Contrast catheter

Abstract

To provide a contrast catheter that can simplify manipulation for delivering a suction catheter to a lesion part, and reduce the number of devices to be used.SOLUTION: A contrast catheter 10 is a catheter comprising a long tubular shaft 20. The shaft 20 comprises: a base part 23 extending along a long axis direction, and whose outside diameter is 5.0 mm to 7.0 mm; a tip part 22 arranged on the tip side of the base part 23, and whose outside diameter is 1.3 mm to 3.3 mm; and an intermediate part 24 whose outside diameter is decreased toward a base end of the tip part 22 from a tip of the base part 23.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to an angiography catheter used when inserting an aspiration catheter for aspirating thrombi into a blood vessel. [Background technology]

[0002] Pulmonary embolism is a disease in which a blood clot blocks the pulmonary artery, causing breathing difficulties, etc., and requires treatment to remove the blood clot as soon as possible. A suction catheter with an outer diameter of about 5.3 mm to 8.0 mm is usually used to treat pulmonary embolism.

[0003] When inserting the suction catheter into a blood vessel, a dilator is inserted inside to improve support. As the dilator, for example, as shown in Patent Document 1, a device having a long shaft and a tapered portion near the tip of the shaft whose outer diameter becomes smaller from the base end toward the tip can be used. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] International Publication No. 2009 / 014723 Summary of the Invention [Problem to be solved by the invention]

[0005] Since the outer diameter of the suction catheter is relatively large, a highly supportive guidewire must be inserted into the blood vessel to reach the lesion where the thrombus is located. For this reason, in the treatment of pulmonary embolism using a suction catheter, a contrast catheter with a guidewire inserted therethrough is first delivered to the lesion, and the guidewire is replaced with a highly supportive guidewire while the contrast catheter is still in place. Next, the contrast catheter is removed, and a catheter assembly with a dilator inserted into the lumen of the suction catheter is inserted into the blood vessel and delivered to the lesion along the highly supportive guidewire. Once the suction catheter has been delivered to the lesion, the dilator is removed, and suction of the thrombus begins.

[0006] Thus, when aspirating thrombi, multiple devices must be repeatedly inserted and removed, making the procedure complicated.

[0007] The present invention has been made to solve the above-mentioned problems, and aims to provide a contrast catheter that can simplify the procedure of delivering a suction catheter to a lesion and reduce the number of devices used. [Means for solving the problem]

[0008] The contrast catheter (1) according to the present invention which achieves the above-mentioned object is a catheter having a long tubular shaft, the shaft having a base portion extending along the longitudinal direction and having an outer diameter of 5.0 mm to 7.0 mm, a tip portion located distal to the base portion and having an outer diameter of 1.3 mm to 3.3 mm, and an intermediate portion whose outer diameter decreases from the tip of the base portion toward the base end of the tip portion. Effect of the Invention

[0009] The contrast catheter configured as described above has a large base diameter, so it can support a large diameter suction catheter, and has a thin tip, so it can be inserted to the lesion in the same way as a normal contrast catheter. Therefore, the contrast catheter can be inserted near the lesion and the suction catheter can be inserted to the lesion, simplifying the procedure of delivering the suction catheter to the lesion.

[0010] (2) In the contrast catheter of (1) above, the tip portion may have a three-dimensional shape including a base curved portion, an intermediate curved portion, and a tip curved portion, thereby enabling the contrast catheter to be easily inserted into a path having complex bends.

[0011] (3) In the contrast catheter of (1) or (2) above, the intermediate portion may have a longitudinal length of 50 mm to 200 mm. As a result, the contrast catheter has a tapered portion that is long in the longitudinal direction, and the dimensional difference and physical property difference between the tip and base of the contrast catheter change gradually along the longitudinal direction. Since the dimensional difference changes gradually along the longitudinal direction, the risk of damage to the vascular wall or thrombus detachment can be reduced when the contrast catheter is inserted into a blood vessel. Furthermore, since the physical property difference changes gradually along the longitudinal direction, the deliverability of the contrast catheter can be improved. As a result, the risk of damage to the vascular wall or thrombus detachment can be reduced when the contrast catheter and the suction catheter are inserted into a blood vessel. Furthermore, since the physical property difference changes gradually along the longitudinal direction, the deliverability of the contrast catheter and the suction catheter can be improved.

