a is a right-hand thread (positive thread), and the second female thread portion 63b is a left-hand thread (reverse thread). A plurality of grooves 63c are formed on the outer peripheral surface of the connecting female screw member 63 along the axial direction in order to prevent slippage when the operator rotates the connecting female screw member 63 by hand.

The male threaded portion 61b of the first male threaded member 61 is screwed into the first female threaded portion 63a of the connecting female threaded member 63, and the male threaded portion 62b of the second male threaded member 62 is screwed into the second female threaded portion 63b of the connecting female threaded member 63. The fitting convex portion 61c of the member 61 is inserted into the fitting recess 62c of the second male thread member 62, and the connecting female thread member 63 is rotated in a predetermined direction with respect to the first male thread member 61 and the second male thread member 62. The state shown in FIG. 6A (initial state) is used. From this state, when the connecting female thread member 63 is rotated in the direction opposite to the predetermined direction with respect to the first male thread member 61 and the second male thread member 62, as shown in FIG. 6B, the first male thread member 61 and the second male thread member 61 and the second male thread member 62. The male screw member 62 moves in a direction away from each other.

When the connecting female thread member 63 is rotated in the predetermined direction with respect to the first male thread member 61 and the second male thread member 62, the first male thread member 61 and the second male thread member 62 are close to each other as shown in FIG. 6A. You can move it in the direction and undo it. Therefore, by rotating the connecting female screw member 63, the sheath main body 20 fixed to the second male screw member 62 is pushed out to the distal end side with respect to the operation portion 3 to which the first male screw member 61 is fixed, or The extrusion can be released (pulled back to the proximal end side). Moreover, the extrusion amount of the sheath main body 20 can be arbitrarily adjusted according to the rotation amount of the connecting female screw member.

The fitting convex portion 61c of the first male thread member 61 and the fitting recess 62c of the second male thread member 62 are the first male thread member 61 and the first male thread member 61 screwed into the connecting female thread member 63 as the connecting female thread member 63 rotates. It functions as a rotation regulating means for regulating the rotation of the second male screw members 62 without hindering their contact with each other. Therefore, it is possible to prevent the second male screw member 62 from being dragged by the rotation of the connecting female screw member 63 and rotating due to the rotation of the connecting female screw member 63, and the sheath main body 20 may be unnecessarily twisted. It is possible to prevent the sheath body 20 from being extruded insufficiently. However, such rotation regulating means is not essential and may be omitted.

In the present embodiment, the cross-sectional shapes of the fitting convex portion 61c and the fitting concave portion 62c are substantially rectangular with rounded corners as shown in FIGS. 7B and 7D, but the first male screw member 61 Any other shape can be used as long as it can regulate the mutual rotation of the first male screw member 61 and the second male screw member 62 without hindering the sliding of the second male screw member 62 in the axial direction. There may be.

Further, in the present embodiment, the first male screw member 61 is provided with the fitting convex portion 61c, and the second male screw member 62 is provided with the fitting recess 62c. On the contrary, the first male screw member 61 is provided with the fitting recess 62c. The fitting concave portion similar to the above may be provided on the second male screw member 62 with the same fitting convex portion as the fitting convex portion 61c.

Further, in the present embodiment, the first male threaded portion 61b and the first female threaded portion 63a are right-hand threads, and the second male threaded portion 62b and the second female threaded portion 63b are left-handed threads. On the contrary, the first male threaded portion is The 61b and the first female threaded portion 63a may be left-handed, and the second male-threaded portion 62b and the second female-threaded portion 63b may be right-handed.

When the operation unit 3 is in the neutral state shown in FIG. 1 and the rotation regulating means 6 is in the initial state shown in FIG. 6A, both the wire W1 and the wire W2 are in a substantially untensioned state, and the tip of the sheath 2 is deflected. As shown in FIGS. 1 and 3A, the portion 21 is in a linearly extended state. At this time, since no compressive force acts on the deflection portion 21 in the axial direction, the deflection portion 21 is not compressed and the dimension of the deflection portion 21 in the axial direction is L1 to form the deflection portion 21. Due to the nature of the porous tube, the deflection portion 21 is in a relatively soft state.

