Intravenous catheter

Abstract

To provide a venous catheter that is easy to insert into veins and has good passage through lesions. [Solution] A venous catheter 1 having a long tubular shaft portion 2 and being inserted into a vein of a living body, wherein the shaft portion 2 has a base portion 40 having a constant outer diameter along the long axis and a tapered portion 45 from the tip of the base portion 40 to the tip of the shaft portion 2, the inner diameter of the base portion 40 is 0.86 mm or more and 1.2 mm or less, the outer diameter of the base portion 40 is 1.5 mm or more and 2.2 mm or less, and the length of the tapered portion 45 along the long axis is 10 mm or more.

Description

Technical Field

[0001] The present invention relates to a venous catheter that is inserted into a vein of a living body and used.

Background Art

[0002] As a method for treating lesions such as stenosis and occlusion that occur in blood vessels, there is endovascular treatment in which treatment is performed from inside the blood vessel using a device inserted percutaneously into the blood vessel. In endovascular treatment, a catheter is used to reach a diagnostic contrast agent, a guide wire, etc. to the lesion site.

[0003] Patent Document 1 discloses a catheter that is inserted into the lumen of a guiding catheter to improve the kink resistance and reachability of the guiding catheter. This catheter has a tapered portion that tapers at the tip.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] In the treatment of deep vein thrombosis, a guide wire is passed through thrombi that have occurred in the iliac vein, femoral vein, and popliteal vein. In order to support the passage of the guide wire through the lesion in this case, a support catheter is used. Conventionally, arterial support catheters are known as support catheters. Therefore, arterial support catheters are also diverted in the treatment of veins.

[0006] Veins have a larger diameter than arteries. Therefore, when an arterial support catheter is inserted into a vein, a large gap is created between the outer surface of the support catheter and the inner wall of the vein, making the support catheter prone to bending within the vein. For this reason, there is a need for devices specifically designed for passage through lesions in veins.

[0007] The present invention was made to solve the above-mentioned problems and aims to provide a venous catheter that is easy to insert into a vein and has good passage through lesions. [Means for solving the problem]

[0008] (1) A venous catheter that achieves the above objective is a venous catheter having a long tubular shaft portion and being inserted into a vein of a living body, wherein the shaft portion has a base portion having a constant outer diameter along the longitudinal axis and a tapered portion from the tip of the base portion to the tip of the shaft portion, the inner diameter of the base portion is 0.86 mm or more and 1.2 mm or less, the outer diameter of the base portion is 1.5 mm or more and 2.2 mm or less, and the length of the tapered portion along the longitudinal axis is 10 mm or more. [Effects of the Invention]

[0009] As described above, the venous catheter has an outer diameter that matches the inner diameter of the vein into which it is inserted, thus minimizing the gap between the outer surface of the shaft and the inner wall of the vein during insertion. Furthermore, because the shaft has a large wall thickness at the base, it has high rigidity and prevents bending within the vein, making insertion easier.

[0010] (2) In the intravenous catheter described in (1) above, the shaft portion may have an outer diameter of 1.05 mm at its tip, and the length of the tapered portion along the longitudinal axis may be 10 mm or more and 20 mm or less. This allows the tapered portion to be formed with a long and gentle slope along the longitudinal axis, thereby improving passage through the lesion.

[0011] (3) In the intravenous catheter described in (1) above, the length of the shaft portion along the longitudinal axis of the tapered portion may be greater than 12 mm. This makes it possible to further increase the length along the longitudinal axis of the tapered portion and improve the passability through the lesion. [Brief explanation of the drawing]

[0012] [Figure 1] This is an overall view of the catheter according to this embodiment. [Figure 2] This is a magnified cross-sectional view showing the proximal shaft portion of the catheter shaft. [Figure 3] This is a front view showing a magnified portion of the reinforcing layer. [Figure 4] This is a magnified view showing the tip portion of the catheter shaft. [Modes for carrying out the invention]

[0013] Embodiments of the present invention will be described below with reference to the drawings. Note that the dimensions in the drawings may be exaggerated for illustrative purposes and may differ from the actual dimensions. In addition, in this specification and drawings, components having substantially the same functional configuration are denoted by the same reference numerals to avoid redundant explanation. In this specification, the side of the venous catheter that is inserted into the blood vessel will be referred to as the "tip side," and the side that is operated will be referred to as the "proximal side."

[0014] In this specification, the direction in which a venous catheter extends in its natural state (without any external force applied and in a straight state) is defined as the "long axis direction." The direction of rotation with respect to the long axis direction of the venous catheter is defined as the "circumferential direction." In a venous catheter, the side inserted into the blood vessel is defined as the tip, and the end opposite the tip is defined as the proximal end. Furthermore, the portion including a certain range in the long axis direction from the tip (extent) is defined as the "tip," and the portion including a certain range in the long axis direction from the proximal end (very proximal end) is defined as the "proximal end." In this context, clockwise rotation is defined as right rotation and counterclockwise rotation as left rotation, with the long axis as the center and viewed from the proximal end.