[0012] (4) In any of the contrast catheters (1) to (3) above, a detachable hub may be provided at the base end of the shaft, whereby when inserting the suction catheter into a blood vessel, the hub can be removed to insert the suction catheter without removing the contrast catheter, simplifying the procedure.

[0013] (5) In any of the contrast catheters (1) to (4) above, the outer diameter of the tip portion of the shaft may be larger than the outer diameter of the base portion, and the outer diameter of the intermediate portion may be decreased from the tip of the base portion toward the base end of the tip portion. This allows the thickness of the shaft to decrease from the base portion toward the tip portion, thereby ensuring the rigidity of the base portion while increasing the flexibility of the tip portion.

[0014] (6) In any of the contrast catheters (1) to (5) above, the shaft may have a base rigid section, a tip flexible section located distally of the base rigid section and more flexible than the base rigid section, and an intermediate property transition section whose physical properties change from the tip of the base rigid section toward the base end of the tip flexible section. This allows the base of the shaft to have high rigidity and the tip to have high flexibility, making it easy to insert into a blood vessel and providing sufficient support when inserting the suction catheter.

[0015] (7) In the contrast catheter according to any one of (1) to (6) above, at least a portion of the tip portion may have a constant rigidity along the longitudinal direction, which makes it easier to insert the contrast catheter into a curved blood vessel. [Brief description of the drawings]

[0016] [Figure 1] FIG. 2 is an overall front view of the contrast catheter and the suction catheter according to the present embodiment. [Diagram 2] 1 is an enlarged cross-sectional view of the vicinity of the middle portion of an imaging catheter in a state in which the imaging catheter is inserted into the suction catheter. FIG. [Diagram 3] FIG. 2 is a front view of the vicinity of the tip of a contrast catheter inserted into a suction catheter. [Figure 4] 1A and 1B are diagrams showing the tip of a contrast catheter, where (a) is a plan view, (b) is a view taken along the line B in (a), and (c) is a view taken along the line C in (a). [Diagram 5] 1 is a cross-sectional view of a proximal end portion of a sheath device in a state where an angiography catheter is inserted into a blood vessel. FIG. [Figure 6] FIG. 2 is a partial cross-sectional view of a state in which the tip of a contrast catheter is inserted into a heart. [Figure 7] 13 is a cross-sectional view of the vicinity of the base end of the sheath device in a state in which an aspiration catheter is inserted into a blood vessel along with the contrast catheter from which the hub has been removed. FIG. [Figure 8] 13 is a cross-sectional view of the proximal end portion of the sheath device in a state where the hub of the aspiration catheter is attached after the hub of the contrast catheter is inserted from the proximal end portion of the contrast catheter to the distal end side. FIG. [Figure 9] FIG. 11 is an enlarged cross-sectional view of the vicinity of the middle portion of a shaft according to a modified example. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0017] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. Note that dimensions in the drawings may be exaggerated and may differ from actual dimensions for convenience of explanation. In addition, in this specification and the drawings, components having substantially the same functional configurations are given the same reference numerals to avoid duplicated explanation. In this specification, the side of the device that is inserted into the living body is referred to as the "distal side" and the side that is operated is referred to as the "base side".

[0018] The contrast catheter 10 of this embodiment is a medical device used in the treatment of pulmonary embolism, and is used when inserting into a blood vessel a suction catheter 13 that is inserted into a pulmonary artery to suction thrombi.

