JP2013153892A - Catheter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress decline of operability in a catheter having a guide wire tube.SOLUTION: A suction catheter 10 includes a catheter body 11. The catheter body 11 includes a suction tube 14 and a guide wire tube 15 joined to a distal end side of the suction tube 14. The suction tube 14 has an intermediate layer 29 in a peripheral wall of the suction tube 14 in which a knitted body 30 formed by winding a reinforcing wire 35 in the axial direction of the suction tube 14 is buried. The intermediate layer 29 extends to the distal end side further than a proximal end of the guide wire tube 15 from the proximal side of the guide wire tube 15 in the axial direction. A prescribed range at least including an overlapping part overlapping with the guide wire tube 15 in the axial direction in the intermediate layer 29 is a low-rigidity area 52 formed so that the rigidity is lower than the rigidity on the proximal side.

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 such a catheter, for example, a guide wire tube is joined to the distal end side of the suction tube by heat welding or the like.

  In the suction catheter, a braided layer may be formed by embedding a braided body in the peripheral wall portion of the suction tube for the purpose of reinforcing the suction tube. The braided body is formed by winding a plurality of wires along the axial direction of the suction tube. The braided layer extends in the axial direction in the suction tube, and is provided, for example, so that a part thereof overlaps with the guide wire tube in the axial direction. In this case, the suction tube can be reinforced to the distal end side.

JP 2004-222946 A

  By the way, in order to improve the operability of the catheter, the performance required for the catheter includes, for example, force transmission when inserting the catheter into a blood vessel and kink resistance. Here, in order to improve these performances, it is desirable that the catheter has a high rigidity on the proximal side and a low rigidity on the distal side.

  However, since the above-described suction catheter is provided with a guide wire tube on the distal end side thereof, when the guide wire is inserted into the lumen of the guide wire tube, the suction catheter is not intended on the distal end side of the catheter. There is a risk that rigidity will increase. Moreover, since the braided body provided in the suction tube is provided so as to partially overlap the guide wire tube in the axial direction, there is a concern that the rigidity of the braided body is increased. Therefore, it can be said that the above-described suction catheter is not preferable in terms of operability.

  Therefore, in order to improve this, it is conceivable to suppress an increase in rigidity on the distal end side of the catheter by setting the rigidity of the braided layer to be low as a whole. However, in this case, although it is possible to suppress an increase in rigidity on the distal end side, there is a possibility that the rigidity is insufficient on the proximal side. is there.

  The present invention has been made in view of the above circumstances, and a main object of the present invention is to suppress a decrease in operability in a catheter having a guide wire tube.

  In order to solve the above-described problem, a catheter of a first invention includes a main tube, and a guide wire tube provided to be joined to the distal end side of the main tube and having a lumen through which the guide wire can be inserted. The main tube includes a reinforcing layer in which a reinforcing body formed by winding a reinforcing wire in the axial direction of the main tube is embedded in the peripheral wall portion, and the reinforcing layer includes the axis Direction, extending from the proximal side of the guide wire tube to the distal side of the proximal end portion of the guide wire tube, and overlapping portions overlapping the guide wire tube in the axial direction in the reinforcing layer. The predetermined range including at least a low-rigidity region formed so as to be less rigid than the proximal side. And features.

  According to the present invention, the guide wire tube is provided on the distal end side of the main tube, and the rigidity of the reinforcing layer of the main tube is set to be low at a portion overlapping the guide wire tube in the axial direction. Therefore, increase in rigidity on the distal end side of the catheter can be suppressed. On the other hand, since the rigidity is set higher on the proximal side than the low-rigidity region in the reinforcing layer, the rigidity can be increased on the proximal side of the catheter. Thereby, in a catheter having a guide wire tube, it is possible to suppress a decrease in force transmission and kink resistance when the catheter is inserted into the body, and as a result, it is possible to suppress a decrease in operability.

  By the way, it is also conceivable to suppress an increase in rigidity on the distal end side of the catheter by not providing a reinforcing layer in a range where the main tube overlaps with the guide wire tube. However, in that case, the strength of the tube is reduced at the distal end side of the main tube, and the main tube is crushed or deformed, or it is difficult to stably support the guide wire tube on the main tube. There is a risk of In this regard, according to the present invention, the above-described effects can be obtained without causing such inconvenience.

  In the catheter of the second invention according to the first invention, in the reinforcing layer, the inclination of the reinforcing line with respect to the axial direction of the main tube is different between the low-rigidity region and a region closer to the low-rigidity region. Thus, the rigidity of the low-rigidity region is lower than that of the region on the proximal side.

