double lumen catheter

Abstract

A double-lumen catheter according to the present invention comprises a circumferential wall 101 forming a lumen extending from a proximal end to a distal end, and a barrier wall 102 that divides the lumen into a first passage 110 and a second passage 120 that extend in the longitudinal direction. The position of the distal end of the circumferential wall 101 is aligned on the first passage 110 side and the second passage 120 side. The barrier wall 102 comprises a protruding part 103 that protrudes distally beyond the distal end of the circumferential wall 101, and the protruding part 103 has a letter-U shape as seen in planar view. The first passage 110 comprises, in the distal section thereof, a first passage slit 111 formed by cutting out a portion of the circumferential wall 101 in the circumferential-direction-center of the circumferential wall 101.

Description

[Technical Field]

[0001] The present disclosure relates to a double lumen catheter. [Background technology]

[0002] In the field of hemodialysis, blood is extracted from a patient's blood vessels, treated outside the body, and then returned to the blood vessels. In emergency dialysis or when it is difficult to create a shunt, blood is extracted and returned using a catheter inserted into the blood vessels.

[0003] In such cases, a double-lumen catheter having a passage for blood removal and a passage for blood return is used. Double-lumen catheters are required to achieve good insertability, reduced blood removal and return failure, reduced recirculation, and the like.

[0004] In order to meet these requirements, it has been considered to offset the positions of the end holes of the blood removal passage and the blood return passage, or to provide side holes in the side walls (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2001-104486 Summary of the Invention [Problem to be solved by the invention]

[0006] However, although the blood drainage and blood inflow passages in double-lumen catheters are generally predetermined, in cases where the catheter is left in place for a long period of time, reverse connection may be performed, temporarily switching the blood drainage and blood inflow sides to deal with blockages or stenosis. If the end hole position is shifted to reduce recirculation in the case of forward connection, recirculation may become more likely to occur in the case of reverse connection.

[0007] Furthermore, if the catheter sticks to the blood vessel wall, it can cause poor blood drainage. Blood can also stagnate, leading to the development of thrombi. Therefore, there is a need for catheters that are not only recirculating but also less susceptible to these problems.

[0008] An object of the present disclosure is to realize a double lumen catheter that is less likely to stick to the blood vessel wall and that suppresses recirculation. [Means for solving the problem]

[0009] A first aspect of the double-lumen catheter of the present disclosure comprises a peripheral wall that forms a lumen extending from the base end to the tip, and a partition that divides the lumen into a first passage and a second passage extending in the longitudinal direction, the peripheral wall has tips that are aligned on the first passage side and the second passage side, the partition has a protruding portion that protrudes further toward the tip than the tip of the peripheral wall, and the first passage has a first passage slit at its tip portion that is formed by cutting out a portion of the peripheral wall in the circumferential center of the peripheral wall.

[0010] The first aspect of the double-lumen catheter has a protrusion, which can reduce recirculation. Furthermore, the catheter has a first passage slit formed by cutting out a portion of the peripheral wall, which makes it less likely to stick to the blood vessel wall.

[0011] In the first aspect of the double-lumen catheter, the second passage may have a second passage slit at the distal end formed by cutting out a portion of the peripheral wall in the circumferential center of the peripheral wall. This configuration makes it less likely for the catheter to stick to the blood vessel wall.

[0012] In this case, the second passage slit can be configured to have a different longitudinal length than the first passage slit. With this configuration, the arrangement of the base ends of each slit differs depending on the longitudinal position, making it difficult for recirculation to occur during forward connection or reverse connection. This can further reduce recirculation.

[0013] In the first aspect of the double-lumen catheter, the first passage may have a first passage through-hole penetrating the peripheral wall on the proximal side of the first passage slit. This configuration makes it more difficult for the first passage slit to stick to the blood vessel wall.

[0014] In this case, a plurality of first passage through-holes may be provided and arranged in a staggered pattern. Such a configuration can further reduce the likelihood of adhesion of the first passage through-hole to the blood vessel wall. Furthermore, adjacent first passage through-holes may be provided on opposite sides of the first passage slit.