[0019] As shown in FIG. 1, the contrast catheter 10 has a long tubular shaft 20 and a hub 21 provided at the base end of the shaft 20. The hub 21 can be removed from the shaft 20. However, the hub 21 may be fixed with an adhesive or the like so that it cannot be removed from the shaft 20. The hub 21 is formed so as to be screwed onto the base end 20a of the shaft 20. The shaft 20 has a base portion 23 with a large outer diameter, a tip portion 22 arranged on the tip side of the base portion 23 and having a smaller outer diameter than the base portion 23, and a tapered intermediate portion 24 whose outer diameter decreases from the tip of the base portion 23 toward the base end of the tip portion 22. The tip portion 22 of the shaft 20 has a three-dimensional shape that is bent multiple times. At least a part of the tip portion 22 in the long axis direction has constant inner and outer diameters and also has constant rigidity.

[0020] The suction catheter 13 has a long tubular suction shaft 40 and a hub 41 provided at the base end of the suction shaft 40. The hub 41 allows the contrast catheter 10 to be inserted and allows a device for suction to be connected. In addition, a valve body 41a is provided inside the hub 41, through which the inserted device passes and which prevents fluid from flowing out from the suction shaft 40 side.

[0021] Each tube of the contrast catheter 10 and the suction catheter 13 is formed so as to have an outer layer on the outside of an inner layer having a lumen. The inner layer is preferably formed of a low-friction material so that the guide wire 14 can slide easily inside. The low-friction material is, for example, fluororesin such as PTFE (polytetrafluoroethylene) and PFA (tetrafluoroethylene-perfluoroalkoxyethylene copolymer) or silicone resin, but is not limited thereto. The material constituting the outer layer is not particularly limited, but examples thereof include polystyrene, polyolefin, polyurethane, polyester, polyamide, styrene-based, polyolefin-based, polyurethane-based, polyester-based, polyamide-based, polybutadiene-based, transpolyisoprene-based, fluororubber-based, chlorinated polyethylene-based, and other thermoplastic elastomers, polyether ketone, polyimide-based, and the like, and one or a combination of two or more of these (polymer alloy, polymer blend, laminate, etc.) can be used. Alternatively, among various elastomers, polyester elastomer, polyamide elastomer, etc. can be preferably used. Each tube may also have a reinforcing layer made of a braid between the inner layer and the outer layer.

[0022] At least the outer circumferential surface of the tip of the shaft 20 of the contrast catheter 10 may be coated with a lubricating coat. The lubricating coat is applied over a range from the tip of the shaft 20 to a predetermined distance (e.g., 400 mm) in the proximal direction. The lubricating coat is, for example, a hydrophilic polymer, and examples of the lubricating coat include cellulose-based polymers, polyethylene oxide-based polymers, maleic anhydride-based polymers (e.g., maleic anhydride copolymers such as methyl vinyl ether-maleic anhydride copolymers), acrylamide-based polymers (e.g., polyacrylamide, glycidyl methacrylate-dimethylacrylamide block copolymers), water-soluble nylon, polyvinyl alcohol, polyvinylpyrrolidone, and derivatives thereof. The hydrophilic polymer forms a strong water immobilization layer on its surface, and exhibits high affinity to the blood in the blood vessel and the blood vessel wall surface, as well as low friction. Alternatively, the lubricating coat may be a fluorine-based resin such as polytetrafluoroethylene (PTFE), a low-friction material such as high-density polyethylene (HDPE), and the like.

[0023] As shown in FIG. 2, the base portion 23 of the angiography catheter 10 is inserted into the lumen 43 of the suction catheter 13, and the intermediate portion 24 and the tip portion 22 are exposed on the tip side from the tip of the suction catheter 13. The inner diameter D1 of the angiography catheter 10 is 0.89 mm to 1.40 mm, and is constant over the base portion 23, the intermediate portion 24, and the tip portion 22. The outer diameter D2 of the angiography catheter 10 at the tip portion 22 is 1.3 mm to 3.3 mm. The outer diameter D3 of the angiography catheter 10 at the base portion 23 is 5.0 mm to 7.0 mm. The inner diameter D4 of the suction catheter 10 is 5.0 mm to 8.0 mm, and preferably 5.5 mm to 7.5 mm. The outer diameter D5 of the suction catheter 13 is 6.0 mm to 8.0 mm.