[0015] The venous catheter 1 according to this embodiment is inserted into any one of the iliac vein, femoral vein, or popliteal vein, and is used to support the passage of the guide wire through the lesion. As shown in FIG. 1, the venous catheter 1 has a long tubular shaft portion 2, a hub 3 connected to the proximal end of the shaft portion 2, and a kink-resistant protector 4 surrounding the connection portion of the shaft portion 2 and the hub 3.

[0016] The shaft portion 2 is a flexible tubular member, and a lumen 5, which is a lumen, is formed inside from the proximal end to the distal end. The guide wire is inserted through the lumen 5 when the venous catheter 1 is inserted into the blood vessel.

[0017] The effective length of the shaft portion 2 is not particularly limited, but is, for example, 600 mm to 2500 mm. The effective length of the shaft portion 2 is the length of the portion that can be inserted into the blood vessel or the sheath, and more preferably 600 mm to 1350 mm. In this embodiment, the effective length is the length from the foremost end of the kink-resistant protector 4 to the foremost end of the shaft portion 2, and is 900 mm.

[0018] The shaft portion 2 has a base portion 40 having a constant outer diameter along the long axis direction, and a tapered portion 45 having a tapered outer diameter from the distal end of the base portion 40 to the distal end of the shaft portion 2. The base portion 40 extends from the kink-resistant protector 4 toward the distal end side and occupies most of the length of the shaft portion 2 in the long axis direction.

[0019] The hub 3 is liquid-tightly fixed to the proximal end portion of the shaft portion 2 by an adhesive, heat fusion, a stopper (not shown), or the like. The hub 3 functions as an insertion port for the guide wire into the lumen 5. Further, the hub 3 also functions as a gripping portion when operating the venous catheter 1.

[0020] The hub 3 is not particularly limited, but is formed of a resin such as polycarbonate, polyamide, polysulfone, polyarylate, or a methacrylate-butylene-styrene copolymer.

[0021] The kink protector 4 is provided so as to surround the connection part between the shaft part 2 and the hub 3, and suppresses the kink of the shaft part 2 at the connection part between the shaft part 2 and the hub 3. The kink protector 4 is formed of an elastic material such as an elastomer, natural rubber, or silicone resin.

[0022] As shown in FIG. 2, the shaft part 2 includes an inner layer 10 having a lumen 5, a reinforcing body 20 disposed outside the inner layer 10, and an outer layer 30 disposed outside the inner layer 10 and the reinforcing body 20.

[0023] The inner layer 10 has a lumen 5 formed therein. The inner layer 10 is formed of a fluororesin such as polytetrafluoroethylene (PTFE) or a low-friction material such as high-density polyethylene (HDPE). Alternatively, the inner layer 10 may be formed of a thermoplastic resin such as a polymer material such as polyolefin (polyethylene, polypropylene, polybutene, ethylene-propylene copolymer, ethylene-vinyl acetate copolymer, ionomer, or a mixture of two or more thereof), polyvinyl chloride, polyamide, polyester elastomer, polyamide elastomer, polyurethane, polyurethane elastomer, polyimide, fluororesin, or a mixture thereof, or a thermosetting resin such as an epoxy resin.

[0024] The outer layer 30 is a tubular member that covers the outer periphery of the inner layer 10 and the reinforcing body 20. The outer layer 30 is formed of a thermoplastic resin such as a polymer material such as polyolefin (polyethylene, polypropylene, polybutene, ethylene-propylene copolymer, ethylene-vinyl acetate copolymer, ionomer, or a mixture of two or more thereof), polyvinyl chloride, polyamide, polyester elastomer, polyamide elastomer, polyurethane, polyurethane elastomer, polyimide, fluororesin, or a mixture thereof, or a thermosetting resin such as an epoxy resin.

[0025] As shown in Figure 3, the reinforcing body 20 is formed by weaving together a first reinforcing body 21 wound around the shaft portion 2 in either a clockwise or counterclockwise direction, and a second reinforcing body 22 wound around the shaft portion 2 in the other direction, i.e., the opposite direction, so that they intersect each other. The first reinforcing body 21 and the second reinforcing body 22 can be made of stainless steel such as SUS304 or SUS316, or tungsten. The wire diameter of the first reinforcing body 21 and the second reinforcing body 22 is set to 0.06 mm or more and 0.1 mm or less. The reinforcing body 20 is provided at the base portion 40 of the shaft portion 2, from the base end to a position closer to the base end than the tapered portion 45.

[0026] As shown in Figure 4, the tapered portion 45 is not provided with a reinforcing member 20. The tapered portion 45 has both an outer diameter and an inner diameter that decreases towards the tip. A tip 48 is provided at the tip of the tapered portion 45.

[0027] The dimensions of shaft portion 2 are described below. The veins of the lower limbs into which shaft portion 2 is inserted generally have an inner diameter of 2 to 16 mm. Veins also have characteristics such as thinner and more easily torn vessel walls compared to arteries, and a large number of microchannels on their surface. To prevent bending when inserted into a vein and to ensure good passage through the lesion, shaft portion 2 is set to the following dimensions. Of the shaft portion 2, the outer diameter D1 of the base portion 40 is 1.5 mm to 2.2 mm, and the inner diameter D2 of the base portion 40 is 0.86 mm to 1.2 mm. The total length (L1) of the tapered portion 45 along the long axis is 10 mm to 20 mm. The outer diameter D3 at the tip of shaft portion 2 is 1.05 mm, and the inner diameter D4 at the tip of shaft portion 2 is 0.90 mm to 0.92 mm.

