Catheter and method for manufacturing same

Abstract

Provided is a catheter that is improved in terms of ease of insertion into a body cavity such as a blood vessel and in terms of safety so as to prevent a member inserted into a lumen of the catheter from breaking a wall of the shaft.　A catheter 100 having a longitudinal direction has a shaft 30 extending in the longitudinal direction. The shaft 30 has a first lumen 10 and a second lumen 20 each extending in the longitudinal direction. In a cross section perpendicular to the longitudinal direction, when a straight line S1 connecting a centroid 10C of the first lumen 10 and a centroid 20C of the second lumen 20 intersects a periphery of the shaft 30 at two points A and B, and a straight line S2 passing through a midpoint O of a line segment AB and perpendicular to the line segment AB intersects the periphery of the shaft 30 at two points C and D, a line segment CD is shorter than the line segment AB, and the periphery of the shaft 30 has first portions 31 positioned outside a virtual ellipse VO having the line segment AB as a major axis and the line segment CD as a minor axis.

Description

Catheter and method of manufacturing the same

[0001] The present invention relates to a catheter and a method for manufacturing a catheter.

[0002] Catheters that can be inserted into body cavities such as blood vessels for examining and treating lesions are used. The catheter is delivered to the lesion by, for example, following a guidewire that has been inserted into the lesion. For example, Patent Document 1 proposes a catheter having a first lumen and a second lumen, with one or more radiopaque markers disposed at the distal ends of the first and second lumens, and the second lumen having a rigidity that increases continuously or stepwise toward the proximal end, thereby reducing the risk of the guidewire penetrating the lumen during operation. Patent Document 2 also proposes a catheter having a lumen region in which at least two lumens are arranged side by side, the lumen region having different bending rigidity depending on the bending direction, with the rigidity decreasing from the proximal end toward the distal end, and a low-strength region in a portion of the tubular wall of the two lumens, thereby providing good path-following ability and preventing a penetrating object such as a guidewire from breaking through the wall surrounding the lumen.

[0003] JP 2009-082566 A International Publication No. 2018 / 083905

[0004] A catheter is inserted into a blood vessel in, for example, a limb or the groin, and delivered to a lesion. At this time, the catheter is inserted into the body along a guidewire that has been inserted into the lesion beforehand. However, conventional catheters such as those disclosed in Patent Documents 1 and 2 sometimes have difficulty advancing through curved blood vessels from the insertion site to the lesion. In addition, there is room for improvement in terms of safety, such as preventing guidewires and other therapeutic instruments inserted into the catheter lumen from breaking through the lumen wall.

[0005] Furthermore, catheters are inserted into blood vessels, such as those in the limbs or groin, and delivered to the lesion. At this time, the catheter is inserted into the body along a guidewire that has already been inserted into the lesion. Therefore, the cross-sectional shape perpendicular to the longitudinal direction of the catheter shaft may be deformed from a circular shape so that the catheter can follow the guidewire and pass through curved blood vessels. The cross-sectional shape perpendicular to the longitudinal direction of the catheter shaft may also be changed depending on the longitudinal position. However, conventional catheter manufacturing methods have not made it easy to manufacture catheters with cross-sectional shapes that deviate from a circular shape or that vary depending on the longitudinal position.

[0006] The present invention has been made in consideration of the above circumstances, and an object of the present invention is to provide a catheter that improves insertability through body cavities such as blood vessels and that can improve safety by preventing a member inserted into the catheter lumen from breaking through the wall of the shaft. Another object of the present invention is to provide a method for manufacturing a catheter that can easily manufacture catheters with various cross-sectional shapes to improve insertability through body cavities such as blood vessels.

[0007] Catheters according to embodiments of the present invention that can solve the above problems are as follows: [1] A catheter having a longitudinal direction, comprising: a shaft extending in the longitudinal direction, the shaft having first and second lumens extending in the longitudinal direction, wherein, in a cross section perpendicular to the longitudinal direction, when two points where a line connecting the centroid of the first lumen and the centroid of the second lumen intersects with an outer edge of the shaft are defined as points A and B, and two points where a line passing through the midpoint of a line segment AB and perpendicular to the line segment AB intersects with the outer edge of the shaft are defined as points C and D, a line segment CD is shorter than the line segment AB, and the outer edge of the shaft has a first portion located outside an imaginary ellipse whose major axis is the line segment AB and whose minor axis is the line segment CD.

[0008] In a cross section perpendicular to the longitudinal direction, line segment CD is shorter than line segment AB, thereby reducing the cross-sectional area of ​​the shaft. This reduces the area of ​​contact between the shaft and the wall of a body cavity, such as a blood vessel, thereby improving catheter insertability. Furthermore, line segment CD being shorter than line segment AB makes it easier to bend the shaft so that the ends of the shorter line segment CD, i.e., points C and D, are on the inside or outside of the curve. This makes it easier for the shaft to follow the curvature of a body cavity, such as a blood vessel, further improving catheter insertability. Furthermore, since the outer edge of the shaft has a portion located outside an imaginary ellipse with line segment AB as the major axis and line segment CD as the minor axis, the shaft can be thickened around the lumen, preventing a guidewire or other therapeutic instrument inserted through the lumen from breaking through the shaft wall, thereby improving safety. Thus, the catheter has a configuration that allows the shaft to be thickened around the lumen while reducing its cross-sectional area, thereby enabling both improved insertability and prevention of breakthrough.

[0009] A catheter according to an embodiment of the present invention is preferably any one of the following [2] to

[11] . [2] The catheter according to [1], wherein, in a cross section perpendicular to the longitudinal direction, an outer edge of the shaft has a second portion located inside the imaginary ellipse. [3] The catheter according to [2], wherein a guidewire is inserted through the first lumen, and, in the cross section perpendicular to the longitudinal direction, when the side of point A with respect to line segment CD is a first region and the side of point B with respect to line segment CD is a second region, the first lumen is disposed in the first region and the second lumen is disposed in the second region, the first portion and the second portion are disposed in the first region, and the first portion is disposed in the second region. [4] The catheter according to [2], wherein a guidewire is inserted through the first lumen, and in a cross section perpendicular to the longitudinal direction, when the side of point A with respect to line segment CD is defined as a first region and the side of point B with respect to line segment CD is defined as a second region, the first lumen is disposed in the first region and the second lumen is disposed in the second region, only the second portion is disposed in the first region, and the first portion is disposed in the second region. [5] The catheter according to [2], wherein a guidewire is inserted through the first lumen, and when the side of point A with respect to line segment CD is defined as a first region and the side of point B with respect to line segment CD is defined as a second region in the cross section perpendicular to the longitudinal direction, the first lumen is disposed in the first region and the second lumen is disposed in the second region, the first portion is disposed in the first region, and the first portion and the second portion are disposed in the second region. [6] The catheter according to [2], wherein a guidewire is inserted through the first lumen, and in a cross section perpendicular to the longitudinal direction, when the side of point A with respect to line segment CD is a first region and the side of point B with respect to line segment CD is a second region, the first lumen is disposed in the first region, the second lumen is disposed in the second region, the first portion is disposed in the first region, and only the second portion is disposed in the second region. [7] The catheter according to [1], wherein in a cross section perpendicular to the longitudinal direction, an outer edge of the shaft does not have a portion located inside the imaginary ellipse.[8] The catheter according to any one of [1] to [7], wherein the shaft has a first tubular member disposed inside the shaft, and the first lumen is the inner cavity of the first tubular member. [9] The catheter according to any one of [1] to [8], wherein the shaft has a second tubular member disposed inside the shaft, and the second lumen is the inner cavity of the second tubular member.

[10] The catheter according to any one of [1] to [9], wherein, in a cross section perpendicular to the longitudinal direction, the outer edge of the shaft has a linear portion.

[11] A catheter according to any of [1] to

[10] , wherein in the longitudinal direction, the distal end of the catheter has a distal region, an intermediate region located proximal to the distal region, and a proximal region located proximal to the intermediate region, and in a cross section perpendicular to the longitudinal direction, the area defined by the outer edge of the shaft in the distal region is smaller than the area defined by the outer edge of the shaft in the intermediate region, and the area defined by the outer edge of the shaft in the proximal region is smaller than the area defined by the outer edge of the shaft in the intermediate region.

[0010] The manufacturing method of a catheter according to an embodiment of the present invention that has solved the above problems is as follows:

[12] A manufacturing method of a catheter, comprising the steps of: preparing a resin mold having a longitudinal direction and a radial direction and an inner cavity extending in the longitudinal direction, inserting a first tubular member made of resin into the inner cavity of the mold, inserting a first elongated member into the inner cavity of the first tubular member, arranging an outer member outside the mold to obtain a multilayer body in which the outer member, the mold, the first tubular member, and the first elongated member are arranged in this order from the outside in the radial direction, heating the multilayer body, removing the mold and the outer member, and removing the first elongated member, wherein the mold has elasticity.

[0011] The elasticity of the mold allows the lumen of the mold to expand when the first tubular member is inserted into the lumen of the mold and the first elongated member is inserted into the lumen of the first tubular member. By placing an outer member on the outside of the mold in this state to obtain a multilayer body and heating the multilayer body, a catheter having a shaft with a cross-sectional shape that conforms to the shape of the lumen of the mold can be easily manufactured. By changing the lumen shape of the mold, catheters having shafts with various cross-sectional shapes can be manufactured.

[0012] A method for manufacturing a catheter according to an embodiment of the present invention is preferably any one of the following

[13] to

[23] .

[13] The method for manufacturing a catheter according to

[12] , wherein the size of the lumen of the mold after the step of obtaining the multilayer body is the same as the size of the lumen of the mold when nothing is inserted into the lumen of the mold or is expanded.

[14] The method for manufacturing a catheter according to

[12] or

[13] , wherein the melting point M of the resin constituting the mold is higher than the melting point M1 of the resin constituting the first tubular member, and the heating temperature in the step of heating the multilayer body is higher than the melting point M1 but lower than the melting point M.

[15] The method for manufacturing a catheter according to any one of

[12] to

[14] , wherein, in a cross section perpendicular to the longitudinal direction, when nothing is inserted into the lumen of the mold, the lumen of the mold has a first axis that passes through the centroid of the lumen of the mold and connects two points on the inner wall of the mold, the first axis being the longest among line segments, and a second axis that passes through the midpoint of the first axis, is perpendicular to the first axis, and is shorter than the first axis, and the inner wall of the mold has a portion that is located outside an imaginary ellipse whose major axis is the first axis and whose minor axis is the second axis.

[16] The method for manufacturing a catheter according to any one of

[12] to

[15] , wherein, in the step of inserting the first tubular member into the lumen of the mold, the first tubular member is visible from outside the mold.

[17] The method for manufacturing a catheter according to any one of

[12] to

[16] , further comprising the step of inserting a third tubular member into the lumen of the mold outside the first tubular member before the step of heating the multilayer body, and the first tubular member is disposed in the lumen of the third tubular member.

[18] A method for manufacturing a catheter described in any of

[12] to

[17] , further comprising the steps of: before the step of heating the multilayer body, inserting a second tubular member into the inner cavity of the mold so that the second tubular member is aligned radially outside the first tubular member; inserting a second elongated member into the inner cavity of the second tubular member; and inserting a third tubular member into the inner cavity of the mold so that the second tubular member is aligned radially outside the first tubular member and the second tubular member; and further comprising the step of removing the second elongated member; and in the step of inserting the third tubular member, the first tubular member and the second tubular member are arranged in the inner cavity of the third tubular member.

