JP7009368B2 - Manufacturing method of suction catheter and suction catheter - Google Patents

Description

One aspect of the present invention relates to a suction catheter and a method for manufacturing a suction catheter that sucks and removes a substance in the body to the outside of the body.

A suction catheter that is introduced into the body and sucks and removes substances inside the body by the negative pressure applied from the hand end of the catheter is known. As such a suction catheter, for example, in Patent Document 1, a thrombus suction catheter that introduces a tube having a suction port on the distal side into a blood vessel to reach the lesion site and sucks and removes a thrombus from the suction port. Is disclosed.

Japanese Unexamined Patent Publication No. 2007-236633

In such a catheter, it is required to suppress the occlusion of the lumen due to the aspirated thrombus. Therefore, a catheter with an increased inner diameter of the lumen has been proposed. A catheter having a large inner diameter of the lumen has a high suction performance, and it is considered that the occlusion of the lumen is suppressed. However, considering the peripheral reachability of the suction port of the catheter, further improvement is required.

Therefore, an object of one aspect of the present invention is to provide a suction catheter and a method for manufacturing a suction catheter that can improve the suction efficiency.

The suction catheter according to one aspect of the present invention comprises a tube having a lumen extending from the proximal side to the distal side and a suction port formed on the distal side of the lumen, the suction port having a lumen extending. In the arrangement of the tube, which has a portion inclined with respect to the plane orthogonal to the first direction, the distal end of the suction port is on the upper side in the vertical direction, and the proximal end of the suction port is on the lower side in the vertical direction. When the cross section orthogonal to the first direction of the lumen at the first position where the proximal end of the suction port is located in the direction is the first cross section, the first cross section has the maximum length in the width direction orthogonal to the vertical direction. The large part is located below the vertical center position in the first cross section.

A substance such as a thrombus or a foreign substance sucked by the suction catheter is sucked into the lumen from the proximal side portion in the first direction of the suction port. In other words, when the tube arranged as described above is viewed from the side orthogonal to the first direction, the substance sucked by the suction catheter is sucked into the lumen from the lower portion of the suction port of the tube. In the suction catheter according to one aspect of the present invention, when the tube arranged as described above is viewed from the first direction, the maximum width portion in the first cross section is lower than the vertical center position in the first cross section. Since it is formed so as to be located on the side, the part where the substance is sucked into the lumen is wide. Therefore, the substance is not caught in the portion of the suction port where the substance is first sucked into the lumen. As a result, the suction efficiency can be improved. It should be noted that the orthogonality referred to here includes substantially orthogonality.

In the suction catheter according to one aspect of the present invention, the first cross section may have a bottom extending in the width direction at the lower end in the vertical direction. In the suction catheter having this configuration, the bottom where the substance is most sucked is widened at the suction port, so that the substance can be sucked more effectively.

In the suction catheter according to one aspect of the present invention, the maximum length in the vertical direction of the first cross section may be shorter than the maximum length in the width direction. The first cross section of the lumen is a so-called horizontally long shape. For this reason, the shape balance is better than that of a circular lumen having the same circumference, so that the resistance at the time of inserting the catheter is reduced and the peripheral reachability of the catheter is improved.

In the suction catheter according to one aspect of the present invention, the lumen may have a first cross-sectional shape at a first position extending proximally for a predetermined distance. With the suction catheter having the above configuration, the substance can be sucked more smoothly.

In the suction catheter according to one aspect of the present invention, the tube changes its cross section from the first cross section to the second cross section having a shape different from the first cross section at a position proximal to the first position in the first direction. It may further have a cross-section switching portion. In the suction catheter having this configuration, the sucked suction substance easily collides with the inner surface of the tube, and the vibration due to the collision of the suction substance with the shaft becomes strong. Therefore, the operator of the suction catheter can sense the vibration. As a result, the operator can grasp the suction status of the substance.

In the suction catheter according to one aspect of the present invention, the cross-section switching portion may change the cross-section from the first cross-section to the second cross-section having a different shape and cross-sectional area from the first cross-section. With the suction catheter of this configuration, the operator can grasp the suction status of the substance.

In the suction catheter according to one aspect of the present invention, the end side of the cross-section switching portion may be located within 20 mm from the first position in the first direction. With the suction catheter having this configuration, it becomes possible to more reliably suppress the obstruction in the vicinity of the suction port, and it becomes more reliable to apply vibration to the tube.

In the suction catheter according to one aspect of the present invention, the cross-section switching portion may be a taper formed on at least a part of the inner surface forming the lumen. With the suction catheter having this configuration, the cross-section switching portion can be easily formed.

In the suction catheter according to one aspect of the present invention, the end portion between the inner surface of the tube and the outer surface of the tube on either the upper side or the lower side in the vertical direction of the suction port is concave or convex with respect to the suction surface forming the suction port. It may be.

A substance such as a thrombus or a foreign substance sucked by the suction catheter is sucked into the lumen from the proximal side portion in the first direction of the suction port. In other words, when the tube arranged as described above is viewed from the side orthogonal to the first direction, the substance sucked by the suction catheter is sucked into the lumen from the lower portion of the suction port of the tube. In the suction catheter according to one aspect of the present invention, in the arrangement of the tube as described above, the end portion between the inner surface of the tube and the outer surface of the tube on either the upper side or the lower side in the vertical direction of the suction port forms the suction port. It is concave or convex with respect to the suction surface. Therefore, the thrombus easily enters in the convex portion, and the thrombus in contact with the edge of the tube is cut in the concave portion, so that the thrombus can be easily sucked. As a result, clogging of the lumen by the suction substance can be suppressed.

In the suction catheter according to one aspect of the present invention, the shape of the portion concave or convex with respect to the suction surface forming the suction port may be defined by a curved surface. This makes it easier to aspirate the thrombus that has approached the suction port. In addition, damage to blood vessels can be suppressed.

