JP7312200B2 - basket catheter - Google Patents

Description

The present invention relates to a catheter capable of trapping foreign objects in a basket.

A basket catheter (basket forceps) in which a SUS wire or a shape memory alloy such as Ni—Ti is woven in a basket shape or a balloon catheter for stone removal is used for the treatment of calculus occurring in the bile duct. In the basket catheter, the basket part for trapping foreign substances such as calculi is formed by binding a plurality of metal wires at two points, one on the distal end and one on the proximal side of the distal end. The wire is bent or helically twisted to form a cage. The basket catheter reaches the treatment site such as the inside of the bile duct through the forceps port of the endoscope. The basket part is housed in, for example, a sheath made of resin when it is delivered to the treatment part, and is expanded in a basket shape by exposing it from the distal end of the sheath when capturing a foreign object. After accommodating the foreign matter in the basket, the basket catheter is pulled out from the treatment site to remove the foreign matter.

In order to perform minimally invasive treatment, it is necessary to reliably deliver the catheter to the treatment site in a short operating time. When accessing the papilla from the tip of the endoscope, it is required to insert the catheter appropriately and easily without getting caught in the bile duct insertion opening. Therefore, attempts have been made to improve the insertability of the catheter (Patent Documents 1 and 2).

For example, in Patent Literature 1, a basket catheter is delivered to the treatment site by being guided by a guide wire. In Patent Document 1, a basket portion is connected to the distal end portion of an operation wire that is inserted through an elongated sheath, and a distal tip is fixed to the distal end portion of the basket portion, and the basket portion moves in response to pushing and pulling operations of the operation wire. In a basket forceps that is operated to move from a retracted position in which the portion is stored in the sheath to an expanded position in which the sheath is pushed forward and expanded, a guide wire communicates between the front surface of the distal tip and the outer peripheral surface of the basket forceps. A basket forceps with an insertion hole is disclosed.

Patent document 2 has a flexible main tube, a first lumen and a second lumen that are open at the distal end and the proximal end of the main body tube and communicate between the distal end and the proximal end, and the distal end side is curved. A bendable catheter is disclosed that is provided with an operable bend and a bend operation wire for bending the bend.

JP-A-2004-249093 International Publication No. 2012/039199 Pamphlet

However, simply providing a guide wire lumen or making the tip of the catheter bendable causes narrowing and extension in a direction different from that of the catheter, such as the papilla at the entrance to the bile duct. Inserting a catheter into a body cavity relies heavily on the skill of the operator, and it has not always been possible to obtain a satisfactory operation. Therefore, the present invention provides a multi-lumen tube with a curved distal portion, determines the running positions of a plurality of lumens, and has a catheter tip portion of a predetermined shape, so that the papilla at the entrance to the bile duct, etc. An object of the present invention is to provide a basket catheter with improved ease of catheter insertion into the body cavity of the body.

One embodiment of the basket catheter of the present invention that can solve the above problems is a multi-lumen tube having a distal side and a proximal side and having a basket lumen and a guide wire lumen, and a basket lumen and an expandable basket portion having a plurality of elastic wires retractably inserted from a distal end thereof, the multi-lumen tube having a curved portion at its distal portion. , the guidewire lumen is located closer to the outer periphery of the curved portion than the basket lumen, and point A below is located on the proximal side of the multi-lumen tube in the longitudinal direction of point B below. It has a gist of it.
(Point A) Point A is a point on the distal side opening edge of the guidewire lumen on the plan view of the multi-lumen tube viewed from the distal side to the proximal side, and is located from the outer periphery of the multi-lumen tube. The most recent point.
(Point B) Point B is the most distal point from point A among the points on the outer periphery of the multi-lumen tube on the plan view of the multi-lumen tube viewed from the distal side to the proximal side. , the point on the distal opening edge of the guidewire lumen that is most proximal from point P on the plan view.

The distance in the longitudinal direction of the multi-lumen tube between points C and D below is preferably shorter than the distance in the longitudinal direction of the multi-lumen tube between points A and B.
(Points C and D) Points C and D are points on the distal opening edge of the basket lumen on the plan view of the multi-lumen tube viewed from the distal side to the proximal side. The line connecting points A and B and the line connecting points C and D are parallel, and points C and D are most distal to each other.