[0015] In the first aspect of the double-lumen catheter, the second passage has second passage through-holes penetrating the peripheral wall, and the second passage through-holes may be arranged in a staggered pattern. This configuration can further reduce adhesion to the blood vessel wall. Furthermore, adjacent second passage through-holes may be located on opposite sides of the first passage slit. This configuration can further reduce adhesion during reverse connection.

[0016] In this case, the second passage through-hole closest to the base end may be located closer to the base end than the first passage slit. By adopting such a configuration, it is possible to make it even more difficult for recirculation to occur during reverse connection.

[0017] In this case, the first passage may have a first passage through-hole penetrating the peripheral wall on the base end side of the first passage slit, and the first passage through-hole closest to the tip end and the second passage through-hole closest to the base end may be located on opposite sides of the first passage slit. By adopting such a configuration, it is possible to further reduce the likelihood of recirculation.

[0018] A third aspect of the double-lumen catheter of the present disclosure comprises a peripheral wall that forms a lumen extending from the base end to the tip, and a partition that divides the lumen into a first passage and a second passage extending in the longitudinal direction, the peripheral wall has tips aligned on the first passage side and the second passage side, the first passage and the second passage have first passage slits and second passage slits formed by cutting out a portion of the peripheral wall from the side edge of the partition, respectively, and the tip surfaces of the peripheral wall and the partition may be approximately S-shaped when viewed from the tip side. This configuration can reduce recirculation.

[0019] In the third aspect of the double-lumen catheter, the first passage slit and the second passage slit may be located on opposite sides of the circumferential direction, which can further reduce recirculation.

[0020] In the third aspect of the double-lumen catheter, the first passage slit and the second passage slit may have a narrower slit width at the distal end than at the proximal end. This configuration suppresses the venting pressure near the proximal end of the slit, making it more difficult for the catheter to stick to the blood vessel wall.

[0021] One embodiment of the tunneler of the present disclosure comprises a shaft portion and a connecting portion provided on the base end side of the shaft portion to which a double-lumen catheter is connected, the double-lumen catheter having a protruding portion where a partition dividing a lumen surrounded by a peripheral wall into two passages protrudes toward the tip end, the connecting portion having an inserting portion that is inserted into one of the two passages and fits into it, and a non-inserting portion provided between the inserting portion and the shaft portion, the non-inserting portion having an outer diameter smaller than the base end of the shaft portion and an outer diameter larger than the tip end of the inserting portion, and a length equal to or greater than the length of the protruding portion.

[0022] With this configuration, it can be easily connected to a double lumen catheter having a protrusion.

[0023] In one embodiment of the tunneler, the difference between the radius of the non-insertion portion and the radius of the insertion portion can be equal to or less than the thickness of the bulkhead of the double-lumen catheter, thereby minimizing bending of the protruding portion.

[0024] Another aspect of the tunneler of the present disclosure includes a shaft portion, an insertion portion provided at the proximal end of the shaft portion and inserted into one of the passages of the double-lumen catheter, and a curved connecting portion connecting the shaft portion and the insertion portion, such that when the insertion portion is inserted into one of the passages of the double-lumen catheter, the central axis of the shaft portion coincides with the central axis of the double-lumen catheter. This configuration makes it easy to cover the connection portion with a sheath.

[0025] One aspect of the catheter combination of the present disclosure comprises a double lumen catheter of the present disclosure and a tunneler.

[0026] One embodiment of the catheter complex may further include a sheath that covers the connection between the double lumen catheter and the tunneler. [Effects of the Invention]

[0027] The double lumen catheter of the present disclosure can reduce sticking and recirculation. [Brief explanation of the drawings]