[19] The method for manufacturing a catheter according to any one of

[12] to

[18] , wherein the mold has a first end and a second end in the longitudinal direction, a first region and a second region closer to the second end than the first region, and in a cross section perpendicular to the longitudinal direction, an area of ​​the lumen of the mold in the first region is smaller than an area of ​​the lumen of the mold in the second region.

[20] The method for manufacturing a catheter according to any one of

[12] to

[19] , wherein the mold has a first end and a second end in the longitudinal direction, a first region, a second region closer to the second end than the first region, and a third region closer to the second end than the second region, and in a cross section perpendicular to the longitudinal direction, an area of ​​the lumen of the mold in the first region is smaller than an area of ​​the lumen of the mold in the second region, and an area of ​​the lumen of the mold in the third region is smaller than an area of ​​the lumen of the mold in the second region.

[21] The method for manufacturing a catheter according to any one of

[12] to

[20] , wherein the step of preparing a mold includes the steps of preparing a resin tube, inserting a core material into the lumen of the resin tube, injecting a curable resin into the resin tube in the radial direction but outside the core material, and removing the core material.

[22] The method for manufacturing a catheter according to any one of

[12] to

[20] , wherein the step of preparing a mold includes the steps of preparing a metal mold having a lumen extending in the longitudinal direction, inserting a core material into the lumen of the metal mold, injecting a curable resin into the resin tube in the radial direction but outside the core material, and removing the metal mold and the core material.

[23] The method for manufacturing a catheter according to

[21] or

[22] , wherein the curable resin has mold-releasability from the first tubular member.

[0013] According to the above catheter, the cross-sectional area of ​​the shaft can be reduced, thereby improving the insertability of the catheter. Furthermore, the thickness of the shaft around the lumen can be increased, preventing a guidewire or other medical device inserted into the lumen from breaking through the shaft wall, thereby improving safety. Furthermore, according to the above catheter manufacturing method, catheters having shafts with various cross-sectional shapes can be easily manufactured. As a result, the insertability of the catheter when inserted into a body cavity such as a blood vessel can be improved.

[0014] 17A and 17B are cross-sectional views taken along III-III of the catheter shown in FIG. 1; a cross-sectional view showing a modification of the cross-sectional view of FIG. 3; a cross-sectional view showing a further modification of the cross-sectional view of FIG. 3; a cross-sectional view showing a further modification of the cross-sectional view of FIG. 3; a cross-sectional view showing a further modification of the cross-sectional view of FIG. 3; a cross-sectional view perpendicular to the longitudinal direction of a catheter according to yet another embodiment of the present invention; a cross-sectional view perpendicular to the longitudinal direction of a catheter according to yet another embodiment of the present invention; a cross-sectional view showing a modification of the cross-sectional view of FIG. 9; a side view of a catheter according to yet another embodiment of the present invention; a cross-sectional view XII-XII of the catheter shown in FIG. 11; a cross-sectional view XIII-XIII of the catheter shown in FIG. 11; a cross-sectional view XIV-XIV of the catheter shown in FIG. 11; a side view of a catheter according to yet another embodiment of the present invention; a side view of a catheter according to one embodiment of the present invention; a side view of a mold according to one embodiment of the present invention; a cross-sectional view XVIII-XVIII of the mold shown in FIG. 17A and 17B are cross-sectional views perpendicular to the longitudinal direction showing a state in which a first tubular member having a first elongated member inserted into its lumen is inserted into the lumen of a mold in a method of manufacturing a catheter according to one embodiment of the present invention. 20 is a cross-sectional view perpendicular to the longitudinal direction, illustrating a state in which an outer member is disposed outside the mold shown in FIG. 19. A cross-sectional view perpendicular to the longitudinal direction of a shaft obtained after the steps of removing the mold and the outer member and removing the first elongated member in a method for manufacturing a catheter according to one embodiment of the present invention. A cross-sectional view perpendicular to the longitudinal direction, illustrating a state in which a third tubular member is further inserted into the lumen of the mold and outside the first tubular member in a method for manufacturing a catheter according to another embodiment of the present invention. A cross-sectional view perpendicular to the longitudinal direction, illustrating a state in which a second tubular member, a second elongated member, and a third tubular member are further inserted into the lumen of the mold in a method for manufacturing a catheter according to yet another embodiment of the present invention. A cross-sectional view perpendicular to the longitudinal direction of a shaft obtained after removing the mold, the outer member, the first elongated member, and the second longevity member from the state shown in FIG. 23. A side view of a mold according to another embodiment of the present invention. A cross-sectional view taken along the line XXVI-XXVI of the mold shown in FIG. 25.Figure 26 is a cross-sectional view taken along the line XXVII-XXVII of the mold shown in Figure 25. Figure 27 is a side view of a mold according to yet another embodiment of the present invention. Figure 28 is a cross-sectional view perpendicular to the longitudinal direction illustrating steps of preparing a mold according to one embodiment of the present invention. Figure 29 is a cross-sectional view perpendicular to the longitudinal direction illustrating steps of preparing a mold according to another embodiment of the present invention. Figure 30 is a cross-sectional view perpendicular to the longitudinal direction illustrating steps of preparing a mold according to yet another embodiment of the present invention.

[0015] The present invention will be described below based on the embodiments, but the present invention is not limited to the following embodiments and can be implemented with appropriate modifications within the scope of the above and below-described purposes, and all such modifications are included within the technical scope of the present invention. In addition, hatching and component symbols may be omitted in each drawing for convenience. In such cases, please refer to the specification or other drawings. Furthermore, the dimensions of various components in the drawings may differ from the actual dimensions, as priority is given to helping understand the features of the present invention.

[0016] 1. Catheter A catheter according to an embodiment is a catheter having a longitudinal direction, and has a shaft extending in the longitudinal direction, the shaft having a first lumen and a second lumen extending in the longitudinal direction, and in a cross section perpendicular to the longitudinal direction, when two points where a line connecting the centroid of the first lumen and the centroid of the second lumen intersect with the outer edge of the shaft are defined as points A and B, and two points where a line passing through the midpoint of a line segment AB and perpendicular to the line segment AB intersect with the outer edge of the shaft are defined as points C and D, a line segment CD is shorter than the line segment AB, and the outer edge of the shaft has a first portion located outside an imaginary ellipse whose major axis is the line segment AB and whose minor axis is the line segment CD.

[0017] In a cross section perpendicular to the longitudinal direction, line segment CD is shorter than line segment AB, thereby reducing the cross-sectional area of ​​the shaft. This reduces the area of ​​contact between the shaft and the wall of a body cavity, such as a blood vessel, thereby improving catheter insertability. Furthermore, line segment CD being shorter than line segment AB makes it easier to bend so that the ends of the shorter line segment CD, i.e., points C and D, are on the inside or outside of the curve. This makes it easier for the shaft to follow the curvature of a body cavity, such as a blood vessel, further improving catheter insertability. Furthermore, since the outer edge of the shaft has a first portion located outside an imaginary ellipse with line segment AB as the major axis and line segment CD as the minor axis, the thickness of the shaft around the lumen can be increased, preventing a guidewire or other therapeutic instrument inserted through the lumen from breaking through the shaft wall, thereby improving safety. Thus, the catheter has a configuration that allows the cross-sectional area to be reduced while increasing the thickness of the shaft around the lumen, thereby enabling both improved insertability and prevention of breakthrough.

[0018] Catheters according to embodiments of the present invention will be described below with reference to FIGS. 1 to 15. FIG. 1 is a side view of a catheter according to one embodiment of the present invention. FIG. 2 is a side view of a catheter according to another embodiment of the present invention. FIG. 3 is a cross-sectional view taken along III-III of the catheter shown in FIG. 1. FIGS. 4 to 7 are cross-sectional views showing different modifications of the cross-sectional view of FIG. 3. FIGS. 8 and 9 are cross-sectional views perpendicular to the longitudinal direction of catheters according to different embodiments. FIG. 10 is a cross-sectional view showing a modification of the cross-sectional view of FIG. 9. FIG. 11 is a side view of a catheter according to yet another embodiment of the present invention. FIGS. 12 to 14 are cross-sectional views taken along XII-XII, XIII-XIII, and XIV-XIV of the catheter shown in FIG. 11, respectively. Note that a guidewire disposed in the first lumen is omitted from FIGS. 4 to 10 and FIGS. 12 to 14. FIG. 15 is a side view of a catheter according to yet another embodiment of the present invention.

[0019] In this specification, the direction toward the user's hand in the longitudinal direction x is referred to as the proximal side, and the direction opposite the proximal side, i.e., the direction toward the treatment target, is referred to as the distal side. In this specification, the distal end of each member refers to the end located most distally of each member, and the proximal end of each member refers to the end located most proximal of each member. The distal end portion refers to the distal end and the peripheral portion of the distal end, and the proximal end portion refers to the proximal end and the peripheral portion of the proximal end. The first lumen 10 and the second lumen 20 are sometimes collectively referred to as lumens.

[0020] As shown in Figures 1 and 2, the catheter 100 has a longitudinal direction x, the catheter 100 has a shaft 30 extending in the longitudinal direction x, and the shaft 30 has a first lumen 10 and a second lumen 20 extending in the longitudinal direction x.

[0021] For example, by inserting a guidewire 40, which has been inserted in advance into a lesion in a blood vessel such as a coronary artery, into the first lumen 10, the catheter 100 can be delivered to the lesion along the guidewire 40. For example, an intravascular treatment device such as a balloon catheter or an extension catheter, or a member such as another wire, can be inserted into the second lumen 20.

[0022] 1, the first lumen 10 preferably has a distal opening 10D at its distal end, which can serve as an entrance or exit for the guidewire 40.

[0023] 1, the second lumen 20 preferably has a distal opening 20D on its distal side, which may serve as an entrance or exit for other therapeutic devices.

[0024] The diameters of the first lumen 10 and the second lumen 20 can be, for example, 0.1 mm or more, 0.2 mm or more, 0.3 mm or more, or 0.8 mm or less, 0.7 mm or less, or 0.6 mm or less, which allows insertion of a member such as a guidewire 40 into the lumens and facilitates insertion of the catheter 100 into a body cavity.

[0025] 1, the catheter 100 further includes a handle 50 disposed proximally of the shaft 30, and the proximal opening 10P of the first lumen 10 is located distally of the proximal opening 20P of the second lumen 20, and the proximal opening 20P of the second lumen 20 preferably communicates with the inner cavity of the handle 50. In this manner, the catheter 100 may be a so-called rapid exchange catheter. If the catheter 100 is a rapid exchange catheter, the length of the guidewire 40 can be shortened.

[0026] Preferably, the catheter 100 further includes two handles disposed proximal to the shaft 30, and the proximal opening 10P of the first lumen 10 and the proximal opening 20P of the second lumen 20 are connected to the two handles, respectively. Alternatively, as shown in FIG. 2 , the catheter 100 may include a handle 50 disposed proximal to the shaft 30, and the proximal opening 10P of the first lumen 10 and the proximal opening 20P of the second lumen 20 may be connected to the handle 50, with the first lumen 10 and the second lumen 20 communicating with the inner cavity of the handle 50. In this manner, the catheter 100 may be a so-called over-the-wire catheter. By using the catheter 100 as an over-the-wire catheter, the first lumen 10 and the second lumen 20 can be configured to be aligned radially of the shaft 30 in a region from the distal end to the proximal end in the longitudinal direction x of the shaft 30.