[0028] Examples 1 to 4 show the shaft portion 2 of a venous catheter 1 that meets these dimensional requirements. For comparative examples, the dimensions of the shaft portion of an arterial catheter are also shown.

[0029] (Example 1) Base outer diameter (D1): 1.6mm Base inner diameter (D2): 1.05mm Tip outer diameter (D3): 1.05 mm Tip inner diameter (D4): 0.90 mm Tapered section length (L1): 10mm

[0030] (Example 2) Base outer diameter (D1): 1.6mm Base inner diameter (D2): 1.05mm Tip outer diameter (D3): 1.05 mm Tip inner diameter (D4): 0.90 mm Tapered section length (L1): 20mm

[0031] (Example 3) Base outer diameter (D1): 1.8mm Base inner diameter (D2): 1.05mm Tip outer diameter (D3): 1.05 mm Tip inner diameter (D4): 0.90 mm Tapered section length (L1): 10mm

[0032] (Example 4) Base outer diameter (D1): 1.8mm Base inner diameter (D2): 1.05mm Tip outer diameter (D3): 1.05 mm Tip inner diameter (D4): 0.90 mm Tapered section length (L1): 20mm

[0033] (Comparative example) Base outer diameter (D1): 1.4mm Base inner diameter (D2): 1.05mm Tip outer diameter (D3): 1.05 mm Tip inner diameter (D4): 0.90 mm Tapered section length (L1): 12mm

[0034] The shaft portion 2 of the venous catheter 1 in this embodiment has a larger base outer diameter D1 compared to the shaft portion of the arterial catheter in the comparative example, while the base inner diameter D2 is the same. As a result, the shaft portion 2 of the venous catheter 1 has a smaller gap with the inner wall surface of the blood vessel when inserted into a vein, and its greater wall thickness provides high rigidity. This makes the shaft portion 2 of the venous catheter 1 less likely to bend in the vein, facilitating insertion. Furthermore, the length of the tapered portion 45 along the long axis of the shaft portion 2 of the venous catheter 1 can be made longer than the 12 mm of the arterial catheter. This allows for improved passage through lesions within blood vessels.

[0035] As described above, the (1) venous catheter 1 according to this embodiment is a venous catheter 1 having a long tubular shaft portion 2 that is inserted into a vein of the living body, and the shaft portion 2 has a base portion 40 having a constant outer diameter along the long axis and a tapered portion 45 from the tip of the base portion 40 to the tip of the shaft portion 2, the inner diameter of the base portion 40 is 0.86 mm or more and 1.2 mm or less, the outer diameter of the base portion 40 is 1.5 mm or more and 2.2 mm or less, and the length of the tapered portion 45 along the long axis is 10 mm or more. Since the venous catheter 1 configured in this way has an outer diameter that matches the inner diameter of the vein into which it is inserted, the gap between the outer surface of the shaft portion 2 and the inner wall of the vein can be reduced during insertion. In addition, because the wall thickness of the shaft portion 2 at the base portion 40 is large, it has high rigidity and can suppress bending in the vein, so insertion can be made easier.

[0036] (2) In the intravenous catheter 1 described in (1) above, the shaft portion 2 may have an outer diameter of 1.05 mm at its tip, and the length of the tapered portion 45 along the longitudinal axis may be 10 mm or more and 20 mm or less. This allows the tapered portion 45 to be formed with a long and gentle slope along the longitudinal axis, which improves the passage through the lesion.

[0037] (3) In the venous catheter 1 described in (1) above, the length of the shaft portion 2 along the longitudinal axis of the tapered portion 45 may be greater than 12 mm. This makes it possible to increase the length along the longitudinal axis of the tapered portion 45 and further improve the passability through the lesion.

[0038] 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. [Explanation of Symbols]

[0039] 1 Catheter 2. Shaft section 3 Hubs 4 Kink-resistant protector 5 lumens 10 Inner layer 20 Reinforcement 21. First reinforcement 22 Second reinforcement 30 outer layer 40 base 45 Tapered section 48 Tips

Claims

1. A venous catheter having a long, tubular shaft portion and being inserted into a vein in the body, The shaft portion has a base portion having a constant outer diameter along the long axis, and a tapered portion from the tip of the base portion to the tip of the shaft portion, The inner diameter of the base is 0.86 mm or more and 1.2 mm or less. The outer diameter of the base is 1.5 mm or more and 2.2 mm or less. A venous catheter in which the length of the tapered portion along the longitudinal axis is 10 mm or more.

2. The intravenous catheter according to claim 1, wherein the shaft portion has an outer diameter of 1.05 mm at its tip, and the length along the long axis of the tapered portion is 10 mm or more and 20 mm or less.

3. The intravenous catheter according to claim 1, wherein the length of the shaft portion along the longitudinal axis direction of the tapered portion is greater than 12 mm.

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