In the suction catheter according to one aspect of the present invention, the end portion between the inner surface of the tube and the outer surface of the tube below the vertical direction of the suction port may be convex with respect to the suction surface forming the suction port. .. With a suction catheter of this configuration, thrombi can easily enter the lumen.

In the suction catheter according to one aspect of the present invention, the end portion between the inner surface of the tube and the outer surface of the tube above the vertical direction of the suction port may be concave with respect to the suction surface forming the suction port. .. In the suction catheter of this configuration, the thrombus in contact with the edge of the tube is cut, so that the thrombus can be easily sucked.

In the suction catheter according to one aspect of the present invention, the straight line on the suction surface, and when the straight line connecting the upper end of the tube and the lower end of the tube is used as the reference line, the upper end of the suction port in the vertical direction is the reference. It is concave in line symmetry with respect to the line, and the lower end portion of the suction port in the vertical direction may be convex in line symmetry with respect to the reference line.

In the suction catheter according to one aspect of the present invention, in the cross section when the tube is cut in the first direction, the first proximal end on the outer surface side of the end portion in the vertical lower direction of the lumen is the second on the inner surface side of the end portion. Located proximal to one distal end, the straight line connecting the first proximal end and the first distal end is tilted in the range of 2 ° or more and 60 ° or less with respect to the first direction, and is rumen. The second distal end on the outer surface side of the end in the vertical direction is located distal to the second proximal end on the inner surface side of the end, and the second distal end and the second proximal end are located. The straight line connecting the two may be inclined in a range of 2 ° or more and 60 ° or less with respect to the first direction. The suction catheter having such a structure has a sharply pointed shape in the direction in which the substance is sucked. The substance sucked into the suction port is shredded by such sharp edges. As a result, it is possible to prevent the lumen from being blocked by a large substance being caught in the vicinity of the suction port.

In the suction catheter according to one aspect of the present invention, in the cross section when the tube is cut in the first direction, the first proximal end on the outer surface side of the end portion in the vertical lower direction of the lumen is the second on the inner surface side of the end portion. Located proximal to one distal end, the second distal end on the outer surface side of the end vertically above the rumen is located distal to the second proximal end on the inner surface side of the end. However, the end portion between the inner surface of the tube and the outer surface of the tube below the vertical direction of the suction port is concave or convex with respect to the straight line connecting the first proximal end and the first distal end. The end portion between the inner surface of the tube and the outer surface of the tube above the vertical direction of the suction port may be concave or convex with respect to the straight line connecting the second distal end and the second proximal end. This makes it easier to suck the thrombus that has approached the suction port.

In the suction catheter according to one aspect of the present invention, the curvature at the proximal end of the suction port may be smaller than the curvature at the distal end when the suction port is viewed from below in the vertical direction. In a suction catheter having such a configuration, when the suction port is viewed from below in the vertical direction, the curvature (degree of bending) at the proximal end of the suction port is smaller than the curvature at the distal end, that is, suction. The radius of curvature at the proximal end of the mouth is greater than the radius of curvature at the distal end. Therefore, since the effective portion for cutting the thrombus becomes large in the suction port, it is easy to cut the thrombus. The curvature referred to here includes the case where the curvature is 0, that is, the case where the curvature is a straight line. As a result, clogging of the lumen by the suction substance can be suppressed.

In the suction catheter according to one aspect of the present invention, when the suction port is viewed from below in the vertical direction, the proximal end of the suction port is linear in the width direction orthogonal to both the first direction and the vertical direction. May extend to. In this suction catheter configuration, the proximal end of the suction port extends linearly in the width direction, making it easier to cut the thrombus. As a result, clogging of the lumen by the suction substance can be suppressed. Orthogonality here includes substantially orthogonality.

The method for manufacturing a suction catheter according to one aspect of the present invention is a method for manufacturing a suction catheter provided with a tube having a suction port for a substance on the distal side, and in an insertion step of inserting a core material into the tube and an insertion step. A deformation step of deforming the tube into which the core material is inserted, a cutting step of cutting one end of the deformed tube in the deformation step so as to be inclined with respect to a plane orthogonal to the first direction in which the lumen extends, and a cutting step. After that, it includes a removal step of removing the core material from the tube.

In the tube manufactured by the above-mentioned method for manufacturing a suction catheter, in the above-mentioned arrangement of the tube, the end portion between the inner surface of the tube and the outer surface of the tube on either the upper side or the lower side in the vertical direction of the suction port is the suction port. It is concave or convex with respect to the suction surface forming the above. Therefore, the thrombus easily enters in the convex portion, and the thrombus in contact with the edge of the tube is cut in the concave portion, so that the thrombus can be easily sucked. As a result, clogging of the lumen by the suction substance can be suppressed.

According to one aspect of the present invention, suction efficiency can be improved.

FIG. 1 is a cross-sectional view of the suction catheter according to the embodiment when the suction catheter is cut along the first direction. FIG. 2 is a diagram showing a cross-sectional configuration taken along the line AA in FIG. FIG. 3 is a diagram showing a cross-sectional configuration along the DD line in FIG. FIG. 4A is a diagram showing a cross-sectional structure taken along the line CC in FIG. 1, and FIG. 4B is a diagram showing a cross-sectional structure taken along the line BB in FIG. FIG. 5 is a bottom view of the suction port of the suction lumen of the suction catheter according to the embodiment as viewed from below in the vertical direction. FIG. 6 is a bottom view of a suction port in a suction lumen according to a different embodiment as viewed from below in the vertical direction. FIG. 7 is a perspective view showing the distal end surface of the suction port of the second tube of the suction catheter according to the first modification. FIG. 8A is a cross-sectional view in the first direction showing the distal end surface of the suction port of the second tube of the suction catheter according to the first modification, and FIG. 8B is an enlarged cross-sectional view of the upper end portion. FIG. 8 (c) is an enlarged cross-sectional view of a lower end portion. 9 (a) to 9 (c) are views illustrating an example of a process of a method for manufacturing a suction catheter according to the first modification. 10 (a) to 10 (f) are examples of cross-sectional views of the suction lumen in the catheter according to the modified example.