[0027] The catheter 100 has a handle 50, which allows the practitioner to insert the catheter 100 into the body by grasping and pushing the handle 50. The outer diameter of the handle 50 is not particularly limited as long as it has a shape that allows the practitioner to grip it with their fingers. The handle 50 is preferably a resin molded product obtained by a method such as injection molding. Examples of resins include polyolefin resins such as polyethylene and polypropylene, polycarbonate resins, and (meth)acrylic resins. Of these, transparent resins such as polycarbonate and polymethyl methacrylate are preferred. This improves visibility from the outside of the handle 50 and improves operability when inserting a guidewire 40 into the first lumen 10 or another member into the second lumen 20.

[0028] The resin constituting the shaft 30 preferably contains at least one selected from the group consisting of polyethylene, polyurethane, polyurethane-based thermoplastic elastomer, styrene-based thermoplastic elastomer, polyamide elastomer, and polyamide. Of these, the resin constituting the shaft 30 more preferably contains at least one selected from the group consisting of polyurethane and polyamide elastomer.

[0029] The first lumen 10 and the second lumen 20 can be formed, for example, by inserting two core materials into the inner cavity of a resin tube that forms the shaft 30, heat-processing the resin tube, and then removing the core materials.

[0030] The outer diameter of the shaft 30 can be, for example, 0.5 mm or more, 0.6 mm or more, 0.7 mm or more, and 2.0 mm or less, 1.5 mm or less, or 1.0 mm or less.

[0031] 1, particularly when the catheter 100 is a rapid exchange catheter, the catheter 100 preferably further includes an outer member 60 extending in the longitudinal direction x. The outer member 60 preferably has an inner lumen 60A extending in the longitudinal direction x, and a portion of the shaft 30 is preferably disposed in the inner lumen 60A. The outer member 60 can form a double-tube structure (coaxial structure), which can protect the shaft 30 and improve the transmission of pushing force.

[0032] The outer member 60 is preferably disposed proximal to the proximal end of the first lumen 10 in the longitudinal direction x, which allows the outer diameter of the outer member 60 to be reduced.

[0033] The outer member 60 preferably has a fixed portion at its distal end that is secured to the shaft 30 and a fixed portion at its proximal end that is secured to the handle 50 .

[0034] The catheter 100 may have an outer member 60 even if it is an over-the-wire catheter.

[0035] The outer member 60 preferably contains the same resin as the shaft 30 or a harder resin, and more preferably is made of a harder resin. A harder resin can improve pushability.

[0036] As shown in Figure 3, in a cross section perpendicular to the longitudinal direction x, when two points A and B are defined as the intersection of a line S1 connecting the centroid 10C of the first lumen 10 and the centroid 20C of the second lumen 20 with the outer edge of the shaft 30, and two points C and D are defined as the intersection of a line S2 passing through the midpoint O of a line segment AB and perpendicular to the line segment AB with the outer edge of the shaft 30, the line segment CD is shorter than the line segment AB. Because the line segment CD is shorter than the line segment AB, the cross-sectional area of ​​the shaft 30 can be made smaller than when the shape of the outer edge of the shaft 30 in the cross section perpendicular to the longitudinal direction x is a shape whose length does not change depending on the direction, such as a circle. This reduces the area of ​​contact of the shaft 30 with the wall of a body cavity, such as a blood vessel, and reduces the resistance of the shaft 30 against the wall of the body cavity, thereby improving the insertability of the catheter 100.

[0037] Furthermore, because the line segment CD is shorter than the line segment AB, the ends of the shorter line segment CD, i.e., points C and D, are more likely to bend on the inside or outside of the curve. This makes it easier for the shaft 30 to follow the curve of a body cavity such as a blood vessel, further improving the insertability of the catheter 100.

[0038] Length L of line segment CD ＣＤ The length L of the line segment AB ＡＢ The ratio (L ＡＢ / L ＣＤ The value of (a) can be, for example, 1.05 or more, 1.1 or more, 1.2 or more, 1.3 or more, 1.5 or more, or 5 or less, 4 or less, 3 or less, 2 or less, or 1.8 or less.

[0039] Specifically, the length L of the line segment AB ＡＢ The length L of the line segment CD can be, for example, 0.5 mm or more, 0.6 mm or more, 0.7 mm or more, and 1.5 mm or less, 1.2 mm or less, or 1.0 mm or less. ＣＤ can be, for example, 0.3 mm or more, 0.4 mm or more, 0.5 mm or more, and 1.2 mm or less, 1.0 mm or less, or 0.8 mm or less.

[0040] Since the outer edge of the shaft 30 has a first portion 31 located outside an imaginary ellipse VO whose major axis is the line segment AB and whose minor axis is the line segment CD, the thickness of the shaft 30 around the lumen can be increased, thereby preventing the guide wire 40 or other therapeutic instruments inserted into the lumen from breaking through the wall of the shaft 30, thereby improving safety.

[0041] As described above, the catheter 100 has a configuration that allows the thickness of the shaft 30 around the lumen to be increased while reducing the cross-sectional area, thereby enabling both improved insertion of the catheter 100 and prevention of the guide wire 40 or other therapeutic instruments from puncturing it.

[0042] The range occupied by the first portion 31 in the 360° circumferential direction of the shaft 30 can be, for example, 30° or more, 45° or more, 60° or more, 90° or more, 120° or more, or less than 360°, 320° or less, 270° or less, 240° or less, or 180° or less. When a plurality of first portions 31 are arranged spaced apart in the circumferential direction of the shaft 30 as shown in FIG. 4 , the range occupied by the first portion 31 in the 360° circumferential direction of the shaft 30 is the total range of the plurality of first portions 31. When a plurality of first portions 31 are arranged spaced apart in the circumferential direction of the shaft 30, the range occupied by one of the plurality of first portions 31 in the circumferential direction of the shaft 30 can be, for example, 5° or more, 10° or more, 15° or more, 30° or more, 45° or more, 90° or more, 120° or less, 110° or less, or 100° or less. Alternatively, the first portion 31 may occupy the entire 360° radial direction of the shaft 30 .

[0043] A configuration having a first part 31 in which the line segment CD is shorter than the line segment AB and the outer edge of the shaft 30 is positioned outside the imaginary ellipse VO can be obtained by using a mold that conforms to the outer edge shape of the shaft 30 to be manufactured and molding resin in the mold.

[0044] 4, in the catheter 100, the outer edge of the shaft 30 preferably has a second portion 32 located inside an imaginary ellipse VO in a cross section perpendicular to the longitudinal direction x. Having the second portion 32 located inside the imaginary ellipse VO makes it easier to reduce the cross-sectional area of ​​the shaft 30, thereby reducing the area of ​​contact of the shaft 30 with the wall of a body cavity such as a blood vessel and further improving the insertability of the catheter.

[0045] 1 and 4 , a guidewire 40 is inserted through the first lumen 10, and in a cross section perpendicular to the longitudinal direction x, when a first region R1 is located on the side of point A relative to a line segment CD and a second region R2 is located on the side of point B relative to the line segment CD, the first lumen 10 is disposed in the first region R1, the second lumen 20 is disposed in the second region R2, and it is preferable that the first portion 31 and the second portion 32 are disposed in the first region R1, and the first portion 31 is disposed in the second region R2. By disposing the first portion 31 and the second portion 32 in the first region R1 in which the first lumen 10, which is the lumen through which the guidewire 40 is inserted, is disposed, the shaft 30 is more likely to bend from the boundary between the first portion 31 and the second portion 32, i.e., the boundary between the thicker and thinner portions of the shaft 30 relative to the imaginary ellipse VO, and the shaft 30 can be more easily aligned with the guidewire 40 inserted into a body cavity such as a curved blood vessel. This makes it easier to deliver the catheter 100 to the lesion.

[0046] In the above configuration, only the first portion 31, in which the outer edge of the shaft 30 is located outside the imaginary ellipse VO, may be disposed in the second region R2. A member such as a therapeutic instrument is inserted into the second lumen 20 disposed in the second region R2, and by disposing only the first portion 31 in the second region R2, the wall thickness of the shaft 30 in the second region R2 can be increased, thereby preventing the member such as the therapeutic instrument from breaking through the wall of the shaft 30.

[0047] 1 and 5 , a guidewire 40 is inserted through the first lumen 10, and in a cross section perpendicular to the longitudinal direction x, when a first region R1 is located on the side of point A relative to a line segment CD and a second region R2 is located on the side of point B relative to the line segment CD, the first lumen 10 is disposed in the first region R1 and the second lumen 20 is disposed in the second region R2, and it is preferable that only the second portion 32 is disposed in the first region R1 and the first portion 31 is disposed in the second region R2. Only the first portion 31 may be disposed in the second region R2, or both the first portion 31 and the second portion 32 may be disposed in the second region R2. By disposing only the second portion 32 in the first region R1 and the first portion 31 in the second region R2, the shaft 30 is more likely to bend starting from the boundary between the first region R1 and the first portion 31 in the second region R2, making it easier to align the shaft 30 with the guidewire 40 inserted into a curved body cavity such as a blood vessel. This facilitates delivery of the catheter 100 to a lesion. Furthermore, the cross-sectional area of ​​the first region R1 perpendicular to the longitudinal direction x can be reduced, further improving the insertability of the catheter 100. Furthermore, by disposing the first portion 31 in the second region R2 on the second lumen 20 side, the wall thickness of the shaft 30 in the second region R2 can be increased, thereby preventing other therapeutic instruments inserted through the second lumen 20 from breaking through the wall of the shaft 30. This effect can be further enhanced if only the first portion 31 is disposed in the second region R2. The boundary between the first region R1 and the second region R2 is preferably the boundary between the second portion 32 and the first portion 31 .

[0048] 1 and 6 , a guidewire 40 is inserted through the first lumen 10, and in a cross section perpendicular to the longitudinal direction x, when a first region R1 is on the side of point A relative to a line segment CD and a second region R2 is on the side of point B relative to the line segment CD, the first lumen 10 is disposed in the first region R1 and the second lumen 20 is disposed in the second region R2, and it is preferable that the first region R1 includes the first portion 31 and the second region R2 includes the first portion 31 and the second portion 32. Although both the first portion 31 and the second portion 32 may be disposed in the first region R1, it is more preferable that only the first portion 31 be disposed. By arranging the first portion 31 and the second portion 32 in the second region R2 where the second lumen 20 is disposed, the shaft 30 is more likely to bend from the boundary between the first portion 31 and the second portion 32, i.e., the boundary between the thicker and thinner portions of the shaft 30 relative to the imaginary ellipse VO, which is the starting point, making it easier to align the shaft 30 with a curved body cavity such as a blood vessel. Furthermore, the smaller cross-sectional area on the second lumen 20 side makes it easier to improve the insertability of the catheter 100. Furthermore, by arranging the first portion 31 in the first region R1 on the side of the first lumen 10 through which the guidewire 40 is inserted, the thickness of the shaft 30 in the first region R1 can be increased, thereby preventing the guidewire 40 from breaking through the wall of the shaft 30. This effect can be further enhanced if only the first portion 31 is disposed in the first region R1.

