Catheter assembly

Abstract

The present invention provides a catheter assembly that can suppress kinking and improve indentation and vascular conformability. [Solution] A catheter assembly 10 comprising a catheter 20 and a stylet 30, wherein in an assembled state in which the catheter hub 70 and the stylet hub 100 are connected, the proximal end of the tapered portion 92 provided on the stylet 30 is positioned in the longitudinal axis direction X to coincide with the proximal opening 63 of the guidewire lumen provided on the catheter 20, or to a position on the proximal side of the guidewire lumen proximal opening 63, and is positioned on the distal side of the proximal tube 43 extending from the catheter hub 70 toward the distal side.

Description

Technical Field

[0001] The present invention relates to a catheter assembly having a catheter and a stylet that can be inserted into the catheter.

Background Art

[0002] Conventionally, as a device for removing a thrombus formed in a blood vessel, a suction catheter that sucks and removes a thrombus from inside the blood vessel is known. For example, Patent Document 1 discloses a device including a rapid exchange type suction catheter and a core wire that can be inserted into the suction catheter. By inserting the core wire into the suction catheter, when moving the suction catheter to a target position, it is possible to suppress the suction catheter from kinking.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the device described in Patent Document 1, the core wire is inserted only up to the middle from the proximal end side to the distal end of the suction catheter. The pushing property of the device represents the transmission property of the force applied to the proximal end side of the device to the distal end side, and it is considered that the rigidity of the device mainly contributes to this. Therefore, at the distal end portion where the core wire of the suction catheter is not inserted, the pushing property decreases and kinking may occur. However, if a core wire having a constant outer diameter from the proximal end to the distal end is inserted into the lumen of the suction catheter, the rigidity of the entire device with the core wire inserted into the suction catheter becomes too high, and the blood vessel followability decreases. The blood vessel followability represents the ease of insertion into and passage through a bent blood vessel, and it is considered that the flexibility of the device mainly contributes to this.

[0005] The present invention was made to solve the above-mentioned problems, and aims to provide a catheter assembly that can suppress kinking and improve indentation and vascular conformability. [Means for solving the problem]

[0006] The above objective is achieved by the invention described in (1) or (2) below.

[0007] (1) One embodiment of a catheter assembly according to the present invention is a catheter assembly comprising a catheter and a stylet insertable into the catheter, wherein the catheter comprises a catheter hub disposed at the proximal end of the catheter, a catheter body extending from the catheter hub toward the tip and having a lumen formed thereon, and a guide tube fixed to the tip of the catheter body and having a guide wire lumen formed thereon that opens at a guide wire lumen proximal opening on the tip side of the catheter hub, wherein the catheter body comprises a proximal tube extending from the catheter hub toward the tip and a tube that is more flexible than the proximal tube and extends from the tip of the proximal tube toward The stylet has a tip-side tube extending toward the end, and the stylet has a stylet hub connectable to the catheter hub, a shaft extending toward the tip from the stylet hub, and a coil fixed to the tip of the shaft, the shaft having a proximal-side shaft extending toward the tip from the stylet hub, and a tapered portion having an outer diameter that gradually decreases toward the tip from the tip of the proximal-side shaft, and in an assembled state in which the catheter hub and the stylet hub are connected, the proximal end of the tapered portion is positioned toward the tip of the guidewire lumen proximal opening and toward the tip of the proximal-side tube.

[0008] (2) Another embodiment of the catheter assembly according to the present invention is a catheter assembly comprising a catheter and a stylet insertable into the catheter, wherein the catheter comprises a catheter hub disposed at the proximal end of the catheter, a catheter body extending from the catheter hub toward the tip and having a lumen formed thereon, and a guide tube fixed to the tip of the catheter body and having a guide wire lumen formed thereon that opens at a guide wire lumen proximal opening toward the tip of the catheter hub, wherein the catheter body comprises a proximal tube extending from the catheter hub toward the tip and a tip tube that is more flexible than the proximal tube and extends from the tip of the proximal tube toward the tip The stylet comprises a stylet hub connectable to the catheter hub, a shaft extending from the stylet hub toward the tip, and a coil fixed to the tip of the shaft. The shaft comprises a proximal shaft extending from the stylet hub toward the tip, and a tapered portion having an outer diameter that gradually decreases from the tip of the proximal shaft toward the tip. In the assembled state in which the catheter hub and the stylet hub are connected, the proximal end of the tapered portion is positioned in the longitudinal direction to coincide with the proximal opening of the guidewire lumen, or to a position on the proximal side of the proximal opening of the guidewire lumen, and to the tip of the proximal tube. [Effects of the Invention]

[0009] In the catheter assembly described in (1) above, the proximal end of the tapered section is positioned on the distal side of the proximal tube, so the tapered section, which reduces bending rigidity, does not overlap with the proximal tube, which greatly contributes to the pushability of the catheter assembly. Therefore, the catheter assembly can achieve high pushability. Furthermore, since the tapered section, which gradually reduces bending rigidity, overlaps with the part of the catheter assembly that greatly contributes to vascular followability on the distal side of the proximal tube, the catheter assembly can suppress kinking with the presence of the stylet while improving vascular followability with the tapered section. In addition, since the proximal end of the tapered section is positioned on the distal side of the proximal opening of the guidewire lumen, the catheter assembly can improve vascular followability in the part of the catheter assembly that is on the distal side of the proximal opening of the guidewire lumen from which the guidewire is led out.