When the

grip portions

32, 32 of the rotation operation member 31 are operated to rotate the rotation operation member 31 in the direction of the arrow A1 in FIG. 1 from the neutral state, the wire W1 is pulled and the wire W2 is pulled along with this rotation. By being loosened, the deflection portion 21 at the tip is deflected as shown by arrow A3 in FIGS. 1 and 3 (b).

On the contrary, when the

grip portions

32, 32 of the rotation operation member 31 are operated to rotate the rotation operation member 31 in the direction of the arrow A2 in FIG. 1, the wire W1 is loosened and the wire W2 is pulled. The deflection portion 21 at the tip is deflected as shown by arrow A4 in FIGS. 1 and 3 (b).

When it is desired to fix the shape of the deflection portion 21 in a state where the deflection portion 21 is deflected, the rotation operation member 31 is pressed against the holding portion 42 by rotating the knob member 5 clockwise and tightening the knob member 5. The rotation operation member 31 is fixed at the current position, and the shape of the deflection portion 21 is fixed. When it is desired to release the fixed shape of the deflection portion 21 (when it is desired to adjust the deflection state), the rotation operation member 31 is held by the holding portion 42 by rotating the knob member 5 counterclockwise to loosen it, contrary to the above. It is in a state of being loosely pressed, and a state in which the rotation operation member 31 can rotate. As a result, the shape of the deflection portion 21 is not fixed, and the deflection state of the deflection portion 21 can be adjusted by gripping the grip portion 32 and rotating the rotation operation member 31.

Next, the operation unit 3 is set to the neutral state shown in FIG. 1, the rotation regulating means 6 is set to the initial state shown in FIG. 6A, and the connecting female thread member 63 of the hardness adjusting means 6 is set to the first male screw as shown in FIG. 6B. The member 61 and the second male screw member 62 are rotated so as to be separated from each other, and the sheath 2 is pushed out to the operating portion 3 by a predetermined amount. In this state, substantially equal tension is applied to both the wires W1 and W2, and the distal end of the deflection portion 21 is substantially constrained by the wires W1 and W2, so that the proximal end of the deflection portion 21 is extruded. It is pressed by the distal end of the sheath body 20, and as a result, a compressive force acts on the deflection portion 21 in the axial direction. Due to this compressive force, the deflection portion 21 is compressed (shortened) in the axial direction, and as shown in FIG. 3C, the dimension of the deflection portion 21 in the axial direction becomes L2, which is smaller than L1, and the deflection portion 21 The deflecting portion 21 is in a relatively hard state according to the properties of the porous tube constituting the above.

The connecting female thread member 63 of the hardness adjusting means 6 is rotated so that the first male thread member 61 and the second male thread member 62 are close to each other, and as shown in FIG. 6A, the extrusion is released, that is, the sheath body portion 20 is operated. When the deflection portion 21 is pulled back by a predetermined amount with respect to 3, the compressive force on the deflection portion 21 is released, and the deflection portion 21 can be returned to a relatively soft state.

If necessary, the connecting female screw member 63 of the hardness adjusting means 6 is rotated so that the first male screw member 61 and the second male screw member 62 are separated from each other, and the rotation operation is performed with the deflection portion 21 hardened. By rotating the member 31, as shown in FIG. 3D, it is possible to deflect the member 31 in a compressed state. Further, the connecting female screw member 63 of the hardness adjusting means 6 is rotated so that the first male screw member 61 and the second male screw member 62 are close to each other, and the rotation operation member 31 is rotated with the deflection portion 21 softened. After the deflecting portion 21 is appropriately deflected, the connecting female thread member 63 of the hardness adjusting means 6 is rotated so that the first male thread member 61 and the second male thread member 62 are separated from each other, so that FIG. 3 (d) shows. As shown, it can also be compressed to make it rigid. Further, if necessary, the flexibility of the deflection portion 21 can be changed and controlled by appropriately adjusting the amount of rotation of the connecting female screw member 63.