Both points C and D are preferably located distally beyond point B.

It is preferable that point C and/or point D be located proximal to point B.

The angle between the line connecting points A and B and the longitudinal axis direction of the multi-lumen tube is 20° or more and less than 80°, and the angle between the line connecting points C and D and the longitudinal axis direction of the multi-lumen tube. is preferably 70° or more.

The angle between the line connecting points A and B and the longitudinal axis direction of the multi-lumen tube is 20° or more and 50° or less, and the angle between the line connecting points C and D and the longitudinal axis direction of the multi-lumen tube. is preferably 70° or more.

Preferably, the distal opening edges of the guidewire lumen are not coplanar.

A chamfer is preferably provided on the side of the distal end of the multi-lumen tube.

The chamfered portion is preferably formed to cut 1/10 to 1/3 of the length of the outer circumference of the distal end of the multi-lumen tube.

Preferably, the corners of the distal end of the multi-lumen tube are rounded.

Lubricant is preferably applied to the lumen of the guidewire lumen.

According to the basket catheter of the present invention, when accessing the papilla from the distal end of the endoscope, the catheter can be inserted appropriately and easily without being caught in the bile duct insertion opening. This shortens the procedure time and enables minimally invasive treatment.

FIG. 1(a) shows a side view (partial cross-sectional view) of a basket catheter according to one embodiment of the present invention, and FIG. 1(b) shows the distal end portion of the basket catheter shown in FIG. 1(a). Represents a magnified view. 2 depicts a perspective view of the distal end of the multi-lumen tube shown in FIG. 1; FIG. FIG. 3(a) shows a plan view of the multi-lumen tube shown in FIG. 2 as viewed from the direction of the arrow, and FIG. 3(b) shows a view from the distal side to the proximal side of the multi-lumen tube according to another embodiment. Fig. 3(c) shows a plan view from the distal side to the proximal side of a multi-lumen tube according to yet another embodiment. FIG. 4(a) shows a longitudinal cross-sectional view of the distal end of the multi-lumen tube shown in FIG. 1, and FIGS. FIG. 10 depicts a longitudinal cross-sectional view of the proximal end; Figure 5(a) shows a longitudinal cross-sectional view of the distal end of a multi-lumen tube according to one embodiment of the present invention, and Figure 5(b) shows a distal end of a multi-lumen tube according to another embodiment. Fig. 5(c) depicts a longitudinal cross-section of the distal end of a proximal end, and Fig. 5(c) depicts a longitudinal cross-section of the distal end of a multi-lumen tube according to yet another embodiment. 1 depicts a perspective view of the distal end of a multi-lumen tube, according to one embodiment of the present invention; FIG. The top view which looked at the multi-lumen tube shown in FIG. 6 from the arrow direction is represented. FIG. 4 depicts a longitudinal cross-sectional view of the distal end of a multi-lumen tube according to one embodiment of the present invention;

Hereinafter, the present invention will be described based on the embodiments, but the present invention is not limited by the following embodiments, and can be implemented by making appropriate changes within the scope that can conform to the gist of the preceding and following descriptions. are also possible, and all of them are included in the technical scope of the present invention. In each drawing, for the sake of convenience, hatching, member symbols, etc. may be omitted, but in such cases, the specification and other drawings shall be referred to. In addition, the dimensions of various members in the drawings may differ from the actual dimensions, since priority is given to helping to understand the features of the present invention.

First, the basic configuration of the basket catheter according to the embodiment of the present invention will be described with reference to FIG. FIG. 1 shows a side view and a partial cross-sectional view of a basket catheter 1 according to one embodiment of the present invention. A basket catheter 1 according to an embodiment of the present invention is a medical treatment instrument having a basket-shaped basket portion 11 that has a distal side and a proximal side and traps foreign matter such as calculus in the body. A basket catheter may be hereinafter simply referred to as a "catheter". Here, the proximal side of the catheter refers to the direction toward the hand side of the user or the operator with respect to the extending direction of the catheter, and the distal side refers to the direction opposite to the proximal side, that is, the side of the subject to be treated. pointing in the direction. The direction from the proximal side of the catheter to the distal side is called the longitudinal direction LD. Similarly, the direction from the distal side to the proximal side of the catheter is the longitudinal direction LD.