  Here, it is examined whether the rigidity of the reinforcing layer becomes higher when the inclination of the reinforcing line relative to the axial direction of the main tube (hereinafter referred to as the inclination of the reinforcing line for short) is increased or decreased. When the inclination of the reinforcement line is increased, the reinforcement line is less resistant to bending when the catheter is bent in a direction perpendicular to the axial direction, whereas the inclination of the reinforcement line is reduced. The reinforcing wire tends to be a bending resistance. From this point, it is considered that the smaller the inclination of the reinforcing wire, the higher the rigidity. On the other hand, when the inclination of the reinforcing wire is increased, the winding pitch of the reinforcing wire is reduced, so that the reinforcing wire is arranged in a dense state, whereas the inclination of the reinforcing wire is reduced. In this case, since the winding pitch of the reinforcing wire is increased, the reinforcing wire is disposed in a rough state. When the reinforcing wire is dense, the amount of material constituting the reinforcing wire per unit length of the main tube increases, and when the reinforcing wire is rough, the reinforcement per unit length of the main tube is increased. The amount of material constituting the wire is reduced. From this point, it is considered that the greater the inclination of the reinforcing wire, the higher the rigidity.

  In consideration of these factors, the strength of the reinforcement wire itself, the strength (rigidity) of the reinforcement wire itself, etc., determines whether the stiffness of the reinforcement wire is lower or higher. it is conceivable that. Therefore, in the present invention, the rigidity of the low-rigidity region is made lower than that of the proximal region by making the inclination of the reinforcing line different between the low-rigidity region and the proximal region. I am going to do that. According to this, the rigidity of the low-rigidity region can be made lower than that of the region closer to the proximal side by a simple method of changing the inclination of the reinforcing wire in the axial direction. Therefore, the effect of the first invention can be obtained relatively easily.

  The catheter of the third invention is the catheter of the second invention, wherein the reinforcement layer has a lower inclination in the reinforcement layer relative to the axial direction of the main tube in the low rigidity region than in the proximal side. Then, the rigidity of the low-rigidity region is lower than that on the proximal side.

  According to the present invention, in the reinforcing layer, the inclination of the reinforcing line with respect to the axial direction is set to be smaller than that in the proximal side in the low-rigidity region. As a result, the winding pitch of the reinforcing wire is increased. In this case, since the reinforcing wire can be provided in a relatively rough state in the low-rigidity region, the rigidity in the low-rigidity region can be made lower than that on the proximal side.

  Further, when the reinforcing wires are densely arranged in the main tube and when the reinforcing wires are roughly arranged, the outer diameter of the main tube is easily reduced when the wires are roughly arranged. In this regard, according to the above configuration in which the reinforcing wire is arranged in a rough state in the distal low rigidity region, it is easy to reduce the outer diameter of the distal side of the main tube, and as a result, the catheter is inserted into the body. It becomes possible to improve the insertion property at the time of insertion.

  The catheter according to a fourth aspect of the present invention is the catheter according to any one of the first to third aspects, wherein the reinforcing layer has a distal end portion located at an intermediate position of the guide wire tube in the axial direction. The tube is provided with a non-reinforcing region in which the reinforcing layer does not exist on the distal side of the reinforcing layer.

  According to the present invention, the main tube includes a portion where the reinforcing layer is provided and a portion where the reinforcing layer is not provided (non-reinforcing region) in a range overlapping with the guide wire tube in the axial direction. The former is disposed on the proximal side and the latter is disposed on the distal side. In this case, in the region where the guide wire tube is provided, the rigidity of the distal side can be made lower than the proximal side, so that the insertion of the catheter can be improved.

  The catheter of the fifth invention is the catheter according to any one of the first to fourth inventions, wherein the peripheral wall portion of the main tube has an outer layer made of a resin material on an outer peripheral side of the reinforcing layer. A plurality of outer layer regions aligned in the axial direction, and the plurality of outer layer regions are formed such that the rigidity thereof decreases from the proximal one toward the distal one; Is characterized in that its proximal end portion is located at an intermediate position in the axial direction of the outer layer region.

  According to the present invention, in addition to the reinforcing layer, the outer layer is also formed so that its rigidity decreases from the proximal side to the distal side, so that the rigidity of the catheter is directed from the proximal side to the distal side. Therefore, it can be said that this is a more preferable configuration. Further, the proximal end of the low-rigidity region in the reinforcing layer, that is, the portion where the rigidity changes in the reinforcing layer is set at an intermediate position in the axial direction of the outer layer region, so the portion where the rigidity of the reinforcing layer changes in size and the outer layer Is shifted in the axial direction from the point where the rigidity of the shaft changes. In this case, since the rigidity of the catheter can be lowered in multiple steps from the proximal side to the distal side by the reinforcing layer and the outer layer, the insertion property of the catheter can be further enhanced. In this case, it is desirable to reduce the difference in rigidity between two outer layer regions adjacent in the axial direction. If it does so, it can suppress that a kink generate | occur | produces between those outer-layer area | regions from which those rigidity differs.

  A catheter of a sixth invention is a suction catheter used for sucking and removing foreign substances in any one of the first to fifth inventions, and the main tube is a suction tube having a suction lumen. It is characterized by that.

  According to the present invention, since the reinforcing layer is provided so as to partially overlap the guide wire tube in the axial direction in the suction tube, the suction tube can be reinforced to the distal end side. Accordingly, it is possible to suppress the occurrence of crushing on the distal end side of the suction tube, that is, in the vicinity of the suction port, when the inside of the lumen is set to a negative pressure so as to suck foreign matter through the suction lumen. Therefore, it is possible to suppress the above-described decrease in operability while suppressing a decrease in suction performance.