In the above-described embodiment, as the deflection portion 21, the sheath 2 is continuous with the sheath main body 20 whose flexibility does not substantially change even when a compressive force is applied in the axial direction and the distal end of the sheath main body 20. 21 is made of a porous tube that is joined in such a manner and is compressed according to the degree of compressive force acting in the axial direction to become hard, and then returns to the original state to become soft when the compressive force is released. It is composed of and. Then, the wires W1 and W2 inserted through the plurality of wire lumens 23a to 23d of the sheath 2 act to release the compressive force for compressing the deflection portion 21 in the axial direction and the deflection force for deflecting the deflection portion 21. I am doing it.

As a result, the wires W1 and W2 are set to the neutral state, the hardness adjusting means 6 is set to the initial state, and one of the wires W1 and W2 is brought close to each other while maintaining the soft state without applying a compressive force to the deflection portion 21. By pulling to the position end side, the deflecting portion 21 can be deflected, and since the deflecting portion 21 is in a soft state at this time, good operability can be realized. On the other hand, for example, in the case of breaking through (penetrating) a narrowed portion in a lumen of the body such as a bile duct, if the deflecting portion 21 is in a soft state, bending or buckling may occur and insertion may be difficult. In this case, by operating the hardness / softness adjusting means 6 to push out the sheath main body portion 20, a compressive force is applied to the deflection portion 21 to make the sheath body portion 21 into a rigid state. Therefore, it is possible to reduce the occurrence of bending or buckling in the deflection portion 21, and it is possible to improve the insertability of the catheter.

Further, in the above-described embodiment, when the sheath main body 20 is extruded and the deflection portion 21 is compressed, the distal end of the deflection portion 21 is restrained by a pair of wires W1 and W2 for deflecting the deflection portion 21. However, the distal end of the deflection portion 21 may be constrained by a means other than the wires W1 and W2. For example, as a means for restraining the distal end of the deflection portion 21, it is slidable into the lumen (main lumen 22) of the sheath 2 (sheath body portion 20 and deflection portion 21) and is larger than the inner diameter of the main lumen 22. A compression tube having a slightly smaller outer diameter is inserted, the distal end of the compression tube is connected to the distal end of the deflection portion 21 to restrain it, and the sheath main body portion 21 is pushed out to the deflection portion 21. A compressive force may be applied. In this case, the function as the main lumen is borne by the lumen of the compression tube.

Further, in the above-described embodiment, the substantially half W1a on one end side of the wire W1 is inserted into the lumen 23a for wire, the substantially half W1b on the other end side is inserted into the lumen 23b for wire, and the one end side of the wire W2 is inserted. Approximately half W2a is inserted through the wire lumen 23c, and approximately half W2b on the other end side is inserted through the wire lumen 23d. Since the wires W1 and W2 are each folded back at the distal end of the deflection portion 21, it is not necessary to provide a member for fixing the wire such as a tip or a pull ring, and the number of parts can be reduced. At the same time, since it is not necessary to attach the member for fixing the wire to the catheter tube and to connect the wire to the member, the man-hours for manufacturing the member can be reduced. Further, since it is not necessary to secure an area for providing a member for fixing the wire in the structure of the catheter sheath 1, the structural limitation of the catheter sheath 1 can be reduced, for example, the sheath 2 (main). It is possible to increase the opening area of the distal end (tip) of the lumen 22).