The basket catheter 1 is used for treatment using an endoscope, and is placed in the body from the distal side of the forceps opening of the endoscope to reach a treatment site through the endoscope's forceps opening. All materials of the catheter 1 are desirably biocompatible.

The multi-lumen tube 2 has a distal side and a proximal side, and has a basket lumen 4 and a guidewire lumen 3 . An expandable basket portion 11 having a plurality of elastic wires 12 protrudingly interposed from a distal end thereof is provided in the basket lumen 4, and the basket portion 11 extends through the basket lumen 4 during delivery within the body cavity. 4, and protrudes from the distal end of the basket lumen 4 when it reaches the treatment section, and can catch foreign objects and the like.

The multi-lumen tube 2 is preferably a resin tube. A resin tube can be manufactured, for example, by extrusion molding. Examples of resins include polyamide-based resins, polyester-based resins, polyurethane-based resins, polyolefin-based resins, fluorine-based resins, vinyl chloride-based resins, silicone-based resins, and natural rubber. These may use only one type, and may use two or more types together. Among them, polyamide-based resins, polyester-based resins, polyurethane-based resins, polyolefin-based resins, and fluorine-based resins are preferably used.

The multi-lumen tube 2 may be composed of a single layer, or may be composed of multiple layers. In addition, a part of the multi-lumen tube 2 may be composed of a single layer in the longitudinal direction LD, and the other part may be composed of a plurality of layers.

Basket portion 11 is used to trap foreign objects within the body. As shown in FIG. 1 , basket portion 11 is disposed distally of basket lumen 4 and is formed by a plurality of elastic wires 12 . The elastic wire 12 is given a curved shape or a bent shape, and is formed in a basket shape. The shape of the elastic wire 12 may be a shape passing on the same plane, or a shape such as a spiral shape in which the entire wire is not on the same plane.

The elastic wire 12 is a linear member having elasticity, and is preferably made of shape memory alloy or shape memory resin. The elastic wire 12 is, for example, a single wire or twisted wire made of stainless steel such as SUS304, SUS316, platinum, nickel, cobalt, chromium, titanium, tungsten, aluminum, gold, silver, Ni--Ti alloy, Co--Cr alloy, or the like. It may be a wire metal wire. Among them, a metal wire made of a Ni—Ti alloy is preferable. The number of elastic wires 12 is not particularly limited, but may be, for example, 3 or more, 4 or more, 5 or more, 6 or more, 8 or more, 10 or more, or 20 or less and 15 or less. may be

The outer diameter of the elastic wire 12 is preferably one-half or less, more preferably one-fifth or less, and even more preferably one-seventh or less of the diameter of the basket lumen 4 . As the outer diameter of the elastic wire 12 is smaller, the load when the basket part 11 is drawn into the basket lumen 4 can be reduced. Specifically, the outer diameter of the elastic wire 12 is preferably 0.26 mm or less, more preferably 0.20 mm or less.

The plurality of elastic wires 12 of the basket portion 11 may be bound by the tip 13, for example, or may be bound by a method such as heat sealing, silver brazing, adhesion, or caulking. Also, the plurality of elastic wires 12 may be bound by forming a knot. Although not shown, the distal tip 13 may have wire insertion holes into which the distal ends of the plurality of elastic wires 12 are inserted. The distal tip 13 may have a plurality of such insertion holes.

The distal tip 13 may be made of the same material as the elastic wire 12, or may be made of a different material. For example, both the distal tip 13 and the elastic wire 12 can be made of a metal material and fixed by welding. Alternatively, the tip 13 may be made of a resin material and adhered to the elastic wire 12 using an adhesive. Different materials such as a metal material and a resin material may be used as the material of the distal tip 13 . In this case, for example, the portion to which the elastic wire 12 is fixed can be made of a metal material, and the resin portion can be provided on the distal side of the metal portion. This makes the fixation stronger and less likely to damage the living body. The distal tip 13 may also be made of the same material as the multi-lumen tube 2, or may be made of a different material.