[0010] In the catheter assembly described in (2) above, the proximal end of the tapered portion is positioned more towards the tip than the tip of the proximal tube, so the tapered portion, which reduces bending rigidity, does not overlap with the proximal tube, which greatly contributes to the pushability of the catheter assembly. Therefore, the catheter assembly can achieve high pushability. Furthermore, since the tapered portion, which gradually reduces bending rigidity, overlaps with the part of the catheter assembly that greatly contributes to vascular followability more towards the tip than the proximal tube, the catheter assembly can suppress kinking with the presence of the stylet while improving vascular followability with the tapered portion. In addition, since the proximal end of the tapered portion is positioned at a location that coincides with the proximal opening of the guidewire lumen in the longitudinal direction, or more towards the proximal opening of the guidewire lumen, the tapered portion is positioned to overlap with the part of the guide tube from the proximal opening of the guidewire lumen to the tip. Therefore, the catheter assembly can improve vascular followability in the part from the proximal opening of the guidewire lumen to the tip.

[0011] (3) In the catheter assembly described in (1) or (2) above, the catheter may be capable of applying suction force from the catheter hub through the lumen to the opening at the tip of the lumen. This can suppress kinking of the catheter assembly having a catheter capable of applying suction force, and can improve pushability and vascular conformability. [Brief explanation of the drawing]

[0012] [Figure 1] This is a plan view showing the catheter and stylet of the catheter assembly according to the embodiment in an assembled state. [Figure 2] This is a plan view showing the catheter and stylet of the catheter assembly according to the embodiment separated. [Figure 3] This is a cross-sectional view showing the proximal end of a catheter assembly according to an embodiment. [Figure 4] This is a cross-sectional view showing the tip portion of the catheter assembly according to the embodiment. [Figure 5] This is a cross-sectional view showing the tip of a modified catheter assembly. [Modes for carrying out the invention]

[0013] Embodiments of the present invention will be described below with reference to the drawings. Note that the dimensional ratios in the drawings may be exaggerated for illustrative purposes and may differ from the actual ratios. In the following description, the side of the catheter assembly that is operated will be referred to as the "proximal end," and the side that is inserted into the body will be referred to as the "proximal end."

[0014] The catheter assembly 10 according to an embodiment of the present invention is a device that is elongated in the longitudinal direction X, and as shown in Figures 1 to 4, comprises a catheter 20 and a stylet 30. The catheter 20 is used to aspirate and remove thrombi in the cardiovascular system. The object to be aspirated by the catheter 20 is not limited to thrombi, but may be, for example, plaque, atheroma, calcified lesions, etc. The stylet 30 prevents the catheter 20 from kinking when it reaches the target position. With the stylet 30 inserted into the lumen 41 of the catheter 20, the catheter assembly 10 moves through the lumen of a device such as a guiding catheter or sheath inserted percutaneously into the blood vessel and is pushed to the vicinity of the lesion in the blood vessel. After the tip of the catheter assembly 10 reaches the vicinity of the lesion in the blood vessel, the stylet 30 is withdrawn from the catheter 20. After this, the thrombus in the blood vessel is aspirated using the lumen 41 of the catheter 20.

[0015] First, let's describe the catheter 20. The catheter 20 is a rapid exchange type in which a guide wire is inserted only at the tip, and comprises a flexible tubular catheter body 40, a guide tube 60 fixed to the tip of the catheter body 40, a catheter hub 70 fixed to the proximal end of the catheter body 40, and a kink-resistant protector 80.

[0016] The catheter body 40 is a flexible tube, and a lumen 41 is formed in the approximate center of the catheter body 40, extending along its entire length. The lumen 41 opens at the catheter tip opening 42, which is formed at the tip of the catheter body 40.

[0017] The catheter body 40 comprises a proximal tube 43, an distal tube 44, and a tip 45. The proximal tube 43 is fixed at its proximal end to the catheter hub 70 and extends from the catheter hub 70 toward the distal end. The proximal tube 43 is formed by an inner layer 46 that forms the inner surface of the proximal tube 43, a proximal outer layer 47 that forms the outer surface of the proximal tube 43, and a reinforcing layer 48 located between the inner layer 46 and the proximal outer layer 47. Different colored depth markers 58 are placed on the outer surface of the proximal outer layer 47 to allow the operator to determine how far the catheter 20 is pushed into the blood vessel.