Further, both the substantially half W1a inserted through the wire lumen 23a of the wire W1 and the substantially half W1b inserted through the wire lumen 23b are pulled so that a deflection force for deflecting the deflection portion 21 is applied. ing. Therefore, the force can be applied to a relatively wide range in the circumferential direction of the sheath 2 according to the distance (angle distance) between the wire lumen 23a and the wire lumen 23b. The same applies to the wire W2. As a result, the force applied to the wire is smaller than that in which the deflection operation is performed by pulling a single wire inserted through a single lumen without folding back, so that there is a risk of wire breakage due to the deflection operation. It becomes smaller. Further, it is possible to reduce the blurring of the distal end portion when deflecting the deflection portion 21, and it is possible to realize stable deflection. For the same reason, it becomes possible to stably apply a compressive force to the deflection portion 21.

However, one wire is inserted into each of the wire lumens 23a to 23d, that is, four wires are provided, and the distal end of each wire is connected (engaged) to the distal end of the deflection portion 21. Of course, it may be configured to be used. In this case, the number of lumens for wires and the number of wires may be 3 or 5 or more, respectively.

In the above-described embodiment, two wires, a wire W1 inserted through the wire lumen 23a and the wire lumen 23b, and a wire W2 inserted through the wire lumen 23c and the wire lumen 23d, are used. As shown in 4A to 4C, the wire W3 and the wire W4 may be added to form a configuration in which four wires are used.

That is, about half of the wire W3 on one end side is inserted into the lumen 23a for the wire, and the intermediate portion W3c is folded back at the distal end surface to which the tip protection member 29 of the sheath 2 is joined, and the other end. Approximately half of the side W3b is inserted through the wire lumen 23c. About half of the wire W4 on one end side is inserted into the lumen 23b for wire, and the intermediate portion W4c is folded back at the distal end surface to which the tip protection member 29 of the sheath 2 is joined, and the other end side. Approximately half W4b is inserted through the wire lumen 23d. With this configuration, one wire can be appropriately selected from the wires W1 to W4 and pulled to enable deflection in four directions. Further, the deflecting portion 21 can be deflected in an arbitrary direction by 360 ° by appropriately selecting a combination of two adjacent wires W1 to W4 and adjusting the balance of the pulling force of each. Then, in a state where tension is applied evenly to all of the wires W1 to W4, or the wires W1 and W2, or the wires W3 and W4, the hardness adjusting means 6 is operated to push out the sheath body 20 to push out the deflection portion 21. Can be made hard. In addition, in response to the addition of the wires W3 and W4, it is necessary to appropriately change the configuration of the operation unit 3, such as adding a rotation operation member similar to the rotation operation member 31 in the operation unit 3.

Further, in the example shown in FIGS. 4A to 4C, a case where four wire lumens 23a to 23d are provided and four wires W1 to W4 are provided has been described. For example, as shown in FIGS. 5A to 5C, The number of wire lumens can be increased or decreased, and the number of wires can be increased or decreased accordingly.

That is, in FIG. 5A, six wire lumens 24a are provided at an angle pitch of 60 °, and six wires W5 are provided. As a result, when the wires W5 are pulled one by one, the deflection portion 21 can be deflected in six directions, and the combination of two adjacent wires W5 is appropriately selected to adjust the balance of the pulling forces of each. By doing so, the deflection portion 21 can be deflected by 360 ° in any direction. In FIG. 5B, three wire lumens 25a are provided at an angular pitch of 120 °, and three wires W6 are provided. As a result, when the wires W6 are pulled one by one, the deflection portion 21 can be deflected in three directions, and the combination of two adjacent wires W6 is appropriately selected to adjust the balance of the pulling forces of each. By doing so, the deflection portion 21 can be deflected by 360 ° in any direction. In FIG. 5C, 24 wire lumens 26a are provided at an angle pitch of 15 °, and 24 wires W7 are provided. As a result, the deflection portion 21 can be deflected in 24 directions when the wires W7 are pulled one by one. These are examples, and the number of lumens for wires may be 3 or more, and the number of wires may be 2 or more.