The multi-lumen tube 2 has a bend 21 at its distal end. The curved portion 21 can be formed by shaping resin by thermal processing or the like. By imparting a curved shape to the distal portion of the multi-lumen tube 2 to form a curved portion 21, the basket catheter 1 can be inserted into a body cavity that curves and extends, such as the papilla at the entrance to the bile duct. easier to do. A core material having a predetermined curved shape is inserted into the lumen of the multi-lumen tube 2, the curved portion is heated to a temperature below the melting point of the multi-lumen tube 2, and then cooled to give the multi-lumen tube 2 a curved shape. can be given.

The cross-sectional shape of the multi-lumen tube 2 perpendicular to the longitudinal axis direction LD is preferably circular or elliptical.

The guide wire lumen 3 is arranged closer to the outer circumference of the curved portion 21 than the basket lumen 4 is. The guidewire lumen 3 is a lumen for inserting a guidewire. Inserting the proximal end of a guide wire, the distal end of which is placed in the treatment area in advance, into the distal end of the guide wire lumen 3 of the basket catheter 1, and moving the basket catheter 1 into the body cavity along the guide wire. , the basket catheter 1 is delivered to the treatment site. By moving the multi-lumen tube 2 along this guide wire, the basket catheter 1 can be easily delivered to the treatment site.

The shape of the guidewire lumen 3 in a cross section perpendicular to the longitudinal axis direction LD is not limited, and may be circular, elliptical, polygonal, a part thereof, or a composite shape thereof. It may be of regular shape, but circular and elliptical are preferred.

The length of the cross section perpendicular to the longitudinal direction LD of the guidewire lumen 3 can be appropriately set according to the size of the guidewire to be inserted into the guidewire lumen 3 . For example, the major axis is preferably 1/2 or less, more preferably 1/3 or less, of the major axis of the cross section of the multi-lumen tube 2 perpendicular to the longitudinal direction LD. In addition, it is preferable that the major axis is one-fifth or more of the major axis of the section of the multi-lumen tube 2 perpendicular to the longitudinal direction LD. Since the major diameter of the cross section perpendicular to the longitudinal direction LD of the guide wire lumen 3 has the above ratio to the major diameter of the cross section perpendicular to the longitudinal direction LD of the multi-lumen tube 2, the guide wire lumen 3 The slidability of the guide wire inside is improved, and the distal end of the multi-lumen tube 2 can be easily formed into a desired shape without hindering the provision of the basket lumen 4, the third lumen 5, and the like. Become.

Lubricant may be applied to the lumen of the guidewire lumen 3 . The lubricant allows the guide wire to slide with low resistance when it slides in the guide wire lumen 3, so that the guide wire can be delivered to the treatment site and the multi-lumen tube 2 can be delivered to the treatment site along the guide wire. easier to deliver. The type of lubricant is not particularly limited as long as it has biocompatibility.

The basket lumen 4 is arranged closer to the inner peripheral side of the curved portion 21 than the guide wire lumen 3 . A basket lumen 4 is a lumen for inserting an elastic wire 12 having a basket portion 11 .

The shape of the basket lumen 4 in a cross section perpendicular to the longitudinal direction LD is not limited, and may be circular, elliptical, polygonal, a part thereof, a composite shape thereof, or a completely irregular shape. , but circular and elliptical are preferred.

The major diameter of the cross section perpendicular to the longitudinal direction LD of the basket lumen 4 can be appropriately set according to the size of the basket to be inserted into the basket lumen 4 . For example, the major axis can be half the major axis of the section of the multi-lumen tube 2 perpendicular to the longitudinal direction LD. Since the major diameter of the section perpendicular to the longitudinal axis direction LD of the basket lumen 4 has the above ratio to the major diameter of the section perpendicular to the longitudinal axis direction LD of the multi-lumen tube 2, the inside of the basket lumen 4 The slidability of the elastic wire is improved, and the distal end of the multi-lumen tube 2 can be easily formed into a desired shape without hindering the provision of the guide wire lumen 3, the third lumen 5, and the like. .