[0018] The tip-side tube body 44 is formed by an inner layer 46 that forms the inner surface of the tip-side tube body 44, a tip-side outer layer 49 that forms the outer surface of the tip-side tube body 44, and a reinforcing layer 48 located between the inner layer 46 and the tip-side outer layer 49. The inner layer 46 of the tip-side tube body 44 is integrally formed with the inner layer 46 of the base-side tube body 43. Similarly, the reinforcing layer 48 of the tip-side tube body 44 is integrally formed with the reinforcing layer 48 of the base-side tube body 43. The tip-side outer layer 49 comprises a first outer layer 50, a second outer layer 51, a third outer layer 52, and a fourth outer layer 53. The first outer layer 50, the second outer layer 51, the third outer layer 52, and the fourth outer layer 53 are arranged from the tip side to the base side to form a single tube body. The fourth outer layer 53 has a lower Shore hardness than the base-side outer layer 47 adjacent to the base side. The third outer layer 52 has a lower Shore hardness than the fourth outer layer 53 adjacent to the proximal end. The second outer layer 51 has a lower Shore hardness than the third outer layer 52 adjacent to the proximal end. The first outer layer 50 has a lower Shore hardness than the second outer layer 51 adjacent to the proximal end.

[0019] The reinforcing layer 48 is for reinforcing the catheter body 40 and has a plurality of reinforcing wires 57. The gaps between the plurality of reinforcing wires 57 in the reinforcing layer 48 are configured such that the material of the proximal outer layer 47, the distal outer layer 49, or the inner layer 46 can enter. Examples of the reinforcing layer 48 include a structure in which the reinforcing wires 57 are woven into a tubular shape. Note that the reinforcing layer 48 may be formed by winding one or more reinforcing wires 57 in a spiral (coil) shape. The reinforcing wires 57 are formed of a metal such as stainless steel or NiTi. The cross-sectional shape of the reinforcing wires 57 is not particularly limited and may be, for example, rectangular, square, circular, or elliptical. Also, one reinforcing wire 57 may be a bundle of two or more wire materials. The catheter body 40 having the reinforcing layer 48 can ensure sufficient rigidity and strength without increasing the wall thickness, that is, while keeping the inner diameter of the catheter body 40 relatively large.

[0020] The tip 45 is flexible and reduces damage to blood vessels by the tip of the catheter body 40 when the catheter 20 is inserted into the body. The tip 45 is formed by a tip inner layer 54 that forms the inner surface of the tip 45 and a tip outer layer 55 that forms the outer surface of the tip 45. The tip surface 56 of the tip 45 is inclined at an angle greater than 0 degrees and less than 90 degrees with respect to a plane perpendicular to the long axis direction X. The tip surface 56 is inclined such that the side where the guide tube 60 on the outer surface of the catheter body 40 is fixed protrudes in the tip direction. By inclining the tip surface 56 of the tip 45, the catheter tip opening 42 becomes wider compared to the case where it is not inclined (when the angle α is 0 degrees), and the suction performance of the catheter 20 can be improved.

[0021] The tip outer layer 55 is formed to be more flexible than the first outer layer 50 adjacent to the proximal side. The tip inner layer 54 is disposed on the distal side of the inner layer 46. The tip inner layer 54 may be integrally formed with the inner layer 46 or formed as a separate member. The tip inner layer 54 may be formed of the same material as the inner layer 46 or a different material. Note that the tip 45 may be formed of a single layer.

[0022] The inner layer 46 and the tip inner layer 54 are preferably formed from a low-friction material. This allows the inner layer 46 and the tip inner layer 54 to move in the longitudinal axis X with low sliding resistance when inserting and removing a device such as a stylet 30 into the lumen 41, or when aspirating a thrombus, thereby improving operability and suction performance. Examples of low-friction materials include fluororesin materials such as polytetrafluoroethylene (PTFE) and tetrafluoroethylene-perfluoroalkoxyethylene copolymer (PFA), and the embodiment uses PFA.

[0023] The constituent materials of the proximal end outer layer 47 and the tip end outer layer 49 include, for example, various thermoplastic elastomers such as styrene-based, polyolefin-based, polyurethane-based, polyester-based, polyamide-based, polybutadiene-based, trans-polyisoprene-based, fluororubber-based, and chlorinated polyethylene-based materials. One or more of these can be combined (polymer alloy, polymer blend, laminate, etc.), preferably with a contrast agent mixed in. In this embodiment, a polyamide elastomer, barium sulfate, and pigment are mixed together.

[0024] The constituent materials of the tip outer layer 55 include, for example, various rubber materials such as natural rubber, isoprene rubber, butadiene rubber, chloroprene rubber, silicone rubber, fluororubber, and styrene-butadiene rubber, as well as various thermoplastic elastomers such as styrene-based, polyolefin-based, polyurethane-based, polyester-based, polyamide-based, polybutadiene-based, trans-polyisoprene-based, fluororubber-based, and chlorinated polyethylene-based materials. In this embodiment, a polyamide elastomer is mixed with barium sulfate and a pigment.

