Multi-lumen catheter

Abstract

This multilumen catheter comprises a tubular main body 101 that is surrounded by an outer wall 113 extending from the proximal end to the distal end. The interior of the main body 101 is divided into a plurality of lumens including a first lumen 111 and a second lumen 112 by a partition wall 114 extending in the longitudinal direction. A second opening face 122 at the distal end of the second lumen 112 is positioned at the distal end side of a first opening face 121 at the distal end of the first lumen 111. The outer wall 113 comprises a first outer wall part 115 forming the first lumen 111 and a second outer wall part 116 forming the second lumen 112. The first outer wall part 115 has a first lumen slit 123 that is formed by notching a part of the distal end thereof. The main body 101 has a flexible part 141 having a low hardness. The flexible part 141 is formed so as to include the distal end of the first outer wall part 115 where the first lumen slit 123 is formed.

Description

[Technical Field]

[0001] The present disclosure relates to multi-lumen catheters. [Background technology]

[0002] In the field of hemodialysis, blood is extracted from a patient's blood vessels, purified outside the body, and then returned to the blood vessels. In such cases, a multi-lumen catheter is used, which has at least two lumens: one for extracting blood from the patient's blood vessels and one for returning the purified blood to the patient's blood vessels.

[0003] Methods for inserting this catheter into a blood vessel include, for example, a method using an introducer sheath and the Seldinger technique. The former is a method in which the catheter is placed into an introducer sheath that has already been inserted into the blood vessel and the catheter is inserted along the lumen of the introducer sheath to the desired location. The latter is a method in which a wire that has already been inserted into the blood vessel is passed through the lumen of the catheter and the catheter is inserted along the wire to the desired location.

[0004] Introducer sheaths are sometimes provided with a check valve, and a catheter must pass through this check valve to be inserted into the introducer sheath. Furthermore, in the Seldinger technique, a catheter is inserted directly into a blood vessel, so a catheter with excellent insertability is particularly required.

[0005] In order to satisfy such a demand, it has been conventional to provide the opening positions of the blood removal lumen and the blood return lumen offset in the longitudinal direction (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Laid-Open No. 2008-132256 Summary of the Invention [Problem to be solved by the invention]

[0007] In the catheter of Patent Document 1, the cross-sectional area at the opening position of the blood return lumen at the catheter tip can be reduced, improving the insertability of the tip. However, because the cross-sectional area at the opening position of the blood removal lumen remains unchanged, the insertion resistance of the catheter increases sharply at this position, resulting in a problem in which the overall insertability is hardly improved.

[0008] An object of the present disclosure is to realize a multi-lumen catheter that is easy to insert. [Means for solving the problem]

[0009] One embodiment of the catheter of the present disclosure comprises a cylindrical main body surrounded by an outer wall extending from the base end to the tip, the interior of the main body being partitioned into multiple lumens, including a first lumen and a second lumen, by longitudinally extending partitions, the second opening surface at the tip of the second lumen being located more distal than the first opening surface at the tip of the first lumen, the outer wall having a first outer wall portion forming the first lumen and a second outer wall portion forming the second lumen, the first outer wall portion having a first lumen slit formed by cutting out a portion of the tip, the main body having a flexible portion having a lower hardness than the rest of the main body, and the flexible portion being formed to include the tip portion of the first outer wall portion in which the first lumen slit is formed.

[0010] With this configuration, when the catheter is inserted, the tip of the first outer wall portion, where the first lumen slit is formed, deforms to enter the lumen of the first lumen. Therefore, during insertion, the cross-sectional area of ​​the main body portion is reduced at the position of the first opening, and a sudden increase in insertion resistance does not occur, resulting in excellent catheter insertability. The tip of the first outer wall portion returns to its original shape after the catheter is placed in the blood vessel. This distributes the suction pressure when blood is removed from the first lumen, making it less likely for the catheter to stick to the blood vessel wall.

[0011] In one aspect of the multi-lumen catheter, the first lumen slit is preferably provided in the circumferential center of the first outer wall portion. This configuration prevents a decrease in the rigidity of the distal end of the first outer wall portion and also prevents the first opening from being blocked or narrowed by pressure from the blood vessel wall or the like.

[0012] In one aspect of the multi-lumen catheter, the flexible portion is preferably formed to include the position of the base end of the first lumen slit to the tip of the main body. This configuration allows the first outer wall portion to easily deform so as to enter the lumen of the first lumen, making the change in insertion resistance more gradual, further improving the insertability of the catheter. It also makes it less likely that the blood vessel will be damaged during insertion of the catheter.

[0013] In one embodiment of the multi-lumen catheter, the first outer wall portion preferably has at least one first lumen side hole located closer to the proximal end than the first lumen slit. This configuration further distributes the suction pressure when blood is removed from the first lumen, making it less likely for blood to stick to the blood vessel wall. It also makes it easier to ensure the amount of blood removed.

[0014] In one aspect of the multi-lumen catheter, it is preferable that the second outer wall portion has a second lumen slit formed by cutting out a portion of the tip, and the flexible portion is formed to include the tip of the second outer wall portion where the second lumen slit is formed. With this configuration, the tip of the second outer wall portion where the second lumen slit is formed deforms to enter the inner cavity of the second lumen. This reduces the cross-sectional area of ​​the main body portion at the position of the second opening surface during insertion, further improving the insertability of the catheter. Furthermore, after the catheter is placed in the blood vessel, the tip of the second outer wall portion returns to its original shape, which distributes the suction pressure when blood is removed from the second lumen, making it less likely for blood to stick to the blood vessel wall.

[0015] In one embodiment of the multi-lumen catheter, the second outer wall portion preferably has at least one second lumen side hole. This configuration disperses the suction pressure when blood is removed from the second lumen, making it less likely for the blood to stick to the blood vessel wall. Furthermore, the amount of blood removed can be easily ensured.