Either the major diameter of the section perpendicular to the longitudinal direction LD of the guide wire lumen 3 or the major diameter of the section perpendicular to the longitudinal direction LD of the basket lumen 4 may be larger or the same.

The multi-lumen tube 2 may have a third lumen 5 other than the guidewire lumen 3 and basket lumen 4 . The third lumen 5 can be used as a lumen for an auxiliary treatment instrument or as a lumen for fluid injection. By using the auxiliary treatment instrument, it is possible to remove a foreign body caught in the basket part 11, observe the inside of the body cavity, observe the foreign body, etc., prevent incarceration, increase the options of procedures according to the case, and reduce the risk of injury. Effects such as promotion of invasive treatment can be obtained. Auxiliary treatment tools include balloon catheters, microcatheters, forceps, laser probes, fiberscopes, and electrohydraulic impact crushing probes. Even when the third lumen 5 is present, the guidewire lumen 3 is arranged on the outermost side of the bending portion 21 .

The multi-lumen tube 2 may have further lumens. In either case, the guidewire lumen 3 is arranged on the outermost peripheral side of the bending portion 21 .

A basket catheter 1 according to one embodiment of the present invention is characterized by the shape of the distal end of a multi-lumen tube 2, as shown in FIGS. FIG. 2 represents a perspective view of the distal end of the multi-lumen tube 2 shown in FIG. In one embodiment shown in FIGS. 1 and 2, the multi-lumen tube 2 on the side of the guidewire lumen 3 is obliquely formed.

The shape of the distal end of the multi-lumen tube 2 will be described in detail below with reference to FIGS. 3-5. On the plan view of the multi-lumen tube 2 viewed from the distal side to the proximal side, a point on the distal side opening edge 31 of the guidewire lumen 3 and closest to the outer circumference 22 of the multi-lumen tube 2 Let A be a point. On the plan view, the most distal point from point A among the points on the outer circumference 22 of the multi-lumen tube 2 is defined as point P, and on the plan view, on the distal side opening edge 31 of the guidewire lumen 3 , and the closest point from point P is point B. In the basket catheter according to the embodiment of the present invention, when defined in this way, the point A is closer to the proximal side than the point B in the longitudinal direction LD of the multi-lumen tube 2 .

Examples of points A and B will be described with reference to FIGS. 3(a) to 3(c). FIG. 3(a) is a plan view of the multi-lumen tube 2 shown in FIG. 2 as viewed in the direction of the arrow. The arrow direction is the longitudinal direction LD at the distal end of the multi-lumen tube 2 . The plan view represents a plan view of the multi-lumen tube 2 viewed from the distal side to the proximal side, and when both the guide wire lumen 3 and the basket lumen 4 have circular cross sections perpendicular to the longitudinal direction LD. is an example. In FIG. 3( a ), a point on the distal opening edge 31 of the guidewire lumen 3 and closest to the outer circumference 22 of the multi-lumen tube 2 is point A. Point P is the point on the outer circumference 22 of the multi-lumen tube 2 at the position, and point B is the point on the distal opening edge 31 of the guidewire lumen 3 that is closest to the point P. .

FIG. 3(b) is a plan view of the multi-lumen tube 2 according to another embodiment viewed from the distal side to the proximal side, and the section perpendicular to the longitudinal direction LD of the guidewire lumen 3 is The outer circumference 22 of the multi-lumen tube 2 has a sector shape that is part of a concentric circle, and the basket lumen 4 has a circular cross section perpendicular to the longitudinal axis direction LD. In this case, there are a plurality of points A on the distal opening edge 31 of the guidewire lumen 3 that are closest to the outer circumference 22 of the multi-lumen tube 2, and each point A has a point B. can be defined. Only one example of points A and B is shown in FIG. 3(b).

FIG. 3( c ) is a plan view of a multi-lumen tube 2 according to yet another embodiment, viewed from the distal side to the proximal side, and the multi-lumen tube 2 has a third lumen 5 . Also in this case, on the plan view of the multi-lumen tube 2 viewed from the distal side to the proximal side, a point on the distal side opening edge 31 of the guidewire lumen 3 and the outer circumference of the multi-lumen tube 2 Assuming that the most recent point from 22 is point A, point B can be determined through the above process.