[0049] 1 and 7 , a guidewire 40 is inserted through the first lumen 10, and in a cross section perpendicular to the longitudinal direction x, when a first region R1 is located on the side of point A relative to a line segment CD and a second region R2 is located on the side of point B relative to the line segment CD, the first lumen 10 is disposed in the first region R1 and the second lumen 20 is disposed in the second region R2, and it is preferable that the first region R1 includes the first portion 31 and the second region R2 includes only the second portion 32. Only the first portion 31 may be disposed in the first region R1, or both the first portion 31 and the second portion 32 may be disposed in the first region R1. By disposing the first portion 31 in the first region R1 and only the second portion 32 in the second region R2, the shaft 30 is more likely to bend starting from the boundary between the second region R2 and the first portion 31 in the first region R1, making it easier to align the shaft 30 with the guidewire 40 inserted into a curved body cavity such as a blood vessel. This facilitates delivery of the catheter 100 to a lesion. Furthermore, the cross-sectional area of ​​the second region R2 perpendicular to the longitudinal direction x can be reduced, further improving the insertability of the catheter 100. Furthermore, by disposing the first portion 31 in the first region R1 on the first lumen 10 side, the wall thickness of the shaft 30 in the first region R1 can be increased, thereby preventing the guidewire 40 inserted into the first lumen 10 from breaking through the wall of the shaft 30. This effect can be further enhanced if only the first portion 31 is disposed in the first region R1. The boundary between the first region R1 and the second region R2 is preferably the boundary between the first portion 31 and the second portion 32.

[0050] 3 , in a cross section perpendicular to the longitudinal direction x, the outer edge of the shaft 30 does not have to have a portion located inside the imaginary ellipse VO. By making the line segment CD shorter than the line segment AB, the cross-sectional area of ​​the shaft 30 perpendicular to the longitudinal direction x can be reduced, improving the insertability of the catheter 100. Furthermore, by not having a portion of the outer edge of the shaft 30 located inside the imaginary ellipse VO, the thickness of the shaft 30 around the lumen can be increased, making it easier to prevent the guide wire 40 or other treatment instruments inserted into the lumen from breaking through the wall of the shaft 30.

[0051] As shown in Figure 8, the shaft 30 preferably has a first tubular member 11 disposed inside the shaft 30, and the first lumen 10 is the inner cavity of the first tubular member 11. By forming the first lumen 10 using the first tubular member 11, which is a member different from the shaft 30, the shaft 30 and the first tubular member 11 can be made of different materials. This allows the first tubular member 11 to be made of a more flexible material and improves the slipperiness of the inner cavity of the first tubular member 11, making it easier to insert the guidewire 40 into the first lumen 10, which is the inner cavity of the first tubular member 11, and further improving the insertability when the catheter 100 is inserted into the body along the guidewire 40.

[0052] 9 , the shaft 30 preferably has a second tubular member 21 disposed inside the shaft 30, and the second lumen 20 is the inner cavity of the second tubular member 21. By forming the second lumen 20 using the second tubular member 21, which is a member different from the shaft 30, the shaft 30 and the second tubular member 21 can be made of different materials. This allows the second tubular member 21 to be made of a more flexible material or improves the slipperiness of the inner cavity of the second tubular member 21, making it easier to insert other therapeutic instruments into the second lumen 20, which is the inner cavity of the second tubular member 21.

[0053] The material constituting the first cylindrical member 11 and the second cylindrical member 21 may include at least one selected from the group consisting of, for example, polyolefin-based resins such as polyethylene, polypropylene, ethylene-propylene copolymers, and mixtures thereof; fluorine-based resins such as polytetrafluoroethylene, tetrafluoroethylene-perfluoroalkyl vinyl ether copolymers, tetrafluoroethylene-hexafluoropropylene copolymers, tetrafluoroethylene-ethylene copolymers, polyvinylidene fluoride, polychlorotrifluoroethylene, ethylene-chlorotrifluoroethylene copolymers, and mixtures thereof; polyamide-based resins; polyester-based resins; polyurethane-based resins; vinyl chloride-based resins; silicone-based resins; and natural rubber.

[0054] As shown in FIG. 9 , the shaft 30 includes a first tubular member 11 and a second tubular member 21 disposed inside the shaft 30. The first lumen 10 may be the inner cavity of the first tubular member 11, and the second lumen 20 may be the inner cavity of the second tubular member 21. By using different materials for the first tubular member 11 and the second tubular member 21, the hardness of the resin primarily occupying the first region R1 and the hardness of the resin primarily occupying the second region R2 can be made different, thereby imparting hardness directionality to the shaft 30. This further improves the flexibility of the shaft 30. Furthermore, when forming a lumen inside the shaft 30 by thermal processing during the manufacture of the catheter 100, some materials may flow, making it impossible to maintain the lumen. However, using materials with high melting points for the first tubular member 11 and the second tubular member 21 makes it easier to form the lumen.

[0055] Although not shown, the shaft 30 may have only the second tubular member 21 .

[0056] Preferably, the first tubular member 11 and the second tubular member 21 each have one or more layers extending in the longitudinal direction x. The multiple layers preferably have an inner layer and an outer layer that encloses at least a portion of the inner layer. The multiple layers may further have an intermediate layer positioned between the inner layer and the outer layer. The number of intermediate layers may be one, or two or more. Preferably, the multiple layers contain a material different from that of adjacent layers.

[0057] When the first tubular member 11 and / or the second tubular member 21 has multiple layers, the inner layer preferably contains at least one resin selected from the group consisting of polyolefin resins and fluororesins. This improves the slidability of the guide wire 40 inserted through the first lumen 10 and other therapeutic instruments inserted through the second lumen 20. The outer layer preferably contains a flexible resin. The flexible resin in the outer layer makes the catheter 100 more easily bendable. The flexible resin preferably contains at least one resin selected from the group consisting of polyethylene, polyurethane, polyurethane-based thermoplastic elastomer, styrene-based thermoplastic elastomer, polyamide elastomer, and polyamide, and more preferably contains at least one resin selected from the group consisting of polyurethane and polyamide elastomer.

[0058] It is preferable that at least a portion of the inner surface of the shaft 30 is fixed to the outer surface of the first cylindrical member 11 or the second cylindrical member 21. This makes it difficult for the shaft 30 to twist or twist. Examples of the manner of fixing include welding, adhesion, etc.

[0059] As shown in FIG. 10 , the first tubular member 11 may include a reinforcing member 12, and the second tubular member 21 may include a reinforcing member 22. Hereinafter, the reinforcing member 12 and the reinforcing member 22 may be referred to as reinforcing members. Both the first tubular member 11 and the second tubular member 21 may include a reinforcing member, or either the first tubular member 11 or the second tubular member 21 may include a reinforcing member. This more easily prevents breakthrough of a guidewire 40 inserted through the first lumen 10, which is the inner cavity of the first tubular member 11, or another therapeutic instrument inserted through the second lumen 20, which is the inner cavity of the second tubular member 21. Furthermore, when a lumen is formed by thermal processing on the inside of the shaft 30 during manufacturing of the catheter 100, depending on the material, resin may flow and the lumen may not be able to be maintained. However, by including a reinforcing member in the first tubular member 11 or the second tubular member 21, the lumen can be easily formed.

[0060] The reinforcing member is preferably a braided body made of braided wires, a coiled body made of spirally wound wires, or a combination thereof. In particular, the reinforcing member is preferably a braided body. This facilitates improving the rigidity of the first tubular member 11 and the second tubular member 21. Examples of wires included in the reinforcing member include metal wires such as stainless steel, titanium, nickel-titanium alloy, cobalt-chromium alloy, tungsten alloy, and alloys thereof. Among these, the metal wire is preferably stainless steel. The metal wire may be a solid wire or a twisted wire. Alternatively, the wire included in the reinforcing member may be a fiber such as polyarylate fiber, aramid fiber, ultra-high molecular weight polyethylene fiber, PBO fiber, carbon fiber, or a blend thereof. The fiber may be a monofilament or a multifilament. The reinforcing member may contain an X-ray opaque material to facilitate confirmation of the position of the first tubular member 11 and the second tubular member 21 under X-ray fluoroscopy. The X-fiber impermeable substance is preferably at least one selected from the group consisting of lead, barium, iodine, tungsten, gold, platinum, iridium, platinum-iridium alloy, stainless steel, titanium, cobalt-chromium alloy, palladium, bismuth, and tantalum.

[0061] 3, in a cross section perpendicular to the longitudinal direction x, the outer edge of the shaft 30 preferably has a straight portion 30S. By having the straight portion 30S, the shaft 30 can be easily curved starting from the straight portion 30S, making it easier to align the shaft 30 within a body cavity such as a curved blood vessel, and the insertability of the catheter 100 can be further improved.

[0062] As shown in Figures 11 to 14, in the longitudinal direction x, the distal end of the catheter 100 has a distal region 101, an intermediate region 102 located proximal to the distal region 101, and a proximal region 103 located proximal to the intermediate region 102, and in a cross section perpendicular to the longitudinal direction x, it is preferable that the area defined by the outer edge of the shaft 30 in the distal region 101 is smaller than the area defined by the outer edge of the shaft 30 in the intermediate region 102, and that the area defined by the outer edge of the shaft 30 in the proximal region 103 is smaller than the area defined by the outer edge of the shaft 30 in the intermediate region 102. Because the area defined by the outer edge of the shaft 30 in the distal region 101 and the proximal region 103 is smaller than the area defined by the outer edge of the shaft 30 in the intermediate region 102, a gap (clearance) can be provided between the shaft 30 and the wall of a body cavity, such as a blood vessel, into which the catheter 100 is inserted, in the distal region 101 and the proximal region 103, thereby reducing the contact area between the body cavity wall and the shaft 30 and further improving the insertability of the catheter 100. Note that, in the longitudinal direction x, the distal end of the catheter 10 has the distal region 101, the intermediate region 102 located proximal to the distal region 101, and the proximal region 103 located proximal to the intermediate region 102 means that the distal region 101, the intermediate region 102, and the proximal region 103 are located in this order without overlapping with each other in the longitudinal direction x.

[0063] Alternatively, in a cross section perpendicular to the longitudinal direction x, the area defined by the outer edge of the shaft 30 in the distal region 101 may be smaller than the area defined by the outer edge of the shaft 30 in the intermediate region 102, and the area defined by the outer edge of the shaft 30 in the proximal region 103 may be larger than the area defined by the outer edge of the shaft 30 in the intermediate region 102. This makes it easier to insert the catheter 100 into a body cavity, since the area defined by the outer edge of the shaft 30 in a cross section perpendicular to the longitudinal direction x decreases from the proximal side to the distal side.

[0064] 12 and 14 , in a cross section perpendicular to the longitudinal direction x, the shapes of the shaft 30 in the distal region 101 and the proximal region 103 may be different. Alternatively, although not shown, in a cross section perpendicular to the longitudinal direction x, the shapes of the shaft 30 in the distal region 101 and the proximal region 103 may be the same.

[0065] 13 , the shaft 30 may have a portion in the longitudinal direction x that does not have the first portion 31, where the outer edge of the shaft 30 is located outside the imaginary ellipse VO in a cross section perpendicular to the longitudinal direction x. Even if there is a portion that does not have the first portion 31, the catheter 100 has the first portion 31 in a portion other than the portion that does not have the first portion 31, thereby improving the insertability of the catheter 100.