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. The side view which shows the structure of a catheter main body. Explanatory drawing for demonstrating the manufacture procedure of a suction catheter. The side view which shows the structure of the catheter main body in other embodiment. The side view which shows the structure of the catheter main body in other embodiment.

  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 inside thereof, and the guide wire tube 15 has a guide wire lumen 18 (see FIG. 2) into which the guide wire 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 in detail with reference to FIG. FIG. 2 is a longitudinal sectional view showing the configuration of the catheter body 11.

  As shown in FIG. 2, 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. ing. 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 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 a plurality of outer layers 31 to 34 arranged in the axial direction, and the outer layers 31 to 34 are welded to each other. Here, each of the outer layers 31 to 34 corresponds to an outer layer region. The outer layers 31 to 34 are arranged in the order of the outer layer 31, the outer layer 32, the outer layer 33, and the outer layer 34 from the proximal side to the distal side. Each of these outer layers 31 to 34 is formed of a polyamide-based resin such as polyamide or polyamide elastomer. Each outer layer 31-34 has its hardness gradually reduced from the proximal one to the distal one, and therefore its rigidity is from the proximal one to the distal one. It is getting smaller step by step. Specifically, each of the outer layers 31 to 34 is formed using a polyamide-based resin (material) having a different hardness, although each is formed using a polyamide-based resin.

  However, the outer layers 31 to 34 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 28 is not necessarily formed from the four outer layers 31 to 34 having different hardnesses, and may be formed from two or three outer layers having different hardnesses, or may be formed from five or more outer layers. Good. Further, the outer layer 28 may be formed of a single (one) outer layer, and in that case, the hardness is constant throughout the entire axial direction of the outer layer 28. Further, instead of or in addition to making the hardness of each outer layer 31 to 34 different, the rigidity of each outer layer 31 to 34 may be made different by making the thickness of each outer layer 31 to 34 different.

  Of the outer layers 31 to 34, the peripheral wall portion 36 surrounding the inner cavity 21a in the outermost layer 34 on the most distal side is formed with a thick portion 36a in which a portion in the circumferential direction is thicker than other portions. Has been. In the thick portion 36a, a proximal portion of the guide wire tube 15 (a proximal guide tube 41 described later in detail) is embedded. In the peripheral wall portion 36, the proximal end portion of the thick portion 36 a is a step portion 37 that creates a step between the outer peripheral surface of the outer layer 34 (thick portion 36 a) and the outer peripheral surface of the outer layer 33. 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, and the guidewire G is drawn out from the guidewire lumen 18 through the opening 38. Is possible.

  The intermediate layer 29 is formed of a metal braid 30 and corresponds to a reinforcing layer. The braided body 30 is a reinforcing body for reinforcing the proximal suction tube 21, and is formed by braiding stainless reinforcing wires 35 (wires) in a mesh shape (see FIG. 3). 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. From the point that the intermediate layer 29 is formed by the braided body 30, the intermediate layer 29 can also be referred to as a braided layer.

  Further, a part of the inner layer 27 and the intermediate layer 29 extends to the distal side of the outer layer 28 (outer layer 34), 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 formed of a polyamide elastomer having a hardness equal to or lower than the hardness of the outer layer 34. 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. In the suction tube 14, the distal suction tube 22 corresponds to an unreinforced region.

  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, the peripheral wall portion 47 surrounding the inner cavity 22 a is formed with a thick portion 47 a that is thicker than a portion in the circumferential direction. The thick portion 47a is provided at the same position in the circumferential direction as the thick portion 36a of the outer layer 34 of the proximal suction tube 21, and the thick portion 47a includes a distal portion of the guide wire tube 15 ( In detail, a distal guide tube 42) to be described later is embedded.

  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 proximal end portion of the outer layer 28 (outer layer 34) 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 with nylon resin, and has a guide wire lumen 18 extending over the entire length in the inside thereof. The guide wire tube 15 is provided so as to extend over both the proximal suction tube 21 and the distal suction tube 22 in the axial direction of the suction tube 14. Specifically, the guide wire tube 15 is embedded in the thick portion 47a of the distal suction tube 22 and the thick portion 36a of the outer layer 34 of the proximal suction tube 21, respectively. 36a 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 part 36 a of the outer layer 34 of the proximal suction tube 21. The proximal guide tube 41 is welded to the outer layer 34 in such an embedded state, and as a result, is welded to the proximal suction tube 21. Specifically, the entire area of the proximal guide tube 41 in the axial direction is embedded in the thick portion 36a, and the distal end thereof is the distal end of the outer layer 34 (that is, the outer layer 28) in the axial direction. At the same position. Therefore, the joint 39 of the proximal suction tube 21 described above extends not only to the outer layer 34 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, 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. ing. Thereby, the lumen 42a (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 39 are welded to each other. 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 intermediate layer 29 of the proximal suction tube 21 will be described in detail with reference to FIG. FIG. 3 is a side view showing the configuration of the catheter body 11.

