JP2013184020A - Catheter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a catheter with a guidewire tube embedded in a peripheral wall part of a main tube, wherein deterioration of insertion property can be suppressed by preventing the guidewire tube from coming off from the main tube.SOLUTION: A catheter body 11 of a suction catheter has a suction tube 14 and a guidewire tube 15. Among a thick part of a peripheral wall part of the suction tube 14 and a peripheral wall part of the guidewire tube 15 of the catheter body 11, a portion which is on a further opposite side of a suction lumen 17 than a guidewire lumen 18 in a lumen parallel direction X and extends in the axis line direction from an opening 38 acts as easily breakable parts 50 and 51. When a wire leading-out part of the guidewire G is bent toward a side separating from the suction tube 14, the easily breakable parts 50 and 51 break more easily than a portion between the suction lumen 17 and the guidewire lumen 18 at the peripheral wall part of the suction tube 14 does.

Description

  The present invention relates to a catheter.

  Conventionally, an aspiration catheter for aspirating and removing a foreign substance such as a thrombus existing in a blood vessel is known (for example, see Patent Document 1). Some suction catheters include a suction tube having a suction lumen for sucking foreign matter, and a guide wire tube having a guide wire lumen through which a guide wire can be inserted. In this case, the suction tube and the guide wire tube are joined by, for example, heat welding.

  When introducing this type of suction catheter into the body, the guiding catheter is first inserted through a sheath introducer that has been previously inserted into the body. After inserting the guiding catheter, the guide wire is inserted into the guiding catheter and introduced to a predetermined position in the body. Thereafter, the guide wire is inserted into the guide wire tube of the suction catheter, and the suction catheter is introduced to the treatment target site in the body along the guide wire in the inserted state.

  When the suction catheter is led out of the body after the suction and removal, the suction catheter is led out along the guide wire with the guide wire and guiding catheter held in the body. In this case, for example, while holding the portion of the guide wire led out from the proximal end opening of the guiding catheter with one hand, the suction catheter is pulled out of the body with the other hand. At this time, the lead-out portion held by hand in the guide wire is located away from the suction catheter so that it does not interfere with the withdrawal of the suction catheter, for example, in the lumen alignment direction in which the suction lumen and the guide wire lumen are aligned. It is bent to the side away from the suction catheter (suction tube).

  By the way, as a suction catheter having a guide wire tube, there is one in which the guide wire tube is embedded in a peripheral wall portion of the suction tube. FIG. 8 shows a cross-sectional view of such a suction catheter. In the suction catheter 80 shown in FIG. 8, a part in the circumferential direction of the peripheral wall portion 82 of the suction tube 81 is a thick portion 82 a that is thicker than other portions. A guide wire tube 83 is embedded in the thick portion 82a, and the guide wire tube 83 is joined to the suction tube 81 by thermal welding in the embedded state.

  In the suction catheter 80 of FIG. 8, a recess 87 that is recessed toward the boundary between the guide wire tube 83 and the suction lumen 84 is formed on the outer peripheral surface of the suction tube 81. When the suction tube 81 and the guide wire tube 83 are thermally welded, the resin material forming the suction tube 81 is brought into a molten state. At that time, since the molten resin material enters the boundary portion (valley portion) between the guide wire tube 83 and the suction lumen 84, the recess portion 87 is formed on the outer peripheral surface of the suction tube 81 accordingly. .

JP 2004-222946 A

  By the way, when the aspiration catheter is led out of the body, since the aspiration catheter is pulled out in a state where the lead-out portion of the guide wire from the guiding catheter is bent, the distal end side of the aspiration catheter is connected to the guiding catheter. When the guide wire tube is pulled out to the vicinity of the proximal end opening and the guide wire tube is led out from the proximal end opening of the guiding catheter, the suction catheter is then pulled out along the guiding catheter, while the guide wire tube is in the bent state. It will be guided to the side away from the suction tube along the wire. Therefore, a load on the side away from the guide wire tube is generated.

  In addition, when the entire guide wire tube is positioned more distal than the guiding catheter when the suction catheter is introduced into the body, a part of the guide wire is guided when the suction catheter is pulled out of the body. There is a risk of forming a loop between the proximal end of the wire tube and the distal end of the guiding catheter, in which case the suction catheter is pulled out along the guiding catheter, whereas the guidewire tube is a looped guidewire. Will be guided to the side away from the suction tube. Therefore, in this case as well, the load on the side to be separated is generated in the guide wire tube as described above.

  Here, in the suction catheter 80 described above, since the recess 87 is formed on the outer peripheral surface of the suction tube 81, when the guide wire tube 83 is loaded on the side away from the suction tube 81, the recess is formed. Stress concentration occurs in the portion 87, and as a result, the suction tube 81 may break between the suction lumen 84 and the guide wire tube 83 starting from the recessed portion 87. In that case, the guide wire tube 83 may be detached from the peripheral wall portion 82 of the suction tube 81 with the breakage. If so, there is a possibility that the operability of the suction catheter 80 is lowered due to the detached portion.

  The present invention has been made in view of the above circumstances, and in the configuration in which the guide wire tube is embedded in the peripheral wall portion of the main tube, the operability is reduced by preventing the guide wire tube from being detached from the main tube. The main object is to provide a catheter capable of suppressing the above.

  In order to solve the above-mentioned problem, a catheter of a first invention is a catheter comprising a main tube having a main lumen and a guide wire tube having a guide wire lumen through which a guide wire can be inserted. A holding portion for holding the guide wire tube is provided around a main lumen, and the holding portion and the guide wire tube are led out from the lumen to the proximal side in the guide wire inserted through the guide wire lumen. When the guide wire tube is bent to the side away from the main tube, and the load on the side away from the guide wire tube is generated, the holding of the guide wire tube by the holding portion is released. Be formed to break before And butterflies.

  According to the present invention, the guide wire tube is held by the holding portion provided around the main lumen in the main tube. Then, in the guide wire inserted through the guide wire lumen of the guide wire tube, the wire lead-out portion led out from the lumen to the proximal side is bent to the side away from the main tube, so that the guide wire tube goes to the side away from the guide wire tube. When the load occurs, the holding portion and the guide wire tube are broken before the holding of the guide wire tube by the holding portion is released. Thereby, since it can prevent that a guide wire tube detach | leaves from a main tube, the fall of operativity accompanying the detachment | leave of a guide wire tube can be suppressed.