[0066] The length of the portion of the shaft 30 in the longitudinal direction x where the first portion 31 is not present is preferably 20% or less, more preferably 10% or less, and even more preferably 5% or less, of the length of the first lumen 10 in the longitudinal direction x. The lower limit of the ratio of the length of the portion of the shaft 30 in the longitudinal direction x where the first portion 31 is not present to the length of the first lumen 10 in the longitudinal direction x is 0%, and may be, for example, 1% or more. If the ratio of the length of the portion of the shaft 30 in the longitudinal direction x where the first portion 31 is not present to the length of the first lumen 10 in the longitudinal direction x is within the above-mentioned range, the shaft 30 can be configured to include the first portion 31 in the portion outside the above-mentioned range, thereby improving the insertability and safety of the catheter 100. Specifically, the ratio of the length of the portion of the shaft 30 in the longitudinal direction x where the first portion 31 is present to the length of the first lumen 10 in the longitudinal direction x is preferably 80% or more, more preferably 90% or more, and even more preferably 95% or more. The upper limit of the ratio of the length of the portion of the shaft 30 having the first portion 31 in the longitudinal direction x to the length of the first lumen 10 in the longitudinal direction x is 100%, and may be, for example, 99% or less.

[0067] The shaft 30 may have a radiopaque marker at the distal end, which makes it easier to identify the position of the opening of the lumen.

[0068] The radiopaque marker provided on the shaft 30 is preferably ring-shaped or coil-shaped, and more preferably ring-shaped. The radiopaque marker preferably contains a radiopaque material, and more preferably is made of a radiopaque material. The radiopaque material is preferably at least one selected from the group consisting of lead, barium, iodine, tungsten, gold, platinum, iridium, platinum-iridium alloy, stainless steel, titanium, cobalt-chromium alloy, palladium, bismuth, and tantalum.

[0069] 15 , the shaft 30 may have a configuration in which the distal opening 10D of the first lumen 10 is located distal to the distal opening 20D of the second lumen 20. This makes it easier for the catheter 100 to bend in the portion distal to the distal opening 20D of the second lumen 20, and makes it easier for the catheter 100 to follow the guidewire 40 when the guidewire 40 is inserted through the first lumen 10.

[0070] Although not shown, the catheter 100 may further have a tip extending in the longitudinal direction x. The tip preferably has an inner lumen extending in the longitudinal direction x, and at least the distal end of the shaft 30 is disposed within the inner lumen. This makes it easier for the tip and the shaft 30 to bend integrally.

[0071] It is preferable that at least a portion of the inner surface of the tip is fixed to the outer surface of the shaft 30. This makes it easier for the tip and the shaft 30 to bend integrally. Examples of the manner of fixing include welding, adhesion, etc.

[0072] The chip preferably contains a flexible resin. The flexible resin preferably contains at least one selected from the group consisting of polyethylene, polyurethane, polyurethane-based thermoplastic elastomer, styrene-based thermoplastic elastomer, polyamide elastomer, and polyamide, and more preferably contains at least one selected from the group consisting of polyurethane and polyamide elastomer. The polyethylene is preferably low-density polyethylene having a specific gravity of 0.91 to 0.92.

[0073] The tip preferably has a region in which the ratio of the major axis to the minor axis in a cross section perpendicular to the longitudinal direction x is 1.0 to 1.1. This region preferably includes the distal end of the tip. This makes it easier to prevent deformation, such as twisting, of the distal end of the tip. It is more preferable that the tip consists of this region.

[0074] The catheter 100 can be preferably used for treatment of narrowed or blocked passages such as blood vessels in the body, and can be preferably used for performing coronary intervention (PCI) for lesions at the bifurcation of coronary arteries.

[0075] 2. Catheter Manufacturing Method A catheter manufacturing method according to an embodiment includes the steps of preparing a resin mold having a lumen extending in the longitudinal direction and having longitudinal and radial directions, inserting a resin first tubular member into the lumen of the mold, inserting a first elongated member into the lumen of the first tubular member, arranging an outer member outside the mold to obtain a multilayer body in which the outer member, mold, first tubular member, and first elongated member are arranged in this order from the outside in the radial direction, heating the multilayer body, removing the mold and the outer member, and removing the first elongated member, wherein the mold is elastic.

[0076] The elasticity of the mold allows the lumen of the mold to expand when the first tubular member is inserted into the lumen of the mold and the first elongated member is inserted into the lumen of the first tubular member. By placing an outer member on the outside of the mold in this state to obtain a multilayer body and heating the multilayer body, a catheter having a shaft with a cross-sectional shape that conforms to the shape of the lumen of the mold can be easily manufactured. By changing the lumen shape of the mold, catheters having shafts with various cross-sectional shapes can be manufactured.

[0077] A method for manufacturing a catheter according to an embodiment of the present invention will be described below with reference to FIGS. 16 to 31 . FIG. 16 is a side view of a catheter according to an embodiment of the present invention. FIG. 17 is a side view of a mold according to an embodiment of the present invention. FIG. 18 is a cross-sectional view taken along the line XVIII-XVIII of the mold shown in FIG. 17 . FIG. 19 is a cross-sectional view perpendicular to the longitudinal direction illustrating a state in which a first tubular member, having a first elongated member inserted into its lumen, is inserted into the lumen of a mold in a method for manufacturing a catheter according to an embodiment of the present invention. FIG. 20 is a cross-sectional view perpendicular to the longitudinal direction illustrating a state in which an outer member is disposed outside the mold shown in FIG. 19 . FIG. 21 is a cross-sectional view perpendicular to the longitudinal direction of a shaft obtained after the steps of removing the mold and the outer member and the step of removing the first elongated member in a method for manufacturing a catheter according to an embodiment of the present invention. FIG. 22 is a cross-sectional view perpendicular to the longitudinal direction illustrating a state in which a third tubular member is further inserted into the lumen of a mold outside the first tubular member in a method for manufacturing a catheter according to another embodiment of the present invention. FIG. 23 is a cross-sectional view perpendicular to the longitudinal direction illustrating a state in which a second tubular member, a second elongated member, and a third tubular member have been further inserted into the lumen of a mold in a method for manufacturing a catheter according to yet another embodiment of the present invention. FIG. 24 is a cross-sectional view perpendicular to the longitudinal direction of a shaft obtained after removing the mold, outer member, first elongated member, and second elongated member from the state shown in FIG. 23. FIG. 25 is a side view of a mold according to another embodiment of the present invention. FIGS. 26 and 27 are cross-sectional views taken along lines XXVI-XXVI and XXVII-XXVII, respectively, of the mold shown in FIG. 25. FIG. 28 is a side view of a mold according to yet another embodiment of the present invention. FIG. 29 is a cross-sectional view perpendicular to the longitudinal direction illustrating a step of preparing a mold according to one embodiment of the present invention. FIG. 30 is a cross-sectional view perpendicular to the longitudinal direction illustrating a step of preparing a mold according to another embodiment of the present invention. FIG. 31 is a cross-sectional view perpendicular to the longitudinal direction illustrating a step of preparing a mold according to yet another embodiment of the present invention.

[0078] In this specification, the components used in the manufacturing method of a catheter, such as the mold 240, the first tubular member 210, the first elongated member 211, the outer member 250, and the multi-layer body 260, each have a longitudinal direction and a radial direction, but for ease of understanding, the description will be given assuming that all components have the longitudinal direction x1 and radial direction y1 of the mold 240. However, this does not mean that all components are necessarily arranged in the same direction, and the longitudinal direction and radial direction of each component may be different from each other or the same.

[0079] In this specification, when describing a catheter, the direction toward the user's hand in the longitudinal direction x2 is referred to as the proximal side, and the direction opposite the proximal side, i.e., the direction toward the treatment target, is referred to as the distal side. In this specification, the distal end of each member refers to the end located most distally of each member, and the proximal end of each member refers to the end located most proximal of each member. The distal end refers to the distal end and the surrounding area of ​​the distal end, and the proximal end refers to the proximal end and the surrounding area of ​​the proximal end.

[0080] A method for manufacturing a catheter according to an embodiment of the present invention is a method for manufacturing a catheter 300 as shown in Fig. 16. The catheter 300 has a longitudinal direction x2, and the catheter 300 has a shaft 310 extending in the longitudinal direction x2, and the shaft 310 has a lumen 320 extending in the longitudinal direction x2.

[0081] For example, a guide wire that has been inserted in advance into a lesion in a blood vessel such as a coronary artery can be inserted into the lumen 320, allowing the catheter 300 to be delivered to the lesion along the guide wire. Also, for example, an intravascular treatment device such as a balloon catheter or an extension catheter can be inserted into the lumen 320.

[0082] 16, the shaft 310 preferably has a distal opening 320D at the distal end of the lumen 320. The distal opening 320D can serve as an entrance or exit point for members such as a guidewire or a treatment tool.

[0083] In a cross section perpendicular to the longitudinal direction x2, the major axis of the lumen 320 can be, for example, 0.1 mm or more, 0.3 mm or more, 0.5 mm or more, or 3.0 mm or less, 2.0 mm or less, or 1.5 mm or less. This allows a member such as a guidewire to be inserted into the lumen 320, making it easier to insert the catheter 300 into a body cavity. Here, the major axis refers to the length of the longest line segment connecting two points on the outer edge of the lumen 320 and passing through the centroid in a cross section perpendicular to the longitudinal direction x2. Hereinafter, the same applies to the major axes of other members.

[0084] As shown in FIG. 16, the catheter 300 further has a handle 330 disposed proximally of the shaft 310, and it is preferable that the proximal opening 320P of the lumen 320 communicates with the inner cavity of the handle 330.

[0085] The cross-sectional shape of the shaft 310 perpendicular to the longitudinal direction x2 may deviate from a perfect circle or from an ellipse, and the cross-sectional shape of the shaft 310 perpendicular to the longitudinal direction x2 may vary depending on the position in the longitudinal direction x2. A catheter 300 having such a shaft 310 can be manufactured by the following manufacturing method.

[0086] As shown in FIG. 17, first, a resin mold 240 having a longitudinal direction x1 and a radial direction y1 and an inner cavity 240a extending in the longitudinal direction x1 is prepared.

[0087] The cross-sectional shape of the inner cavity 240a of the mold 240 perpendicular to the longitudinal direction x1 may be the same or different along the longitudinal direction x1.

[0088] The resin constituting the mold 240 preferably includes at least one selected from the group consisting of silicone-based resins, synthetic rubbers such as styrene butadiene rubber, chloroprene rubber, butyl rubber, urethane rubber, and acrylonitrile rubber, thermosetting elastomers such as fluorine-based rubber and acrylic rubber, and natural rubber. Among these, the resin constituting the mold 240 is more preferably silicone-based resin.