[0016] In one aspect of the multi-lumen catheter, it is preferable that the first opening surface is inclined toward the proximal end relative to the partition wall, and the second opening surface is perpendicular to the partition wall. This configuration makes it possible to more gently change the insertion resistance at the first opening surface, further improving the ease of insertion of the catheter. In addition, it is possible to reduce the suction pressure at the first opening surface and easily ensure the amount of blood removal.

[0017] In one embodiment of the multi-lumen catheter, the number of lumens is preferably three or more. This configuration allows for the administration of drug solutions and the measurement of central venous pressure simultaneously with hemodialysis, thereby reducing the burden on the patient and the surgeon.

[0018] In one aspect of the multi-lumen catheter, the proximal end of the main body is preferably provided with a plurality of branch tubes, each connected to a plurality of lumens and having a connector on the proximal end side. With this configuration, the main body can be connected to a blood circuit or the like via the connectors to perform hemodialysis. [Effects of the Invention]

[0019] According to the multi-lumen catheter of the present disclosure, the first outer wall portion has a first lumen slit, and the tip portion of the first outer wall portion in which the first lumen slit is formed is included in the flexible portion, thereby achieving excellent catheter insertability. [Brief explanation of the drawings]

[0020] [Figure 1] 1 is an overall side view of a multi-lumen catheter according to one embodiment. FIG. [Figure 2] 1 is an overall perspective view of a multi-lumen catheter according to one embodiment. FIG. [Figure 3] 1 is an overall perspective view of a multi-lumen catheter according to one embodiment. FIG. [Figure 4] FIG. 2 is a view of the multi-lumen catheter of FIG. 1 as seen from the proximal end side. [Figure 5] FIG. 1 is a right side view showing a multi-lumen catheter according to one embodiment. [Figure 6] FIG. 1 is a left side view showing a multi-lumen catheter according to one embodiment. [Figure 7] FIG. 1 is a top view of a multi-lumen catheter according to one embodiment. [Figure 8] FIG. 1 is a bottom view of a multi-lumen catheter according to one embodiment. [Figure 9] FIG. 6 is a view of the multi-lumen catheter of FIG. 5 as seen from the distal end side. [Figure 10] FIG. 6 is a view of the multi-lumen catheter of FIG. 5 as seen from the proximal end side. [Figure 11] FIG. 1 is a perspective view showing a multi-lumen catheter according to one embodiment. [Figure 12] FIG. 10 is a perspective view showing a multi-lumen catheter according to a first modified example. [Figure 13] FIG. 10 is a perspective view showing a multi-lumen catheter according to a second modified example. [Figure 14] FIG. 10 is an overall perspective view of a multi-lumen catheter according to a fourth modified example. [Figure 15] FIG. 10 is a right side view showing a multi-lumen catheter according to a fourth modified example. [Figure 16] FIG. 10 is a left side view showing a multi-lumen catheter according to a fourth modified example. [Figure 17] FIG. 10 is a top view showing a multi-lumen catheter according to a fourth modified example. [Figure 18] FIG. 10 is a bottom view showing a multi-lumen catheter according to a fourth modified example. [Figure 19]FIG. 10 is an overall side view of a multi-lumen catheter according to a fifth modified example. [Figure 20] FIG. 11 is an overall perspective view of a multi-lumen catheter according to a fifth modified example. [Figure 21] FIG. 11 is an overall perspective view of a multi-lumen catheter according to a fifth modified example. [Figure 22] FIG. 10 is a right side view showing a multi-lumen catheter according to a fifth modified example. [Figure 23] FIG. 10 is a left side view showing a multi-lumen catheter according to a fifth modified example. [Figure 24] FIG. 10 is a top view showing a multi-lumen catheter according to a fifth modified example. [Figure 25] FIG. 11 is a bottom view showing a multi-lumen catheter according to a fifth modified example. [Figure 26] FIG. 23 is a view of the multi-lumen catheter of FIG. 22 as seen from the distal end side. [Figure 27] FIG. 23 is a view of the multi-lumen catheter of FIG. 22 as seen from the proximal end side. [Figure 28] FIG. 11 is a perspective view showing a multi-lumen catheter according to a fifth modified example. [Figure 29] FIG. 10 is a perspective view showing a multi-lumen catheter according to a sixth modified example. [Figure 30] FIG. 13 is a top view showing a multi-lumen catheter according to a seventh modified example. [Figure 31] FIG. 13 is a bottom view showing a multi-lumen catheter according to a seventh modified example. [Figure 32] FIG. 13 is a top view showing a multi-lumen catheter according to an eighth modified example. [Figure 33] FIG. 13 is a bottom view showing a multi-lumen catheter according to an eighth modified example. DETAILED DESCRIPTION OF THE INVENTION

[0021] The multi-lumen catheter (hereinafter referred to as "catheter") of the present disclosure is used for hemodialysis by being placed in a patient's blood vessel, purifying blood drawn from a blood removal lumen outside the body, and returning the purified blood to the blood vessel through a blood return lumen.

[0022] As shown in FIGS. 1 to 11 , the catheter of this embodiment includes a cylindrical main body (catheter tube) 101 surrounded by an outer wall 113 extending from the base end to the tip. A partition wall 114 extending in the longitudinal direction is provided inside the main body 101. The interior of the main body 101 is partitioned by the partition wall 114 into a first lumen 111 and a second lumen 112. The outer wall 113 has a first outer wall portion 115 that forms the first lumen 111 and a second outer wall portion 116 that forms the second lumen 112. The first lumen 111 is formed by the first outer wall portion 115 and the partition wall 114, and the second lumen 112 is formed by the second outer wall portion 116 and the partition wall 114.

[0023] When using the catheter of this embodiment, the up, down, left, and right directions are not particularly limited, but in the following, the side where the first lumen 111 is provided relative to the partition wall 114 will be referred to as the upper side, and the side where the second lumen 112 is provided relative to the partition wall 114 will be referred to as the lower side. Furthermore, with the first lumen 111 being the upper side, the right side when viewing the main body portion 101 from the tip side will be referred to as the right side surface, and the left side will be referred to as the left side surface.