In any embodiment consistent with the spirit of the present invention, points A and B can be determined in the same manner, with point A being closer to the longitudinal direction LD of the multi-lumen tube 2 than point B. on the rank side.

The fact that the point A is closer to the proximal side of the multi-lumen tube 2 in the longitudinal direction LD than the point B will be described with reference to FIG. 4(a). FIG. 4(a) represents a cross-sectional view of the distal end portion of the multi-lumen tube 2 shown in FIG. 1 in the longitudinal direction LD, and points A and B shown in FIG. ) correspond to points A and B shown in FIG. Since the multi-lumen tube 2 on the side of the guide wire lumen 3 is obliquely formed, the point A is closer to the proximal side of the multi-lumen tube 2 in the longitudinal axis direction LD than the point B.

Since the point A is closer to the proximal side in the longitudinal direction LD of the multi-lumen tube 2 than the point B, the multi-lumen tube 2 can be easily inserted into the body cavity along the guidewire without being caught by the body cavity wall or the like. It is possible to shorten the time for delivering the basket catheter 1 to the treatment site and to perform minimally invasive treatment.

On the plan view of the multi-lumen tube 2 viewed from the distal side to the proximal side, a line connecting points A and B on the distal side opening edge 41 of the basket lumen 4 (hereinafter referred to as line AB are defined as points C and D, which are furthest to each other among the intersection points obtained by translating the points C and D. That is, points C and D are points on the distal side opening edge 41 of the basket lumen 4 on the plan view of the multi-lumen tube 2 viewed from the distal side to the proximal side, and are points A and The line connecting point B and the line connecting points C and D are parallel, and points C and D are most distal to each other. Here, being most distal to each other means that the distance between points C and D on the distal side opening edge 41 of the basket lumen 4 is maximized. When the points C and D are defined in this way, the distance between the points C and D in the longitudinal direction LD of the multi-lumen tube 2 is the distance between the points A and B in the longitudinal direction of the multi-lumen tube 2 . It is preferably shorter than the distance in LD.

That the distance in the longitudinal direction LD of the multi-lumen tube 2 between the points C and D is shorter than the distance in the longitudinal direction LD of the multi-lumen tube 2 between the points A and B means that the point C and the point The angle between the line connecting D (hereinafter sometimes referred to as line CD) and the longitudinal direction LD of the multi-lumen tube 2 is the angle between the line AB and the longitudinal direction LD of the multi-lumen tube 2. means greater than angle. When the angle between the line CD and the longitudinal axis direction LD of the multi-lumen tube 2 is large, that is, when the basket lumen 4 side of the distal end of the multi-lumen tube 2 is formed straight, FIG. As shown, the elastic wire 12 does not contact the distal opening edge 41 of the basket lumen 4 unbalancedly, so that the basket portion 11 can protrude in a desired shape. If the angle between the line CD and the longitudinal axis direction LD of the multi-lumen tube 2 is small, the distal end of the multi-lumen tube 2 on the side of the basket lumen 4 is formed obliquely, and the basket portion 11 is formed at an angle. When protruding, the elastic wire 12 contacts the distal side opening edge 41 of the basket lumen 4 unbalancedly, and in addition to the shape of the protruded basket portion 11 being distorted, the basket portion 11 protrudes obliquely, This is not preferable because it becomes difficult to reach the basket portion 11 in the desired direction.

As examples of points C and D, points C and D corresponding to points A and B shown in FIGS. 3(a) to 3(c) are shown in FIGS. show.

Both points C and D are located distally beyond point B, i.e., are located as distal as point B, or are located distally beyond point B. is preferred.

FIG. 4(a) is a cross-sectional view in the longitudinal direction LD of the distal end of the multi-lumen tube 2 when points C and D are both located as far distally as point B. FIG. In the cross-sectional view, the distal end of the multi-lumen tube 2 on the side of the guidewire lumen 3 is formed obliquely, and the distal ends of the guidewire lumen 3 and the basket lumen 4 are the same amount toward the distal side. are placed.