  The catheter according to a second aspect of the present invention is the catheter according to the first aspect, wherein the holding portion is a thick portion that is a part of the circumferential direction of the peripheral wall portion surrounding the main lumen and is thicker than other portions. The guide wire tube is embedded in the thick part, and a lead-out port is formed in the thick part for leading the guide wire inserted through the guide wire lumen to the proximal side from the lumen. Among the tube-embedded portions composed of the thick portion and the peripheral wall portion of the guide wire tube, the main lumen and the guide wire lumen are arranged in the lumen arrangement direction in which the main lumen and the guide wire lumen are arranged. Is a portion on the opposite side, and a portion extending from the outlet in the catheter axial direction is an easily breakable portion, and the easily breakable portion is the guide wire. The main lumen and the guide wire in the peripheral wall portion of the main tube when a load is generated on the guide wire tube as it is bent away from the main tube. It is formed so as to be more easily broken than a portion between the lumen.

  According to the present invention, the guide wire tube is embedded in a thick portion formed in a part in the circumferential direction in the peripheral wall portion of the main tube, whereby the tube is held by the main tube. Of the tube-embedded portion consisting of the thick portion of the main tube and the peripheral wall portion of the guide wire tube, it is the portion on the opposite side of the main lumen from the guide wire lumen in the lumen alignment direction and extends axially from the outlet. The extending part is an easily breakable part. In this case, when the guide wire tube is bent to the side away from the main tube and the guide wire tube is subjected to a load on the side away from the main tube, the peripheral wall portion of the main tube is connected to the main lumen and the guide wire. The easily breakable portion breaks before breaking with the lumen. As a result, it is possible to prevent breakage between both lumens in the peripheral wall portion of the main tube, and therefore, it is possible to prevent the guide wire tube from being detached from the peripheral wall portion (thick portion) of the main tube along with such breakage. Can do. Therefore, it is possible to suppress a decrease in operability associated with detachment of the guide wire tube.

  The catheter of the third invention is the catheter according to the second invention, wherein the thick part is provided on the distal side of the middle position of the main tube in the axial direction. A stepped portion that forms a step on the outer peripheral surface is formed between the thick portion and a region closer to the thicker portion, and the outlet is formed in the stepped portion.

  According to the present invention, since the outlet is formed in the step portion formed in the peripheral wall portion of the main tube, the outlet is opened toward the proximal side. In this case, since the guide wire is led out along the main tube from the outlet to the proximal side, the guide outlet is compared with the case where the outlet is opened radially outward on the outer peripheral surface of the main tube. It is possible to suppress bending of the wire lead-out portion of the wire. Thereby, the load to the side away from the main tube which acts on a guide wire tube by the bending of a guide wire can be reduced, As a result, the detachment | leave from the thick part of a guide wire tube can be suppressed.

  The catheter of the fourth invention is the catheter according to the second or third invention, wherein the outer peripheral surface of the peripheral wall portion of the main tube is provided with a recessed portion that is recessed toward the boundary portion between the main lumen and the guide wire lumen. It is not formed.

  In the configuration in which the outer wall of the peripheral wall portion of the main tube has a recessed portion that is recessed toward the boundary between the main lumen and the guide wire lumen, the wire lead-out portion of the guide wire is bent toward the side away from the main tube. Along with this, when a load is applied to the guide wire tube, stress concentration occurs in the dent, and the peripheral wall of the main tube breaks between both lumens starting from the dent. Is done. Therefore, in the present invention, in view of this point, the concave portion on the outer peripheral surface of the peripheral wall portion of the main tube is not formed. As a result, it is possible to avoid breakage of the peripheral wall portion of the main tube starting from the recessed portion, and as a result, the easily breakable portion can be more easily broken than the portion between the two lumens in the peripheral wall portion of the main tube. it can.

  The catheter of the fifth invention is the catheter of the fourth invention, wherein the outer peripheral surface of the peripheral wall portion of the main tube has a curved shape that protrudes outward in the entire circumferential direction so that the concave portion is not formed on the outer peripheral surface. It is characterized by doing so.

  According to the present invention, since the outer peripheral surface of the peripheral wall portion of the main tube has a curved shape that protrudes outward in the entire circumferential direction, the portion between the main lumen and the guide wire lumen in the peripheral wall portion of the main tube is formed. The thickness can be increased. Thereby, an easily breakable part can be made to break still easier than the part between both lumens in the peripheral wall part of a main tube.

  The catheter according to a sixth aspect of the present invention is the catheter according to any one of the second to fifth aspects, wherein the thick portion is provided on a more distal side than an intermediate position in the axial direction of the main tube. The peripheral wall portion is formed with a step portion that causes a step in the outer peripheral surface between the thick portion and the region closer to the thick portion, and the outlet port is formed in the step portion. The step portion is formed to be inclined with respect to the axial direction so as to approach the main lumen side from the distal side toward the proximal side.

  By the way, when the guide wire tube is bent to the side away from the main tube and the guide wire tube is loaded on the side away from the main tube, the peripheral wall portion of the main tube becomes the main lumen and the guide wire lumen. When breaking along the gap, the step formed at the proximal end of the thick portion, more specifically, the fracture occurs starting from the root of the step that becomes the radially inner end of the step Can be considered. Here, when the stepped portion extends in a direction orthogonal to the axial direction, stress concentration is likely to occur at the base portion of the stepped portion, and it is considered that the above-described breakage is likely to occur. Therefore, in the present invention, focusing on this point, the stepped portion is formed to be inclined with respect to the axial direction so as to approach the main lumen side from the distal side toward the proximal side. Thereby, since stress concentration generated at the root portion of the step portion can be relaxed, it is possible to suppress the peripheral wall portion of the main tube from breaking along both lumens starting from the root portion. Therefore, as a result, it is possible to make it easier to break the easily breakable portion than the portion between the two lumens in the peripheral wall portion of the main lumen.

FIG. 2 is a schematic overall side view showing a configuration of a suction catheter. The longitudinal cross-sectional view which shows the structure of a catheter main body. It is a cross-sectional view which shows the structure of a catheter main body, (a) is the AA sectional view of FIG. 2, (b) shows the BB sectional view. Explanatory drawing for demonstrating the effect | action of the easily breakable part in a suction catheter. Explanatory drawing for demonstrating the manufacture procedure of a suction catheter. The cross-sectional view which shows the structure of the catheter main body in other embodiment. The cross-sectional view which shows the structure of the catheter main body in other embodiment. The longitudinal cross-sectional view which shows the structure of the conventional suction catheter.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings. In the present embodiment, a suction catheter for sucking a thrombus is embodied. FIG. 1 is a schematic overall side view showing the configuration of a suction catheter.