Hereinafter, the suction catheter 1 of the embodiment will be described with reference to the drawings. The suction catheter 1 is introduced into the body and is used to suck and remove the thrombus generated in the blood vessel to the outside of the body by the negative pressure applied from the hand side (proximal side) of the suction catheter 1. In the description of the drawings, the same elements may be designated by the same reference numerals and duplicate description may be omitted.

In the following description, in the first direction in which the suction catheter 1 extends, the operation side of the suction catheter 1 (left side in FIG. 1) is defined as the proximal side, and the side opposite to the operation side of the suction catheter 1 is the human body. The side introduced into (the right side of FIG. 1) is defined as the distal side. Further, in FIGS. 1 to 6, the width of the suction lumen 10 is the direction orthogonal to the first direction and the vertical direction, with the first direction in which the suction catheter 1 extends as the X-axis direction and the vertical direction as the Z-axis direction. The direction may be indicated as the Y-axis direction. The first direction in which the suction catheter 1 extends is also the longitudinal direction when the suction catheter 1 is viewed from the side.

As shown in FIG. 1, the suction catheter 1 has a suction lumen 10 extending from the proximal end to the distal end and a guide wire lumen 20 extending along the suction lumen 10 on the distal side of the suction lumen 10. is doing. The suction lumen 10 serves as a flow path for a thrombus or the like sucked from a suction port 11 provided at the distal end of the suction lumen. The guide wire lumen 20 is a lumen through which a guide wire (not shown) for guiding the suction port 11 of the suction lumen 10 to the target portion is passed. Hereinafter, the portion where the suction lumen 10 extends independently is referred to as a first shaft 3, and the portion where the suction lumen 10 and the guide wire lumen 20 extend side by side is referred to as a second shaft 5.

The first shaft 3 comprises a first tube 31 forming a suction lumen 10. As shown in FIG. 2, the first tube 31 is a hollow member extending in one direction, and is a member having an annular cross section (hereinafter, simply referred to as “cross section”) orthogonal to the longitudinal direction. The inner surface 31a of the first tube 31 forms the suction lumen 10, and the suction lumen 10 extends from the proximal side to the distal side. The first tube 31 is made of a resin material. Examples of resin materials include at least one selected from polyamide resins, polyamide elastomers, polyurethane resins, polyether resins, polyester resins, polyimide resins, and polyethylene resins.

The first tube 31 may be a member including an inner layer and an outer layer. Examples of materials forming the inner layer include polytetrafluoroethylene (PTFE), tetrafluoroethylene / perfluoroalkyl vinyl ether copolymer (PFA), tetrafluoroethylene / hexafluoropropylene copolymer (FEP), and tetrafluoroethylene. -Includes fluororesins such as ethylene copolymer (ETFE), polyvinylidene fluoride (PVDF), polychlorotrifluoroethylene (PCTFE), high-density polyethylene and the like. Examples of the material forming the outer layer include elastomers such as polyamide elastomers, polyester elastomers and polyolefin elastomers.

A braided tube may be used as the first tube 31. The braided tube is a tube formed of resin or the like and containing a braided structure made of resin or metal. The braided structure is, for example, a structure made of a braided linear object provided around the lumen of the tube. The braided structure may be a structure in which one wire is wound or arranged along a lumen. Since the material or structure of the braid constituting the braided tube does not limit the effect of one aspect of the invention, various materials or structures are available. Metal can be used as the material for braiding, and various cross sections such as stainless steel such as SUS304 and SUS316, spring steel, piano wire, oil tempered wire, Co-Cr alloy, Ni-Ti alloy, etc. are used as circles, ellipses, and squares. It is possible to use a metal braided by holding one or a plurality of metal wires processed into a shape.

The first shaft 3 may have a double tube structure in which another tube is arranged inside or outside the first tube 31.

As shown in FIG. 1, a hub 35 is provided at the proximal end 3b of the first shaft 3. A suction device (not shown) such as a syringe is connected to the hub 35 via, for example, a Y-shaped connector (not shown). The negative pressure suction force by the suction device is applied to the suction lumen 10 of the first tube 31 through the hub 35. The hub 35 is formed of, for example, a styrene-butadiene copolymer. The proximal end 31b of the first tube 31 is adhered to the hub 35 with an adhesive 37. The adhesive 37 is, for example, a urethane adhesive. The suction lumen 10 of the first tube 31 communicates with the opening 35a of the hub 35.

The second shaft 5 is formed by a second tube (tube) 41 and a third tube 61. The second tube 41 has a suction lumen 10 extending in the first direction from the proximal side to the distal side, and the third tube 61 has a guide wire lumen 20 extending in the first direction from the proximal side to the distal side. Have. For convenience of explanation, the second tube 41 and the third tube 61 are shown in a state of being different from the main body resin 71 as shown in FIG. 3, but the second tube 41 and the third tube 61 are shown. The outer shape of the three tubes 61 does not have to retain the shape shown in FIG. That is, the boundaries between the second tube 41, the third tube 61, and the main body resin 71 may be in an unclear state.

The second tube 41 is a hollow member extending in the first direction and is made of a resin material. The suction lumen 10 is formed by the inner surface 41a of the second tube 41. The example of the resin material forming the second tube 41 is the same as the example of the material forming the first tube 31 described above. Similarly, the second tube 41 may be a member including an inner layer and an outer layer, and the material thereof may be the same as that of the example of the first tube 31. Similarly, a braided tube may be used as the second tube 41, and the material example thereof may be the same as that of the first tube 31.