FIGS. 4(b) and 4(c) show the longitudinal direction LD of the distal end of the multi-lumen tube 2 when both points C and D are located distal to point B. It is a sectional view. In the cross-sectional view, the distal end of the multi-lumen tube 2 on the side of the guidewire lumen 3 is obliquely shaped, and the distal end of the basket lumen 4 is farther than the distal end of the guidewire lumen 3. placed on the position side.

When both the points C and D are located beyond the point B, there is nothing on the distal side of the distal end of the basket lumen 4 to prevent the basket part 11 from projecting and retracting, so that the basket part 11 can be pushed out of the treatment part. This is preferable because the basket portion 11 can be projected to a desired position when the treatment is performed by projecting the portion 11 .

Point C and/or point D may be arranged more proximal than point B. FIG. 4(d) shows the length of the distal end of the multi-lumen tube 2 when point C is located distally to point B and point D is located proximally to point B. It is a cross-sectional view in the axial direction LD. In the cross-sectional view, the distal end of the multi-lumen tube 2 is obliquely formed on both the guide wire lumen 3 side and the basket lumen 4 side. is smaller than the angle φ between the line CD and the longitudinal direction LD of the multi-lumen tube 2 . Here, both the angle θ formed by the line AB and the longitudinal axis direction of the multi-lumen tube 2 and the angle φ formed by the line CD and the longitudinal axis direction of the multi-lumen tube 2 are angles that are not obtuse. shall refer to

FIG. 4(e) is a cross-sectional view of the distal end portion of the multi-lumen tube 2 in the longitudinal direction LD when both points C and D are located proximal to point B. FIG. In the cross-sectional view, the distal end of the multi-lumen tube 2 on the side of the guidewire lumen 3 is obliquely shaped, and the distal end of the basket lumen 4 is closer than the distal end of the guidewire lumen 3 . placed on the position side.

When the multi-lumen tube 2 is inserted into the body cavity along the guidewire inserted through the guidewire lumen 3, the points A to D have the above relationship, so that the multi-lumen tube 2 does not get caught on the body cavity wall or the like. It can be easily inserted, the time for delivering the basket catheter 1 to the treatment site can be shortened, and minimally invasive treatment is possible.

The angle θ between the line AB and the longitudinal axis direction LD of the multi-lumen tube 2 is preferably 20° or more and less than 80°. Also, the angle φ between the line CD and the longitudinal axis direction LD of the multi-lumen tube 2 is preferably 70° or more. θ and φ both refer to the non-obtuse angles as described above. The guide wire lumen 3 side of the multi-lumen tube 2 is formed within the above range of θ, the basket lumen 4 side of the multi-lumen tube 2 is formed within the above range of φ, and θ is smaller than φ. It becomes easy to move the multi-lumen tube 2 in the body cavity along. Further, when φ is 70° or more, it becomes easy to project the basket portion 11 in a desired direction.

The angle θ between the line AB and the longitudinal axis direction LD of the multi-lumen tube 2 is more preferably 20° or more and 50° or less, and more preferably 25° or more and 45° or less. Further, φ is more preferably 80° or more, and may be 90°.

The distal opening edge 31 of the guidewire lumen 3 may or may not be coplanar. FIG. 4 shows an example in which the distal opening edges 31 of all the guidewire lumens 3 are on the same plane. FIG. 5 shows an example in which the distal opening edge 31 of the guidewire lumen 3 is not coplanar. 5(a) and 5(b) are cross-sectional views in the longitudinal direction LD of the distal end of the multi-lumen tube 2, showing the distal opening of the guidewire lumen 3 between points A and B. This is an example when the edge 31 is curved. FIG. 5(c) is a cross-sectional view of the distal end portion of the multi-lumen tube 2 in the longitudinal direction LD. It is an example consisting of a straight line. Not limited to these examples, in the cross-sectional view of the distal end of the multi-lumen tube 2 in the longitudinal direction LD, the distal side opening edge 31 of the guidewire lumen 3 between points A and B is a plurality of straight lines. It may consist of or may be amorphous.