  As shown in FIG. 1, the suction catheter 10 has a length of 1 to 2 m, and includes a catheter body 11 and a hub 12 attached to a proximal end portion (base end portion) of the catheter body 11. It has. The catheter body 11 includes a suction tube 14 and a guide wire tube 15 provided on the distal end side (tip side) of the suction tube 14, and is formed by joining the tubes 14 and 15 by welding. Has been. The suction tube 14 has a suction lumen 17 therein, and the guide wire tube 15 has a guide wire lumen 18 (see FIG. 2) into which the guide wire G is inserted.

  The hub 12 has a fluid passage 12 a communicating with the suction lumen 17 of the suction tube 14 inside thereof. A syringe S is connected to the hub 12 as a suction tool. By applying a negative pressure to the suction lumen 17 using the syringe S, it is possible to suck a thrombus and the like through the lumen 17. It has become. Incidentally, as the suction tool, an electric vacuum pump or the like is used in addition to the syringe S.

  Next, the configuration of the catheter body 11 will be described with reference to FIGS. 2 and 3. FIG. 2 is a longitudinal sectional view showing the configuration of the catheter body 11. 3A and 3B are cross-sectional views showing the configuration of the catheter body 11, wherein FIG. 3A shows a cross section taken along the line AA in FIG. 2, and FIG. 3B shows a cross section taken along the line BB. Incidentally, the longitudinal section is a section parallel to the longitudinal direction (catheter axial direction) of the catheter body 11, and the transverse section is a section orthogonal to the longitudinal direction.

  As shown in FIGS. 2 and 3, the catheter body 11 is formed by welding the suction tube 14 and the guide wire tube 15 to each other as described above. The suction tube 14 includes a proximal suction tube 21 and a distal suction tube 22 provided at a more distal side than the proximal suction tube 21, and the tubes 21 and 22 are joined to each other by welding. Yes. Here, the suction tube 14 corresponds to a main tube.

  The proximal suction tube 21 forms a predetermined range from the proximal end portion to the distal side of the suction tube 14. The proximal suction tube 21 has a tubular shape, and has a lumen 21a extending continuously over the entire longitudinal direction. The proximal suction tube 21 has a multilayer structure in which a plurality of types of materials including a synthetic resin are laminated. Specifically, the proximal suction tube 21 is provided between the inner layer 27 that forms the inner peripheral surface of the tube 21, the outer layer 28 that forms the outer peripheral surface of the tube 21, and the inner layer 27 and the outer layer 28. And an intermediate layer 29. The inner layer 27, the outer layer 28, and the intermediate layer 29 constitute a peripheral wall portion 46 of the proximal suction tube 21.

  The inner layer 27 is formed of a synthetic resin, and specifically is formed using polytetrafluoroethylene (PTFE). However, the inner layer 27 is not necessarily formed of PTFE, and may be formed of other synthetic resins such as polyvinylidene fluoride and perfluoroalkoxy resin.

  The outer layer 28 is made of a synthetic resin. The outer layer 28 includes an outer layer 31 that constitutes a predetermined range from the proximal end portion of the proximal suction tube 21 toward the distal side, and an outer layer 32 that constitutes a range farther to the distal side. The outer layer 28 is formed by welding these outer layers 31 and 32 to each other. Each of the outer layers 31 and 32 is formed of a polyamide-based resin such as polyamide or polyamide elastomer. The outer layer 32 has a lower hardness than the outer layer 31. Therefore, the outer layer 32 is less rigid than the outer layer 31.

  The outer layers 31 and 32 are not necessarily formed of a polyamide-based resin, and may be formed of other synthetic resins such as polyimide, polyimide elastomer, polypropylene, polyethylene, polyethylene terephthalate, polyurethane, and silicon rubber. Further, the outer layer 31 may be constituted by a plurality of outer layers arranged in the axial direction. In that case, it is desirable to form the plurality of outer layers so that rigidity (hardness) decreases from the proximal one toward the distal one.

  The outer layer 32 is formed with a thick portion 32a in which a portion in the circumferential direction is thicker than other portions (see FIG. 3B). In the thick portion 32a, a proximal portion of the guide wire tube 15 (a proximal guide tube 41 described later in detail) is embedded. Here, the thick portion 32a corresponds to a holding portion, and the thick portion 32a is held by embedding a proximal portion of the guide wire tube 15.

  At the proximal end portion of the thick portion 32a, a step portion 37 is formed that creates a step between the outer peripheral surface of the thick portion 32a and the outer peripheral surface of the outer layer 31. The stepped portion 37 is formed to be inclined with respect to the axial direction so as to approach the suction lumen 17 side from the distal side toward the proximal side. Further, the step portion 37 is provided on the proximal side with respect to the guide wire tube 15.

  The stepped portion 37 is formed with an opening 38 that opens the guidewire lumen 18 of the guidewire tube 15 toward the proximal side. The opening 38 has an elliptical shape whose opening shape is long in the inclination direction of the stepped portion 37. However, the shape of the opening 38 is not necessarily such a shape, and may be other shapes such as a circular shape (perfect circle shape). The opening 38 functions as a lead-out port that guides the guide wire G from the guide wire lumen 18 to the proximal side. Specifically, the guide wire G is led out from the opening 38 through an inner region surrounded by the stepped portion 37.

  The intermediate layer 29 (braided layer) is formed of a metal braided body 30 (see FIG. 4). The braided body 30 is a reinforcing body for reinforcing the proximal suction tube 21, and is formed by braiding stainless steel reinforcing wires 35 into a mesh shape. The resin of the outer layer 28 enters between the plurality of reinforcing wires 35 in the braided body 30, and the inserted resin is in contact with the inner layer 27. In FIG. 2, for the sake of convenience, the intermediate layer 29 is shown in a state in which a gap between the reinforcing wires 35 of the braided body 30 is filled.

  Further, a part of the inner layer 27 and the intermediate layer 29 extends to the distal side with respect to the outer layer 28 (outer layer 32), and the extended part is joined to the distal suction tube 22. It is part 39.