[0024] When hemodialysis is performed using the catheter of this embodiment, in normal forward connection, the first lumen 111 is used as the blood removal lumen and the second lumen 112 is used as the blood return lumen. In addition, reverse connection, in which the functions are swapped, can also be used to prevent adhesion to the blood vessel wall, etc. In reverse connection, the second lumen 112 is used as the blood removal lumen and the first lumen 111 is used as the blood return lumen.

[0025] The first lumen 111 and the second lumen 112 are formed symmetrically with respect to the partition wall 114. This makes the cross-sectional areas of the first lumen 111 and the second lumen 112 equal, making it easy to ensure the amount of blood removed from the second lumen 112 even when the two are connected in reverse. This also makes extrusion molding easier when manufacturing the main body 101. Note that, from the perspective of ensuring the amount of blood removed from the first lumen 111 when the two are connected in forward direction, the partition wall 114 can also be provided so that the cross-sectional area of ​​the first lumen 111 is larger than the cross-sectional area of ​​the second lumen 112.

[0026] The first lumen 111 and the second lumen 112 are formed to have a semicircular cross section. This allows the inner cavity of the main body 101 to be efficiently utilized, ensuring large cross-sectional areas for the first lumen 111 and the second lumen 112. Therefore, when connected in forward direction, the amount of blood removed from the first lumen 111 can be ensured, and the suction pressure can be reduced to prevent adhesion to the blood vessel wall. Furthermore, when connected in reverse direction, the same effect can be obtained in the second lumen 112.

[0027] The outer diameter φ of the main body 101 is not particularly limited, but is preferably 2 mm or more, more preferably 2.5 mm or more, from the viewpoint of ensuring a sufficient blood flow rate. Also, from the viewpoint of ease of insertion into a blood vessel, it is preferably 6 mm or less, more preferably 5 mm or less.

[0028] The thickness of the outer wall 113 of the main body 101 is not particularly limited, but from the viewpoint of the strength of the catheter, it is preferably 0.1 mm or more, more preferably 0.2 mm or more, and from the viewpoint of the flexibility of the catheter, it is preferably 0.8 mm or less, more preferably 0.6 mm or less.

[0029] The catheter of this embodiment is an end-hole type in which the openings at the tips of the first lumen 111 and the second lumen 112 are each provided on the tip side of the main body 101. The second opening surface 122 at the tip of the second lumen 112 is located more distal than the first opening surface 121 at the tip of the first lumen 111. Furthermore, in the catheter of this embodiment, the second opening surface 122 is located at the tip of the main body 101. This makes the cross-sectional area of ​​the tip of the main body 101 smaller than when the first opening surface 121 and the second opening surface 122 are provided at the same position in the longitudinal direction, thereby improving the insertability of the catheter. Furthermore, during forward connection, recirculation, in which blood returned from the second lumen 112 is directly drawn into the first lumen 111, can be made less likely to occur.

[0030] From the viewpoints of catheter insertability and avoiding recirculation during forward connection, it is preferable that the first opening surface 121 be as far away as possible from the second opening surface 122. Specifically, the distance L1 from the tip (second opening surface 122) of the main body 101 to the first opening surface 121 can be preferably 3 mm or more, more preferably 7 mm or more. On the other hand, from the viewpoint of the length of the catheter, it is preferable that the distance from the tip of the main body 101 not be too long. Specifically, the distance L1 from the tip (second opening surface 122) of the main body 101 to the first opening surface 121 can be preferably 25 mm or less, more preferably 15 mm or less.

[0031] The partition 114 extends from the base end to the tip of the main body 101. The width of the partition 114 is constant from the base end of the main body 101 to the position of the first opening surface 121, and is formed so as to gradually narrow from the position of the first opening surface 121 to the tip of the main body 101. The second outer wall 116 is formed so that the inner cavity of the second lumen 112 gradually narrows toward the tip of the main body 101 in accordance with the change in the width of the partition 114. This reduces resistance when inserting the catheter and makes it less likely to damage the blood vessel. The position at which the width of the partition 114 narrows is not particularly limited as long as it is closer to the tip than the first opening surface 121, and the width of the partition 114 can be gradually narrowed from any position.

[0032] The first opening surface 121 is cut so that the first outer wall portion 115 is gradually positioned closer to the base end as it moves away from the partition wall 114, and is provided at an angle toward the base end with respect to the partition wall 114. This reduces the resistance when inserting the catheter and reduces the risk of damaging the blood vessel, compared to when the first opening surface 121 is perpendicular to the partition wall 114. Furthermore, the size of the first opening surface 121 (the area of ​​the opening surface) is larger than when the first opening surface 121 is perpendicular to the partition wall 114. This reduces the suction pressure during forward connection, making it less likely for the first opening surface 121 to stick to the blood vessel wall. Furthermore, the amount of blood removed from the first lumen 111 can be easily ensured.

[0033] From the viewpoint of catheter insertability, the opening angle θ1 formed by the first opening surface 121 and the partition wall 114 can be preferably 60° or less, and more preferably 50° or less. On the other hand, from the viewpoint of preventing poor blood removal caused by the first opening surface 121 sticking to the blood vessel wall due to suction pressure during forward connection, the opening angle θ1 can be preferably 15° or more, and more preferably 25° or more.

[0034] The second opening surface 122 is provided so as to be perpendicular to the partition wall 114. This makes it possible to prevent the second opening surface 122 from sticking to the blood vessel wall when the second opening surface 122 is reversely connected.

[0035] The first outer wall portion 115 has a first lumen slit 123 formed by cutting out a portion of the tip. The first lumen slit 123 has a predetermined width. As a result, during forward connection, the flow of blood sucked into the first lumen 111 is also dispersed into the first lumen slit 123, reducing the suction pressure and making it less likely for the blood to stick to the blood vessel wall. Furthermore, even if the first opening surface 121 is blocked by a thrombus or the like, the first lumen 111 can remain open.

[0036] The first lumen slit 123 is provided in the circumferential center of the first outer wall portion 115. This prevents a decrease in the rigidity of the first outer wall portion 115 when the catheter is placed in a blood vessel. It also prevents the first opening surface 121 from being blocked or narrowed by pressure from the blood vessel wall or the like.