[0025] The guide tube 60 is a tube in which a guidewire lumen 61 into which a guidewire can be inserted is formed. The guide tube 60 is fixed to the outer surface of the tip of the catheter body 40 so as to be along the long axis of the catheter body 40. The guide tube 60 has a guidewire lumen tip opening 62 at the tip end and a guidewire lumen proximal opening 63 at the proximal end. In the long axis direction X, the tip of the guide tube 60 is positioned to approximately coincide with the tip of the catheter body 40. The tip of the guide tube 60 may be positioned further forward than the tip of the catheter body 40. The guidewire lumen tip opening 62 is located at the very tip of the catheter 20. Since the catheter 20 is a rapid exchange type, the guidewire lumen proximal opening 63 is located further forward than the catheter hub 70. Furthermore, the guidewire lumen proximal opening 63 is located near the proximal end of the tip-side tube 44. The guidewire lumen base opening 63 may be positioned towards the tip of the tip side tube 44, towards the base, or at the same position as the base of the tip side tube 44 in the longitudinal axis direction X. In this embodiment, the guidewire lumen base opening 63 is positioned to overlap with the third outer layer 52 of the tip side tube 44 in the longitudinal axis direction X, but is not limited thereto.

[0026] Examples of materials that can be used for the guide tube 60 include materials applicable to the base-side outer layer 47, tip-side outer layer 49, or tip-tip outer layer 55 as described above.

[0027] The outer diameter of the catheter body 40 in the first embodiment is a so-called 6Fr, for example, 1.40 mm to 1.70 mm, with 1.70 mm being one example. If the outer diameter is too large, the maneuverability when moving the catheter body 40 within the blood vessel will decrease, and the burden on the patient may increase.

[0028] The inner diameter of the catheter body 40 is, for example, 0.99 mm to 1.10 mm, with 0.99 mm being one example. If the inner diameter is too small, the ability to aspirate objects such as thrombi will decrease accordingly, which is undesirable.

[0029] The effective length L1 of the catheter 20 is, for example, 1400 mm. This allows the operator to insert the catheter 20 from the femoral artery and reach the coronary artery while maintaining maneuverability. The effective length L1 of the catheter 20 is the length of the portion that can be inserted into blood vessels, guiding catheters, sheaths, and other devices. In this embodiment, the effective length L1 of the catheter 20 is the length from the tip of the kink-resistant protector 80 to the tip of the guide tube 60 in the longitudinal axis direction X.

[0030] The dimensions of each part of the catheter 20 are not particularly limited. The length L2 in the longitudinal direction X of the tip 45 is, for example, 9 mm. The length L3 in the longitudinal direction X of the first outer layer 50 is, for example, 70 mm. The length L4 in the longitudinal direction X of the second outer layer 51 is, for example, 60 mm. The length L5 in the longitudinal direction X of the third outer layer 52 is, for example, 100 mm. The length L6 in the longitudinal direction X of the fourth outer layer 53 is, for example, 60 mm. The length L7 in the longitudinal direction X of the proximal end tube 43 is, for example, 1100 mm. The length L10 in the longitudinal direction X of the depth marker 58 is, for example, 100 mm.

[0031] The catheter hub 70 is fixed to the proximal end of the catheter body 40. The catheter hub 70 has a catheter hub lumen 71 that communicates with the lumen 41. The catheter hub lumen 71 opens at the catheter hub opening 72 on the proximal end. A male threaded portion 73 is formed on the outer surface of the proximal end of the catheter hub 70. The male threaded portion 73 can be screwed into a female threaded portion 106 formed on a rotatable connecting portion 102, which will be described later and is rotatably provided on the stylet hub 100. The male threaded portion 73 and the female threaded portion 106 form a locking mechanism that holds the catheter hub 70 and the stylet hub 100 connected.

[0032] The constituent materials of the catheter hub 70 include, for example, various resins such as styrene-based, polyolefin-based, polyurethane-based, polyester-based, polyamide-based, polybutadiene-based, trans-polyisoprene-based, fluororubber-based, and chlorinated polyethylene-based resins or various thermoplastic elastomers, and combinations of one or more of these (polymer alloys, polymer blends, laminates, etc.).

[0033] The length L9 of the catheter hub 70 in the longitudinal direction X (the length from the proximal end of the kink protector 80 to the proximal end of the catheter hub 70) is, for example, 22.3 mm.

[0034] The kink-resistant protector 80 is attached to cover the portion connecting the catheter body 40 and the catheter hub 70, thereby suppressing kinking of the catheter body 40 at that location.

[0035] The length L8 of the long axis X of the kink protector 80 is, for example, 37.5 mm.

[0036] Next, the stylet 30 will be described. The stylet 30 comprises a shaft 90 that can be inserted into the catheter body 40, a stylet hub 100 fixed to the proximal end of the shaft 90, and a coil 110 fixed to the tip of the shaft 90.