[0028] [Figure 1] FIG. 1 is a perspective view showing a double lumen catheter according to a first embodiment. [Figure 2] FIG. 2 is a top view showing the double lumen catheter according to the first embodiment. [Figure 3] FIG. 3 is a side view showing the double lumen catheter according to the first embodiment. [Figure 4] FIG. 4 is a bottom view showing the double lumen catheter according to the first embodiment. [Figure 5]FIG. 5 is a front view showing the double lumen catheter according to the first embodiment. [Figure 6] FIG. 6 is a top view showing a double lumen catheter according to a first modified example of the first embodiment. [Figure 7] FIG. 7 is a bottom view showing a double lumen catheter according to a first modified example of the first embodiment. [Figure 8] FIG. 8 is a top view showing a double lumen catheter according to a second modification of the first embodiment. [Figure 9] FIG. 9 is a bottom view showing a double lumen catheter according to a second modified example of the first embodiment. [Figure 10] FIG. 10 is a top view showing a double lumen catheter according to a third modified example of the first embodiment. [Figure 11] FIG. 11 is a bottom view showing a double lumen catheter according to a third modified example of the first embodiment. [Figure 12] FIG. 12 is a perspective view showing a double lumen catheter according to the second embodiment. [Figure 13] FIG. 13 is a side view showing a double lumen catheter according to the second embodiment. [Figure 14] FIG. 14 is a side view of a tunneler according to one embodiment. [Figure 15] FIG. 15 is a side view showing a modified example of the tunneler. DETAILED DESCRIPTION OF THE INVENTION

[0029] As shown in Figures 1 to 5, the double lumen catheter of the first embodiment is a tube made of resin or the like, and includes a peripheral wall 101 that forms a lumen extending from the base end to the tip, and a partition wall 102 that divides the lumen into a first passage 110 and a second passage 120. The peripheral wall 101 has the same positions of the tips on the first passage 110 side and the second passage 120 side, so that the end hole of the first passage 110 and the end hole of the second passage 120 are also aligned. The partition wall 102 has a protruding portion 103 that protrudes further toward the tip side than the tip of the peripheral wall 101, and the protruding portion 103 is U-shaped in plan view.

[0030] The double lumen catheter of this embodiment can suppress recirculation during reverse connection because the positions of the tips of the peripheral wall 101 on the first passage 110 side and the second passage 120 side are aligned. Furthermore, by providing the protrusion 103, the effect of further reducing recirculation can be obtained.

[0031] The double-lumen catheter of this embodiment has a first passage slit 111 and a plurality of first passage through-holes 112 at the distal end portion of the first passage 110, and has a plurality of second passage through-holes 122 at the distal end portion of the second passage 120. The distal end portion of the peripheral wall 101 has a first distal portion peripheral wall 115 and a second distal portion peripheral wall 116 on either side of the first passage slit 111. The second passage through-hole 122 is disposed between the distal end portion of the first passage slit 111 and the first passage through-hole 112. More specifically, the second passage through-hole 122 on the proximal side is located between the proximal end of the first passage slit 111 and the first passage through-hole on the distal side.

[0032] The double lumen catheter of this embodiment has the first passage slit 111, so when the first passage 110 is used as a blood removal lumen, the flow of blood drawn into the first passage 110 can be dispersed so that it does not concentrate at the end hole at the tip. This makes it possible to prevent recirculation, in which blood flowing out from the tip of the second passage 120 is directly drawn back into the first passage 110. Furthermore, dispersion of the blood flow makes it less likely for the blood vessel wall to stick to the catheter. Furthermore, increasing the number of openings can also make it less likely for blockages due to thrombi to occur.

[0033] The double lumen catheter of this embodiment has a first tip peripheral wall 115 and a second tip peripheral wall 116 on either side of a first passage slit 111 provided in the circumferential center of the peripheral wall 101, thereby preventing a decrease in the rigidity of the first passage slit 111 and preventing the tip of the peripheral wall 101 from being blocked or narrowed by pressure from a blood vessel wall or the like during use.

[0034] The first passage 110 also has first passage through-holes 112. This further disperses the flow of blood drawn into the first passage 110, making it less likely for the catheter to stick to the blood vessel wall. From the viewpoint of reducing sticking to the blood vessel wall, it is preferable to provide the first passage through-holes 112 at positions as far away from the first passage slits 111 as possible. Sticking to the blood vessel wall can be further reduced by arranging the first passage through-holes 112 in a staggered arrangement. When arranging the first passage through-holes 112 in a staggered arrangement, it is preferable to arrange adjacent first passage through-holes 112 at positions as far away from each other as possible. For example, it is preferable that the angle formed by the line connecting the first passage through-holes 112 and the center of the circle formed by the peripheral wall 101 between two adjacent first passage through-holes 112 be 120° to 180°. However, the first passage through-holes 112 may also be arranged in series in the longitudinal direction.