[0037] First lumen slit 123 can be formed by making a cut from the tip of first outer wall portion 115 and then heating it. In this way, first lumen slit 123 can be easily formed without requiring a complicated process. Furthermore, in this way, burrs are less likely to be generated when first lumen slit 123 is formed, which is also excellent in safety.

[0038] The length L2 of the first lumen slit 123 is not particularly limited, but is preferably 2 mm or more and 15 mm or less, more preferably 5 mm or more and 10 mm or less, from the viewpoint of reducing adhesion to the blood vessel wall.

[0039] The width of first lumen slit 123 is not particularly limited, but is preferably 0.1 mm or more and 2.5 mm or less. Furthermore, from the viewpoint of ensuring the rigidity of first outer wall portion 115, the width of first lumen slit 123 is preferably 2.5% to 63% of the outer diameter φ of the catheter. Note that, although the width of first lumen slit 123 in this embodiment is constant in the longitudinal direction, it is not limited to this and can also be changed in the longitudinal direction. For example, the width of first lumen slit 123 can be gradually increased from the distal end to the proximal end.

[0040] A first lumen side hole 125 that connects the first lumen 111 to the outside is provided at the tip portion of the first outer wall portion 115. This further disperses the flow of blood drawn into the first lumen 111 during forward connection, making it less likely for the blood to stick to the blood vessel wall. Also, the amount of blood removed from the first lumen 111 can be easily ensured. Furthermore, even if the first opening surface 121 and / or the first lumen slit 123 are blocked by a thrombus or the like, the first lumen 111 can remain open.

[0041] From the viewpoint of enhancing the suction pressure dispersion effect, it is preferable to provide multiple first lumen side holes 125 and arrange them at intervals in the longitudinal direction. In the catheter of this embodiment, two first lumen side holes 125 are provided, but the number of first lumen side holes 125 is not particularly limited, and three or more can be provided.

[0042] From the viewpoint of reducing sticking to the blood vessel wall, it is preferable to provide first lumen side hole 125 at a position as displaced as possible from first lumen slit 123, and it is more preferable to provide it closer to the proximal end than first lumen slit 123. Furthermore, by arranging multiple first lumen side holes 125 in a so-called staggered pattern, in which they are displaced from each other both in the longitudinal direction and width direction of first lumen 111, it is possible to further reduce sticking to the blood vessel wall.

[0043] When arranging the first lumen side holes 125 in a staggered pattern, it is preferable to arrange adjacent first lumen side holes 125 at positions as offset as possible. For example, for two adjacent first lumen side holes 125, it is preferable that the angle formed by the line connecting the plurality of first lumen side holes 125 and the center of the circle formed by outer wall 113 is 110° to 160°. Note that the first lumen side holes 125 are preferably arranged on opposite sides of the first lumen slit 123.

[0044] Furthermore, it is preferable that the first lumen side holes 125 are arranged at equal intervals in the longitudinal direction. For example, when the first lumen side holes 125 are arranged in series in the longitudinal direction, the length of the straight line connecting the centers of the first lumen side holes 125 between two adjacent first lumen side holes 125 is preferably 2 mm to 5 mm. Note that the first lumen side holes 125 can also be arranged at unequal intervals in the longitudinal direction. Furthermore, the arrangement of the first lumen side holes 125 is not limited to a staggered arrangement, and they can also be arranged in series in the longitudinal direction.

[0045] The diameter of the first lumen side hole 125 is not particularly limited, but is preferably 0.5 mm or more and 2.0 mm or less. When multiple first lumen side holes 125 are provided, some of the diameters may be different. Furthermore, first lumen side holes 125 may be provided as needed, and a configuration without a first lumen side hole 125 is also possible.

[0046] The main body 101 is provided with a flexible portion 141. The flexible portion 141 is formed to have a lower hardness than other portions 142 of the main body 101 other than the flexible portion 141. The flexible portion 141 is formed to include the tip portion of the first outer wall portion 115 in which the first lumen slit 123 is formed.

[0047] 7, the distal end portion of first outer wall portion 115 included in flexible portion 141 is a portion S of the portion of first outer wall portion 115 where first lumen slit 123 is formed, the portion S being distal from a position at least halfway along length L2 of first lumen slit 123. For this reason, flexible portion 141 only needs to include portion S, which is at least the distal half of the portion of first outer wall portion 115 where first lumen slit 123 is formed. However, flexible portion 141 may include an even wider range, and may, for example, include the entire portion where first lumen slit 123 is formed.

[0048] As a result, when inserting the catheter, the tip portions of the first outer wall portion 115 on both sides of the first lumen slit 123 deform so as to enter the inner cavity of the first lumen 111. This reduces the cross-sectional area of ​​the main body portion 101 at the position of the first opening surface 121 during insertion, preventing the first opening surface 121 from acting as insertion resistance and achieving excellent catheter insertability. This also reduces the burden on the patient and the surgeon. Note that the tip portions of the first outer wall portion 115 return to their original shape when the catheter is placed in the blood vessel, thereby achieving excellent catheter insertability without affecting the function of the first lumen 111.

[0049] It is preferable that flexible section 141 includes the portion of first outer wall section 115 where first lumen slit 123 is formed, from the position of the base end of first lumen slit 123 to the tip side. This makes it easier for first outer wall section 115 on both sides of first lumen slit 123 to deform so as to enter the inner cavity of first lumen 111 from the position of the base end of first lumen slit 123. As a result, the cross-sectional area of ​​main body section 101 at the position of first opening surface 121 during insertion becomes even smaller, and the change in insertion resistance becomes more gradual, resulting in better insertability of the catheter.

[0050] Furthermore, it is more preferable that the flexible section 141 includes the area from the base end position of the first lumen slit 123 to the tip (second opening surface 122) of the main body section 101. This allows for excellent catheter insertability and also makes it less likely that the catheter will damage the blood vessel when passing through the blood vessel.