[0037] The shaft 90 comprises a proximal shaft 91 extending from the stylet hub 100 toward the tip, a tapered portion 92 extending from the tip of the proximal shaft 91 toward the tip, and a fixing portion 93 fixed to the coil 110 at the tip of the tapered portion 92. The proximal shaft 91 has a substantially constant outer diameter along the longitudinal axis X. The tapered portion 92 has an outer diameter that gradually decreases in a tapered manner from the tip of the proximal shaft 91 toward the tip. By incorporating the tapered portion 92 into the catheter assembly 10, the bending rigidity of the catheter assembly 10 is gradually reduced toward the tip, thereby suppressing the occurrence of kinking due to local changes in bending rigidity and providing appropriate flexibility to improve vascular followability. If the length of the tapered portion 92 in the longitudinal axis X is too short (the proximal shaft 91 is too long), vascular followability will decrease, and the shaft 90 will be too stiff, making it difficult to advance through curves in the blood vessel. If the length of the tapered section 92 in the longitudinal direction X is too long (or the tapered section 92 is too short), the shaft 90 becomes too soft and its ability to be pushed in decreases.

[0038] The fixing portion 93 is located at the tip of the shaft 90 and is fixed to the tip of the coil 110. The fixing portion 93 is a material that has been melted and solidified by, for example, soldering, brazing, or welding, but it may also be an adhesive. The shaft 90 may have a portion with a constant outer diameter in the longitudinal direction X, closer to the tip than the tapered portion 92.

[0039] The coil 110 is positioned to surround the narrow portion at the tip of the shaft 90 in order to maintain the outer diameter while reducing the bending rigidity of the tip of the stylet 30. The tip of the coil 110 is fixed to the fixing portion 93 of the shaft 90. The base end of the coil 110 overlaps with the tapered portion 92 in the longitudinal axis direction X.

[0040] The constituent materials of the shaft 90 and coil 110 include, for example, metals such as stainless steel and NiTi.

[0041] The dimensions of each part of the stylet 30 are not particularly limited. The outer diameter of the base shaft 91 is, for example, 0.42 mm. The length L11 in the longitudinal direction X from the tip of the shaft 90 to the base of the tapered portion 92 is, for example, 170 mm to 200 mm. The outer diameter of the coil 110 is, for example, 0.4 mm. The length L12 in the longitudinal direction X of the coil 110 is, for example, 50 mm to 60 mm. The effective length L13 of the stylet 30 in the longitudinal direction X is, for example, 1412 mm. In this embodiment, the effective length L13 of the stylet 30 is the length from the tip of the stylet hub 100 to the tip of the shaft 90 in the longitudinal direction X.

[0042] The stylet hub 100 comprises a stylet hub body 101 and a rotatable connecting portion 102 that is rotatable relative to the stylet hub body 101. The stylet hub body 101 is fixed to the base end of the shaft 90 and has a stylet hub lumen 103 that penetrates in the longitudinal axis direction X. A stylet hub male thread portion 107 is formed on the outer surface of the base end of the stylet hub 100. The stylet hub lumen 103 opens at the stylet hub tip opening 104 on the tip side of the stylet hub body 101 and also opens at the stylet hub base end opening 105 on the base end side. In the assembled state, the outer surface of the stylet hub body 101 can be in close contact with the inner surface of the catheter hub lumen 71.

[0043] The rotating connector 102 is connected to the outer surface of the stylet hub body 101 so as to be rotatable around the long axis of the stylet hub body 101. The inner circumferential surface of the rotating connector 102 has a female threaded portion 106 that can be screwed into the male threaded portion 73 of the catheter hub 70.

[0044] The constituent materials of the stylet hub 100 include, for example, materials applicable to the catheter hub 70 described above.

[0045] Next, the catheter assembly 10 will be described. The catheter assembly 10 is assembled by inserting the stylet 30 into the lumen 41 of the catheter 20 and connecting the stylet hub 100 to the catheter hub 70. In the assembled catheter assembly 10, the catheter 20 and stylet 30 cannot be separated until the connection is released.

[0046] When assembling the catheter 20 and stylet 30, the stylet 30 is inserted into the catheter hub opening 72 from the tip end and pushed forward until the outer surface of the tip of the stylet hub body 101 is in close contact with the inner surface of the catheter hub lumen 71. Next, when the rotating coupling part 102 is rotated, the male threaded part 73 is screwed into the female threaded part 106, as shown in Figure 3, and the catheter hub 70 and stylet hub 100 are connected in an assembled state. In the assembled state, the relative movement and rotation of the catheter 20 and stylet 30 are restricted. This allows the operator to manipulate the catheter 20 and stylet 30 as a single unit when inserting the catheter assembly 10 into a blood vessel. As a result, the catheter assembly 10 is easy to operate and safety is improved by preventing the catheter 20 and stylet 30 from unexpectedly coming off.