The distal end of the first tube 31 (not shown) and the proximal end of the second tube 41 (not shown) are connected to each other and the suction lumen 10 of the first tube 31 and the suction lumen of the second tube 41 are connected to each other. 10 communicates with each other. The same tube may be arranged through the first shaft 3 and the second shaft 5, and for example, the second tube 41 may extend from the first shaft 3 to the second shaft 5.

The first tube 31 and the second tube 41 may be integrally formed as one tube, or a plurality of different tubes may be connected in the middle. When integrally formed, the first tube 31 and the second tube 41 may be made of the same resin material. When connected, tubes made of the same resin material may be connected to each other, or tubes made of different resin materials may be connected to each other. The connecting portion may be connected to each other by using an adhesive or a connecting member, or the tubes may be melted and connected.

As shown in FIG. 1, the distal end surface 41b of the second tube 41 is inclined. Specifically, the distal end surface 41b of the second tube 41 is inclined at a predetermined angle with respect to the direction in which the second tube 41 extends (first direction). Specifically, as shown in FIG. 1, the distal end face 41b of the second tube 41 is distal to proximal so that the upper end is distal and the lower end is proximal. It is continuously inclined toward. The end face 41b is open and communicates with the suction lumen 10. A part of the end face 41b may be closed. The inclination may be linear or curved in a side view. It may be a combination of a straight line and a curved line. The end face 41b may have a shape in which the upper end is on the distal side and the lower end is on the proximal side, and the shape may change in a stepped shape due to a step or the like, and the shape may be a combination of a straight line and a curved line. There may be.

A suction port 11 is provided at the distal end of the second tube 41. The suction port 11 is formed to include a part or all of the end face 41b. The suction port 11 is provided along the longitudinal direction of the second tube 41, one end on the distal side and the other end on the proximal side. The length L0 (see FIG. 1) in the first direction from the proximal end 11b to the distal end 11a of the suction port 11 can be, for example, 2.0 mm or more and 10 mm or less. As described above, since the end surface 41b at the distal end of the second tube 41 is inclined, the suction port 11 provided on the end surface is in an inclined state with respect to the surface orthogonal to the first direction of the suction lumen 10. It is formed. In the side view of the second tube 41, the distal end 11a of the suction port 11 is on the upper side in the vertical direction, and the proximal end 11b of the suction port 11 is on the lower side in the vertical direction.

As shown in FIG. 5, in the suction port 11, the curved shape of the proximal side end portion 11d including the proximal side proximal end 11b when viewed from the vertical direction is distal including the distal end 11a. It may be different from the curved shape of the side end portion 11c. Specifically, the radius of the curve in the curved shape of the proximal side end 11d may be larger than the radius of the curve in the curved shape of the distal end 11c. That is, the degree of bending (curvature) in the curved shape of the proximal side end portion 11d may be smaller than the degree of bending (curvature) in the curved shape of the distal side end portion 11c. With this configuration, the effective portion for cutting the thrombus in the suction port 11 becomes large, and the thrombus is easily cut. As a result, it is possible to suppress the obstruction of the suction lumen 10 by a suction substance such as a thrombus. For example, the curvature of the proximal side end 11d of the suction port 11 may be 1.74 × 10 ³ rad / m or less. Thereby, the obstruction suppressing effect can be further enhanced. rad / m is a unit of curvature and indicates degrees (angle) / perimeter (length).

As an example of a different embodiment, as shown in FIG. 6, the curved shape of the proximal side end portion 111d including the proximal side proximal end 11b when viewed from the vertical direction is formed in the width direction (Y-axis direction). ) May be formed linearly. This is also an example of the case where the curvature on the proximal side is made smaller (curvature 0). With this configuration, the thrombus is easily caught by the suction port 11, and the effective portion for cutting the thrombus in the suction port 11 becomes large, so that the thrombus is easily cut. As a result, it is possible to suppress the obstruction of the suction lumen 10 by a suction substance such as a thrombus.

As shown in FIG. 1, the third tube 61 is a hollow member extending in one direction and is made of a resin material. The guide wire lumen 20 is formed by the inner surface 61a of the third tube 61. An opening 21 and an opening 22 are provided at each of the distal end and the proximal end of the third tube 61. The opening 21 and the opening 22 are formed along a plane orthogonal to the first direction of the suction lumen 10. The third tube 61 is made of a resin material. The example of the resin material forming the third tube 61 is the same as the example of the material forming the first tube 31 described above. Similarly, the third tube 61 may be a member including an inner layer and an outer layer, and the material thereof may be the same as that of the example of the first tube 31. Similarly, a braided tube may be used as the third tube 61, and the material example thereof may be the same as that of the first tube 31.

The first tube 31, the shaft and the second tube 41, and the third tube 61 may have a multi-layer structure including a plurality of resin materials and other materials. When a plurality of resin materials are used, the resin materials may be the same or different from each other. Further, for example, a metal ring or plate may be placed on the portion of the tube facing the lumen or other portion. Resin or metal wire can also be wrapped around the tube.

The third tube 61 may be provided with a marker (not shown) formed of a material that is impermeable to X-rays (radiation). The marker is, for example, an annular member made of an alloy containing gold, platinum, tungsten, platinum (Pt) and indium (Ir). The marker is attached to the third tube 61 so as to surround the third tube 61 in the circumferential direction. This allows the operator to grasp the position of the distal end of the second shaft 5 based on the X-ray transmission image.

In the second shaft 5, the second tube 41 and the third tube 61 are integrally formed. Specifically, the third tube 61 is integrated with the main body resin 71 formed of the resin material in a state where the third tube 61 is arranged vertically above the second tube 41. In this embodiment, the main body resin 71 is formed of a thermoplastic resin, for example, a polyamide elastomer (PAE) or a polyamide elastomer. The main body resin 71 is formed, for example, by heating the shrink tube covered with the second tube 41 and the third tube 61. As a result, the outer surface (outer shape) 71a of the second shaft 5 is formed. Here, “integration” means that the boundaries between the second tube 41, the third tube 61, and the main body resin 71 may be unclear, or even if the boundaries are clear as shown in FIG. good. The second tube 41, the third tube 61, and three members having different tube materials may be integrated, or two lumens may be formed in one member and the three members may be integrated. Only the second tube 41 and the third tube 61 may be integrated. In this case, the main body resin 71 is formed by the melted second tube 41 and third tube 61.