[0051] When flexible portion 141 includes the position of the base end of first lumen slit 123 to the tip (second opening surface 122) of main body portion 101, the longitudinal range of flexible portion 141 is preferably 5 mm or more, more preferably 10 mm or more, from the tip of main body portion 101, from the viewpoint of catheter insertability. On the other hand, the longitudinal range of flexible portion 141 is preferably 50 mm or less, more preferably 40 mm or less, from the tip of main body portion 101, from the viewpoint of catheter operability.

[0052] The flexible portion 141 can be formed using polyurethane, polyvinyl chloride, silicone, ethylene-vinyl acetate copolymer, polyamide, etc. Of these, it is preferable that the flexible portion 141 be formed using polyurethane.

[0053] Furthermore, the portion 142 other than the flexible portion 141 of the main body 101 is required to have a hardness that allows it to maintain a stable shape within the blood vessel and does not damage the blood vessel. From these perspectives, the portion 142 other than the flexible portion 141 can be formed using polyurethane, polyvinyl chloride, silicone, polyethylene, polypropylene, ethylene-vinyl acetate copolymer, polyamide, or the like. Among these, it is preferable to use polyurethane, which has a hardness that does not impair the insertability of the catheter and has the property of being hard at room temperature but soft at the temperature inside the body. From the perspective of facilitating welding, the flexible portion 141 and the portion 142 other than the flexible portion 141 are preferably formed from the same material, but may also be formed from different materials.

[0054] If the portion 142 other than the flexible portion 141 is formed from a material whose flexibility decreases significantly with increasing temperature, there will be a predetermined difference in hardness between the flexible portion 141 and the portion 142 other than the flexible portion 141 at room temperature before the catheter is inserted. On the other hand, when the catheter is inserted into a blood vessel and warmed by the temperature inside the body, the hardness of the portion other than the flexible portion 141 decreases significantly, and the difference in hardness between the flexible portion 141 and the portion 142 other than the flexible portion 141 becomes smaller than before insertion. This prevents the catheter from bending at the boundary between the flexible portion 141 and the portion 142 other than the flexible portion 141 inside the blood vessel while maintaining the insertability of the catheter, making it less likely to damage the blood vessel.

[0055] The tip side of the main body 101 can also be made a different color from the other parts of the main body 101. This makes it easier for the surgeon to recognize the position of the tip of the main body 101, improving the operability of the catheter. Also, at least a part of the main body 101 can be made of a material containing a contrast agent such as barium sulfate, bismuth tungstate, or bismuth oxide so that the insertion position of the catheter can be identified.

[0056] The length of main body 101 is not particularly limited, but from the viewpoint of the catheter placement site, it is preferably 10 cm or more, more preferably 13 cm or more, and preferably 40 cm or less, more preferably 30 cm or less.

[0057] Branch pipes 103A and 103B extend from the base end of main body 101 via branching section 102. The distal end of branch pipe 103A is connected to first lumen 111. The distal end of branch pipe 103B is connected to second lumen 112. Connectors (not shown) are connected to the proximal ends of branch pipes 103A and 103B, respectively. In Figures 1 to 4, the connectors are covered with protective caps 131A and 131B, respectively, and main body 101 can be connected to a blood circuit or the like via these connectors.

[0058] A clamp 132A is attached to branch pipe 103A, and a clamp 132B is attached to branch pipe 103B. By providing clamps 132A and 132B to branch pipes 103A and 103B, respectively, branch pipes 103A and 103B can be closed when performing treatment such as heparin lock.

[0059] The catheter of this embodiment can be modified in various ways. In the modifications described below, only the parts that differ from this embodiment will be described. Explanations of configurations that are common to this embodiment will be omitted as appropriate. Furthermore, common parts will be given the same reference numerals as in this embodiment.

[0060] As a first modified example, as shown in Fig. 12, the first opening surface 121 can be made perpendicular to the partition wall 114. This makes it less likely for the catheter to stick to the blood vessel wall during forward connection. Furthermore, in the first modified example, when the catheter is inserted, the tip ends of the first outer wall portion 115 on both sides of the first lumen slit 123 deform so as to enter the inner cavity of the first lumen 111. This makes it possible to prevent the first opening surface 121, which is perpendicular to the partition wall 114, from creating insertion resistance.

[0061] 13, a second lumen slit 124 can be provided at the tip of the second outer wall portion 116. This disperses the flow of blood sucked into the second lumen 112 during reverse connection, reducing the suction pressure and making it less likely for the blood to stick to the blood vessel wall. It also makes it less likely for recirculation to occur during reverse connection.

[0062] From the viewpoint of preventing a decrease in the rigidity of second outer wall portion 116, second lumen slit 124 is preferably provided in the circumferential center of second outer wall portion 116. The length of second lumen slit 124 is not particularly limited, but from the viewpoint of reducing sticking to the blood vessel wall, it is preferably 2 mm or more and 15 mm or less. Furthermore, the width of second lumen slit 124 is not particularly limited, but from the viewpoint of ensuring the rigidity of second outer wall portion 116, it is preferably 0.1 mm or more and 2.5 mm or less, and is preferably 2.5% to 63% of the outer diameter φ of the catheter.

[0063] In the second modified example, flexible portion 141 is formed to include not only the distal end portion of first outer wall portion 115 but also the distal end portion of second outer wall portion 116 in which second lumen slit 124 is formed. Here, the distal end portion of second outer wall portion 116 included in flexible portion 141 refers to the portion of second outer wall portion 116 in which second lumen slit 124 is formed, the portion being distal from a position at least halfway along the length of second lumen slit 124. For this reason, flexible portion 141 provided on second outer wall portion 116 only needs to include at least the distal half of the portion of second outer wall portion 116 in which second lumen slit 124 is formed, and may also include the entire portion in which second lumen slit 124 is formed.

[0064] As a result, when the catheter is inserted, the tip portions of the second outer wall portion 116 on both sides of the second lumen slit 124 deform so as to enter the inner cavity of the second lumen 112. This reduces the cross-sectional area of ​​the main body portion 101 at the position of the second opening surface 122 during insertion, thereby achieving excellent catheter insertability. Note that the tip portions of the second outer wall portion 116 return to their original shape when the catheter is placed in the blood vessel, thereby achieving excellent catheter insertability without affecting the function of the second lumen 112.