[0035] When the first passage 110 is used as a blood return lumen, the first passage slits 111 disperse the outflow of blood, making it less likely that recirculation will occur, in which blood flowing out of the first passage 110 is simply sucked into the end hole of the second passage 120. Furthermore, since the second passage through-holes 122 are provided at the tip of the second passage 120, the flow of blood sucked into the second passage 120 is also dispersed. This further reduces the recirculation rate during reverse connection. From this perspective, it is preferable that the second passage through-hole closest to the base end is located closer to the base end than the first passage slits 111. Furthermore, the second passage through-holes 122 can also reduce sticking to the blood vessel wall during reverse connection. From the perspective of reducing sticking to the blood vessel wall, it is preferable that the second passage through-holes 122 are also arranged in a staggered pattern. In this case, it is preferable to position adjacent second passage through-holes 122 as far apart as possible, and for example, it is preferable that the angle formed by the straight line connecting the second passage through-holes 122 and the center of the circle formed by the peripheral wall 101 for two adjacent second passage through-holes 122 be 120° to 180°.

[0036] By providing the second passage through-hole 122, even if the tip of the second passage 120 is blocked due to the influence of a blood clot or the like, the second passage through-hole 122 makes it possible to keep the second passage 120 open.

[0037] From the viewpoint of reducing recirculation, it is preferable that the second passage through-hole 122 on the base end side is provided more distal than the first passage through-hole 112 on the tip end side and more proximal than the proximal end of the first passage slit 111. Furthermore, when the first passage through-holes 112 and the second passage through-holes 122 are both arranged in a staggered manner, it is preferable that the second passage through-hole 122 on the base end side be located on the opposite side of the first passage slit 111 from the first passage through-hole 112 on the tip end side, from the viewpoint of further reducing the occurrence of recirculation.

[0038] In the double-lumen catheter of this embodiment, the first passage slit 111 is provided in the circumferential center of the first passage 110 portion of the circumferential wall 101. With this configuration, a first tip portion circumferential wall 115 and a second tip portion circumferential wall 116 are formed on both sides of the first passage slit 111. By providing the first passage slit 111 in the circumferential center, the rigidity of at least one of the first tip portion circumferential wall 115 or the second tip portion circumferential wall 116 is reduced, making it possible to prevent the end hole of the first passage 110 from being blocked during placement in a blood vessel. The width W1 of the first passage slit 111 is not particularly limited, but is preferably about 15% to 35% of the outer diameter φ1 of the catheter. The length L1 of the first passage slit 111 is not particularly limited, but is preferably about 1.5 to 2.5 times the outer diameter φ1 of the catheter. In this embodiment, the outer diameter φ1 of the catheter is 4.3 mm, and the width W1 of the first passage slit 111 is 1 mm, and the length L1 is 8 mm. It is preferable that the first passage slit 111 has a wall surface rounded.

[0039] The first passage through-holes 112 are side holes that penetrate the peripheral wall 101 and connect the first passage 110 to the outside, and a plurality of them are provided spaced apart from one another in the longitudinal direction. This embodiment shows an example in which there are two first passage through-holes 112, but three or more first passage through-holes 112 may be provided. In this embodiment, adjacent first passage through-holes 112 are arranged in a so-called staggered pattern, that is, at positions offset in both the longitudinal direction and the width direction of the first passage 110, and further, are arranged alternately on opposite sides of the first passage slit 111. The first passage through-holes 112 can be arranged at equal intervals in the longitudinal direction, but can also be arranged at unequal intervals.

[0040] The second passage through-holes 122 are side holes that penetrate the peripheral wall 101 and connect the second passage 120 to the outside, and a plurality of them are provided at intervals in the longitudinal direction. In this embodiment, an example is shown in which there are two second passage through-holes 122, but three or more second passage through-holes 122 may be provided. The second passage through-holes 122 are also arranged in a staggered pattern. It is preferable that the second passage through-hole 122 closest to the base end is arranged on the opposite side of the first passage through-hole 112 closest to the tip end, with the first passage slit 111 interposed therebetween, and it is more preferable that the first passage through-holes 112 and the second passage through-holes 122 are arranged in a staggered pattern as a whole.