As shown in FIGS. 1, 3 and 4, the suction lumen 10 formed by the inner surface 41a of the second tube 41 may change its cross section from the proximal side to the distal side. In the first direction of the second tube 41, the cross section of the suction lumen 10 at the first position P1 where the proximal end 11b of the suction port 11 is located is defined as the first cross section. As shown in FIG. 3, the first cross section is formed by an arc-shaped first inner surface 42 and a second inner surface (bottom) 43 having a curvature smaller than that of the first inner surface 42.

Here, the maximum width portion 13 having the maximum length w in the width direction (Y-axis direction) in the first cross section is located below the vertical center position M in the first cross section. That is, a portion where the thrombus is sucked into the suction lumen 10 is widely formed. Therefore, the thrombus does not get caught in the portion of the suction port 11 where the thrombus is first sucked into the suction lumen 10. As a result, the suction efficiency can be improved.

Further, the maximum length h in the vertical direction of the first cross section may be shorter than the maximum length w in the width direction. In other words, the first cross section may have a horizontally long shape. With such a configuration, the lower portion of the first cross section in which the thrombus is sucked can be widened at the suction port 11, so that the thrombus can be sucked from the suction port 11 more effectively. Further, by having such a cross-sectional shape, the shape balance is better than that of a circular lumen having the same circumference, so that the resistance at the time of inserting the catheter is reduced. As a result, the insertability of the catheter into the blood vessel can be improved, and the peripheral reachability of the catheter is improved. The second tube 41 having such a cross section is formed by, for example, inserting a stainless steel core material having a cross section substantially the same as the first cross section into a tube having a substantially annular cross section, which is manufactured by extrusion molding. It can be manufactured by heating the tube. The maximum length h in the vertical direction of the first cross section may be greater than or equal to the maximum length w in the width direction.

As shown in FIG. 1, the shape of the first cross section of the suction lumen 10 may continue from the first position P1 to the proximal side by a predetermined distance L1. As a result, the substance can be sucked in more smoothly. At a position proximal to the first position P1 in the first direction, the cross-section switching portion 15 that switches from the first cross-section to the second cross-section (see FIG. 4B) having a shape different from that of the first cross-section is the first. It may be formed starting from the second position P2 which is separated from the first position P1 by a predetermined distance L1 in the direction.

The distance L1 between the first position P1 and the second position P2 can be, for example, 2 mm to 20 mm. Further, the lower limit value of the distance L1 can be 2 mm or more, and the upper limit value of the distance can be 10 mm or less. In the present embodiment, the cross-section switching portion 15 is arranged starting from the second position P2 20 mm from the first position P1 in the first direction. As a result, it becomes possible to more reliably suppress the blockage due to the thrombus in the vicinity of the suction port 11, and the vibration is more reliably applied to the second tube 41. The vibration is more reliably applied because the sucked suction substance tends to collide with the inner surface of the tube, and the vibration due to the collision of the suction substance with the shaft becomes stronger.

In the present embodiment, the cross-sectional switching portion 15 changes the cross-sectional shape of the suction lumen 10 from the first cross-section (see FIG. 3) to the second cross-section (see FIG. 4 (b)) having a different shape and cross-sectional area from the first cross-section. May be changed. The cross-section switching portion 15 may be a taper formed on at least a part of the inner surface 41a of the second tube 41 forming the suction lumen 10. The cross-section switching portion 15 is formed from the second position P2 to the third position P3 of the second tube 41. Such a shape change makes it easier for the thrombus to be cut. Further, such a shape change promotes the efficiency of thrombus suction, and also has an effect of suppressing the thrombus from being clogged in the second tube 41, that is, the suction lumen 10 from being blocked.

The cross-sectional switching portion 15 may gently change the cross-sectional shape of the suction lumen 10 by a taper provided on the inner surface (inner wall) of the suction lumen 10, or may change the cross-sectional shape by a step provided instead of the taper. good. A plurality of cross-section switching portions 15 having such a taper or a step may be provided. The change in the shape of the suction lumen may be not only a change in which the cross-sectional area becomes smaller from the distal side to the proximal side but also a change in which the cross-sectional area becomes larger. The vibration generated by the change in the shape of the flow path is sensed by the operator of the suction catheter 1, and the operator can grasp the suction status of the thrombus. At the third position P3, the cross-sectional shape of the suction lumen 10 formed by the inner surface 41a of the second tube 41 is substantially circular. The suction lumen 10 has a shape of the second cross section extending to the proximal end 3b of the first shaft 3, that is, the hub 35. The two-dot chain line shown in FIGS. 4 (a) and 4 (b) indicates the second inner surface 43 which is a part of the inner surface 41a in the first cross section.

As a different embodiment, there may be one or more changes in the shape or cross-sectional area (size) of the suction lumen 10 between the third position P3 and the hub 35. In the suction catheter 1 of the present embodiment, since the cross-sectional shape or cross-sectional area of the suction lumen 10 changes, the sucked suction substance easily collides with the inner surface of the tube, and the suction status of the thrombus can be grasped. The change in cross-sectional shape or cross-sectional area may be a change in which the distal side is small and the proximal side is large. Depending on the application, changes such that the distal side is small and the proximal side is large, and the proximal side is small and the distal side is large can be appropriately combined. Thereby, the suction catheter 1 of the present embodiment can be introduced into the blood vessel more smoothly.