[0065] It should be noted that flexible portion 141 provided on first outer wall portion 115 and flexible portion 141 provided on second outer wall portion 116 may be separate portions or may be continuous portions. Specifically, when the two are separate portions, for example, flexible portion 141 is provided separately in two locations: a portion including the tip portion of first outer wall portion 115 and a portion including the tip portion of second outer wall portion 116. When the two are continuous portions, for example, flexible portion 141 is formed to include from the position of the base end of first lumen slit 123 in main body portion 101 to the tip (second opening surface 122) of main body portion 101.

[0066] As a third modified example (not shown), from the viewpoint of preventing recirculation during reverse connection, the second modified example is further modified so that the positions of the first opening surface 121 and the second opening surface 122 are aligned in the longitudinal direction and provided at the tip of the main body portion 101, and the partition wall 114 can be extended further toward the tip side than the positions of the first opening surface 121 and the second opening surface 122. This makes it less likely that recirculation will occur during reverse connection than in a configuration in which the second opening surface 122 is located closer to the tip side than the first opening surface 121.

[0067] Moreover, in the third modified example, a second lumen slit 124 is formed in the second outer wall portion 116, and the flexible portion 141 is formed to include not only the tip portion of the first outer wall portion 115 but also the tip portions of the second outer wall portion 116 on both sides of the second lumen slit 124. As a result, when inserting the catheter, the first outer wall portion 115 and the second outer wall portion 116 deform so as to enter the inner cavities of the first lumen 111 and the second lumen 112, respectively. Therefore, even when the first opening surface 121 and the second opening surface 122 are aligned in the longitudinal direction, the cross-sectional area at the tip of the main body portion 101 can be reduced, and excellent catheter insertability can be achieved.

[0068] The third modification is particularly preferable when the catheter is inserted using an introducer sheath. When the catheter is inserted into the lumen of the introducer sheath, the first outer wall portion 115 and the second outer wall portion 116 deform, allowing the catheter to easily pass through the check valve. Furthermore, when the catheter is reversely connected, recirculation can be reduced by the partition wall 114 extending distally beyond the positions of the first opening surface 121 and the second opening surface 122.

[0069] As a fourth modified example, as shown in Figures 14 to 18, a plurality of second lumen side holes 126 that communicate between the second lumen 112 and the outside can be provided at the tip portion of the second outer wall portion 116, and some of these can be elliptical in shape extending in the longitudinal direction. This reduces the suction pressure during reverse connection, making it less likely for the second lumen 112 to stick to the blood vessel wall. It also makes it easy to ensure the amount of blood removed from the second lumen 112. Furthermore, even if the second opening surface 122 is blocked by a thrombus or the like, the second lumen 112 can be kept open by the plurality of second lumen side holes 126.

[0070] The size of the elliptical second lumen side hole 126 is not particularly limited, but it is preferably about the same size (length and width) as the second lumen slit 124 from the standpoint of reducing adhesion to the blood vessel wall.

[0071] The elliptical second lumen side hole 126 exhibits more advantageous effects than the second lumen slit 124, for example, when inserting a catheter by the Seldinger method. Specifically, if the second lumen slit 124 is provided when inserting a catheter using a stylet that fills the gap between the blood return lumen and the guidewire in the Seldinger method, there is a risk that the tip of the stylet will protrude from the second lumen slit 124 to the outside of the second lumen 112, which could damage the blood vessel or affect the operability of the catheter. On the other hand, the elliptical second lumen side hole 126 is closed all around, so there is no risk of the stylet protruding, and excellent operability can be obtained.

[0072] Furthermore, a plurality of circular second lumen side holes 126 are formed in the distal end portion of the second outer wall portion 116. Similar to the first lumen side hole 125, the plurality of circular second lumen side holes 126 are preferably arranged in a staggered pattern from the viewpoint of reducing sticking to the blood vessel wall during reverse connection. In the fourth modified example, two circular second lumen side holes 126 are provided, but three or more may be provided, or they may be arranged in series in the longitudinal direction.

[0073] From the viewpoint of reducing recirculation, the second lumen side hole 126 is preferably provided on the distal side relative to the proximal end of the first lumen slit 123.

[0074] In the fourth modified example, the flexible section 141 is formed so as to include the tip end portion of the first outer wall section 115 in which the first lumen slit 123 is formed. From the viewpoint of forming a plurality of second lumen side holes 126, it is preferable that the flexible section 141 does not include the tip end portion of the second outer wall section 116. This prevents the periphery of the second lumen side hole 126 from tearing during hemodialysis, and ensures the strength of the periphery of the second lumen side hole 126.

[0075] Note that the flexible portion 141 may be configured to include the tip portion of the second outer wall portion 116, and may be formed, for example, to include from the position of the base end of the first lumen slit 123 to the tip of the main body portion 101. This makes it easier for the tip portion of the second outer wall portion 116 to deform when inserting the catheter, thereby narrowing or closing the second lumen side hole 126 and reducing the cross-sectional area of ​​the second lumen 112, thereby improving the insertability of the catheter. Note that when the flexible portion 141 includes the tip portion of the second outer wall portion 116, the tip portion of the second outer wall portion 116 may be formed thicker in order to prevent the periphery of the second lumen side hole 126 from tearing.

[0076] In the fourth modified example, some of the multiple second lumen side holes 126 are elliptical, but all may be circular second lumen side holes 126. Furthermore, it is also possible to provide only elliptical second lumen side holes 126 without providing circular second lumen side holes 126, and the number of elliptical second lumen side holes 126 is not particularly limited and may be one or more.

[0077] In the fourth modification, the cross sections of the distal end and proximal end of the main body 101 are similar to those of the catheter according to this embodiment.