[0041] The most distal second passage through-hole 122 is preferably spaced apart from the distal end of the peripheral wall 101. Specifically, the distance from the end of the through-wall to the center of the most distal second passage through-hole 122 is preferably about 0.8 to 1.5 times the outer diameter φ1 of the catheter. Furthermore, all of the first passage through-holes 112 and second passage through-holes 122 are preferably spaced apart at equal intervals in the longitudinal direction. In this case, the distance between the centers of adjacent through-holes is preferably about 3.5 to 5.5 times the diameter of the through-hole. For example, in the case of a catheter with an outer diameter φ1 of 4.3 mm, the through-holes can be spaced apart at 5 mm intervals. However, the longitudinal intervals of the first passage through-holes 112 and the second passage through-holes 122 may be different. Furthermore, all of the first passage through-holes 112 and second passage through-holes 122 may be spaced apart at unequal intervals. The diameters of the first passage through-hole 112 and the second passage through-hole 122 are not particularly limited, but are preferably about 15% to 35% of the outer diameter φ1 of the catheter.

[0042] The diameter of the first passage through-hole 112 and the diameter of the second passage through-hole 122 may be the same or different. In addition, the diameters of some of the first passage through-hole 112 and the second passage through-hole 122 may be different.

[0043] The double-lumen catheter of this embodiment can be modified in various ways. For example, as in a first modified example shown in Figures 6 and 7, the first passage through-holes 112 may not be provided. In the first modified example, the second passage through-holes 122 are provided in series, but the second passage through-holes 122 may also be arranged in a staggered manner.

[0044] As in the second modified example shown in Figures 8 and 9, a second passage slit 121 can be provided instead of the second passage through-hole 122. By providing a slit in the second passage 120 as well, adhesion to the blood vessel wall can be suppressed when the second passage 120 is used as a blood removal lumen. The longitudinal length L2 of the second passage slit 121 can be made shorter than the length L1 of the first passage slit 111. Specifically, it is preferable that L2 be approximately 80% to 45% of L1. However, L2 can also be the same as L1. At least one of the first passage through-hole 112 and the second passage through-hole 122 can also be provided.

[0045] Also, a configuration may be adopted in which neither the second passage through-hole nor the second passage slit is provided on the second passage side. Furthermore, as in a third modified example shown in Figures 10 and 11, a first passage through-hole 112 may be provided instead of the first passage slit 111. In this case as well, at least one of the second passage through-hole 122 and the second passage slit 121 may be provided on the second passage 120 side.

[0046] In this embodiment and each modified example, an example is shown in which the protrusion 103 is a flat U-shape without corners, but the protrusion 103 is not limited to this shape and may have a shape with corners, such as a flat square or trapezoid.

[0047] 12 and 13 show a double-lumen catheter according to a second embodiment. In the double-lumen catheter according to the second embodiment, a first passage 210 and a second passage 220 have a first passage slit 211 and a second passage slit 221, respectively. The first passage slit 211 and the second passage slit 221 are formed by cutting out a portion of the peripheral wall 201 from the side end of the partition wall 202. The first passage slit 211 and the second passage slit 221 are located on opposite sides of each other in the circumferential direction. Therefore, when the double-lumen catheter according to the second embodiment is viewed from the distal end side, the distal end surfaces of the peripheral wall 201 and the partition wall 202 are substantially S-shaped.

[0048] Further, the first passage slit 211 and the second passage slit 221 each include partition-wall-side slit lines 212 and 222, opposing slit lines 213 and 223, and connecting slit lines 214 and 224 connecting these. The connecting slit lines 214 and 224 have a substantially U-shape. In this embodiment, the partition-wall-side slit lines 212 and 222 substantially coincide with the surface of the partition wall 202, but the present invention is not limited to this, and there may be peripheral walls between the partition-wall-side slit lines 212 and 222 and the surface of the partition wall 202.

[0049] Furthermore, since the first passage slit 211 and the second passage slit 221 are located on opposite sides of the circumference, the blood flow on the blood removal side and the blood return side are also separated, making it difficult for recirculation to occur whether the first passage 210 is the blood removal side or the blood return side.