[0089] As shown in Figure 18, the shape of the lumen 240a of the mold 240 in a cross section perpendicular to the longitudinal direction x1 preferably deviates from a circle. That is, the shape of the lumen 240a of the mold 240 in a cross section perpendicular to the longitudinal direction x1 is preferably not a perfect circle or an ellipse. This makes it possible to easily manufacture a catheter 300 in which the outer shape of the shaft 310 in a cross section perpendicular to the longitudinal direction x2 deviates from a circle. Furthermore, the shape of the lumen 240a of the mold 240 in a cross section perpendicular to the longitudinal direction x1 may vary depending on the position in the longitudinal direction x1. This makes it possible to easily manufacture a catheter 300 in which the cross-sectional shape of the shaft 310 perpendicular to the longitudinal direction x2 varies depending on the position in the longitudinal direction x2.

[0090] In a cross section perpendicular to the longitudinal direction x1, the major axis of the lumen 240a of the mold 240 can be set appropriately depending on the major axis of the shaft 310 of the catheter 300 to be manufactured, and can be, for example, 0.5 mm or more, 0.6 mm or more, 0.7 mm or more, or 2.0 mm or less, 1.5 mm or less, or 1.2 mm or less.

[0091] 19 , a manufacturing method according to an embodiment of the present invention includes the steps of inserting a resin first tubular member 210 into the lumen 240a of a mold 240 and inserting a first elongated member 211 into the lumen 210a of the first tubular member 210. Either the step of inserting the resin first tubular member 210 into the lumen 240a of the mold 240 or the step of inserting the first elongated member 211 into the lumen 210a of the first tubular member 210 may be performed first. However, it is preferable to insert the first tubular member 210 into the lumen 240a of the mold 240 after performing the step of inserting the first elongated member 211 into the lumen 210a of the first tubular member 210. The first elongated member 211 improves the rigidity of the first tubular member 210, making it easier to insert the first tubular member 210 into the lumen 240a of the mold 240.

[0092] The resin constituting the first tubular member 210 preferably includes at least one selected from the group consisting of polyethylene, polyurethane, polyvinyl chloride, polyurethane-based thermoplastic elastomer, styrene-based thermoplastic elastomer, polyamide elastomer, and polyamide. Among these, the resin constituting the first tubular member 210 more preferably includes at least one selected from the group consisting of polyurethane and polyamide elastomer. This allows the resin constituting the shaft 310 of the catheter 300 to be any of the above resins.

[0093] The first elongated member 211 may be a solid elongated member, or may be a hollow elongated member such as a cylinder.

[0094] Examples of materials that can be used to form the first elongated member 211 include metals such as stainless steel, iron, aluminum, titanium, nickel-titanium alloy, cobalt-chromium alloy, and alloys thereof, as well as synthetic resins such as fluorine-based resins such as PTFE, PFA, and ETFE; vinyl chloride-based resins; silicone-based resins; polyimide-based resins; and super engineering plastics such as PEEK, PEI, PAI, PPS, PES, and ultra-high density PE.

[0095] As shown in Figure 20, the manufacturing method of an embodiment of the present invention includes the steps of placing an outer member 250 outside a mold 240 to obtain a multilayer body 260 in which the outer member 250, mold 240, first tubular member 210, and first elongated member 211 are arranged in this order from the outside in the radial direction y1, and heating the multilayer body 260.

[0096] By disposing the outer member 250 outside the mold 240, it is preferable that the swelling of the mold 240 outward in the radial direction y1 when the multilayer body 260 is heated be restricted by the outer member 250, and it is more preferable that the swelling be slightly reduced in diameter by the outer member 250. By slightly reducing the diameter, the resin can be pressed into the inner cavity 240a of the mold 240, and the shape of the inner cavity 240a of the mold 240 is traced, making it easier to mold the first tubular member 210.

[0097] Either the step of inserting the resin first tubular member 210 into the inner cavity 240a of the mold 240 or the step of arranging the outer member 250 outside the mold 240 may be performed first, but it is preferable that the step of inserting the resin first tubular member 210 into the inner cavity 240a of the mold 240 is performed first, followed by the step of arranging the outer member 250 outside the mold 240. In the step of inserting the resin first tubular member 210 into the inner cavity 240a of the mold 240, the elasticity of the mold 240 makes it easy to insert the resin first tubular member 210 into the inner cavity 240a of the mold 240, but by performing the step of arranging the outer member 250 outside the mold 240 later, it is possible to prevent the effect of the elasticity of the mold 240 from being impaired by the restriction of the outer member 250.

[0098] The outer member 250 may be, for example, a heat-shrinkable tube made of a polyolefin resin, a fluorine-based resin, or the like, or a cylindrical body made of a metal such as stainless steel, iron, aluminum, titanium, a nickel-titanium alloy, a cobalt-chromium alloy, or an alloy thereof, and may be a cylindrical body that can be separated in the radial direction y1. If the outer member 250 is a heat-shrinkable tube, the contraction force of the heat-shrinkable tube when the multilayer body 260 is heated can be used to restrict the outward expansion of the mold 240 in the radial direction y1 by the outer member 250. If the outer member 250 is a metallic cylindrical body that can be separated in the radial direction y1, the mold 240 is placed in the inner cavity of the cylindrical body while the cylindrical body is separated in the radial direction y1, and then the cylindrical body is closed, so that the outward expansion of the mold 240 in the radial direction y1 when the multilayer body 260 is heated is preferably restricted by the outer member 250, and more preferably, the expansion is slightly reduced in diameter by the outer member 250. By slightly reducing the diameter, the resin can be pressed into the inner cavity 240a of the mold 240, so that the shape of the inner cavity 240a of the mold 240 is traced, making it easier to mold the first tubular member 210.

[0099] The temperature to which the multilayer body 260 is heated depends on the resin constituting the multilayer body 260, and is preferably a temperature at which the first elongated member 211, the mold 240, and the outer member 250 do not melt, but the first tubular member 210 melts. For example, when stainless steel is used for the first elongated member 211, a silicone-based resin is used for the mold 240, a heat-shrinkable tube made of an olefin-based resin is used for the outer member 250, and a polyamide elastomer is used for the first tubular member 210, the temperature to which the multilayer body 260 is heated is preferably 100 to 300°C, more preferably 150 to 250°C, and even more preferably 170 to 230°C. Furthermore, for example, when stainless steel is used for the first elongated member 211, silicone resin is used for the mold 240, a fluorine-based resin heat-shrinkable tube is used for the outer member 250, and polyamide is used for the first tubular member 210, the temperature to which the multilayer body 260 is heated is preferably 100 to 350° C., more preferably 200 to 320° C., and even more preferably 230 to 300° C. When the temperature to which the multilayer body 260 is heated is within the above range, it becomes easier to mold the first tubular member 210 into a shape that conforms to the shape of the inner cavity 240a of the mold 240 while maintaining the shape of the inner cavity 240a of the mold 240.

[0100] The time for heating the multilayer body 260 is preferably 1 second to 60 seconds, more preferably 5 seconds to 30 seconds, and even more preferably 10 seconds to 20 seconds. When the time for heating the multilayer body 260 is within the above range, it becomes easier to mold the first tubular member 210 into a shape that conforms to the shape of the inner cavity 240a of the mold 240 while maintaining the shape of the inner cavity 240a of the mold 240.

[0101] The method for heating the multilayer body 260 is not particularly limited, but any of the following known methods can be used: a method for heating the multilayer body 260 with a heater placed near the multilayer body 260; a method for heating the multilayer body 260 with hot air or a halogen lamp; a method for placing the multilayer body 260 in a furnace; a method for heating the multilayer body 260 by induction heating the outer member 250 if the outer member 250 is made of metal; a method for heating the outer member 250 with a cartridge heater, hand heater, or the like.

[0102] The method for manufacturing a catheter according to an embodiment of the present invention includes the steps of heating the multi-layer body 260 at the above temperature for the above period of time, and then removing the mold 240 and the outer member 250, and removing the first elongated member 211. This allows the manufacture of a shaft 310 having a lumen 320 as shown in FIG.

[0103] The step of removing the mold 240 and the outer member 250 and the step of removing the first elongated member 211 may be performed in either order, but it is preferable to perform the step of removing the first elongated member 211 after the step of removing the mold 240 and the outer member 250. Since the first elongated member 211 remains inserted, the rigidity of the first tubular member 210 is maintained, which makes it easier to remove the mold 240 and the outer member 250.

[0104] The step of removing the mold 240 and the outer member 250 and the step of removing the first elongated member 211 are preferably performed after the heated multilayer body 260 in the step of heating the multilayer body 260 has cooled to below its deflection temperature under load or its Vicat softening point temperature, more preferably after it has cooled to below 60°C, and even more preferably after it has reached room temperature.

[0105] 18 and 20 , the size of the lumen 240a of the mold 240 after the step of obtaining the multi-layer body 260 is preferably the same as or expanded to the size of the lumen 240a of the mold 240 when nothing is inserted into the lumen 240a of the mold 240. It is more preferable that the size of the lumen 240a of the mold 240 after the step of obtaining the multi-layer body 260 is expanded compared to the size of the lumen 240a of the mold 240 when nothing is inserted into the lumen 240a of the mold 240. This allows the first tubular member 210 to be pressed against the lumen 240a of the mold 240, making it easier to mold the first tubular member 210 into a shape that follows the shape of the lumen 240a of the mold 240.

[0106] It is preferable that the melting point M of the resin constituting the mold 240 is higher than the melting point M1 of the resin constituting the first tubular member 210, and that the heating temperature in the step of heating the multilayer body 260 is higher than the melting point M1 but lower than the melting point M. This makes it easier to mold the first tubular member 210 into a shape that conforms to the shape of the inner cavity 240a of the mold 240 while maintaining the shape of the inner cavity 240a of the mold 240.

[0107] The melting point M of the resin that forms the mold 240 is preferably 200 to 350°C. The melting point M1 of the resin that forms the first cylindrical member 210 is preferably 80 to 300°C.

[0108] As shown in Figure 18, in a cross section perpendicular to the longitudinal direction x1, when nothing is inserted into the inner cavity 240a of the mold 240, the inner cavity 240a of the mold 240 has a first axis 240a1 that is the longest of the line segments that pass through the centroid 200O of the inner cavity 240a of the mold 240 and connect two points on the inner wall of the mold 240, and a second axis 240a2 that passes through the midpoint 200M of the first axis 240a1, is perpendicular to the first axis 240a1, and is shorter than the first axis 240a1, and it is preferable that the inner wall of the mold 240 has a portion that is located outside the imaginary ellipse 200VO whose major axis is the first axis 240a1 and whose minor axis is the second axis 240a2. By configuring the cross-sectional shape of the mold 240 as described above, the cross-sectional area of ​​the shaft 310 of the resulting catheter 300 can be reduced, thereby reducing the area where the shaft 310 comes into contact with the wall of a body cavity such as a blood vessel, and improving the insertability of the catheter 300. Furthermore, because the second axis 240a2 is shorter than the first axis 240a1, the portion of the shaft 310 formed by the shorter end of the second axis 240a2 can be easily curved so that it is on the inside or outside of the curve. Therefore, the shaft 310 can easily follow the curve of a body cavity such as a blood vessel, further improving the insertability of the catheter 300. Furthermore, since the inner wall of the mold 240 has a portion located outside the imaginary ellipse 200VO whose major axis is the first axis 240a1 and whose minor axis is the second axis 240a2, the resulting catheter 300 can be configured to have a portion of the shaft 310 around the lumen 320 of the shaft 310 where the wall thickness is thick, thereby preventing a guide wire or other therapeutic instrument inserted into the lumen 320 from breaking through the wall of the shaft 310 and improving safety.