[0024] The shaft 20 of the contrast catheter has a constant inner diameter, but the outer diameter changes so that the wall thickness decreases from the base portion 23 to the tip portion 22, so that the base portion 23 is rigid, the tip portion 22 is flexible, and the physical properties transition along the longitudinal direction in the intermediate portion 24. That is, the shaft 20 has a rigid base portion, a flexible tip portion, and an intermediate transition portion.

[0025] The intermediate portion 24 of the contrast catheter 10 has a length along the longitudinal direction of 50 mm to 200 mm. Since the intermediate portion 24 is long in the longitudinal direction, the difference in size and physical properties between the contrast catheter 10 and the suction catheter 13 through which the contrast catheter 10 is inserted changes gradually along the longitudinal direction. Since the difference in size changes gradually along the longitudinal direction, the risk of damage to the blood vessel wall or thrombus detachment can be reduced when the suction catheter 13 through which the contrast catheter 10 is inserted is inserted into a blood vessel. Furthermore, since the difference in physical properties changes gradually along the longitudinal direction, the deliverability can be improved when the contrast catheter 10 and the suction catheter 13 are combined.

[0026] 3, the distal end portion 22 of the angiography catheter 10 is exposed distally beyond the distal end of the aspiration shaft 40. The guidewire 14 protrudes distally beyond the distal end of the angiography catheter 10.

[0027] As shown in Figures 4(a) to (c), the tip portion 22 has a base curved portion 22a, a base straight portion 22b, an intermediate curved portion 22c, an intermediate straight portion 22d, a tip curved portion 22e, and a most distal portion 22f.

[0028] The base curved portion 22a extends from the tip of the base portion 23, which is closer to the base end than the tip portion 22, toward the tip side, and is curved within a plane. The base straight portion 22b extends from the tip of the base curved portion 22a in a substantially straight line toward the tip side. The middle curved portion 22c extends from the tip of the base straight portion 22b toward the tip side, and is curved within a plane. The middle curved portion 22c is curved in a direction different from the bending direction of the base curved portion 22a. The middle straight portion 22d extends from the tip of the middle curved portion 22c in a substantially straight line toward the tip side. The tip curved portion 22e extends from the tip of the middle straight portion 22d toward the tip side, and is curved within a plane. The most distal portion 22f extends from the tip of the tip curved portion 22e in a substantially straight line toward the tip side. The lumen of the shaft 20 opens at the tip of the most distal portion 22f. The axis of the most distal portion 22f is not located on an extension of the axis of the intermediate straight portion 22d.

[0029] The angle α1 that base straight portion 22b makes with respect to an extension line extending from the tip side part of base 23 toward the tip side is greater than 0° and less than 90°, and is preferably 40° to 85°, and more preferably 40° to 80°. When angle α1 is less than 90°, it can be easily inserted into a curved path from inside the heart toward the pulmonary artery, and a pushing force can be easily transmitted to the tip side.

[0030] The angle α2 that the intermediate straight portion 22d makes with respect to an extension line extending from the base straight portion 22b toward the tip is not particularly limited, but is approximately parallel or exceeds 0° and is less than 180°, is preferably 100° to 175°, and is more preferably 110° to 170°.

[0031] The angle α3 that the most distal portion 22f makes with respect to an extension line extending from the intermediate straight portion 22d toward the tip direction is not particularly limited, but is greater than 0° and less than 180°, preferably 5° to 80°, and more preferably 10° to 60°. The most distal portion 22f is not positioned coaxially with the intermediate straight portion 22d.

[0032] The axis centers of the tip side portion of the base 23, the base curved portion 22a and the base straight portion 22b, are located on the first plane P1. The axis centers of the intermediate curved portion 22c and the intermediate straight portion 22d are located on the second plane P2. The axis centers of the tip curved portion 22e and the most distal portion 22f are located on the third plane P3. The axis center of the base straight portion 22b located on the first plane P1 may also be located on the second plane P2. The axis center of the intermediate straight portion 22d located on the second plane P2 may also be located on the third plane P3.