[0078] As a fifth modified example, as shown in Figures 19 to 28, the distance L1 from the first opening surface 121 to the tip of the main body portion 101 can be increased, and multiple second lumen side holes 126 can be provided at the tip portion of the second outer wall portion 116. By increasing the distance L1, the area of ​​the tip portion of the second outer wall portion 116 can be increased, making it easy to secure a place to provide multiple second lumen side holes 126. It is also possible to suppress sudden changes in insertion resistance and improve the insertability of the catheter. Furthermore, by providing multiple second lumen side holes 126, the flow of blood sucked into the second lumen 112 can be dispersed during reverse connection, making it less likely for the blood to stick to the blood vessel wall.

[0079] From the viewpoint of dispersing suction pressure during reverse connection, the multiple second lumen side holes 126 are preferably spaced apart from one another in the longitudinal direction. Furthermore, from the viewpoint of reducing recirculation, the multiple second lumen side holes 126 are preferably provided closer to the distal end than the first opening surface 121. In the fifth modified example, two second lumen side holes 126 are provided, but the number of second lumen side holes 126 is not particularly limited, and three or more can be provided.

[0080] From the viewpoint of reducing adhesion to the blood vessel wall, it is preferable that the multiple second lumen side holes 126 be arranged in a staggered pattern. In this case, it is preferable that adjacent second lumen side holes 126 are arranged at positions as offset as possible. Note that the arrangement of the second lumen side holes 126 is not limited to a staggered pattern, and they can also be arranged in series in the longitudinal direction. Furthermore, in the fifth modified example, it is also possible to form second lumen side holes 126 that are elliptical in shape.

[0081] In the fifth modified example, the flexible portion 141 is formed so as to include the tip portion of the first outer wall portion 115 in which the first lumen slits 123 are formed, and from the viewpoint of forming a plurality of second lumen side holes 126, it is preferable that the flexible portion 141 does not include the tip portion of the second outer wall portion 116. This prevents the periphery of the second lumen side hole 126 from tearing during hemodialysis, and ensures the strength of the periphery of the second lumen side hole 126. Note that the flexible portion 141 can also be formed so as to include the tip portion of the second outer wall portion 116. In this case, the tip portion of the second outer wall portion 116 can be formed thicker to prevent the periphery of the second lumen side hole 126 from tearing.

[0082] In the fifth variant, the distance L1 from the tip (second opening surface 122) of the main body 101 to the first opening surface 121 is preferably 30 mm or less, more preferably 25 mm or less, from the viewpoint of ensuring space for providing multiple second lumen side holes 126 and improving the insertability of the catheter.

[0083] 29, a second lumen slit 124 and a second lumen side hole 126 can be provided at the tip of the second outer wall portion 116. This allows the second lumen slit 124 to prevent the second outer wall portion 116 from sticking to the blood vessel wall in the longitudinal direction, and the second lumen side hole 126 to prevent the second outer wall portion 116 from sticking to the blood vessel wall in the circumferential direction.

[0084] Furthermore, in the sixth modification, similarly to the second and third modifications, the flexible portion 141 is formed to include not only the tip portion of the first outer wall portion 115 but also the tip portion of the second outer wall portion 116 in which the second lumen slit 124 is formed. As a result, when the catheter is inserted, the tip portions of the second outer wall portion 116 on both sides of the second lumen slit 124 deform to enter the inner cavity of the second lumen 112. Therefore, the cross-sectional area of ​​the main body portion 101 at the position of the second opening surface 122 is reduced during insertion, resulting in excellent catheter insertability.

[0085] 30 and 31, the inside of the main body 101 can be divided into three lumens, including a first lumen 111, a second lumen 112, and a third lumen, by a partition wall 114. This third lumen can be used as a route for administering a medicinal solution, measuring central venous pressure, etc.

[0086] Third opening surface 128 at the tip of the third lumen is provided more distal than first opening surface 121 and second opening surface 122, and is located at the tip of main body 101. This makes it possible to prevent recirculation, in which the medicinal solution supplied from the third lumen to the blood vessel is directly sucked from first lumen 111 during forward connection. Furthermore, the medicinal solution supplied from the third lumen is carried by the blood flowing back from second lumen 112 and the blood flow in the blood vessel in a direction away from first opening surface 121, making it even less likely to recirculate. Furthermore, because third opening surface 128 is located more distal than second opening surface 122, recirculation during reverse connection is also less likely to occur.

[0087] The cross-sectional area of ​​the third lumen is preferably smaller than the cross-sectional areas of the first lumen 111 and the second lumen 112, from the viewpoint of ensuring the blood flow rate through the first lumen 111 and the second lumen 112 and the efficiency of hemodialysis.

[0088] In the seventh modification, a first lumen slit 123 is formed at the tip of the first outer wall portion 115, and a second lumen slit 124 is formed at the tip of the second outer wall portion 116. Furthermore, the flexible portion 141 includes the tip portion of the first outer wall portion 115 that forms the first lumen slit 123 and the tip portion of the second outer wall portion 116 that forms the second lumen slit 124.

[0089] As a result, when the catheter is inserted, the second outer wall portion 116 deforms to enter the inner cavity of the second lumen 112 at the position of the second opening surface 122, and the first outer wall portion 115 deforms to enter the inner cavity of the first lumen 111 at the position of the first opening surface 121. Therefore, the cross-sectional area of ​​the main body portion 101 is reduced at the position of each opening surface during insertion, thereby achieving excellent catheter insertability. In the seventh modification, the flexible portion 141 can also be formed to include the range from the base end of the first lumen slit 123 to the tip of the main body portion 101.

[0090] In the seventh modified example, as in the present embodiment and each modified example, a first lumen side hole 125 and a second lumen side hole 126 can also be provided. When multiple second lumen side holes 126 are provided at the tip portion of second outer wall section 116, it is preferable that the angle formed by the line connecting adjacent second lumen side holes 126 and the center of the circle formed by outer wall 113 be, for example, 50° to 90°. Other configurations of the catheter of the seventh modified example are not particularly limited.