[0050] In this embodiment, the width (slit width) of the first passage slit 211 and the second passage slit 221 in the peripheral wall 201 is narrower on the distal end side than on the proximal end side. This makes it less likely that the distal end of the passage on the side serving as the blood removal lumen will be significantly crushed and blocked. Furthermore, because the slit width is larger on the proximal end side of the slit, it is possible to prevent the concentration of removal blood pressure near the connecting slit line 214. However, the slit width of the first passage slit 211 and the second passage slit 221 can be constant or wider on the distal end side than on the proximal end side.

[0051] The maximum slit width of the first passage slit 211 and the second passage slit 221 is not particularly limited, but is preferably about 15% to 35% of the outer diameter φ1 of the catheter. The length of the slit is not particularly limited, but is preferably about 1.5 to 2.5 times the outer diameter φ1 of the catheter.

[0052] The double-lumen catheter of the second embodiment may also be provided with at least one of a first passage through-hole and a second passage through-hole. The arrangement of the first passage through-hole and the second passage through-hole may be the same as in the first embodiment and its modified examples. Furthermore, the double-lumen catheter of the second embodiment may also be provided with a protrusion on the partition wall 202.

[0053] The double lumen catheter according to each embodiment and modification can be placed in a blood vessel to remove and return blood when performing dialysis without forming a shunt, etc. A hub, connector, etc. can be connected to the proximal end of the catheter as needed.

[0054] The double-lumen catheter according to each embodiment and modification can be formed into a catheter complex by connecting a tunneler to the tip for tunneling into the subcutaneous tissue. After forming a subcutaneous tunnel with the tunneler at the tip and introducing the double-lumen catheter into the subcutaneous tunnel, the tunneler can be removed to place the double-lumen catheter in a blood vessel via the subcutaneous tunnel. The tunneler to be connected is not particularly limited, but for example, one such as that shown in FIG. 14 can be used.

[0055] 14 has a shaft portion 301 and a connecting portion 302 provided at the base end of the shaft portion 301. The shaft portion 301 has a tapered tip portion 311, a main body portion 312 with a fixed diameter, and a small diameter portion 313. The base end of the shaft portion 301 is provided with a tapered portion 314 that prevents the sheath from slipping out.

[0056] Thinner diameter portion 313 is provided to make shaft portion 301 easier to bend, and although two thin diameter portions are provided in Fig. 14, there may be one thin diameter portion, or three or more thin diameter portions. Alternatively, none may be provided.

[0057] The connecting portion 302 has an insertion portion 321 that is inserted into the double lumen catheter, and a non-insertion portion 322 that is provided between the insertion portion 321 and the shaft portion 301 .

[0058] The insertion section 321 has an outer diameter smaller than that of the non-insertion section 322 and has the maximum outer diameter that allows it to be inserted into and fitted into the first passage or the second passage of the double lumen catheter. In Fig. 14, an expanded diameter section 324 that is larger in diameter than the other sections is provided on the proximal end side of the insertion section 321, thereby preventing the inserted catheter from easily slipping out of the insertion section 321. However, it is sufficient that the insertion section 321 can be inserted into the double lumen catheter and not slip out, and the insertion section 321 may also be formed in a straight tapered shape that gradually increases in diameter from the proximal end side to the distal end side, or in a so-called bamboo shoot shape, etc.

[0059] It is preferable that the outer diameter of at least the base end of the insertion section 321 is slightly smaller than the maximum height of the first or second passage of the double lumen catheter, as this facilitates insertion of the insertion section 321. It is also preferable that the maximum outer diameter of the insertion section 321 (outer diameter of the expanded diameter section 324) is slightly larger than the maximum height of the first or second passage of the double lumen catheter, as this makes it difficult for the insertion section 321 to fall out of the catheter. The length of the insertion section 321 is not particularly limited, but is preferably 5 mm or more from the viewpoint of preventing it from falling out, and is preferably 25 mm or less from the viewpoint of operability. It should be noted that the maximum height H of the passage max is the maximum vertical distance from the surface of the partition wall to the inner surface of the peripheral wall, as shown in FIG.

[0060] The non-insertion portion 322 has a larger outer diameter than the end of the insertion portion 321 on the non-insertion portion side, and a first step 322a is formed between the insertion portion 321 and the non-insertion portion 322. On the other hand, the non-insertion portion 322 has a smaller outer diameter than the base end of the tapered portion 314 provided at the base end of the shaft portion 301, and a second step 322b is formed between the non-insertion portion 322 and the shaft portion 301.