  The intermediate layer 29 is formed using the braided body 30 as described above. As shown in FIG. 3, the braided body 30 includes a plurality of reinforcing wires 35 spirally wound along the axial direction of the proximal suction tube 21, and the plurality of reinforcing wires 35 are mesh-shaped. It is formed by weaving into a (mesh shape). The braided body 30 (intermediate layer 29) extends over the entire region in the axial direction in the proximal suction tube 21, and a part thereof overlaps with the guide wire tube 15 in the axial direction.

  Each reinforcing wire 35 extends continuously over the entire extending direction (the same direction as the axial direction of the proximal suction tube 21) in which the braided body 30 extends. The reinforcing wire 35 is constituted by a flat wire made of stainless steel, for example. The reinforcing wire 35 is formed to have a substantially constant wire diameter in the entire axial direction. For example, its cross-sectional area is set to 0.0000785-0.003 mm 2. Moreover, as a flat wire, what has the width | variety more than thickness can be used, for example, the thing of thickness: width = 1: 1 to 1: 5 can be used.

  The reinforcing wire 35 is not necessarily made of stainless steel, but may be made of other metal materials. Further, the reinforcing wire 35 may be made of a non-metallic material such as carbon fiber or nylon instead of the metallic material. Further, the reinforcing wire 35 does not necessarily need to be formed by a flat wire, and may be formed by a wire having another cross-sectional shape such as a round wire. For example, when it comprises with a round wire, it is possible to set a wire diameter to 0.01-0.06 mm.

  The intermediate layer 29 is formed in the proximal suction tube 21 so that its rigidity decreases from the proximal side to the distal side. The intermediate layer 29 includes a high-rigidity region 51, a low-rigidity region 52 that is provided on the distal side of the high-rigidity region 51 and has a lower rigidity than the high-rigidity region 51, and the high-rigidity region 51 and the low-rigidity region And a transition region 53 formed between the respective rigid regions 51 and 52 and having an intermediate rigidity.

  The high-rigidity region 51 is configured from the proximal end of the proximal suction tube 21 to an intermediate position on the proximal side of the guide wire tube 15. It exists in the middle of the axial direction. The low-rigidity region 52 is configured from the distal side to the distal end portion of the proximal suction tube 21 relative to the high-rigidity region 51, and specifically, the proximal end portion is in the middle of the outer layer 31 in the axial direction. Exists in position. In this case, the low-rigidity region 52 is arranged so that a part thereof overlaps the guide wire tube 15 in the axial direction. Therefore, the transition region 53 between the high-rigidity region 51 and the low-rigidity region 52 is disposed at an intermediate position of the outer layer 31 in the axial direction.

  It should be noted that the transition region 53 between the high-rigidity region 51 and the low-rigidity region 52 (and hence the boundary between the high-rigidity region 51 and the low-rigidity region 52) is not necessarily disposed in the middle of the outer layer 31 in the axial direction. Instead, it may be arranged in the middle of either the outer layer 32 or the outer layer 33. Moreover, you may arrange | position in the boundary part of adjacent outer layers 32 and 33, or the boundary part of adjacent outer layers 33 and 34. In short, the position of the boundary between the high-rigidity region 51 and the low-rigidity region 52 may be arbitrary as long as it is closer to the guide wire tube 15.

  In the high-rigidity region 51, the low-rigidity region 52, and the transition region 53, the inclination of the reinforcing wire 35 with respect to the axial direction of the proximal suction tube 21 in the braid 30 is different. Specifically, the inclination (that is, the inclination angle α) of the reinforcing wire 35 with respect to the axial direction of the proximal suction tube 21 becomes smaller in the order of the high-rigidity region 51, the transition region 53, and the low-rigidity region 52. In this order, the winding pitch of the reinforcing wire 35 (specifically, the length by which the reinforcing wire 35 is displaced in the axial direction of the proximal suction tube 21 per turn of the reinforcing wire 35) increases. The inclination angle of the reinforcing wire 35 with respect to the axial direction of the proximal suction tube 21 includes an acute angle side and an obtuse angle side. In this specification, the “inclination angle α” is the acute angle side. The angle of

  In such a configuration, the mesh (mesh) of the braided body 30 is rough in the order of the high-rigidity region 51, the transition region 53, and the low-rigidity region 52. In other words, the axis of the proximal suction tube 21 in the order described above. The amount (total amount) of the reinforcing wire 35 of the braided body 30 per unit length in the direction (hereinafter referred to as per tube unit length) is reduced. Furthermore, in other words, the number of turns of the reinforcing wire 35 per tube unit length is reduced in the above order. As a result, the intermediate layer 29 is formed so that the rigidity decreases in the order of the high rigidity region 51, the transition region 53, and the low rigidity region 52. Here, the amount of the reinforcing wire 35 means the volume or weight of the reinforcing wire 35.