  The distal suction tube 22 is formed in a tubular shape by a polyamide elastomer and has a single layer structure. Specifically, the distal suction tube 22 is made of a polyamide elastomer having a hardness equal to or lower than the hardness of the outer layer 32. Unlike the proximal suction tube 21, the distal suction tube 22 does not have the braided body 30, and is therefore formed with lower rigidity than the proximal suction tube 21.

  The distal suction tube 22 has a lumen 22a extending continuously over the entire length in the inside thereof. The lumen 22a communicates with the lumen 21a of the proximal suction tube 21 on the proximal end side, and the suction lumen 17 is formed by the lumens 21a and 22a.

  The distal end opening of the lumen 22a serves as a suction port 45 for taking a foreign substance such as a thrombus into the suction lumen 17. The distal end face of the distal suction tube 22 is inclined with respect to the axial direction, and a suction port 45 is formed along the inclination. In this case, compared with the case where the suction port 45 is formed along a direction orthogonal to the axial direction, the opening area of the suction port 45 can be increased, and the foreign matter suction performance can be improved.

  In the distal suction tube 22, a peripheral wall portion 47 surrounding the inner cavity 22a is formed with a thick portion 47a in which a portion in the circumferential direction is thicker than other portions (FIG. 3A). )reference). The thick portion 47a is provided at the same position in the circumferential direction as the thick portion 32a of the outer layer 32 of the proximal suction tube 21. A distal portion of the guide wire tube 15 (detailed distal guide tube 42 described later) is embedded in the thick portion 47a. Here, the thick portion 47a corresponds to the holding portion, and the thick portion 47a is held by embedding a distal portion of the guide wire tube 15.

  The proximal end of the distal suction tube 22 is welded to the distal end of the proximal suction tube 21. The joint 39 of the proximal suction tube 21 is inserted on the proximal end side of the distal suction tube 22, and the joint 39 and the distal suction tube 22 are welded in the inserted state. . Further, the proximal end portion of the distal suction tube 22 and the distal end portion of the outer layer 28 (outer layer 32) of the proximal suction tube 21 are welded in a state of abutting each other. Thereby, the proximal suction tube 21 and the distal suction tube 22 are joined to each other.

  The guide wire tube 15 is formed in a tubular shape from a synthetic resin, and has a guide wire lumen 18 extending over the entire length in the inside thereof. The guide wire tube 15 is formed using a material harder than the material forming the suction tube 14 in order to improve the slidability of the guide wire G inserted through the guide wire lumen 18. Specifically, the guide wire tube 15 is made of nylon resin.

  The guide wire tube 15 is provided so as to extend over both the proximal suction tube 21 and the distal suction tube 22 along the axial direction of the suction tube 14. Specifically, the guide wire tube 15 is embedded in the thick part 47a of the distal suction tube 22 and the thick part 32a of the outer layer 32 of the proximal suction tube 21, respectively. 32a and 47a are provided so as to penetrate in the axial direction.

  The guide wire tube 15 includes a proximal guide tube 41 and a distal guide tube 42 that are divided in the axial direction, and is formed by joining the guide tubes 41 and 42 to each other by welding. . Each of these guide tubes 41 and 42 has the same cross-sectional shape, and is welded in a state where the end faces of each other are butted. The guide tubes 41 and 42 have inner cavities 41a and 42a extending continuously over the entire length in the inside thereof. The lumens 41a and 42a communicate with each other, and the guide wire lumen 18 is formed by the lumens 41a and 42a.

  The proximal guide tube 41 is embedded in the thick portion 32 a of the outer layer 32 of the proximal suction tube 21. The proximal guide tube 41 is welded to the outer layer 32 in such an embedded state, and as a result, is welded to the proximal suction tube 21. Specifically, the proximal guide tube 41 has the entire axial direction embedded in the thick portion 32a, and the distal end thereof is located at the same position as the distal end of the outer layer 32 in the axial direction. Therefore, the joint 39 of the proximal suction tube 21 described above extends not only to the outer layer 32 but also to the proximal guide tube 41 distally.

  The distal guide tube 42 is embedded in the thick portion 47a of the distal suction tube 22, and is welded to the distal suction tube 22 in the embedded state. Specifically, in the distal guide tube 42, a part of the peripheral wall portion 44 surrounding the inner cavity 42 a is not embedded in the peripheral wall portion 47 of the distal suction tube 22, and the distal suction tube 22 It is exposed to the lumen 22a. In this case, the lumen 42 a of the tube 42 and the lumen 22 a of the distal suction tube 22 are partitioned by the exposed portion of the distal guide tube 42.

  In this specification, even when a part of the guide wire tube 15 is exposed to the suction lumen 17 in this way, the guide wire tube 15 is embedded in the peripheral wall portion (thick portion) of the suction tube 14. It is assumed that

  A part of the distal guide tube 42 extends further to the distal side than the distal suction tube 22, and the extended part is not embedded in the tube 22. Thereby, the lumen 42a (and thus the guide wire lumen 18) is opened to the outside at the distal end opening of the distal guide tube 42.

  The distal guide tube 42 partially overlaps with the joint portion 39 of the proximal suction tube 21 in the axial direction on the proximal end side, and abuts on the outer peripheral surface of the joint portion 39 at the overlap portion. Yes. In this case, at the overlapping portion, the distal guide tube 42 and the joint 39 of the proximal suction tube 21 are both covered by the peripheral wall 47 of the distal suction tube 22, and the peripheral wall 47 On the other hand, the distal guide tube 42 and the joint portion 39 are welded to each other (see FIG. 3B). That is, the distal guide tube 42 and the proximal suction tube 21 are joined to each other through the peripheral wall portion 47.

  Next, the cross-sectional shape of the catheter body 11 will be described with reference to FIG.

  As shown in FIG. 3B, in the catheter body 11, a region in which the proximal guide tube 41 is embedded in the outer layer 32 (thick portion 32a) of the proximal suction tube 21 (hereinafter referred to as a proximal embedded region). In other words, the cross section of the catheter body 11, that is, the cross section of the proximal suction tube 21 is the lumen 21 a (and hence the suction lumen 17) of the proximal suction tube 21 and the lumen 41 a ( As a result, a long oval shape is formed in the lumen arrangement direction X in which the guide wire lumens 18) are arranged. In other words, in the proximal embedded region, the outer peripheral surface of the proximal suction tube 21 (outer layer 28) has a curved shape that protrudes outward in the entire circumferential direction. Therefore, in the said area | region, the dent does not exist over the whole circumferential direction in the outer peripheral surface of the proximal suction tube 21, Therefore Therefore, the proximal suction tube 21 exists in the outer peripheral surface of the proximal suction tube 21. There is no indentation toward the boundary between the inner lumen 21a and the inner lumen 41a of the proximal guide tube 41.