[0033] The second plane P2 is a plane different from the first plane P1. The angle β of the second plane P2 with respect to the first plane P1 on the distal side of the base curved portion 22a is more than 0° and less than 180°, preferably 30° to 150°, and more preferably 80° to 100°. Since the second plane P2 is different from the first plane P1, the shaped portion 24 having the base curved portion 22a and the intermediate curved portion 22c can have a twisted shape that draws a three-dimensional spiral. Therefore, the distal end portion 22 of the shaft 20 is easily aligned with the inner wall surface of the blood vessel, and the posture within the blood vessel is easily stabilized. In addition, when the proximal end portion of the contrast catheter 10 is rotated in the direction in which the contrast catheter 10 is wound toward the distal end side, the rotational force is efficiently transmitted to the distal end side, making it easy to push the contrast catheter 10 toward the distal end.

[0034] The third plane P3 is a plane different from the first plane P1 and the second plane P2. The third plane P3 may coincide with the second plane P2, but it is preferable that the third plane P3 does not coincide with the second plane P2. By not coinciding with the second plane P2, the opening of the most distal portion 22f can be oriented in a direction different from the curvature of the intermediate curved portion 22c.

[0035] In this embodiment, the distal curved portion 22e is bent from the base end side toward the tip end side away from the first plane P1. Therefore, the most distal end portion 22f extends from the base end side toward the tip opening 31 so as to move away from the first plane P1. The distal curved portion 22e is bent from the base end side toward the tip end side toward the opposite side of the side where the base portion 23 is located with respect to the second plane P2. Therefore, the most distal end portion 22f extends from the base end side toward the tip opening 31 toward the opposite side of the side where the base portion 23 is located with respect to the second plane P2. The distal curved portion 22e may be bent from the base end side toward the tip end side toward the side approaching the first plane P1. The distal curved portion 22e may be bent from the base end side toward the tip end side on a plane parallel to the first plane P1. The distal curved portion 22e may be bent from the base end side toward the tip end side toward the opposite side of the side where the base portion 23 is located from the second plane P2. It should be noted that base straight portion 22b, intermediate straight portion 22d and tip end portion 22f need only be substantially straight and do not have to be formed as strictly straight lines.

[0036] If the minimum radius of curvature at the base curved portion 22a is R1, the minimum radius of curvature at the middle curved portion 22c is R2, and the minimum radius of curvature at the tip curved portion 22e is R3, then R1>R2>R3 is satisfied. That is, R2 is smaller than R1, and R3 is smaller than R2. The minimum radius of curvature is the radius of curvature of the portion with the smallest radius of curvature among the curved portions.

[0037] Next, a description will be given of a treatment method using the contrast catheter 10 and the suction catheter 13 of this embodiment. The contrast catheter 10 and the suction catheter 13 are used for treating pulmonary embolism.

[0038] First, an insertion path into a blood vessel is secured. To this end, the surgeon percutaneously inserts a sheath device 15 into the femoral vein. As shown in FIG. 5, the surgeon inserts an angiography catheter 10, through which a guidewire 14 has been inserted, into the vein via the sheath device 15. At this time, a hub 21 is attached to the angiography catheter 11. The hub 21 has a luer taper portion 21a at its base end for connecting an instrument such as a syringe. The surgeon pushes the angiography catheter 10 into the vein while leading the guidewire 14.

[0039] 6, the angiography catheter 10 enters the right atrium 103 of the heart 100 from the inferior vena cava 101, passes through the right ventricle 104, and heads toward the pulmonary artery 102. Because the tip 22 of the angiography catheter 10 has the three-dimensional shape described above, the surgeon can easily push the tip 22 through the tortuous path within the heart 100.

[0040] When the tip of the angiography catheter 10 reaches the vicinity of the lesion, the surgeon removes the hub 21 of the angiography catheter 10 and advances the suction catheter 13 into the vein through the sheath device 15. As shown in FIG. 7, by removing the hub 21 of the angiography catheter 10, the suction shaft 40 of the suction catheter 13 can be inserted into the sheath device 15.