  Further, in the transition region 53, the inclination angle α of the reinforcing wire 35 with respect to the axial direction of the proximal suction tube 21 gradually decreases from the proximal side toward the distal side. Specifically, in the transition region 53, the inclination angle α of the reinforcing wire 35 gradually decreases from the proximal end portion toward the distal side from the inclination angle α of the reinforcing wire 35 in the high-rigidity region 51. In addition, the inclination angle α of the reinforcing wire 35 gradually increases from the distal end portion toward the proximal side from the inclination angle α of the reinforcing wire 35 in the low rigidity region 52. Thereby, in the transition region 53, the mesh (mesh) of the braided body 30 gradually changes from dense to coarse from the proximal side to the distal side. Accordingly, in the transition region 53, the rigidity is smoothly lowered from the proximal side (the high rigidity region 51 side) to the distal side (the low rigidity region 52 side). In the configuration in which the regions 51 and 52 are provided, the insertion of the suction catheter 10 is improved and the occurrence of kinks at the boundary between the regions 51 and 52 is suppressed.

  In the transition region 53, the inclination angle α of the reinforcing wire 35 may be constant over the entire axial direction. In this case, the rigidity in the same region 53 is constant over the entire axial direction. Further, the transition area 53 may not be provided. In this case, the high rigidity region 51 and the low rigidity region 52 are continuously formed in the axial direction.

  Next, the manufacturing procedure of the suction catheter 10 will be described with reference to FIG. FIG. 4 is an explanatory diagram for explaining the manufacturing procedure of the suction catheter 10.

  First, as shown in FIG. 4A, a distal tube manufacturing process for manufacturing the distal tube 50 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 suction tube manufacturing process for manufacturing the proximal suction tube 21 is performed. In this step, first, as shown in FIG. 4B, a braided body 30 is formed by winding a plurality of reinforcing wires 35 spirally and wrapping around the outer peripheral surface of the inner tube 55 constituting the inner layer 27. To do. Here, winding of the reinforcing wire 35 is performed by rotating the inner tube 55 in the axial direction while rotating the inner tube 55 in the axial direction while feeding the reinforcing wire 35 by a brader device (not shown), for example. In this case, the inner pipe 55 is kept at a constant rotational speed so that the reinforcing wire 35 is wound around the outer peripheral surface of the inner pipe 55 at a predetermined inclination angle α (in other words, a predetermined winding pitch). The moving speed in the axial direction of 55 is adjusted. The inclination angle α (winding pitch) of the reinforcing wire 35 becomes smaller (larger) as the moving speed of the inner tube 55 is increased.

  It is not always necessary to wind the reinforcing wire 35 at a predetermined inclination angle α by adjusting the moving speed of the inner tube 55 while keeping the rotation speed of the inner tube 55 constant. It may be performed by adjusting the rotation speed of the inner tube 55 while keeping the moving speed of 55 constant. Moreover, you may carry out by adjusting both the moving speed of the inner pipe | tube 55, and a rotational speed.

  Next, as shown in FIG.4 (c), the predetermined range in the outer peripheral side of the braided body 30 is coat | covered with the outer tubes 56-58 which comprise each outer layer 31-33, respectively, and the inner tube 55 (inner layer 27) is covered. ) And the inner peripheral surfaces of the outer tubes 56 to 58 are joined together by heat welding. Thereby, the outer layers 31 to 33 are formed, and the braided body 30 (intermediate layer 29) is interposed between the inner layer 27 and the outer layers 31 to 33.

  Next, as shown in FIG. 4 (d), a proximal tube manufacturing process for manufacturing a proximal tube 49 in which the proximal suction tube 21 and the proximal guide tube 41 are joined is performed. In this step, first, the proximal guide tube 41 is disposed at a predetermined position on the outer peripheral side of the braided body 30, and the proximal guide tube 41 and the braided body 30 (specifically, the braided body 30 is covered with the outer layers 31 to 33). The outer tube 59 that constitutes the outer layer 34 is covered from the outside on both the unexposed portion and heat is applied from the outside by a heater. As a result, the outer tube 59 is melted out, enters between the reinforcing wires 35 of the braided body 30, is welded to the inner layer 27, and is welded to the proximal guide tube 41. By this welding, the outer tube 59 becomes the outer layer 34, and the entire outer layer 28 is formed. And the proximal side tube 49 formed by welding the proximal side suction tube 21 and the proximal side guide tube 41 is manufactured.

  Next, as shown in FIG. 4E, a tube joining step for joining the distal side tube 50 and the proximal side tube 49 is performed. In this step, first, the joint 39 of the proximal suction tube 21 in the proximal tube 49 is inserted into the proximal end portion of the distal suction tube 22 in the distal tube 50, 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 50 and the proximal tube 49 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 briefly described.

  First, a guiding catheter is inserted through a sheath introducer that has been previously inserted into a blood vessel. Next, the guide wire G is inserted through the guide wire lumen 18 of the guide wire tube 15 and through the guiding catheter, and inserted to a position beyond the treatment target site where the thrombus exists. Subsequently, the suction catheter 10 is inserted along the guide wire G to the treatment target site while performing a push-pull operation.