Subsequently, an example of a method for manufacturing the suction catheter 1 will be described. In the manufacture of the suction catheter 1, first, a first tube 31, a second tube 41, and a third tube 61 are prepared. Each tube is formed by extrusion molding with the above materials. Subsequently, a marker is attached to the third tube 61. The marker is caulked and fixed to the third tube 61. Further, the distal end of the first tube 31 is connected to the proximal end of the second tube 41. Subsequently, the second tube 41 and the third tube 61 are arranged in parallel. Specifically, the distal end of the third tube 61 is arranged so as to project distally to the distal end of the second tube 41. The method of connecting the first tube and the second tube can be appropriately selected, such as bonding with an adhesive, heating the tube and welding, and the like.

Next, a stainless steel core material (not shown) is inserted into the second tube 41 and the third tube 61. The cross section of the core material is circular. As the cross-sectional shape of the core material, a shape other than a circular shape can be selected if necessary. The second tube 41 and the third tube 61 are covered with a shrink tube and heated. The shrink tube may be made of a heat resistant resin. Examples of heat-resistant resins include olefin resins. As a result, the second tube 41 and the third tube 61 are welded and integrated. As a result, the main body resin 71 is formed. Next, a stainless steel core material is inserted into the second tube 41. The cross section of the core material has substantially the same cross-sectional shape as the first cross section formed by the inner surface 41a of the second tube 41 as shown in FIG. As an example of the cross-sectional shape of the core material that can be selected, there is the shape shown in FIG. A stainless steel core material is inserted into the third tube 61. The core material used in the above-mentioned heating step may be used as it is. When the shrink tube is covered and heated, the second tube 41 is also heated, and the shape of the inner surface 41a of the second tube 41 is formed into the shape of the inserted core material. As a result, the suction lumen 10 having the first cross section shown in FIG. 3 is formed.

The core material having substantially the same cross-sectional shape as the first cross section is inserted only on the distal side of the second tube 41. The heat generated by inserting and heating the core material is transferred to the portion of the second tube 41 in which the core material is not inserted, whereby the tapered cross-section switching portion 15 is formed. By transferring heat from the core material having substantially the same cross-sectional shape as the first cross section, the circular cross-sectional portion initially formed by the core material has substantially the same cross-sectional shape as the first cross section. The tapered cross-section switching portion 15 is formed by continuously deforming into the first cross-section portion formed by the core material.

Finally, the hub 35 is connected to the proximal end of the first tube 31 by an adhesive 37. The suction catheter 1 is manufactured by the above steps.

Although one embodiment has been described above, one aspect of the present invention is not limited to the above embodiment.

<Modification 1>
The suction catheter 1 according to the modified example will be described mainly with reference to FIGS. 7 to 9. The suction catheter 1 according to the modified example is the suction catheter 1 of the above embodiment, in which the inner surface 41a of the second tube (tube) 41 and the outer surface 41c of the second tube 41 on either the upper side or the lower side in the vertical direction of the suction port 11 The upper end portion 45a and the lower end portion 45b between them are concave or convex with respect to the suction surface F forming the suction port 11. In FIGS. 7 to 9, the third tube 61 forming the guide wire lumen 20 is not shown.

Hereinafter, the first modification will be described in detail. As shown in FIGS. 7 and 8 (a) to 8 (c), the distal end surface 41b of the second tube 41 is a portion including the end surface of the second tube 41 and the end surface of the suction lumen 10. In the distal end 45 of the second tube 41, the upper side in the vertical direction is the upper end portion 45a, and the lower side in the vertical direction is the lower end portion 45b. The upper end portion 45a and the lower end portion 45b between the inner surface 41a of the second tube 41 and the outer surface 41c of the second tube 41 on either the upper or lower side in the vertical direction on the distal side of the second tube 41 are in the width direction (Y axis). In the cross section orthogonal to the direction), it is concave or convex with respect to the straight line connecting the most distal point and the nearest point of the cross section of the second tube 41. That is, the upper end portion 45a and the lower end portion 45b of the second tube 41 in the suction port 11 are formed by a plurality of planes or curved surfaces instead of one plane. As a result, unevenness is formed on the upper end portion 45a and the lower end portion 45b. In the upper end portion 45a and the lower end portion 45b, in the convex portion, a thrombus is likely to enter and it is difficult to damage the blood vessel, and in the concave portion, the thrombus in contact with the edge of the second tube 41 is formed. Since it is cut off, it becomes easier to aspirate the thrombus.

The concave or convex portion of the upper end portion 45a or the lower end portion 45b of the second tube 41 is also concave or convex with respect to the suction port 11. The suction surface F is a flat surface or a curved surface formed by the suction port 11, and is formed by the distal end portion 11c and the proximal side end portion 11d of the suction port 11. When the second tube 41 is viewed from the side, the suction surface F is a flat surface when the suction port 11 is represented by a straight line, and the suction surface F is a curved surface when the suction port 11 is represented by a curved line. Generally, the suction port 11 is formed by cutting off a part of the second tube 41 with a razor or cutting it with scissors. In that case, the thick portion of the second tube 41 is cut at once from the proximal end to the distal end to form the suction port 11.

The concave or convex shape of the upper end portion 45a or the lower end portion 45b of the second tube 41 can be curved. The curved surface is the end portion of the second tube 41, that is, the thick portion of the second tube 41 forming the suction port 11 (the upper end portion 45a which is a portion between the inner surface 41a and the outer surface 41c of the second tube 41). And the lower end portion 45b) is, for example, a case where the shape is a dome-shaped protrusion or depression, or a semi-cylindrical convex or concave shape. By making the shape of the upper end portion 45a or the lower end portion 45b concave or convex, it is possible to facilitate suction of the thrombus approaching the suction port 11 and suppress damage to the blood vessel.