[0041] The suction catheter 13 can be inserted into the blood vessel along the guide wire 14 and the angiography catheter 10 to the lesion. The hub 41 of the suction catheter 13 can be pushed forward from the base end of the shaft 20 of the angiography catheter 10 to the tip side. At this time, the shaft 20 of the angiography catheter 10 penetrates the valve body 41a provided on the hub 41 of the suction catheter 13. The base end 20a of the shaft 20 is tapered, so that the valve body 41a can be easily penetrated. After the base end 20a of the shaft 20 penetrates the valve body 41a of the suction catheter 13, the hub 21 can be reattached to the base end 20a of the shaft 20 as shown in FIG. 8.

[0042] Once the suction catheter 13 has reached the lesion in the pulmonary artery, the surgeon removes the angiography catheter 10 and the guidewire 14. Next, the surgeon connects a suction device to the hub 41 of the suction catheter 13 and starts suctioning the thrombus. Alternatively, the surgeon may insert an assembly of the angiography catheter 10 with the hub 41 fixed to the suction catheter 13 into a blood vessel along the guidewire 14 through the sheath device 15, and after the assembly reaches the lesion in the pulmonary artery, the surgeon may remove the angiography catheter 10 and the guidewire 14, connect a suction device to the hub 41 of the suction catheter 13, and start suctioning the thrombus.

[0043] After the thrombus has been aspirated, the surgeon removes the suction catheter 13 from the blood vessel, completing the procedure.

[0044] As described above, the contrast catheter 10 (1) according to this embodiment is a catheter having a long tubular shaft 20, and the shaft 20 has a base portion 23 extending along the longitudinal direction and having an outer diameter of 5.0 mm to 7.0 mm, a tip portion 22 located distal to the base portion 23 and having an outer diameter of 1.3 mm to 3.3 mm, and an intermediate portion 24 whose outer diameter decreases from the tip of the base portion 23 toward the base end of the tip portion 22. The contrast catheter 10 thus configured can support the suction catheter 13 having a large outer diameter because the base portion 23 has a large outer diameter, and can be inserted to a lesion as in the case of a normal contrast catheter 10 because the tip portion 22 is thin. Therefore, the contrast catheter 10 can insert the suction catheter 13 to the lesion while the contrast catheter 10 is inserted and placed near the lesion, and therefore the procedure for delivering the suction catheter 13 to the lesion can be simplified.

[0045] (2) In the contrast catheter 10 described above in (1), the tip portion 22 may have a three-dimensional shape including the base curved portion 22a, the intermediate curved portion 22c, and the tip curved portion 22e. This allows the contrast catheter 10 to be easily inserted into a complicatedly curved path.

[0046] (3) In the contrast catheter 10 of (1) or (2) above, the intermediate portion 24 may have a longitudinal length of 50 mm to 200 mm. As a result, the contrast catheter 10 has a tapered portion that is long in the longitudinal direction, so that the dimensional difference and physical property difference between the tip and base portions of the contrast catheter 10 change gradually along the longitudinal direction. Since the dimensional difference changes gradually along the longitudinal direction, the risk of damage to the vascular wall or thrombus detachment can be reduced when the contrast catheter 10 is inserted into a blood vessel. Furthermore, since the physical property difference changes gradually along the longitudinal direction, the deliverability of the contrast catheter 10 can be improved. As a result, the risk of damage to the vascular wall or thrombus detachment can be reduced when the contrast catheter 10 and the suction catheter 13 are inserted into a blood vessel. Furthermore, since the physical property difference changes gradually along the longitudinal direction, the deliverability of the contrast catheter 10 and the suction catheter 13 can be improved.

[0047] (4) In any of the contrast catheters 10 described above in (1) to (3), a removable hub 21 may be provided at the base end 20a of the shaft 20. In this way, when inserting the suction catheter 13 into a blood vessel, the hub 21 can be removed, allowing the insertion of the suction catheter 13 without removing the contrast catheter 10, simplifying the procedure.