  Here, when the suction catheter 10 is inserted into the blood vessel, since the guide wire G is inserted through the guide wire tube 15, the portion of the suction catheter 10 where the guide wire tube 15 is provided, that is, the distance of the suction catheter 10 is increased. There is concern about increased rigidity on the distal end side. However, in the suction catheter 10 described above, the intermediate layer 29 provided in the suction tube 14 is a low-rigidity region 52 having a low rigidity in the range overlapping with the guide wire tube 15 in the axial direction. The increase in rigidity on the distal end side is suppressed. On the other hand, since the intermediate layer 29 is a high-rigidity region 51 on the proximal side of the suction tube 14, the rigidity is high on the proximal side of the suction catheter 10. Therefore, in this case, it is possible to suppress a decrease in force transmission and kink resistance when the suction catheter 10 is inserted into the body, and as a result, it is possible to suppress a decrease in operability when the suction catheter 10 is inserted into the body. can do.

  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. Here, in the suction catheter 10 described above, the intermediate layer 29 is provided in part in the range where the suction tube 14 overlaps with the guide wire tube 15 in the axial direction. Therefore, the intermediate layer 29 is provided in the overlapping range. The strength of the distal end side of the suction tube 14 is increased compared to the case where the suction tube 14 is not. Thereby, since it can suppress that the suction tube 14 is crushed when the suction lumen 17 is set to a negative pressure, the above-described decrease in operability can be suppressed while suppressing a decrease in suction performance. .

  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.

  In the intermediate layer 29, the inclination angle α of the reinforcing wire 35 is made smaller in the low-rigidity region 52 than in the regions 51 and 53 on the more proximal side than that in the lower-rigid region 52. By increasing the winding pitch of the reinforcing wire 35 as compared with the regions 51 and 53 on the side, the rigidity in the low-rigid region 52 is reduced as compared with the regions 51 and 53 on the proximal side. In this case, the rigidity of the low-rigidity region 52 is made higher than that by a simple method of changing the inclination angle α (in other words, the winding pitch) of the reinforcing wire 35 at an intermediate position in the axial direction of the proximal suction tube 21. It can be made lower than the proximal regions 51 and 53. Therefore, it is possible to relatively easily obtain the above-described effect of suppressing a decrease in operability by suppressing a decrease in force transmission and kink resistance when the suction catheter 10 is inserted into the body.

  In the suction tube 14, the proximal suction tube 21 having the intermediate layer 29 (braided layer) is disposed so that the distal end portion thereof is located at an intermediate position in the axial direction of the guide wire tube 15. A distal suction tube 22 having no braided layer is provided on the distal side. In this case, a portion where the braided layer is provided and a portion where the intermediate layer 29 (braided layer) is not provided (non-braided region) in a range overlapping the guide wire tube 15 in the axial direction in the suction tube 14. The former is disposed on the proximal side and the latter is disposed on the distal side. Therefore, in the region on the distal end side where the guide wire tube 15 is provided, the rigidity thereof can be made lower on the distal side than on the proximal side, and as a result, the insertion of the suction catheter 10 can be improved. You can plan.

  An outer layer 28 provided outside the intermediate layer 29 in the peripheral wall portion of the suction tube 14 (proximal suction tube 21) is composed of a plurality of outer layers 31 to 34 arranged in the axial direction, and the rigidity of each of the outer layers 31 to 34 is determined. Was formed so as to become smaller from the proximal one toward the distal one. In this case, in addition to the intermediate layer 29, the outer layer 28 is also formed so that the rigidity decreases from the proximal side to the distal side, so that the rigidity of the suction catheter 10 is increased from the proximal side to the distal side. Therefore, it becomes a more preferable configuration for lowering.

  In addition, since the proximal end portion of the low-rigidity region 52 is disposed at an intermediate position in the axial direction of the outer layer 34, the position where the rigidity of the intermediate layer 29 switches between large and small is shifted in the axial direction from the position where the rigidity of the outer layer 28 switches. ing. In this case, since the rigidity of the suction catheter 10 can be lowered in multiple stages from the proximal side to the distal side by the intermediate layer 29 and the outer layer 28, the insertion property of the suction catheter 10 is further improved. be able to.

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

  (1) In the above embodiment, the winding pitch of the reinforcing wire 35 is increased in the low rigidity region 52 in the intermediate layer 29 as compared with the high rigidity region 51 (in other words, in the low rigidity region 52, the high rigidity region 51 The rigidity of the low-rigidity region 52 is made smaller than the rigidity of the high-rigidity region 51 by reducing the inclination of the reinforcing wire 35 with respect to the axial direction of the suction tube 14 as compared with the high-rigidity region 51. The configuration for lowering the rigidity is not necessarily limited to this. For example, the low rigidity region 52 may be formed with a lower rigidity than the high rigidity region 51 by reducing the number of reinforcing wires 35 in the low rigidity region 52 as compared with the high rigidity region 51. A specific example is shown in FIG.