As shown in FIG. 7, the upper end portion 45a between the inner surface 41a of the second tube 41 and the outer surface 41c of the second tube 41 above the vertical direction (Z-axis direction) of the suction port 11 forms the suction port 11. The lower end portion 45b between the inner surface 41a of the second tube 41 and the outer surface 41c of the second tube 41 below the suction surface F in the vertical direction is concave with respect to the suction surface F. It may be convex. Further, it is a straight line on the suction surface F, and is the first on the outer surface side of the lower end portion 45b of the end surface 41b of the second tube 41 and the second distal end 46a on the outer surface side of the upper end portion 45a of the end surface 41b of the second tube 41. When the line connecting the proximal end 46b is defined as the reference line BL, the upper end portion 45a above the vertical direction of the suction port 11 is concave in line symmetry with respect to the reference line BL, and is downward in the vertical direction of the suction port 11. The lower end portion 45b in the above may be convex in line symmetry with respect to the reference line BL.

Further, in the present embodiment, as shown in FIGS. 8 (a), 8 (b) and 8 (c), in the cross section when the second tube 41 is cut in the first direction (X-axis direction). , The second distal end 46a on the outer surface side of the upper end 45a of the end surface 41b in the second tube 41 is farther than the second proximal end 46c (distal end 11a of the suction port 11) on the inner surface side of the upper end 45a. The first proximal end 46b on the outer surface side of the lower end 45b of the end surface 41b in the second tube 41 is the first distal end 46d on the inner surface side of the lower end 45b (proximal end of the suction port 11). It is located proximal to 11b).

The upper end portion 45a of the end surface 41b in the second tube 41 may be tilted in a range (angle α) of 2 ° or more and 60 ° or less with respect to the first direction (X-axis direction). The angle α is the angle formed by the straight line BL1 connecting the second distal end 46a and the second proximal end 46c and the inner surface 41a of the second tube 41. The lower limit value of the angle α is, for example, 10 ° or more, and the upper limit value is, for example, 30 ° or less. The lower end portion 45b of the end surface 41b in the second tube 41 may be tilted in a range (angle α) of 2 ° or more and 60 ° or less with respect to the first direction (X-axis direction), similarly to the upper end portion 45a. The angle α is the angle formed by the straight line BL2 connecting the first proximal end 46b and the first distal end 46d and the inner surface 41a of the second tube 41. The lower limit value of the angle α is, for example, 10 ° or more, and the upper limit value is, for example, 30 ° or less.

With respect to the straight line BL1 connecting the second proximal end 46c and the second distal end 46a, the upper end portion 45a between the vertically upper inner surface of the suction port 11 and the outer surface 41c of the second tube 41 is concave or convex. It may be. Further, with respect to the straight line BL2 connecting the first distal end 46d and the first proximal end 46b, the lower end portion 45b between the vertically lower inner surface of the suction port 11 and the outer surface 41c of the second tube 41 is concave or concave. It may be convex. With a configuration that is concave or convex with respect to the straight line BL1 connecting the second proximal end 46c and the second distal end 46a or the straight line BL2 connecting the first distal end 46d and the first proximal end 46b. The suction efficiency can be further improved.

In the first modification, the straight line BL1 connecting the second distal end 46a and the second proximal end 46c and the straight line BL2 connecting the first proximal end 46b and the first distal end 46d are in the first direction. That is, an example has been described in which the inner surface 41a of the second tube 41 is tilted in a range of 2 ° or more and 60 ° or less with respect to the extending direction, but the tilt is configured to be tilted in a range different from the above range. There may be.

Next, as an example of a method of forming the upper end portion 45a and the lower end portion 45b concavely or convexly, an example of a method of forming the upper end portion 45a concavely and the lower end portion 45b convexly is mainly shown in FIG. 9 (a). )-FIG. 9 (c).

In the manufacture of the suction catheter 1, first, a first tube 31, a second tube 41, and a third tube 61 are prepared.

Next, the core material 80 is inserted into the second tube 41 extending in the first direction as shown in FIG. 9A (insertion step). The core material to be inserted is preferably a deformable material and a material having an outer diameter smaller than that of the suction lumen 10 of the second tube. Next, the second tube 41 into which the core material 80 is inserted is deformed (deformation step). For example, the second tube can be deformed to be crushed. Then, as shown in FIG. 9B, one end of the second tube 41 deformed in the deformation step is cut so as to be inclined with respect to the plane orthogonal to the first direction of the suction lumen 10. C1: Cutting step). When the core material 80 is removed from the second tube 41 after the cutting step (removal step), the second tube 41 is released from the above deformation as shown in FIG. 9 (c). As a result, as shown in FIGS. 7 and 8A, the upper end portion 45a of the suction port 11 in the vertical direction is concave with respect to the suction surface F forming the suction port 11, and the suction port 11 is vertical. A second tube 41 is formed in which the lower end portion 45b at the lower end in the direction is convex with respect to the suction surface F. Only one of the upper end portion 45a and the lower end portion 45b may be cut to be concave or convex with respect to the suction surface F.

The end of the second tube may be formed concave or convex even after all the tubes of the first tube, the second tube, and the third tube are connected and integrated, and the second tube 41 and the first tube may be formed. The third tube 61 may be connected before the second tube 41 and the first tube 31 are connected. If the end of the second tube is formed concave or convex after the second tube 41 and the third tube 61 are connected, a core material or a cover that protects the third tube may be used.

Then, by going through the same manufacturing process as in the above embodiment, the suction catheter 1 according to the modified example is manufactured.

Further, after the suction catheter 1 according to the above embodiment is manufactured as described in the above embodiment, the upper end portion 45a and the lower end portion 45b are removed by cutting or melting the upper end portion 45a and the lower end portion 45b. It may be formed concavely or convexly. Even with such a method, the suction catheter 1 according to the modified example can be manufactured.