  Here, it consists of the thick part 32a of the outer layer 32 of the proximal suction tube 21 and the peripheral wall part 43 surrounding the lumen 41a in the proximal guide tube 41 (that is, the thick part 32a and the peripheral wall part 43). Of the tube-embedded portion), the portion on the opposite side of the guide wire lumen 18 from the suction lumen 17 in the lumen arrangement direction X is an easily breakable portion 50. The easily breakable portion 50 extends in the axial direction from the opening 38 toward the distal side, and the distal end thereof reaches the distal end of the proximal guide tube 41.

  In addition, as shown in FIG. 3 (a), in the catheter body 11, a region in which the distal guide tube 42 is embedded in the peripheral wall portion 47 (thick portion 47a) of the distal suction tube 22 (hereinafter referred to as the distal portion). In the side embedding region), the cross section of the catheter body 11, that is, the cross section of the distal suction tube 22 has an elliptical shape that is long in the lumen arrangement direction X. In other words, in the distal embedded region, the outer peripheral surface of the distal suction tube 22 has a curved surface shape that protrudes outward in the entire circumferential direction. Therefore, in this region, there are no depressions in the entire circumferential direction on the outer peripheral surface of the distal suction tube 22, and therefore, the outer peripheral surface of the distal suction tube 22 has no inner portion of the distal suction tube 22. There is no dent recessed toward the boundary between the cavity 22a and the lumen 42a of the distal guide tube 42.

  Here, of the thick wall portion 47a of the peripheral wall portion 47 of the distal suction tube 22 and the peripheral wall portion 44 of the distal guide tube 42 (that is, the tube burying portion composed of the thick wall portion 47a and the peripheral wall portion 44). Among them, in the lumen arrangement direction X, the portion of the guide wire lumen 18 on the side opposite to the suction lumen 17 is an easily breakable portion 51. The easily breakable portion 51 extends along the axial direction and is continuous with the easily breakable portion 50 at the base end portion. Specifically, the easily breakable portion 51 extends in a range from the proximal end portion of the distal guide tube 42 to the distal end portion of the distal suction tube 22 in the axial direction.

  Next, the effect | action of the easily breakable parts 50 and 51 in the suction catheter 10 is demonstrated based on FIG. FIG. 4 is an explanatory diagram for explaining the operation of the easily breakable portions 50 and 51 in the suction catheter 10.

  FIG. 4A shows a state in which the guide wire G is inserted through the guide wire lumen 18 of the guide wire tube 15. In this state, a part of the guide wire G is led out from the guide wire lumen 18 to the proximal side through the opening 38. Hereinafter, this derived portion is referred to as a wire leading portion 49.

  From the state shown in FIG. 4 (a), as shown in FIG. 4 (b), the wire lead-out portion 49 of the guide wire G is away from the portion proximal to the opening 38 in the suction tube 14 (hereinafter abbreviated). When the guide wire tube 15 is bent to the side away from the suction tube, a load is generated on the side away from the guide wire tube 15. When the load reaches a predetermined size, the easily breakable portion 50 of the catheter body 11 is gradually broken from the peripheral edge of the opening portion 38 toward the distal side. That is, the easily breakable portion of the peripheral wall portion 46 (specifically, the outer layer 32) of the proximal suction tube 21 starts before the breakage between the lumen 21a and the lumen 41a of the proximal guide tube 41 starts. 50 breaks. And if this load with respect to the guide wire tube 15 is continued, the fracture | rupture of the easily breakable part 50 will progress toward a distal side, and the easily breakable part 51 will begin to fracture | rupture after that. That is, the easily breakable portion 51 breaks before the peripheral wall portion 47 of the distal suction tube 22 breaks along the space between the lumen 22a and the lumen 42a of the distal guide tube 42. Therefore, the suction catheter 10 can prevent the peripheral wall portion of the suction tube 14 from being broken between the suction lumen 17 and the guide wire lumen 18 when the above-described load is generated on the guide wire tube 15. As a result, the guide wire tube 15 can be prevented from being detached from the peripheral wall portion of the suction tube 14.

  In short, the easily breakable portions 50, 51 are both lumens 17 in the peripheral wall portions of the suction tube 14 (specifically, the peripheral wall portions 46, 47 of the suction tubes 21, 22) when the above-described load is generated in the guide wire tube 15. , 18 is formed so as to be more easily broken than the portion between them. In other words, the easily breakable portions 50 and 51 are formed so as to be broken before the holding of the guide wire tube 15 by the thick portions 32a and 47a is released. Here, the easily breakable portions 50 and 51 will be described in more detail. On the outer peripheral surface of the proximal suction tube 21, the boundary portion between the lumen 21a and the lumen 41a of the proximal guide tube 41 as described above. There is no dent that is recessed toward the end, and there is also a dent that is recessed toward the boundary between the lumen 22 a and the lumen 42 a of the distal guide tube 42 on the outer peripheral surface of the distal suction tube 22. Not done. That is, such a recess does not exist in the entire outer peripheral surface of the suction tube 14. Therefore, when the above-described load is generated on the guide wire tube 15, it is avoided that the peripheral wall portion of the suction tube 14 breaks between the suction lumen 17 and the guide wire lumen 18 starting from the dent. As a result, the easily breakable portions 50 and 51 are more easily broken than the portion between the lumens 17 and 18 in the peripheral wall portion of the suction tube 14.

  More specifically, since the outer peripheral surface of each suction tube 21, 22 has a curved shape that protrudes outward in the entire circumferential direction, between the lumens 17, 18 in the peripheral wall portions 46, 47 of each suction tube 21, 22. This part is thicker. Therefore, also from this point, it can be said that the easily breakable portions 50 and 51 are more easily broken than the portions between the lumens 17 and 18 in the suction tubes 21 and 22.

  Next, the manufacturing procedure of the suction catheter 10 will be described with reference to FIG. FIG. 5 is an explanatory diagram for explaining the manufacturing procedure of the suction catheter 10.

  First, as shown in FIG. 5A, a distal tube manufacturing process for manufacturing the distal tube 55 is performed by joining the distal suction tube 22 and the distal guide tube 42 by heat welding. . In this step, the distal guide tube 42 is disposed in the lumen 22 a of the distal suction tube 22 with its outer peripheral surface being in contact with the inner peripheral surface of the distal suction tube 22, and the arrangement state These two tubes 22 and 42 are joined by heat welding.