[0047] Furthermore, in the assembled state, as shown in Figure 4, the tip of the stylet 30 is located proximal to the tip of the catheter 20, does not protrude outward from the catheter tip opening 42, and is located inside the lumen 41. Therefore, when inserting the catheter assembly 10 into a blood vessel, the thin tip of the stylet 30 does not come into contact with the blood vessel, thereby reducing damage to the blood vessel. As an example, the tip of the stylet 30 is positioned to overlap with the first outer layer 50 in the longitudinal axis direction X. In the assembled state, the length L14 in the longitudinal axis direction X from the tip of the catheter 20 towards the proximal end to the tip of the stylet 30 is, for example, 41 mm. The proximal end of the coil 110 overlaps with the second outer layer 51 in the longitudinal axis direction X.

[0048] Furthermore, in the assembled state, the base end of the tapered portion 92 of the stylet 30, the base end of the guide tube 60, and the base end of the tip tube 44 are positioned in substantially the same location along the long axis X.

[0049] Furthermore, in the assembled state, the proximal end of the tapered portion 92 of the stylet 30 is located more towards the tip than the tip of the proximal tube 43 of the catheter 20. For example, the proximal end of the tapered portion 92 overlaps with the third outer layer 52 in the longitudinal axis direction X. As a result, the tapered portion 92 does not overlap with the highly rigid proximal tube 43, which greatly contributes to the pushability of the catheter assembly 10, and therefore the catheter assembly 10 has high pushability. In addition, since the tapered portion 92, whose bending rigidity gradually decreases toward the tip, overlaps with the tip tube 44 of the catheter assembly 10, which is more flexible than the proximal tube 43, the presence of the stylet 30 suppresses kinking, while the tapered portion 92 improves vascular conformability.

[0050] Furthermore, in the assembled state, the proximal end of the tapered portion 92 is located near the proximal opening 63 of the guidewire lumen. Specifically, in the assembled state, the proximal end of the tapered portion 92 is located either on the distal side of the proximal opening 63 of the guidewire lumen, or at a position that coincides with the proximal opening 63 of the guidewire lumen in the longitudinal axis direction X, or on the proximal side of the proximal opening 63 of the guidewire lumen. In the portion of the catheter assembly 10 distal to the proximal opening 63 of the guidewire lumen, the bending rigidity is increased by the amount of the guide tube 60 because the guide tube 60 is fixed to the catheter body 40, which may reduce the ability to follow the blood vessel. In contrast, in this embodiment, since the proximal end of the tapered portion 92 of the stylet 30 is located near the proximal opening 63 of the guidewire lumen in the longitudinal axis direction X, the tapered portion 92, whose bending rigidity gradually decreases toward the distal side, overlaps with the area in which the guide tube 60 of the catheter assembly 10 is positioned. Therefore, the catheter assembly 10 does not become too rigid but changes smoothly, improving both its pushability and its ability to follow the blood vessel.

[0051] In the assembled state, if the proximal end of the tapered portion 92 of the stylet 30 is positioned on the distal side of the guidewire lumen proximal opening 63, the tapered portion 92 is positioned without overlapping with the proximal end of the guide tube 60 in the longitudinal axis X. Therefore, the catheter assembly 10 can improve the vascular tracking ability of the portion on the distal side of the guidewire lumen proximal opening 63 from which the guidewire is led out.

[0052] Furthermore, in the assembled state, if the proximal end of the tapered portion 92 is positioned to coincide with the proximal end opening 63 of the guidewire lumen in the longitudinal axis X, or if it is positioned proximal to the guidewire lumen proximal end opening 63, the tapered portion 92 is positioned to overlap with the proximal end opening 63 of the guidewire lumen in the longitudinal axis X. Therefore, the tapered portion 92 can mitigate local changes in the bending rigidity of the catheter assembly 10 at the position where the proximal end of the guide tube 60, which is prone to large changes in bending rigidity, is provided. As a result, the catheter assembly 10 can bend smoothly, thereby suppressing kinking and improving vascular conformability.

[0053] In the assembled state, the length L14 from the tip of the catheter 20 towards the proximal end of the tapered portion 92 is, for example, 211 mm to 241 mm.

[0054] Next, the method of using the catheter assembly 10 according to this embodiment will be described. As shown in Figures 1, 3, and 4, the operator prepares the assembled catheter 20 and stylet 30, and inserts a syringe filled with physiological saline into the proximal opening 105 of the stylet hub. Next, the operator injects physiological saline from the syringe into the lumen 41 of the catheter 20 through the lumen 103 of the stylet hub. This allows the lumen 41 of the catheter 20 to be primed while the catheter 20 and stylet 30 remain assembled. Note that the method of priming the lumen 41 is not limited to this.

[0055] Next, the surgeon passes the guidewire through the guidewire lumen 61 and inserts the guidewire and catheter assembly 10 into the proximal opening of the guiding catheter or sheath that has been inserted percutaneously into the blood vessel. Since the catheter 20 and stylet 30 are assembled as the catheter assembly 10, the surgeon can smoothly insert the catheter assembly 10 into the blood vessel.