[0091] As an eighth modification, as shown in Figures 32 and 33, the interior of the main body 101 can be divided by a partition 114 into four lumens, including a first lumen 111, a second lumen 112, a third lumen, and a fourth lumen. The fourth lumen, like the third lumen, can be used as a route for administering medicinal solutions, measuring central venous pressure, and the like. In the eighth modification, by providing two lumens other than those for blood removal and blood return, there is no need to secure a new route in situations such as administering multiple medicinal solutions, thereby reducing the burden on the surgeon and patient. Note that a configuration with even more lumens is also possible.

[0092] Fourth opening surface 129 at the tip of the fourth lumen is provided closer to the tip side than first opening surface 121, second opening surface 122, and third opening surface 128, and is located at the tip of main body portion 101. This makes it possible to prevent recirculation of the medicinal solution supplied from the fourth lumen to the blood vessel during forward connection. Similarly, it is possible to prevent recirculation of the medicinal solution supplied from the fourth lumen during reverse connection.

[0093] The cross-sectional area of ​​the fourth lumen is preferably smaller than the cross-sectional areas of the first lumen 111 and the second lumen 112, from the viewpoint of ensuring the blood flow rate through the first lumen 111 and the second lumen 112 and improving the efficiency of hemodialysis.

[0094] In the eighth modified example, a first lumen slit 123 is formed at the tip of the first outer wall portion 115, and a second lumen slit 124 is formed at the tip of the second outer wall portion 116. Furthermore, the flexible portion 141 includes the tip portion of the first outer wall portion 115 that forms the first lumen slit 123 and the tip portion of the second outer wall portion 116 that forms the second lumen slit 124.

[0095] As a result, similar to the seventh modification, the first outer wall portion 115 and the second outer wall portion 116 are deformed when the catheter is inserted, thereby achieving excellent catheter insertability. In the eighth modification, the flexible portion can also be formed to include the area from the base end position of the first lumen slit 123 to the tip end of the main body portion 101.

[0096] In the eighth modified example, as in the present embodiment and each modified example, a first lumen side hole 125 and a second lumen side hole 126 can also be provided. When multiple first lumen side holes 125 are provided at the tip portion of first outer wall section 115, it is preferable that the angle formed by the line connecting adjacent first lumen side holes 125 and the center of the circle formed by outer wall 113 is, for example, 50° to 90°, and the same applies when multiple second lumen side holes 126 are provided. Other configurations of the catheter according to the eighth modified example are not particularly limited.

[0097] Further modifications include the following.

[0098] For example, in the second, third, and sixth to eighth modified examples in which the second lumen slit 124 is provided, the flexible portion 141 is configured to include not only the distal end portion of the first outer wall portion 115 but also the distal end portion of the second outer wall portion 116, but this configuration is not limited to this. In these modified examples, the flexible portion 141 only needs to be formed to include at least the distal end portion of the first outer wall portion 115, and may be configured not to include the distal end portion of the second outer wall portion 116. By forming the flexible portion 141 to include at least the distal end portion of the first outer wall portion 115, it is possible to improve the insertability of the distal end portion of the first outer wall portion 115, which has a large outer diameter and can be difficult to insert.

[0099] In the catheters according to each of the modifications, similarly to the catheter of the first embodiment, branch tubes, connectors, etc. can be connected to the base end side of the main body 101 via a branch portion as needed.

[0100] When the catheters of this embodiment and each of the modified examples are intended for long-term placement, a cuff made of synthetic fiber can be provided on the base end of the main body 101 as needed to prevent infection when the catheter is placed. [Industrial Applicability]

[0101] The catheter of the present disclosure is useful as a multi-lumen catheter with excellent insertability. [Explanation of symbols]

[0102] 101 Main body 102 Branch 103A Branch pipe 103B Branch pipe 111 1st lumen 112 Second Lumen 113 Exterior Wall 114 Bulkhead 115 1st outer wall section 116 Second outer wall section 121 First opening 122 Second opening 123 First lumen slit 124 Second Lumen Slit 125 First lumen side hole 126 Second lumen side hole 128 Third Opening 129 4th opening 131A Protective Cap 131B Protective Cap 132A Clamp 132B Clamp 141 Flexible part 142 Other parts

Claims

1. a cylindrical body portion surrounded by an outer wall extending from a base end to a tip end, The interior of the main body is divided into a plurality of lumens, including a first lumen and a second lumen, by partitions extending in the longitudinal direction, a second opening surface at the tip of the second lumen is located distally of a first opening surface at the tip of the first lumen; the outer wall has a first outer wall portion that forms the first lumen and a second outer wall portion that forms the second lumen, the first outer wall portion has a first lumen slit formed by cutting out a part of a tip end, the main body portion has a soft portion that is lower in hardness than other portions of the main body portion, A multi-lumen catheter, wherein the flexible portion is formed to include at least a portion of the first outer wall portion where the first lumen slit is formed, from a position halfway along the length of the first lumen slit to the tip of the main body portion.

2. The multi-lumen catheter according to claim 1 , wherein the first lumen slit is provided in a circumferential center portion of the first outer wall portion.

3. The multi-lumen catheter according to claim 1 or 2, wherein the flexible portion is formed to include a position from the base end of the first lumen slit to the tip of the main body portion.

4. 4. The multi-lumen catheter according to claim 1, wherein the first outer wall portion has at least one first lumen side hole on the proximal side of the first lumen slit.

5. the second outer wall portion has a second lumen slit formed by cutting out a part of a tip end, 5. The multi-lumen catheter according to claim 1, wherein the flexible portion is formed to include a distal end portion of the second outer wall portion in which the second lumen slit is formed.

6. The multi-lumen catheter according to any one of claims 1 to 5, wherein the second outer wall portion has at least one second lumen side hole.

7. the first opening surface is inclined toward a base end side with respect to the partition wall, The multi-lumen catheter according to any one of claims 1 to 6, wherein the second opening surface is perpendicular to the partition wall.

8. The multi-lumen catheter according to any one of claims 1 to 7, wherein the number of the lumens is three or more.

9. 9. The multi-lumen catheter according to claim 1, wherein a plurality of branch tubes are provided at the base end of the main body, the branch tubes being connected to the plurality of lumens respectively and having connectors on the base end side.

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