In the examples shown in FIGS. 5A-5C, the number of wire lumens and the number of wires are the same, but they may be different, for example, with fewer wires than the number of wire lumens. May be good. Further, in the examples shown in FIGS. 5A to 5C, both ends of the wire are inserted through a pair of adjacent wire lumens. For example, a pair of wire lumens are intermittently selected, and the wires are connected to these lumens. Both ends may be inserted. If the number or arrangement of wire lumens in the sheath 2 is changed, the number of wire insertion holes in the first male threaded portion 61 and the second male threaded portion 62 of the hardness adjusting means 6 may be changed accordingly. The arrangement will be changed.

The embodiments described above have been described for facilitating the understanding of the present invention, and have not been described for limiting the present invention. Therefore, each element disclosed in the above-described embodiment is intended to include all design changes and equivalents belonging to the technical scope of the present invention.

1 ... Catheter sheath (movable catheter)
2 ... Sheath (tube)
20 ... Sheath body (first tube)
21 ... Deflection part (second tube part)
22 ... Main lumen 23a-23d ... Lumen for wire 29 ... Tip protection member 3 ... Operation part 31 ... Rotation operation member 32 ... Grip part 4 ... Grip part 42 ... Holding part 5 ... Knob member 6 ... Hard / soft adjustment means 61 ... First Male screw member 61a ... Operation unit side fixing portion 61b ... Male screw portion 61c ... Fitting convex portion (rotation regulating means)
61d ... Through hole 62 ... Second male screw member 62a ... Sheath side fixing portion 62b ... Male screw portion 62c ... Fitting recess (rotation regulating means)
62d ... Through hole 62e ... Sheath connecting portion 63 ... Connecting female thread member 63a ... First female threaded portion 63b ... Second female threaded portion 63c ... Grooves 64a to 64d, 65a to 65d ... Wire insertion holes W1 to W7 ... Wire (operating means)

Claims

It has a flexible tube having a distal end inserted into the body and a proximal end located outside the body, and an operating portion provided at the proximal end of the tube, by operation in the operating portion. , A movable catheter designed to deflect the deflection part on the distal end side of the tube.
The tube is joined to the first tube portion whose flexibility does not substantially change even when a compressive force is applied in the axial direction, and is continuously connected to the distal end of the first tube portion, and acts in the axial direction. It is provided with a second tube portion as the deflection portion, which is composed of a porous tube that is compressed and hardened according to the degree of the compressive force to be applied, and then returns to the original state and becomes soft when the compressive force is released.
The hardness adjusting means for adjusting the hardness of the second tube portion by leaching the first tube portion toward the distal end side with respect to the operation portion is provided with the proximal end portion of the first tube portion and the said. A movable catheter placed between the operation unit.
The hardness adjusting means is
A substantially cylindrical first male threaded member having a base end portion fixed to one of the proximal end portion of the first tube portion and the operating portion and having a first male threaded portion which is a right-hand thread on the outer surface.
A substantially cylindrical second male screw member having a base end portion fixed to the proximal end portion of the first tube portion and the other of the operation portion and having a second male thread portion which is a left thread on the outer surface.
The first aspect of claim 1, further comprising a first female threaded portion arranged substantially coaxially with each other and having a second female threaded portion into which the first male threaded portion is screwed and a second female threaded portion into which the second male threaded portion is screwed. Movable catheter.
The hardness adjusting means rotates with the rotation of the connecting female screw member without hindering the contact and separation of the first male screw member and the second male screw member screwed into the connecting female screw member, respectively. The movable catheter according to claim 2, further comprising a rotation regulating means for regulating.
The rotation regulating means includes a fitting convex portion provided on one of the first male screw member and the second male screw member so as to project along the axial direction, and the first male screw member and the second male screw member. The movable catheter according to claim 3, which is provided on the other side of the catheter and includes a fitting recess in which the fitting protrusion is slidably fitted.