  Next, a proximal tube manufacturing process for manufacturing a proximal tube 56 in which the proximal suction tube 21 and the proximal guide tube 41 are joined is performed. In this step, first, as shown in FIG. 5B, a plurality of reinforcing wires 35 are spirally braided and wound around the outer peripheral surface of the inner tube 58 constituting the inner layer 27 of the proximal suction tube 21. Thus, the braided body 30 is formed. Thereafter, the outer peripheral side of the braided body 30 is covered with the outer tube 59 constituting the outer layer 31, and the outer peripheral surface of the inner tube 58 and the inner peripheral surface of the outer tube 59 are joined by heat welding. Thus, the outer layer 31 is formed, and the braided body 30 (intermediate layer 29) is interposed between the inner layer 27 and the outer layer 31.

  Next, as shown in FIG. 5C, the proximal guide tube 41 is disposed at a predetermined position on the outer peripheral side of the braided body 30, and both the proximal guide tube 41 and the braided body 30 are connected from the outside. The outer tube 60 constituting the outer layer 32 is covered so as to surround, and heat is applied from the outside of the outer tube 60 by a heater. As a result, the outer tube 60 is melted and enters between the reinforcing wires 35 of the braided body 30 to be welded to the inner layer 27 and to the proximal guide tube 41. By this welding, the outer tube 60 becomes the outer layer 32, and the entire outer layer 28 is formed. And the proximal side tube 56 formed by welding the proximal side suction tube 21 and the proximal side guide tube 41 is manufactured.

  Next, as shown in FIG. 5 (d), a tube joining step for joining the distal side tube 55 and the proximal side tube 56 is performed. In this step, first, the joint 39 of the proximal suction tube 21 in the proximal tube 56 is inserted into the proximal end portion of the distal suction tube 22 in the distal tube 55, and the proximal guide tube 41. And the distal guide tube 42 are arranged in a state in which their end faces are abutted with each other.

  Thereafter, the distal tube 55 and the proximal tube 56 are joined by heat welding. Specifically, the joint 39 of the proximal suction tube 21 and the proximal end side of the distal suction tube 22 are heat-welded, and the distal end surface of the outer layer 28 of the proximal suction tube 21 is far from the distal end surface. The proximal end surface of the distal suction tube 22 is heat welded. Thereby, the suction tube 14 is formed. Further, the proximal guide tube 41 and the distal guide tube 42 are heat-welded. Thereby, the guide wire tube 15 is formed. Therefore, the catheter body 11 is formed as described above.

  Thereafter, as a post-process, a hub connection process for connecting the hub 12 to the catheter body 11 and the like are performed, thereby completing a series of manufacturing processes.

  Next, a procedure for using the suction catheter 10 will be described.

  First, a guiding catheter is inserted through a sheath introducer that has been previously inserted into a blood vessel. After inserting the guiding catheter, the guide wire G is inserted into the guiding catheter and introduced to a position beyond the treatment target site where the thrombus exists. Next, the guide wire G is inserted into the guide wire lumen 18 of the guide wire tube 15, and the suction catheter 10 is inserted along the guide wire G to the treatment target site while being pushed and pulled in the inserted state. After inserting the suction catheter 10 to the treatment target site, the suction lumen 17 of the suction tube 14 is set to a negative pressure using the syringe S connected to the hub 12. Thereby, the thrombus in the blood vessel is removed by suction through the suction lumen 17.

  After the thrombus is removed by suction, the suction catheter 10 is led out of the body along the guide wire G through the guiding catheter. In this case, the suction catheter 10 is pulled out of the body while holding the guiding catheter and the guide wire G in the body. At this time, a part of the guide wire G is led out from the proximal end opening of the guiding catheter, and the suction catheter 10 is pulled out with the other hand while holding the led part with one hand. At this time, the lead-out portion to be held by hand in the guide wire G is located away from the suction catheter 10, for example, in the lumen arrangement direction X, so as not to obstruct the withdrawal of the suction catheter 10. It is bent to the side away from the suction tube 14.

  Here, when the suction catheter 10 is led out, the distal end side of the suction catheter 10 is pulled out to the vicinity of the proximal end opening of the guiding catheter and the guide wire tube 15 is led out from the proximal end opening of the guiding catheter. While the catheter 10 is pulled out along the axial direction of the guiding catheter, the guide wire tube 15 is guided to the side away from the suction catheter 10 along the guide wire G in a bent state. Then, a load on the side away from the guide wire tube 15, specifically, a load on the side away from the suction tube 14 (suction lumen 17) in the lumen arrangement direction X occurs.

  Here, as described above, in the present suction catheter 10, the easily breakable portions 50 and 51 are provided in the catheter body 11, and in this case, the peripheral wall portion 46 (outer layer 32) of the proximal suction tube 21 is the suction lumen 17. The easily breakable portion 50 breaks before breaking between the guide wire lumen 18 and the guide wire lumen 18. Therefore, it is possible to prevent a situation in which the guide wire tube 15 is detached from the outer layer 32 when the outer layer 32 is broken. As a result, when the suction catheter 10 is inserted into the body again and used, the detached portion is sandwiched between the outer peripheral surface of the suction catheter 10 and the inner peripheral surface of the guiding catheter, thereby reducing the insertability. Inconveniences such as incurring can be avoided.

  The suction catheter 10 is mainly passed through a blood vessel as described above and used for treating blood vessels such as coronary arteries, femoral arteries, and pulmonary arteries. It can also be applied to “tubes” and “body cavities”.

  As mentioned above, according to the structure of this embodiment explained in full detail, the following outstanding effects are acquired.

  A stepped portion 37 is formed on the peripheral wall portion 46 of the suction tube 14 to generate a step between the thick portion 32a and a region closer to the thickened portion 32a, and an opening 38 is provided in the stepped portion 37. In this case, since the opening 38 is opened toward the proximal side, the guide wire G can be led out along the suction tube 14 from the opening 38 to the proximal side. Thereby, since it can suppress that the wire derivation | leading-out part 49 of the guide wire G can be bent, the load to the side away from the suction tube 14 which acts on the guide wire tube 15 by the said bending can be reduced. As a result, detachment of the guide wire tube 15 from the suction tube 14 can be suppressed.