[0061] When forming a subcutaneous tunnel using a catheter complex connected to a tunneler, the tunneler is generally inserted into a sheath so that the connection part where the tunneler is connected to the tip of the catheter is covered. For this reason, it is important to be able to connect the catheter and tunneler as smoothly as possible so that they can be inserted into the sheath.

[0062] In the case of a conventional tunneler that does not have a non-insertion section 322, a large step occurs between the connection section and the shaft section. Therefore, when a conventional tunneler is inserted into a double-lumen catheter that has a protruding section, the large step between the connection section and the shaft section causes the protruding section to bend significantly outward, causing the protruding section to protrude from the sheath and fail to cover the connection section.

[0063] However, in the case of the tunneler 300 of this embodiment, the first step 322a is small, so even when the insertion section 321 is inserted into the double-lumen catheter up to its base, the protruding section does not bend significantly and does not protrude from the sheath. Furthermore, the non-insertion section 322 ensures sufficient space for the protruding section, and provides a distance between the distal end of the double-lumen catheter and the shaft section 301, making it easier to move the protruding section radially when the sheath is placed over it. Furthermore, the step 322b between the non-insertion section 322 and the tapered section 314 prevents the protruding section arranged along the non-insertion section 322 from colliding with the sheath in the end face direction. This allows the connecting section to be smoothly inserted into the sheath.

[0064] The outer diameter of the non-insertion portion 322 is preferably larger than the maximum height or width of the first or second passageway so that the non-insertion portion 322 does not enter the first or second passageway of the double-lumen catheter. From the viewpoint of smooth insertion into the sheath, it is preferable that the tip of the protruding portion of the catheter bent by the first step 322a does not extend beyond the peripheral wall of the passageway to which the tunneler is not connected. The length of the non-insertion portion 322 is preferably the same as or longer than the length of the protruding portion of the double-lumen catheter. The size of the second step 322b is preferably equal to or greater than the wall thickness of the protruding portion.

[0065] The maximum outer diameter of the insertion portion 321 and the outer diameter of the non-insertion portion are not particularly limited, but from the viewpoint of obtaining the above-mentioned effects, it is preferable that the maximum outer diameter of the insertion portion 321 is approximately 1.1 to 1.4 times the maximum height Hmax of the passage, and the outer diameter of the non-insertion portion is approximately 1.5 to 1.9 times the maximum height Hmax of the passage.

[0066] In the case of a double lumen catheter in which the maximum heights of the first and second passages are equal and the tip positions are aligned, the insertion part 321 can be inserted into either the first or second passage, but if one of the passages has a slit, it is preferable to insert it into the passage that does not have a slit, as this makes it less likely that the insertion part 321 will come out.

[0067] Although the tunneler 300 of this embodiment can be smoothly inserted into a sheath and facilitates catheter placement even when used in combination with a double-lumen catheter having a protrusion, the tunneler 300 of this embodiment can also be used in combination with a double-lumen catheter without a protrusion.

[0068] The double-lumen catheter of each embodiment can also be combined with a tunneler 300A as shown in FIG. 15 . The tunneler 300A includes a shaft 301, an insertion section 321 inserted into a first passage 351 or a second passage 352 of a double-lumen catheter 350, and a curved connecting section 331 curved in a generally S-shape and disposed between the shaft 301 and the insertion section 321. The curved connecting section 331 is configured so that, when the insertion section 321 is inserted into one of the passages of the double-lumen catheter 350, the central axis of the shaft 301 coincides with the central axis of the double-lumen catheter 350. This configuration prevents significant irregularities from occurring between the tunneler and the double-lumen catheter, making it easy to cover the connection between the catheter and the tunneler with a sheath. Here, "the central axes coincide" refers not only to cases where the central axes are completely aligned, but also to cases where the central axes are misaligned by a few millimeters in either direction, as long as the misalignment does not interfere with insertion into the sheath. [Industrial Applicability]

[0069] The double-lumen catheter of the present disclosure is less likely to stick to the blood vessel wall and can suppress recirculation, making it useful as a hemodialysis catheter, etc. [Explanation of symbols]