  In FIG. 5, the high rigidity region 61 and the low rigidity region 62 are provided adjacent to each other in the intermediate layer 29, and the transition region 53 is not provided between these regions 61 and 62. The high-rigidity region 61 and the low-rigidity region 62 are configured by different braided bodies 64 and 65, respectively, and a reinforcing wire 66 that constitutes the first braided body 64 and a reinforcing wire 67 that constitutes the second braided body 65. Are discontinuous with each other. Each braided body 64, 65 is formed of the same material and the same wire diameter. Each braided body 64, 65 has the same inclination (inclination angle α) of the reinforcing wires 66, 67 with respect to the axial direction of the proximal suction tube 21, and therefore the winding pitch of the reinforcing wires 66, 67 is also the same. It is the same. However, each braided body 64, 65 has a different number of reinforcing wires 66, 67. Specifically, the second braided body 65 has fewer reinforcing wires than the first braided body 64. It has become. In this case, the amount of the reinforcing wires 66 and 67 per unit length in the axial direction of the proximal suction tube 21 is smaller in the low-rigidity region 62 than in the high-rigidity region 61. The rigidity of the low rigidity region 62 can be made lower than the rigidity of the high rigidity region 61.

  (2) In the low-rigidity region 52, only one intermediate layer 29 is provided, whereas in the high-rigidity region 51, a plurality of braid layers are provided in the radial direction, so that the low-rigidity region 52 has lower rigidity than the high-rigidity region 51. It may be made to become. For example, in the configuration of the above embodiment, in the high rigidity region 51, another braided body may be provided on the outer peripheral side of the intermediate layer 29 to form an inner and outer double braided layer. Even in this case, the rigidity of the low-rigidity region can be made lower than that of the high-rigidity region.

  (3) In the above embodiment, by utilizing the characteristic that the rigidity of the intermediate layer 29 (braided body 30) becomes higher as the inclination angle α of the reinforcing wire 35 becomes smaller, the low-rigidity region 52 is more proximal than that. The inclination angle α of the reinforcing wire 35 is made smaller than that of the reinforcing wire 35. However, when the strength (rigidity) of the reinforcing wire 35 is large, for example, the relationship between the inclination angle α of the reinforcing wire 35 and the rigidity of the intermediate layer 29 is May reverse. That is, the rigidity of the intermediate layer 29 may increase as the inclination angle α of the reinforcing wire 35 decreases. An example in that case is shown in FIG.

  In FIG. 6, unlike the above embodiment, in the intermediate layer 29, the inclination angle α of the reinforcing wire 75 is larger in the low rigidity region 72 than in the high rigidity region 71. Specifically, the inclination angle α of the reinforcing wire 75 increases in the order of the high rigidity region 71, the transition region 73, and the low rigidity region 72. In this case, although the mesh (mesh) of the braided body 70 is finer in the above order, the rigidity of the intermediate layer 29 is lowered in the above order. This is because in this example, the strength (rigidity) of the reinforcing wire 75 itself is greater than that of the reinforcing wire 35 of the above embodiment. Specifically, the cross-sectional area of the reinforcing wire 75 is larger than the cross-sectional area of the reinforcing wire 35 in the above-described embodiment. For example, the cross-sectional area is set to 0.003 to 0.00785 mm 2. Moreover, as a flat wire, what has the width | variety more than thickness can be used, for example, the thing of thickness: width = 1: 1 to 1: 5 can be used. When the reinforcing wire 75 is formed of a round wire, it is conceivable to set the wire diameter to, for example, 0.06 to 0.1 mm.

  This point will be described in more detail. When the inclination angle α of the reinforcing wire 75 is large, the reinforcing wire 75 is unlikely to be a bending resistance when the suction catheter 10 is bent in a direction orthogonal to the axial direction. On the other hand, when the inclination angle α of the reinforcing wire 75 is small, the reinforcing wire 75 tends to be a bending resistance. Therefore, from this point, it can be considered that the rigidity of the intermediate layer 29 (braided body 70) increases as the inclination angle α of the reinforcing wire 75 decreases. Therefore, in the present example using the reinforcing wire 75 having a high strength, this tendency appears strongly. As a result, the inclination angle of the reinforcing wire 75 in the order of the high rigidity region 71, the transition region 73, and the low rigidity region 72. By increasing α, the rigidity of the intermediate layer 29 is lowered in this order.

  Even in such a configuration, similarly to the above-described embodiment, the high rigidity region 71, the transition region can be obtained by a simple method of changing the inclination angle α (in other words, the winding pitch) of the reinforcing wire 75 in the middle of the axial direction. 73, the rigidity can be lowered in the order of the low rigidity region 72. Therefore, in the suction catheter 10 having the guide wire tube 15, the effect of improving the operability can be obtained relatively easily.

  (4) In the configuration of the above embodiment, a braided layer may be provided on the distal suction tube 22 in addition to the proximal suction tube 21. For example, it is conceivable to provide a braided layer in the entire axial direction of the distal suction tube 22. In this case, the braided layer is provided over the entire overlapping range (hereinafter also referred to as the guide wire tube overlapping range) overlapping the guide wire tube 15 in the axial direction in the suction tube 14, and the distal end portion of the suction tube 14 It becomes possible to reinforce the suction tube 14 until it extends over.