  The stepped portion 37 was formed to be inclined with respect to the axial direction so as to approach the suction lumen 17 side from the distal side toward the proximal side. Here, when a load is applied to the guide wire tube 15 as the wire lead-out portion 49 of the guide wire G is bent toward the side away from the suction tube 14, the stepped portion 37, specifically, the radially inner portion of the stepped portion 37. It is assumed that stress concentration occurs at the root portion that becomes the end of the slab. In this respect, the above-described configuration can alleviate the stress concentration as compared with the case where the stepped portion 37 extends in a direction orthogonal to the axial direction. Thereby, since it can suppress that the surrounding wall part of the suction tube 14 breaks along between the suction lumen 17 and the guide wire lumen 18 from the root part of the level | step-difference part 37, as a result of the suction tube 14 The easily breakable portions 50 and 51 can be made to break easily than the portion between the lumens 17 and 18 in the peripheral wall portion.

  With the distal guide tube 42 (guide wire tube 15) partially exposed to the lumen 22a (suction lumen 17) of the distal suction tube 22 (suction tube 14), the distal suction tube 22, the peripheral wall 47 is broken at the boundary between the lumen 42 a of the distal guide tube 42 and the lumen 22 a of the distal suction tube 22, and the distal guide tube 42 is embedded. If it is detached from the peripheral wall portion 47, a part of the suction lumen 17 is opened to the outside, and the suction catheter 10 cannot be reused. In this respect, the above configuration in which the easily breakable portion 51 is provided in the catheter body 11 has an advantage that such a problem can be prevented.

  The present invention is not limited to the above embodiment, and may be implemented as follows, for example.

  (1) In the above embodiment, the suction tube 14 (specifically, each suction tube 21, 22) has an elliptical cross section, in other words, the outer peripheral surface of the suction tube 14 is outward in the entire circumferential direction. By adopting a curved surface shape that is convex, a concave portion that is recessed toward the boundary portion between the suction lumen 17 and the guide wire lumen 18 is not formed on the outer peripheral surface, but this may be changed. . For example, a cross-sectional shape as shown in FIG.

  In FIG. 6, the cross section of the proximal suction tube 21 in the lumen arrangement direction X is from the lumen 21 a (suction lumen 17) side toward the lumen 41 a (guide wire lumen 18) side of the proximal guide tube 41. It has a tapered shape. Specifically, the outer peripheral surface of the proximal suction tube 21 is orthogonal to the lumen alignment direction X and the axial direction across the boundary between the lumen 21a and the lumen 41a of the proximal guide tube 41. A pair of plane portions 65 facing in the direction is formed. These flat portions 65 are inclined so as to approach each other in the lumen arrangement direction X from the lumen 21a side of the proximal suction tube 21 toward the lumen 41a side of the proximal guide tube 41. In this case, the flat portion 65 does not form a recessed portion that is recessed toward the boundary between the lumen 21 a and the lumen 41 a of the proximal guide tube 41 on the outer peripheral surface of the proximal suction tube 21. . Accordingly, even in this case, the peripheral wall portion 46 of the proximal suction tube 21 can be prevented from breaking between the suction lumen 17 and the guide wire lumen 18 starting from the dent portion. It is possible to make the easily breakable portion 50 easier to break than the portion between the lumens 17 and 18 in FIG. In the same manner as this, the distal suction tube 22 may be formed with a flat portion on the outer peripheral surface thereof so as not to form a recess.

  (2) By making the cross-sectional shape of the peripheral wall portion (specifically, the peripheral wall portions 43, 44) of the guide wire tube 15 (specifically, each guide tube 41, 42) non-uniform in the circumferential direction, suction lumens in the peripheral wall portion An easily breakable portion of the guide tube that is easier to break than the other portions may be provided in a portion opposite to the portion 17. In this case, the easily breakable portion of the guide tube constitutes a part of the easily breakable portions 50 and 51, and as a result, the easily breakable portions 50 and 51 are replaced with the suction lumen 17 and the guide wire lumen in the peripheral wall portion of the suction tube 14. It can be made to break rather than the part between 18. In general, the guide wire tube 15 (the guide tubes 41 and 42) is formed by extrusion molding. Therefore, with such a configuration, it is relatively easy to adjust the cross-sectional shape of the peripheral wall portion of the guide wire tube 15. The easily breakable portions 50 and 51 can be formed by the method.

  For example, it is conceivable that the guide tube easily breakable portion is formed by making the cross section of the peripheral wall portion of the guide wire tube 15 into an elliptical shape long in the lumen arrangement direction X. An example is shown in FIG. In FIG. 7A, the cross section of the peripheral wall 43 of the proximal guide tube 41 has an elliptical shape that is long in the lumen arrangement direction X. In this case, the thickness of the peripheral wall 43 of the proximal guide tube 41 is constant over the entire circumferential direction. In such a configuration, both end portions in the lumen arrangement direction X of the peripheral wall portion 43 of the proximal guide tube 41 are large curvature portions 66 having a larger curvature than other portions. Of these large curvature portions 66, the large curvature portion 66a on the opposite side of the lumen 21a of the proximal suction tube 21 corresponds to the guide tube easy break portion. In this case, as the wire lead-out portion 49 of the guide wire G is bent to the side away from the portion closer to the proximal side than the opening 38 in the suction tube 14, the load on the side away from the proximal guide tube 41 is increased. When this occurs, it is possible to easily cause stress concentration in the large curvature portion 66a. Thereby, it can be made easy to produce a fracture | rupture in the said large curvature part 66a.

  Moreover, you may form a guide tube easily fracture | rupture part by making the part on the opposite side to the suction lumen 17 among the surrounding wall parts of the guide wire tube 15 thinner than other parts. An example is shown in FIG. In FIG.7 (b), the part on the opposite side to the suction lumen 17 in the lumen arrangement direction X among the surrounding wall parts 43 of the proximal side guide tube 41 becomes the thin part 67 thinned compared with the other part. ing. And this thin part 67 is equivalent to a guide tube easily breakable part. In this case, since the strength (breaking strength) can be reduced in the thin portion 67 of the peripheral wall portion 43 of the proximal guide tube 41, the proximal guide tube 41 can be easily broken at the thin portion 67. it can.

  (3) The easily breakable portion 50 of the catheter body 11 may be provided with a notch formed so as to open at the proximal end and penetrate the easily breakable portion 50. In that case, the easily breakable portion 50 can be easily guided to breakage by using the notch as a trigger.