[0056] The surgeon guides the tip of the catheter assembly 10 along a guidewire (not shown) inserted into the guiding lumen 41 to the target location containing a lesion such as a thrombus. At this time, since the stylet 30 is inserted inside the catheter 20, kinking of the catheter 20 as it passes through the curved blood vessel can be suppressed. After this, the surgeon stops pushing the catheter assembly 10 in. Next, the surgeon rotates the rotating connector 102 to release the screwing of the male threaded part 73 and the female threaded part 106. This releases the connection between the stylet hub 100 and the catheter hub 70. After this, the surgeon removes the stylet 30 from the catheter 20 while leaving the catheter 20 inside the blood vessel.

[0057] Next, the operator directly or indirectly connects a syringe or similar device to the proximal end opening of the catheter 20, applying suction force (negative pressure) to the lumen 41. As a result, the thrombus is drawn from the catheter tip opening 42 into the lumen 41 and discharged to the outside through the catheter hub lumen 71 and catheter hub opening 72.

[0058] As described above, the catheter assembly 10 according to this embodiment is a catheter assembly 10 comprising a catheter 20 and a stylet 30 that can be inserted into the catheter 20, wherein the catheter 20 has a catheter hub 70 disposed at the proximal end of the catheter 20, a catheter body 40 extending from the catheter hub 70 toward the tip and having a lumen 41 formed therein, and a guide tube 60 fixed to the tip of the catheter body 40 and having a guide wire lumen 61 formed therein that opens at a guide wire lumen proximal opening 63 located more distal to the catheter hub 70, wherein the catheter body 40 has a proximal tube 43 extending from the catheter hub 70 toward the tip, and a tube that is more flexible than the proximal tube 43 and is located at the tip of the proximal tube 43 The stylet 30 has a tip-side tube 44 extending from the catheter hub 70 toward the tip, and the stylet 30 has a stylet hub 100 connectable to the catheter hub 70, a shaft 90 extending from the stylet hub 100 toward the tip, and a coil 110 fixed to the tip of the shaft 90, and the shaft 90 has a proximal shaft 91 extending from the stylet hub 100 toward the tip, and a tapered portion 92 having an outer diameter that gradually decreases from the tip of the proximal shaft 91 toward the tip, and in the assembled state in which the catheter hub 70 and the stylet hub 100 are connected, the proximal end of the tapered portion 92 may be positioned toward the tip of the guidewire lumen proximal opening 63 and toward the tip of the proximal tube 43. As a result, the proximal end of the tapered portion 92 of the catheter assembly 10 is positioned more towards the tip than the tip of the proximal tube 43. Therefore, the tapered portion 92, which reduces bending rigidity, does not overlap with the proximal tube 43, which greatly contributes to the pushability of the catheter assembly 10. For this reason, the catheter assembly 10 can achieve high pushability. Furthermore, since the tapered portion 92, which gradually reduces bending rigidity, overlaps with the part of the catheter assembly 10 that greatly contributes to vascular followability more towards the tip than the proximal tube 43, the catheter assembly 10 can improve vascular followability with the tapered portion 92 while suppressing kinking with the presence of the stylet 30. In addition, since the proximal end of the tapered portion 92 is positioned more towards the tip than the proximal opening 63 of the guidewire lumen, the catheter assembly 10 can improve vascular followability in the part of the catheter assembly 10 that is more towards the tip than the proximal opening 63 of the guidewire lumen from which the guidewire is led out.

[0059] Furthermore, in the assembled state in which the catheter hub 70 and the stylet hub 100 are connected, the proximal end of the tapered portion 92 may be positioned in the longitudinal axis direction X to coincide with the proximal opening 63 of the guidewire lumen, or to a position further proximal than the proximal opening 63 of the guidewire lumen, and further forward than the tip of the proximal tube 43. As a result, in the catheter assembly 10, the proximal end of the tapered portion 92 is positioned further forward than the tip of the proximal tube 43, so the tapered portion 92, which reduces bending rigidity, does not overlap with the proximal tube 43, which greatly contributes to the pushability of the catheter assembly 10. Therefore, the catheter assembly 10 can obtain high pushability. Also, since the tapered portion 92, which gradually reduces bending rigidity, overlaps with the part of the catheter assembly 10 that greatly contributes to vascular followability, located further forward than the proximal tube 43, the catheter assembly 10 can suppress kinking with the presence of the stylet 30 while improving vascular followability with the tapered portion 92. Furthermore, since the proximal end of the tapered portion 92 is positioned to coincide with the proximal opening 63 of the guidewire lumen in the longitudinal axis X, or to be positioned proximal to the proximal opening 63 of the guidewire lumen, the tapered portion 92 is positioned to overlap with the portion of the guide tube 60 from the proximal opening 63 of the guidewire lumen towards the tip. As a result, the catheter assembly 10 can improve the vascular tracking ability of the portion of the catheter that includes the proximal opening 63 of the guidewire lumen and is positioned towards the tip of the proximal opening 63 of the guidewire lumen.