[0048] (5) In any of the contrast catheters 10 described above in (1) to (4), the outer diameter of the tip portion 22 of the shaft 20 may be larger than the outer diameter of the base portion 23, and the outer diameter of the intermediate portion 24 may be smaller from the tip of the base portion 23 toward the base end of the tip portion 22. This allows the wall thickness of the shaft 20 to be smaller from the base portion 23 toward the tip portion 22, thereby ensuring the rigidity of the base portion 23 while increasing the flexibility of the tip portion 22.

[0049] (6) In any of the contrast catheters 10 described above in (1) to (5), the shaft 20 may have a base rigid portion, a tip flexible portion located distally of the base rigid portion and more flexible than the base rigid portion, and an intermediate property transition portion whose property changes from the tip of the base rigid portion toward the base end of the tip flexible portion. This allows the base portion 23 of the shaft 20 to have high rigidity and the tip portion 22 to have high flexibility, making it easy to insert into a blood vessel and providing sufficient support when inserting the suction catheter 13.

[0050] (7) In any one of the contrast catheters 10 described above in (1) to (6), at least a portion of the tip portion 22 may have a constant rigidity along the longitudinal direction, which allows the contrast catheter 10 to be easily inserted into a curved blood vessel.

[0051] The present invention is not limited to the above-mentioned embodiment, and various modifications can be made by those skilled in the art within the technical concept of the present invention. In the above-mentioned embodiment, the shaft 20 has a base rigid portion, a tip flexible portion, and an intermediate transition portion by changing the outer diameter of the shaft 20, but the inner diameter of the shaft 20 may be changed. As shown in FIG. 9, the shaft 20 may have a large outer diameter at the base 27, a small outer diameter at the tip 26, and an outer diameter that changes along the longitudinal direction at the intermediate portion 28. The shaft 20 may have a constant inner and outer diameter, and the physical properties of the resin may be changed. Alternatively, the inner diameter of the base 27 may be constant, and the inner diameter of the tip 26 may be small. In these cases, the shaft 20 is configured such that the resin used at the base is highly rigid, the resin used at the tip is less rigid and flexible, and the physical properties of the resin transition at the intermediate portion. [Explanation of symbols]

[0052] 10. Contrast Catheter 13 Suction catheter 14 Guidewire 15 Sheath Device 20 Shaft 20a Proximal end 21 Hub 21a Fixed part 22 Tip 23 Base 24 Middle section 25 lumen 26 Tip 27 Base 28 Middle Section 40 Suction shaft 41 Hub 41a Valve body 43 Lumen

Claims

1. A contrast catheter having a long tubular shaft, The shaft is an angiographic catheter having a base portion extending along the longitudinal axis and having an outer diameter of 5.0 mm to 7.0 mm, a tip portion located distal to the base portion and having an outer diameter of 1.3 mm to 3.3 mm, and an intermediate portion whose outer diameter decreases from the tip of the base portion toward the base end of the tip portion.

2. The angiography catheter according to claim 1 , wherein the tip portion has a three-dimensional shape including a base curved portion, an intermediate curved portion, and a tip curved portion.

3. 2. The catheter according to claim 1, wherein the intermediate portion has a length in the longitudinal direction of 50 mm to 200 mm.

4. 4. The angiography catheter according to claim 1, wherein a detachable hub is provided at a proximal end of the shaft.

5. 4. The contrast catheter according to claim 1, wherein an outer diameter of the tip portion of the shaft is larger than an outer diameter of the base portion, and an outer diameter of the intermediate portion decreases from the tip of the base portion to the base end of the tip portion.

6. 4. The contrast catheter according to claim 1, wherein the shaft comprises a base rigid section, a tip flexible section that is located distal to the base rigid section and is more flexible than the base rigid section, and an intermediate physical property transition section whose physical properties change from the tip of the base rigid section to the base end of the tip flexible section.

7. 4. The catheter according to claim 1, wherein at least a portion of the tip portion has a constant rigidity along the longitudinal axis.

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