[0109] As described above, according to the method for manufacturing a catheter according to an embodiment of the present invention, it is possible to easily manufacture a catheter 300 in which the outer shape of the shaft 310 in a cross section perpendicular to the longitudinal direction x2 deviates from a circular shape, or a catheter 300 in which the cross-sectional shape of the shaft 310 perpendicular to the longitudinal direction x2 varies depending on the position in the longitudinal direction x2, thereby making it possible to both improve the insertability of the catheter 300 and prevent it from breaking through.

[0110] In the step of inserting the first tubular member 210 into the lumen 240a of the mold 240, it is preferable that the first tubular member 210 be visible from outside the mold 240. By being able to see the first tubular member 210 from outside the mold 240, it is possible to confirm whether the first tubular member 210 is properly positioned in the lumen 240a of the mold 240, thereby improving the accuracy and efficiency when manufacturing the catheter 300. In order to make the first tubular member 210 visible from outside the mold 240, it is preferable to use a silicone-based resin or a urethane-based resin as the resin constituting the mold 240, and it is more preferable to use a silicone-based resin.

[0111] 22 , the method for manufacturing a catheter according to an embodiment of the present invention further includes, before the step of heating the multi-layer body 260, a step of inserting a third tubular member 230 into the inner cavity 240a of the mold 240 and outside the first tubular member 210, and the first tubular member 210 is preferably disposed in the inner cavity 230a of the third tubular member 230. As a result, the multi-layer body 260 preferably has a configuration in which the outer member 250, the mold 240, the third tubular member 230, the first tubular member 210, and the first elongated member 211 are arranged in this order from the outside in the radial direction y1. By disposing the third tubular member 230 outside the first tubular member 210, the third tubular member 230 can be welded to the outside of the first tubular member 210 when the multi-layer body 260 is heated, making it easier to mold the first tubular member 210. The shaft 310 of the resulting catheter 300 is preferably composed of a first tubular member 210 and a third tubular member 230 .

[0112] The material constituting the third cylindrical member 230 preferably includes at least one selected from the group consisting of polyethylene, polyurethane, polyurethane-based thermoplastic elastomer, styrene-based thermoplastic elastomer, polyamide elastomer, and polyamide. In particular, the material constituting the third cylindrical member 230 more preferably includes at least one selected from the group consisting of polyurethane and polyamide elastomer.

[0113] When the method for manufacturing a catheter according to an embodiment of the present invention further includes, before the step of heating the multilayer body 260, a step of inserting a third tubular member 230 into the lumen 240a of the mold 240 and outside the first tubular member 210, and the first tubular member 210 is disposed in the lumen 230a of the third tubular member 230, the resin constituting the first tubular member 210 may include at least one selected from the group consisting of, for example, polyolefin-based resins such as polyethylene, polypropylene, ethylene-propylene copolymers, and mixtures thereof; fluorine-based resins such as polytetrafluoroethylene, tetrafluoroethylene-perfluoroalkyl vinyl ether copolymers, tetrafluoroethylene-hexafluoropropylene copolymers, tetrafluoroethylene-ethylene copolymers, polyvinylidene fluoride, polychlorotrifluoroethylene, ethylene-chlorotrifluoroethylene copolymers, and mixtures thereof; polyamide-based resins; polyester-based resins; polyurethane-based resins; vinyl chloride-based resins; silicone-based resins; and natural rubber.

[0114] As shown in Figures 23 and 24, the method for manufacturing a catheter according to an embodiment of the present invention further includes, before the step of heating the multilayer body 260, the steps of inserting a second tubular member 220 into the inner cavity 240a of the mold 240 so that the second tubular member 220 is aligned in the radial direction y1 outside the first tubular member 210, inserting a second elongated member 221 into the inner cavity 220a of the second tubular member 220, and inserting a third tubular member 230 into the inner cavity 240a of the mold 240 outside the first tubular member 210 and the second tubular member 220, and further includes the step of removing the second elongated member 221, and it is preferable that in the step of inserting the third tubular member 230, the first tubular member 210 and the second tubular member 220 are arranged in the inner cavity 230a of the third tubular member 230. In this case, it is preferable that the multilayer body 260 has a portion in at least a part of the circumferential direction of the mold 240, in which the outer member 250, the mold 240, the first cylindrical member 210, and the first elongated member 211 are arranged in this order from the outside in the radial direction y1. Also, in this case, it is preferable that the multilayer body 260 has a portion in at least a part of the circumferential direction of the mold 240, in which the outer member 250, the mold 240, the second cylindrical member 220, and the second elongated member 221 are arranged in this order from the outside in the radial direction y1.

[0115] By further inserting the second tubular member 220, with the second elongate member 221 inserted into the lumen 220a, into the lumen 240a of the mold 240, it is possible to manufacture a multi-lumen shaft 310 having a first lumen 321 and a second lumen 322, as shown in Fig. 24. Although not shown, it is also possible to manufacture a shaft 310 having even more lumens by inserting yet another tubular member into the lumen 240a of the mold 240.

[0116] As shown in Figure 24, by inserting a third tubular member 230 outside the first tubular member 210 and the second tubular member 220, the shaft 310 can be molded so that the first tubular member 210 and the second tubular member 220 are inside the third tubular member 230, and the inner cavity 210a of the first tubular member 210 becomes the first lumen 321 and the inner cavity 220a of the second tubular member 220 becomes the second lumen 322.

[0117] The resin constituting the first cylindrical member 210 can be referred to for the material constituting the second cylindrical member 220 .

[0118] The material constituting the first tubular member 210 and the material constituting the second tubular member 220 may be the same or different. For example, by using different materials for the first tubular member 210 and the second tubular member 220, the flexibility of the first lumen 321 and the second lumen 322 can be changed. This allows for hardness directionality to be imparted to the shaft 310, thereby further improving the flexibility of the shaft 310. Furthermore, when the multilayer body 260 is heated, depending on the materials constituting the first tubular member 210, the second tubular member 220, and the third tubular member 230, the resin may flow, making it difficult to maintain the lumens. However, using a material with a relatively high melting point for the first tubular member 210 or the second tubular member 220 makes it easier to form the lumens.

[0119] 25 to 27 , in the longitudinal direction x1, the mold 240 has a first end 240D and a second end 240P, and the mold 240 has a first region 240A and a second region 240B that is closer to the second end 240P than the first region 240A. In a cross section perpendicular to the longitudinal direction x1, the area of ​​the lumen 240a of the mold 240 in the first region 240A is preferably smaller than the area of ​​the lumen 240a of the mold 240 in the second region 240B. In the mold 240, the average value of the area in the longitudinal direction x of the first region 240A may be smaller than the average value of the area in the longitudinal direction x of the second region 240B, the area may gradually decrease from the first region 240A to the second region 240B, or the area may decrease discontinuously at the boundary between the first region 240A and the second region 240B. For example, when the catheter 300 has a tip at the distal end, the tip is often configured to have a smaller cross-sectional area than the cross-sectional area of ​​the shaft 310 proximal to the tip, thereby improving the insertability of the catheter 300. In a cross section perpendicular to the longitudinal direction x1, the area of ​​the lumen 240a of the mold 240 in the first region 240A is smaller than the area of ​​the lumen 240a of the mold 240 in the second region 240B, so that such a tip can also be manufactured by the catheter manufacturing method according to an embodiment of the present invention.

[0120] Alternatively, not limited to the tip, the cross-sectional area of ​​the shaft 310 itself perpendicular to the longitudinal direction x2 may vary depending on the position in the longitudinal direction x2, and a catheter having such a shaft 310 can also be manufactured by using the mold 240 of the above configuration.

[0121] As shown in Figures 26 and 27, the bore 240a of the mold 240 may be circular.

[0122] As shown in Figure 28, in the longitudinal direction x1, the mold 240 has a first end 240D and a second end 240P, and the mold 240 has a first region 240A, a second region 240B closer to the second end 240P than the first region 240A, and a third region 240C closer to the second end 240P than the second region 240B, and in a cross section perpendicular to the longitudinal direction x1, it is preferable that the area of ​​the inner cavity 240a of the mold 240 in the first region 240A is smaller than the area of ​​the inner cavity 240a of the mold 240 in the second region 240B, and that the area of ​​the inner cavity 240a of the mold 240 in the third region 240C is smaller than the area of ​​the inner cavity 240a of the mold 240 in the second region 240B. As a result, the cross-sectional area perpendicular to the longitudinal axis direction x2 of the shaft 310 molded using the first region 240A and the third region 240C is smaller than the cross-sectional area perpendicular to the longitudinal axis direction x2 of the shaft 310 molded using the second region 240B.Therefore, in the distal and proximal regions of the shaft 310, the gap (clearance) formed between the shaft 310 and the wall of a body cavity, such as a blood vessel, into which the catheter 300 is inserted, is larger than in the intermediate region of the shaft 310, thereby reducing the contact area between the body cavity wall and the shaft 310 and improving the insertability of the catheter 300.

[0123] Alternatively, for example, a manufacturing method using the above-mentioned mold 240 can be used to manufacture a catheter 300 having a tip at the distal end of the shaft 310 with a small cross-sectional area perpendicular to the longitudinal axis direction x2 at the distal and proximal ends and a large cross-sectional area in the middle portion.

[0124] As shown in Figure 29, the step of preparing the mold 240 preferably includes the steps of preparing a resin tube 241, inserting a core material 243 into the inner cavity 241a of the resin tube 241, injecting a curable resin 244 inside the resin tube 241 in the radial direction y1 but outside the core material 243, and removing the core material 243.

[0125] The resin constituting the resin tube 241 and the hardening resin 244 can be referred to the resin constituting the mold 240 described above.

[0126] The resin constituting the resin tube 241 and the resin constituting the curable resin 244 are preferably the same, but may be different as long as they are compatible to a certain extent. This allows the resin tube 241 and the curable resin 244 to be integrated to form the mold 240.

[0127] Materials that can be used to form the core 243 include metals such as stainless steel, iron, aluminum, titanium, nickel-titanium alloys, cobalt-chromium alloys, and alloys of these; thermoplastic resins such as polyethylene, polypropylene, polyacetal, and polyamide; thermosetting resins such as phenolic resins, epoxy resins, and melamine resins; and synthetic resins such as super engineering plastics such as PEEK, PTFE, PEI, PAI, and PPS.

[0128] As shown in Figure 30, the step of preparing the mold 240 preferably includes the steps of preparing a mold 242 having an inner cavity 242a extending in the longitudinal direction x1, inserting a core material 243 into the inner cavity 242a of the mold 242, injecting a curable resin 244 inside the mold 242 but outside the core material 243 in the radial direction y1, and removing the mold 242 and the core material 243.

[0129] As shown in FIG. 31 , the mold 242 may have a mold first part 242A and a mold second part 242B, and the mold first part 242A and the mold second part 242B may be configured to be separable in the radial direction y1. Being separable in the radial direction y1 makes it easier to insert a core material 243 into the inner cavity 242a of the mold 242. Furthermore, being separable in the radial direction y1 makes it easier to remove the mold 242 and the core material 243 to obtain the casting mold 240. While FIGS. 30 and 31 show an embodiment in which the shape of the outer edge of the mold 242 in a cross section perpendicular to the longitudinal direction x1 is circular, the shape of the outer edge of the mold 242 in a cross section perpendicular to the longitudinal direction x1 does not necessarily have to be circular and may be a polygon such as a rectangle, a polygon with rounded corners, a circle, or another irregular shape.