<Modification 2>
In the above embodiment or modification, as shown in FIG. 3, an example in which the first cross section is formed by an arc-shaped first inner surface 42 and a second inner surface 43 having a curvature smaller than that of the first inner surface 42. However, one aspect of the present invention is not limited to this. For example, as shown in FIGS. 10 (a) to 10 (f), the first cross section may have bottom portions 143A, 143B, 143C, 143D, 143E, 143F at the lower end thereof. The bottom portions 143A, 143B, 143C, 143D, 143E, and 143F are substantially linear portions extending in the width direction. Further, in the above embodiment, the second inner surface 43 in the first cross section of the suction lumen 10 may have a substantially linear shape extending in the width direction.

Here, the maximum width portions 13A, 13B, 13C, 13D, 13E, 13F having the maximum length w in the width direction in the first cross section are located below the vertical center position M in the first cross section. In the suction catheter 1 having the second tube 41 having such a first cross section, the bottom 143A, 143B, 143C, 143D, 143E, 143F, which is the part where the thrombus is most sucked in the suction port 11, is compared with the other parts. Since it is spread out, the blood clot can be aspirated more effectively. The second tube 41 having such a first cross section can also be manufactured by the same method as that described in the above embodiment.

Further, if the maximum length h in the vertical direction of the first cross section is shorter than the maximum length w in the width direction, the lower portion where the thrombus is sucked can be widened at the suction port 11, so that it is more effective. The thrombus can be sucked from the suction port 11.

Further, in the above-described embodiment or modified example, as shown in FIG. 3, an example in which the second tube 41 and the third tube 61 are integrally formed by the main body resin 71 has been described, but the present invention is limited to this. Not done. For example, the second tube 41 and the third tube 61 may be fixed to each other by an adhesive or the like.

The various embodiments and modifications described above may be combined in various ways without departing from the spirit of one aspect of the present invention.

1 ... suction catheter, 3 ... first shaft, 5 ... second shaft, 10 ... suction lumen (lumen), 11 ... suction port, 11a ... distal end of suction port, 11b ... proximal end of suction port, 11c ... Distal end, 11d ... Proximal end, 13, 13A, 13B, 13C, 13D, 13E, 13F ... Maximum width, 15 ... Cross section switching, 20 ... Guide wire lumen, 41 ... Second tube ( Tube), 41a ... Inner surface of the second tube, 41b ... End face of the second tube, 43 ... Second inner surface (bottom), 143A, 143B, 143C, 143D, 143E, 143F ... Bottom, 61 ... Third tube, M ... Vertical center position, P1 ... First position.

Claims (13)

A tube having a lumen extending from the proximal side to the distal side and a suction port formed on the distal side in the lumen.
The suction port has a portion inclined with respect to a plane orthogonal to the first direction in which the lumen extends.
In the arrangement of the tube with the distal end of the suction port on the upper side in the vertical direction and the proximal end of the suction port on the lower side in the vertical direction, at the first position where the proximal end of the suction port is located in the first direction. When the cross section of the rumen orthogonal to the first direction is taken as the first cross section,
A suction catheter having a maximum width portion having a maximum length in the width direction orthogonal to the vertical direction in the first cross section, which is located below the center position in the vertical direction in the first cross section. The suction catheter according to claim 1, wherein the first cross section has a bottom extending in the width direction at the lower end in the vertical direction. The suction catheter according to claim 1 or 2, wherein the maximum length of the first cross section in the vertical direction is shorter than the maximum length in the width direction. The suction catheter according to any one of claims 1 to 3, wherein the lumen is a suction catheter in which the shape of the first cross section at the first position continues to the proximal side for a predetermined distance. The tube further has a cross-section switching portion that changes the cross-section from the first cross-section to a second cross-section having a shape different from that of the first cross-section at a position proximal to the first position in the first direction. The suction catheter according to any one of claims 1 to 4. The suction catheter according to claim 5, wherein the cross-section switching portion changes the cross-section from the first cross-section to a second cross-section having a shape and cross-sectional area different from that of the first cross-section. The suction catheter according to claim 5 or 6, wherein the end side of the cross-section switching portion is located within 20 mm from the first position in the first direction. The suction catheter according to any one of claims 5 to 7, wherein the cross-section switching portion is a taper formed on at least a part of the inner surface forming the lumen. When the tube is arranged so that the distal end is on the upper side in the vertical direction and the proximal end is on the lower side in the vertical direction, the tube is placed so as to pass through the distal end and the proximal end. In the cross section of the tube when cut in the direction
The first proximal end on the outer surface side of the lower end, which is the portion between the inner surface of the tube and the outer surface of the tube, below the suction port side of the lumen in the vertical direction, is the lower end portion. Located proximal to the first distal end on the inner surface side
Above the suction port side of the lumen in the vertical direction, the second distal end on the outer surface side of the upper end portion, which is a portion between the inner surface of the tube and the outer surface of the tube, is the upper end portion. Located distal to the second proximal end on the inner surface side,
The lower end portion is concave or convex with respect to a straight line connecting the first proximal end and the first distal end .
The suction catheter according to any one of claims 1 to 8 , wherein the upper end portion is concave or convex with respect to a straight line connecting the second distal end and the second proximal end . The suction catheter according to claim 9 , wherein the lower end portion is convex with respect to a straight line connecting the first proximal end and the first distal end . The suction catheter according to claim 9 or 10 , wherein the upper end portion is concave with respect to a straight line connecting the second distal end and the second proximal end . The straight line connecting the first proximal end and the first distal end is inclined in a range of 2 ° or more and 60 ° or less with respect to the first direction, and the second distal end and the second proximal are inclined. The suction catheter according to any one of claims 9 to 11 , wherein the straight line connecting the ends is inclined in a range of 2 ° or more and 60 ° or less with respect to the first direction. The suction according to any one of claims 1 to 8 , wherein the curvature at the proximal end of the suction port is smaller than the curvature at the distal end when the suction port is viewed from below in the vertical direction. catheter.

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