  In this case, the braided layer provided on the distal suction tube 22 is preferably formed so that its rigidity is lower than that of the intermediate layer 29 of the proximal suction tube 21. By doing so, the rigidity in the region where the guide wire tube 15 is provided in the suction tube 14 can be lowered from the proximal side to the distal side, so that the kink resistance can be improved in the region. it can. Further, there is an advantage that it is possible to suppress a decrease in flexibility at the distal end portion of the tube 14 while reinforcing the distal end portion of the suction tube 14.

  (5) When the suction catheter 10 of the above embodiment is introduced into the coronary artery via the descending aorta, the aortic arch and the ascending aorta, and the coronary artery is removed by suction, the highly rigid portion of the suction catheter 10 becomes the aortic arch. If it is arranged, the operability may be lowered. Therefore, in view of this point, it is conceivable to set a boundary portion between the high-rigidity region 51 and the low-rigidity region 52 in the intermediate layer 29 on the proximal side of the portion disposed on the aortic arch in the suction catheter 10. . In this case, when the suction catheter 10 is introduced into the coronary artery, the low-rigidity region 52 is disposed over the entire region, so that it is possible to prevent a decrease in operability.

  (6) In the above embodiment, the braided body 30 formed by braiding a plurality of reinforcing wires 35 is embedded in the suction tube 14 as a reinforcing member, but this is changed and one reinforcing wire spirals in the axial direction. A coil-shaped reinforcing body wound in a shape may be embedded in the suction tube 14. In this case, in the suction tube 14, it is possible to suppress a decrease in flexibility due to the embedding of the reinforcing body, and thus it is possible to suppress a decrease in followability when the suction tube 14 is inserted into the bent blood vessel.

  (7) In the above embodiment, the intermediate layer 29 has been described as corresponding to the reinforcing layer. However, a combination of the outer layer 28 (outer layer resin) and the braided body 30 (corresponding to the reinforcing body) or an inner layer 27 (inner layer). A combination of the resin) and the braided body 30 can be regarded as a reinforcing layer. Or what combined other resin and the braided body 30 may be considered as a reinforcement layer. In short, a portion where the braided body 30 (reinforcing body) is embedded in the proximal suction tube 21 can be regarded as a reinforcing layer.

  (8) Although the case where the present invention is applied to the suction catheter has been described in the above embodiment, the present invention may be applied to other catheters having a guide wire tube.

  DESCRIPTION OF SYMBOLS 10 ... Suction catheter as a catheter, 14 ... Suction tube as a main tube, 15 ... Guide wire tube, 18 ... Guide wire lumen as a lumen, 28 ... Outer layer, 29 ... Braided layer as a reinforcing layer, 30 ... As a reinforcing body The outer layer as an outer layer region, 35 ... the reinforcing wire, 52 ... the low rigidity region.

Claims (6)

The main tube,
A guide wire tube provided on the distal end side of the main tube and having a lumen through which the guide wire can be inserted, and
The main tube includes a reinforcing layer in which a reinforcing body formed by winding a reinforcing wire in the axial direction of the main tube is embedded in a peripheral wall portion thereof.
The reinforcing layer extends in the axial direction from the proximal side of the guide wire tube to the distal side of the proximal end portion of the guide wire tube,
The predetermined range including at least an overlapping portion overlapping with the guide wire tube in the axial direction in the reinforcing layer is a low rigidity region formed so as to have lower rigidity than the proximal side. A catheter characterized by that.   In the reinforcing layer, the rigidity of the low-rigidity region is made closer to the low-rigidity region and the region closer to the low-rigidity region by making the inclination of the reinforcing line different from the axial direction of the main tube. The catheter according to claim 1, wherein the catheter is lower than the distal region.   In the reinforcing layer, the rigidity of the low-rigidity region is more proximal in the low-rigidity region by reducing the inclination of the reinforcing line relative to the axial direction of the main tube than in the proximal side. The catheter according to claim 2, wherein the catheter is lower than the side. The reinforcing layer has a distal end portion in the middle of the guide wire tube in the axial direction,
The catheter according to any one of claims 1 to 3, wherein a non-reinforcing region in which the reinforcing layer does not exist is provided on the distal side of the reinforcing layer in the main tube. The peripheral wall portion of the main tube has an outer layer made of a resin material on the outer peripheral side of the reinforcing layer,
The outer layer has a plurality of outer layer regions aligned in the axial direction, and the plurality of outer layer regions are formed so that the rigidity decreases from the proximal one toward the distal one,
The catheter according to any one of claims 1 to 4, wherein a proximal end portion of the low-rigidity region is located at an intermediate position in the axial direction of the outer layer region. A suction catheter used to suck and remove foreign matter,
The catheter according to any one of claims 1 to 5, wherein the main tube is a suction tube having a suction lumen.

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