[0060] Furthermore, the catheter 20 can apply suction force from the catheter hub 70 to the opening at the tip of the lumen 41 via the lumen 41. This suppresses kinking of the catheter assembly 10 having the catheter 20 that can apply suction force, and improves its pushability and vascular conformability.

[0061] It should be noted that the present invention is not limited to the embodiments described above, and various modifications can be made by those skilled in the art within the technical framework of the present invention. For example, at least one of the catheter body 40 and the shaft 90 may be curved in a natural state when no external force is acting on it.

[0062] Furthermore, the number of tubular members arranged in the longitudinal axis X direction with different bending stiffnesses to form the tip-side outer layer 49 of the catheter 20 is not limited. For example, the modified example shown in Figure 5 includes a first outer layer 50, a second outer layer 51, and a third outer layer 52, similar to the embodiment described above, but does not include a fourth outer layer 53. The first outer layer 50, the second outer layer 51, and the third outer layer 52 are arranged from the tip side to the proximal end side to form a single tubular body. The third outer layer 52 has lower bending stiffness than the proximal end outer layer 47 adjacent to the proximal end.

[0063] In the assembled state, along the long axis X, the tip of the stylet 30 overlaps the first outer layer 50, the base end of the coil 110 overlaps the second outer layer 51, and the base end of the tapered portion 92 also overlaps the second outer layer 51.

[0064] The outer diameter of the catheter body 40 is, for example, 1.60 mm to 1.96 mm, for example, 1.96 mm, when it is 7 Fr. The inner diameter of the catheter body 40 is, for example, 1.24 mm to 1.30 mm, for example, 1.24 mm. The length L3 in the longitudinal direction X of the first outer layer 50 is, for example, 70 mm. The length L4 in the longitudinal direction X of the second outer layer 51 is, for example, 150 mm. The length L5 in the longitudinal direction X of the third outer layer 52 is, for example, 60 mm. [Explanation of Symbols]

[0065] 10 Catheter Assembly 20 Catheters 30 Stylet 40 Catheter body 41 lumens 42 Catheter tip opening 43. Base end tube 44. End tube 45 Tips 60 Guide tube 61 guidewire lumens 62 Guidewire Lumen Tip Opening 63 Guidewire Lumen Proximal Aperture 70 Catheter Hub 90 shaft 91 Base shaft 92 Tapered section 93 Fixed part 100 Stylet Hub 110 coils

Claims

1. A catheter assembly comprising a catheter and a stylet that can be inserted into the catheter, The aforementioned catheter is A catheter hub is positioned at the proximal end of the catheter, A catheter body extending from the catheter hub toward the tip and having a lumen formed therein, The catheter body has a guide tube that is fixed to the tip of the catheter body and has a guide wire lumen formed thereon that opens at the proximal end opening of the guide wire lumen on the tip side of the catheter hub, The catheter body comprises a proximal tube extending from the catheter hub toward the tip, and an distal tube that is more flexible than the proximal tube and extends from the tip of the proximal tube toward the tip. The aforementioned stylet is, A stylet hub that can be connected to the catheter hub, A shaft extending from the stylet hub toward the tip, The shaft has a coil fixed to the tip of the shaft, The shaft comprises a base shaft extending from the stylet hub toward the tip, and a tapered portion having an outer diameter that gradually decreases from the tip of the base shaft toward the tip. In an assembled state in which the catheter hub and the stylet hub are connected, the proximal end of the tapered portion is positioned on the tip side of the proximal opening of the guidewire lumen, and on the tip side of the tip of the proximal tube, in a catheter assembly.

2. A catheter assembly comprising a catheter and a stylet that can be inserted into the catheter, The aforementioned catheter is A catheter hub is positioned at the proximal end of the catheter, A catheter body extending from the catheter hub toward the tip and having a lumen formed therein, The catheter body has a guide tube that is fixed to the tip of the catheter body and has a guide wire lumen formed thereon that opens at the proximal end opening of the guide wire lumen on the tip side of the catheter hub, The catheter body comprises a proximal tube extending from the catheter hub toward the tip, and an distal tube that is more flexible than the proximal tube and extends from the tip of the proximal tube toward the tip. The aforementioned stylet is, A stylet hub that can be connected to the catheter hub, A shaft extending from the stylet hub toward the tip, The shaft has a coil fixed to the tip of the shaft, The shaft comprises a base shaft extending from the stylet hub toward the tip, and a tapered portion having an outer diameter that gradually decreases from the tip of the base shaft toward the tip. In an assembled state in which the catheter hub and the stylet hub are connected, the proximal end of the tapered portion is positioned in the longitudinal direction to coincide with the proximal opening of the guidewire lumen, or to a position on the proximal side of the proximal opening of the guidewire lumen, and to a distal side of the tip of the proximal tube body.

3. The catheter assembly according to claim 1 or 2, wherein the catheter is capable of applying suction force from the catheter hub through the lumen to the opening at the tip of the lumen.

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