  (4) For example, in the catheter body 11, only the proximal easily breakable portion 50 of the easily breakable portions 50 and 51 may be provided, and the distal easily breakable portion 51 may not be provided. For example, it is conceivable to form a recess that is recessed toward the boundary between the lumen 22 a and the lumen 42 a of the distal guide tube 42 on the outer peripheral surface of the distal suction tube 22. In this case, in a region where the distal guide tube 42 is embedded in the distal suction tube 22 (distal embedded region), the wire lead-out portion 49 of the guide wire G is bent to the side away from the suction tube 14. As a result, when a load is generated on the guide wire tube 15, the peripheral wall portion 47 of the distal suction tube 22 starts from the recessed portion before the portion corresponding to the easily breakable portion 51 in the catheter body 11 breaks. The lumens 17 and 18 will be broken. However, even in such a case, the easily breakable portion 50 on the proximal side can be broken before the portion between the lumens 17 and 18 in the peripheral wall portion 46 (outer layer 32) of the proximal suction tube 21. Therefore, breakage of the peripheral wall portion 46 can be prevented, and as a result, the detachment of the proximal guide tube 41 from the peripheral wall portion 46 can be prevented.

  (5) In the above embodiment, the easily breakable portions 50 and 51 are formed over the range from the opening 38 to the tip of the guide wire tube 15 (the range including the entire region in the axial direction of the guide wire tube 15). You may form a fracture | rupture part in the range from the opening part 38 to the halfway position of the axial direction of the guide wire tube 15. FIG. For example, the structure which attaches the contrast ring which has a contrast function in the middle position of the axial direction in the outer peripheral surface of the guide wire tube 15 (specifically the distal side guide tube 42) can be considered. The contrast ring is made of a material having radiopacity, and is made of, for example, Pt-Ir. In such a configuration, when the easily breakable portion of the catheter body 11 breaks toward the distal end side starting from the opening 38, the breakage is blocked by the contrast ring, and the distal end side of the contrast ring is not broken. That is, the easily breakable portion is formed only in the range from the opening 38 to the base end of the contrast ring.

  According to such a configuration, when a break occurs in the easily breakable portion, a portion of the distal side of the guide wire tube 15 is not broken, so that the insertion state of the guide wire G is maintained. It is possible to prevent the operability of the suction catheter 10 from being lowered. In particular, if the easily breakable portion breaks in the whole axial direction of the guide wire tube 15 in the body, the insertion state of the guide wire G by the guide wire tube 15 cannot be maintained, and the suction catheter 10 is moved along the guide wire G. There is a possibility that inconvenience that the operation becomes impossible may occur, but if the above configuration is adopted, it is possible to avoid such inconvenience.

  (6) In the above embodiment, in the suction tube 14 (proximal suction tube 21), an opening 38 (lead-out port) is formed in the stepped portion 37, and the opening 38 is opened toward the proximal side. By changing this, an opening may be formed on the outer peripheral surface of the suction tube 14, and the opening may be opened outward in the radial direction of the suction tube. Even in this case, the guide wire G can be led out proximally from the guide wire lumen.

  (7) In the above embodiment, the present invention is applied to the suction catheter 10 in which the guide wire tube 15 is embedded in the peripheral wall portion of the suction tube 14 (corresponding to the main tube). The present invention may be applied to other catheters embedded in the peripheral wall portion.

  DESCRIPTION OF SYMBOLS 10 ... Suction catheter as a catheter, 14 ... Suction tube as a main tube, 15 ... Guide wire tube, 17 ... Suction lumen as a main lumen, 18 ... Guide wire lumen, 28 ... Outer layer, 32a ... Thickness as a holding part , 37 ... Stepped part, 38 ... Opening part as outlet, 46 ... Peripheral wall part, 47 ... Peripheral wall part, 47a ... Thick part as holding part, 49 ... Wire outlet part, 50 ... Easily breakable part, 51 ... Easy breaking part, G ... guide wire.

Claims (6)

A main tube having a main lumen;
A guide wire tube having a guide wire lumen through which the guide wire can be inserted;
A catheter comprising:
The main tube has a holding portion for holding the guide wire tube around the main lumen;
The holding portion and the guide wire tube are bent in a direction in which the wire lead-out portion led out from the lumen to the proximal side in the guide wire inserted through the guide wire lumen is bent away from the main tube. The catheter is formed so as to be broken before the holding of the guide wire tube by the holding portion is released when a load on the side away from the guide wire tube is generated. The holding portion is a thick portion that is a part of the circumferential wall portion surrounding the main lumen and is thicker than other portions, and the guide wire tube is embedded in the thick portion. And
The thick portion is formed with a lead-out port for leading the guide wire inserted through the guide wire lumen to the proximal side from the lumen,
Of the tube-embedded portion composed of the thick portion and the peripheral wall portion of the guide wire tube, the main lumen and the guide wire lumen are arranged in the lumen arrangement direction in which the main lumen and the guide wire lumen are arranged. A portion that extends from the outlet in the catheter axial direction is an easily breakable portion,
The easily breakable portion is a peripheral wall portion of the main tube when the guide wire tube is bent to the side away from the main tube and a load is generated on the side of the guide wire tube. The catheter according to claim 1, wherein the catheter is formed so as to be more easily broken than a portion between the main lumen and the guide wire lumen. The thick portion is provided on the distal side of the axial position in the main tube,
A step portion is formed on the peripheral wall portion of the main tube to cause a step in the outer peripheral surface between the thick portion and a region closer to the thick portion, and the outlet port is formed in the step portion. The catheter according to claim 2, wherein the catheter is formed.   The outer peripheral surface of the peripheral wall portion of the main tube is not formed with a concave portion that is recessed toward a boundary portion between the main lumen and the guide wire lumen. catheter.   The outer peripheral surface of the peripheral wall portion of the main tube is formed into a curved shape that protrudes outward in the entire circumferential direction, so that the concave portion is not formed on the outer peripheral surface. catheter. The thick portion is provided on the distal side of the axial position in the main tube,
A step portion is formed on the peripheral wall portion of the main tube to cause a step in the outer peripheral surface between the thick portion and a region closer to the thick portion, and the outlet port is formed in the step portion. Has been
The said level | step-difference part inclines with respect to the axial direction so that it may approach the side of the said main lumen as it goes to a proximal side from a distal side, It forms in any one of Claim 2 thru | or 5 characterized by the above-mentioned. The catheter according to Item.

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