[0070] 101 Peripheral wall 102 Bulkhead 103 Projection 110 1st aisle 111 First passage slit 112 1st passage through hole 115 First tip peripheral wall 116 Second tip peripheral wall 120 2nd aisle 121 Second passage slit 122 2nd passage through hole 201 Peripheral wall 202 Bulkhead 210 1st aisle 211 First Passage Slit 212 Partition side slit line 213 Opposite slit line 214 Connecting slit line 220 2nd aisle 221 Second Passage Slit 222 Bulkhead side slit line 223 Opposite slit line 224 Connecting slit line 300 Tonnera 301 Shaft 302 Connection 311 Tip 312 Main body 313 Thin section 314 Tapered section 321 Insertion part 322 Non-insertion part 322a First step 322b Second step 324 Expanded diameter part 331 Curved joint

Claims

1. a peripheral wall forming a lumen extending from a proximal end to a distal end; a partition wall dividing the lumen into a first longitudinal passage and a second longitudinal passage; The peripheral wall has a tip end aligned with the first passage side and a tip end aligned with the second passage side, the partition wall has a protruding portion that protrudes further toward the tip side than the tip of the peripheral wall, the first passage has a first passage slit at a tip end portion, the first passage slit being formed by cutting out a part of the peripheral wall in a circumferential central portion of the peripheral wall, the tip ends of which are aligned over the entire circumferential length; a double lumen catheter in which the peripheral wall of the second passage does not have a slit, the positions of the tips of the second passage are aligned over the entire circumferential length, and the peripheral wall has a plurality of second passage through-holes, the most distal second passage through-hole being located closer to the tip than the base end of the first passage slit, and the most proximal second passage through-hole being located closer to the base end than the base end of the first passage slit.

2. A double lumen catheter as described in claim 1, wherein the second passage through holes, which are adjacent in axial position, are provided on different sides of two half-circumferential walls formed by dividing the peripheral wall based on the circumferential position of the first passage slit.

3. the first passage has a first passage through-hole penetrating the peripheral wall on a base end side of the first passage slit, 3. The double-lumen catheter according to claim 1, wherein the first passage through-hole closest to the distal end and the second passage through-hole closest to the proximal end are provided on different sides of two half-circumferential walls obtained by dividing the peripheral wall based on the circumferential position of the first passage slit.

4. The double lumen catheter according to any one of claims 1 to 3, wherein the first passage has a first passage through-hole penetrating the peripheral wall on a proximal side of the first passage slit.

5. The double lumen catheter according to claim 4, wherein a plurality of the first passage through-holes are provided and arranged in a staggered pattern.

6. A double lumen catheter as described in Claim 4, wherein the first passage through holes, which are adjacent in axial position, are provided on different sides of two half-circumferential walls formed by dividing the peripheral wall based on the circumferential position of the first passage slit.

7. The double lumen catheter according to any one of claims 1 to 6, A catheter complex comprising:

8. The tunneler comprises: A shaft portion; a connecting portion provided on a proximal end side of the shaft portion and connected to the double lumen catheter; the connecting portion has an insertion portion that is inserted into one of the two passages and fitted therewith, and a non-insertion portion that is provided between the insertion portion and the shaft portion, The catheter complex according to claim 7 , wherein the non-insertion portion has an outer diameter smaller than that of the base end of the shaft portion, an outer diameter larger than that of the tip end of the insertion portion, and a length equal to or greater than that of the protruding portion.

9. The catheter complex according to claim 8 , wherein the difference between the radius of the non-insertion portion and the radius of the insertion portion of the tunneler is equal to or less than the thickness of a septum of the double-lumen catheter.

10. The tunneler comprises: A shaft portion; an insertion section provided on the proximal end side of the shaft section and inserted into one of the passages of the double lumen catheter; a curved connecting portion that connects the shaft portion and the insertion portion, The catheter complex according to claim 7 , wherein when the insertion section is inserted into one of the passages of the double-lumen catheter, a central axis of the shaft section coincides with a central axis of the double-lumen catheter.

11. The catheter complex according to any one of claims 7 to 10, further comprising a sheath covering a connection portion between the double-lumen catheter and the tunneler.

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