A chamfered portion 23 is preferably provided on the side surface of the distal end portion of the multi-lumen tube 2 . An example of the chamfered portion 23 is shown in FIGS. One chamfered portion may be provided, or a plurality of chamfered portions may be provided. By providing the chamfered portion, it becomes easier to insert the multi-lumen tube 2 into the body cavity.

The chamfered portion 23 is preferably formed so as to cut off 1/10 or more of the length of the outer circumference 22 of the distal end portion of the multi-lumen tube 2, more preferably 1/9 or more, and further preferably 1/8 or more. preferable. Also, it is preferably 1/3 or less, more preferably 1/4 or less.

As shown in FIG. 8, corners 24 are preferably rounded in a cross section of the distal end of the multi-lumen tube 2 in the longitudinal direction LD. If the corners 24 are rounded, the possibility of getting caught when inserting the multi-lumen tube 2 into the body cavity can be further reduced.

This application claims the benefit of priority based on Japanese Patent Application No. 2019-016266 filed on January 31, 2019. The entire contents of the specification of Japanese Patent Application No. 2019-016266 filed on January 31, 2019 are incorporated herein by reference.

1: basket catheter 2: multi-lumen tube 3: guide wire lumen 4: basket lumen 5: third lumen 11: basket section 12: elastic wire 13: distal tip 21: curved section 22: outer circumference 23 of multi-lumen tube : Chamfer 24 : Corner 31 : Distal opening edge of guidewire lumen 41 : Distal opening edge of basket lumen LD : Longitudinal axis direction

Claims (8)

a multi-lumen tube having a distal side and a proximal side and having a basket lumen and a guidewire lumen;
a basket catheter having an expandable basket portion having a plurality of elastic wires protrudingly inserted into the basket lumen from a distal end thereof,
The multi-lumen tube has a curved portion at its distal portion,
The guide wire lumen is arranged closer to the outer circumference of the curved portion than the basket lumen,
Point A below is located on the proximal side in the longitudinal direction of the multi-lumen tube than Point B below,
the distance in the longitudinal direction of the multi-lumen tube between point C and point D below is shorter than the distance in the longitudinal direction of the multi-lumen tube between point A and point B;
A basket catheter , wherein the point C and/or the point D is arranged on the proximal side of the point B.
(Point A) Point A is a point on the distal side opening edge of the guidewire lumen on the plan view of the multi-lumen tube viewed from the distal side to the proximal side, and The nearest point from the perimeter of .
(Point B) Point B is the most distal point from point A among the points on the outer circumference of the multi-lumen tube on the plan view of the multi-lumen tube viewed from the distal side to the proximal side. Point P, a point on the distal opening edge of the guidewire lumen that is most proximal from point P on the plan view.
(Points C and D) Points C and D are points on the distal side opening edge of the basket lumen on the plan view of the multi-lumen tube viewed from the distal side to the proximal side. , the line connecting the points A and B and the line connecting the points C and D are parallel, and the points C and D are most distal to each other. A line connecting the points A and B forms an angle of 20° or more and less than 80° with the longitudinal axis of the multi-lumen tube, and a line connecting the points C and D and the longitudinal axis of the multi-lumen tube form an angle of 20° or more and less than 80°. 2. The basket catheter according to claim 1 , wherein the angle between the two is 70° or more. The angle between the line connecting the points A and B and the longitudinal axis direction of the multi-lumen tube is 20° or more and 50° or less, and the line connecting the points C and D and the longitudinal axis direction of the multi-lumen tube are formed. 3. The basket catheter according to claim 2 , wherein the angle between the two is 70° or more. The basket catheter according to any one of claims 1 to 3 , wherein distal side opening edges of the guidewire lumen are not coplanar. The basket catheter according to any one of claims 1 to 4 , wherein a side portion of the distal end portion of the multi-lumen tube is provided with a chamfered portion. 6. The basket catheter according to claim 5 , wherein the chamfered portion is formed to cut 1/10 to 1/3 of the length of the outer circumference of the distal end portion of the multi-lumen tube. The basket catheter according to any one of claims 1 to 6 , wherein corners of the distal end of the multi-lumen tube are rounded. The basket catheter according to any one of claims 1 to 7 , wherein a lubricant is applied to the lumen of the guidewire lumen.

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