[0130] Examples of materials that can be used to form the mold 242 include metals such as stainless steel, iron, aluminum, titanium, nickel-titanium alloys, cobalt-chromium alloys, and alloys thereof. Alternatively, the mold 242 may be made of synthetic resins such as super engineering plastics such as PTFE, PEEK, PEI, PAI, and PPS.

[0131] By injecting hardenable resin 244 between mold 242 and core material 243 and then removing mold 242 and core material 243, a mold 240 made of a single material, hardenable resin 244, can be easily obtained.

[0132] It is preferable that the curable resin 244 has releasability from the first cylindrical member 210. Alternatively, the first cylindrical member 210 may have releasability from the curable resin 244. This allows the mold 240 to be easily removed from the first cylindrical member 210 in the step of removing the mold 240.

[0133] When the third cylindrical member 230 is used, it is preferable that the curable resin 244 also has releasability with respect to the third cylindrical member 230. This allows the mold 240 to be easily removed from the third cylindrical member 230 in the step of removing the mold 240.

[0134] The catheter 300 manufactured by the catheter manufacturing method according to an embodiment of the present invention can be preferably used for the treatment of dilating stenosis or occlusion in passages such as blood vessels in the body, and can be preferably used in performing coronary intervention (PCI) for lesions at the bifurcation of coronary arteries, etc.

[0135] This application claims the benefit of priority based on Japanese Patent Application No. 2024-048355 filed on March 25, 2024, and Japanese Patent Application No. 2024-048356 filed on March 25, 2024. The entire contents of the specifications of Japanese Patent Application No. 2024-048355 filed on March 25, 2024, and Japanese Patent Application No. 2024-048356 filed on March 25, 2024 are incorporated herein by reference.

[0136] 10: First lumen 10C: Centroid of first lumen 10D: Distal opening of first lumen 10P: Proximal opening of first lumen 11: First tubular member 12: Reinforcing member 20: Second lumen 20C: Centroid of second lumen 20D: Distal opening of second lumen 20P: Proximal opening of second lumen 21: Second tubular member 22: Reinforcing member 30: Shaft 30S: Straight portion 31: First part 32: Second part 40: Guidewire 50: Handle 60: Outer member 60A: Lumen 100: Catheter 101: Distal region 102: Intermediate region 103: Proximal region 210: First tubular member 210a: Lumen of first tubular member 211: First elongated member 220: Second tubular member 220a: Inner cavity of second tubular member 221: Second elongated member 230: Third tubular member 230a: Inner cavity of third tubular member 240: Mold 240a: Inner cavity of mold 240a1: First axis 240a2: Second axis 240A: First region 240B: Second region 240C: Third region 240D: First end of mold 240P: Second end of mold 241: Resin tube 241a: Inner cavity of resin tube 242: Mold 242a: Inner cavity of mold 242A: First part of mold 242B: Second part of mold 243: Core material 244: Curable resin 250: Outer member 260: Multilayer body 200O: Centroid of inner cavity of mold 200M: Midpoint of first axis 200VO: Virtual ellipse 300: Catheter 310: Shaft 320: Lumen 321: First lumen 322: Second lumen 320D: Distal opening of lumen 320P: Proximal opening of lumen 330: Handle L ＡＢ : Length of line segment AB L ＣＤ : Length of line segment CD O: Midpoint of line segment AB R1: First region R2: Second region S1: Straight line connecting the centroid of the first lumen and the centroid of the second lumen S2: Straight line passing through the midpoint of line segment AB and perpendicular to line segment AB VO: Virtual ellipse x: Longitudinal direction of catheter x1: Longitudinal direction of mold x2: Longitudinal direction of catheter y1: Radial direction of mold

Claims

1. A catheter having a longitudinal direction, comprising a shaft extending in the longitudinal direction, wherein the shaft has a first lumen and a second lumen extending in the longitudinal direction, wherein, in a cross section perpendicular to the longitudinal direction, when points A and B are defined as two points where a line connecting the centroid of the first lumen and the centroid of the second lumen intersects with the outer edge of the shaft, and points C and D are defined as two points where a line passing through the midpoint of a line segment AB and perpendicular to the line segment AB intersects with the outer edge of the shaft, line segment CD is shorter than line segment AB, and the outer edge of the shaft has a first portion located outside an imaginary ellipse whose major axis is line segment AB and whose minor axis is line segment CD.

2. The catheter according to claim 1, wherein the outer edge of the shaft has a second portion located inside the imaginary ellipse in a cross section perpendicular to the longitudinal direction.

3. A catheter as described in claim 2, wherein a guide wire is inserted through the first lumen, and in a cross section perpendicular to the longitudinal direction, when the side of point A relative to line segment CD is defined as a first region and the side of point B relative to line segment CD is defined as a second region, the first lumen is disposed in the first region and the second lumen is disposed in the second region, the first portion and the second portion are disposed in the first region, and the first portion is disposed in the second region.

4. A catheter as described in claim 2, wherein a guide wire is inserted through the first lumen, and in a cross section perpendicular to the longitudinal direction, when the side of point A relative to line segment CD is defined as a first region and the side of point B relative to line segment CD is defined as a second region, the first lumen is disposed in the first region and the second lumen is disposed in the second region, only the second portion is disposed in the first region, and the first portion is disposed in the second region.

5. A catheter as described in claim 2, wherein a guide wire is inserted through the first lumen, and in a cross section perpendicular to the longitudinal direction, when the side of point A relative to line segment CD is defined as a first region and the side of point B relative to line segment CD is defined as a second region, the first lumen is disposed in the first region, the second lumen is disposed in the second region, the first portion is disposed in the first region, and the first portion and the second portion are disposed in the second region.

6. A catheter as described in claim 2, wherein a guide wire is inserted through the first lumen, and in a cross section perpendicular to the longitudinal direction, when the side of point A relative to line segment CD is defined as a first region and the side of point B relative to line segment CD is defined as a second region, the first lumen is disposed in the first region, the second lumen is disposed in the second region, the first portion is disposed in the first region, and only the second portion is disposed in the second region.

7. The catheter according to claim 1, wherein, in a cross section perpendicular to the longitudinal direction, the outer edge of the shaft does not have a portion located inside the imaginary ellipse.

8. A catheter according to any one of claims 1 to 7, wherein the shaft has a first tubular member disposed inside the shaft, and the first lumen is the inner cavity of the first tubular member.

9. The catheter of claim 8, wherein the shaft has a second tubular member disposed inside the shaft, and the second lumen is the inner cavity of the second tubular member.

10. A catheter according to any one of claims 1 to 7, wherein the outer edge of the shaft has a straight portion in a cross section perpendicular to the longitudinal direction.

11. A catheter according to any one of claims 1 to 7, wherein, in the longitudinal direction, the distal end of the catheter has a distal region, an intermediate region located proximal to the distal region, and a proximal region located proximal to the intermediate region, and in a cross section perpendicular to the longitudinal direction, the area defined by the outer edge of the shaft in the distal region is smaller than the area defined by the outer edge of the shaft in the intermediate region, and the area defined by the outer edge of the shaft in the proximal region is smaller than the area defined by the outer edge of the shaft in the intermediate region.

12. A method for manufacturing a catheter, comprising the steps of: preparing a resin mold having a longitudinal direction and a radial direction and an inner cavity extending in the longitudinal direction; inserting a first tubular member made of resin into the inner cavity of the mold; inserting a first elongated member into the inner cavity of the first tubular member; arranging an outer member outside the mold to obtain a multilayer body in which the outer member, the mold, the first tubular member, and the first elongated member are arranged in this order from the radial outside; heating the multilayer body; removing the mold and the outer member; and removing the first elongated member, wherein the mold is elastic.

13. A method for manufacturing a catheter according to claim 12, wherein the size of the lumen of the mold after the step of obtaining the multilayer body is the same as the size of the lumen of the mold when nothing is inserted into the lumen of the mold or is expanded.

14. A method for manufacturing a catheter as described in claim 12 or 13, wherein the melting point M of the resin constituting the mold is higher than the melting point M1 of the resin constituting the first tubular member, and the heating temperature in the step of heating the multilayer body is higher than the melting point M1 but lower than the melting point M.

15. A method for manufacturing a catheter as described in claim 12 or 13, wherein, in a cross section perpendicular to the longitudinal direction, when nothing is inserted into the inner cavity of the mold, the inner cavity of the mold has a first axis that is the longest of the line segments that passes through the centroid of the inner cavity of the mold and connects two points on the inner wall of the mold, and a second axis that passes through the midpoint of the first axis, is perpendicular to the first axis, and is shorter than the first axis, and the inner wall of the mold has a portion that is located outside an imaginary ellipse whose major axis is the first axis and whose minor axis is the second axis.

16. A method for manufacturing a catheter according to claim 12 or 13, wherein in the step of inserting the first tubular member into the lumen of the mold, the first tubular member is visible from outside the mold.

17. A method for manufacturing a catheter as described in claim 12 or 13, further comprising the step of inserting a third tubular member into the cavity of the mold and outside the first tubular member before the step of heating the multilayer body, and the first tubular member is disposed in the cavity of the third tubular member.

18. A method for manufacturing a catheter as described in claim 12 or 13, further comprising, before the step of heating the multilayer body, the steps of inserting a second tubular member into the inner cavity of the mold so that it is aligned radially outside the first tubular member, inserting a second elongated member into the inner cavity of the second tubular member, and inserting a third tubular member into the inner cavity of the mold so that it is aligned radially outside the first tubular member and the second tubular member, and further comprising the step of removing the second elongated member, and in the step of inserting the third tubular member, the first tubular member and the second tubular member are arranged in the inner cavity of the third tubular member.

19. A method for manufacturing a catheter as described in claim 12 or 13, wherein the mold has a first end and a second end in the longitudinal direction, the mold has a first region and a second region closer to the second end than the first region, and in a cross section perpendicular to the longitudinal direction, the area of ​​the lumen of the mold in the first region is smaller than the area of ​​the lumen of the mold in the second region.

20. A method for manufacturing a catheter as described in claim 12 or 13, wherein the mold has a first end and a second end in the longitudinal direction, a first region, a second region closer to the second end than the first region, and a third region closer to the second end than the second region, and in a cross section perpendicular to the longitudinal direction, the area of ​​the lumen of the mold in the first region is smaller than the area of ​​the lumen of the mold in the second region, and the area of ​​the lumen of the mold in the third region is smaller than the area of ​​the lumen of the mold in the second region.

21. A method for manufacturing a catheter as described in claim 12 or 13, wherein the step of preparing a mold includes the steps of preparing a resin tube, inserting a core material into the inner cavity of the resin tube, injecting a hardening resin inside the resin tube in the radial direction but outside the core material, and removing the core material.

22. A method for manufacturing a catheter as described in claim 12 or 13, wherein the step of preparing a mold includes the steps of preparing a metal mold having an inner cavity extending in the longitudinal direction, inserting a core material into the inner cavity of the mold, injecting a curable resin inside the mold in the radial direction but outside the core material, and removing the mold and the core material.

23. A method for manufacturing a catheter according to claim 21, wherein the curable resin has releasability from the first cylindrical member.

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