WO2022270244A1 - Percutaneous catheter - Google Patents

Abstract

Provided is a percutaneous catheter that is capable of minimizing the occurrence of trouble caused by a reinforcement body while reducing the risk of kinks taking place in a tubular body. A percutaneous catheter 20 is equipped with a tubular body 40 having a lumen 65 formed throughout the entire length thereof. The tubular body 40 comprises: a leading end part 60; an inclined part 61 which extends toward the base end side thereof from the base end of the leading end part 60 and which has an outer diameter that increases toward the base end side; and a base end part 62 which extends toward the base end side from the base end of the inclined part 61 and which has an outer diameter greater than that of the leading end part 60. The base end part 62 has a reinforcement body layer 63. The leading end-side terminal end position of the reinforcement body layer 63 is situated on the base end side of the inclined part 61.

Description

percutaneous catheter

The present invention relates to a percutaneous catheter that is percutaneously inserted into the living body.

In recent years, ECMO (extracorporeal membrane oxygenation) may be used to support life for severe respiratory failure and circulatory failure that are difficult to save with artificial respirators and vasopressors. ECMO is a therapeutic method in which blood is removed from a vein, oxygenated with an artificial lung, and pumped into an artery or vein.

The blood removal cannula used in ECMO is a long tubular percutaneous catheter that is percutaneously inserted into the body. Percutaneous catheters used in ECMO have a relatively large bore. Such a large-bore percutaneous catheter is mainly punctured and inserted into the femoral vein and left in the vena cava via the iliac vein. As a large-diameter percutaneous catheter inserted from the femoral vein, there is, for example, one disclosed in Patent Document 1.

JP-A-3-92170

A percutaneous catheter that is inserted into the vena cava via the femoral vein through the iliac vein has a large diameter. risk of In addition, in ECMO, the patient may be in a bent state by raising the upper body while wearing the device, which increases the risk of kinking of the tubular body at the puncture site of the femoral vein or the iliac vein. If the tubular body kinks, problems such as poor blood circulation, damage to the inner wall of the blood vessel due to the kink, and blood leakage may occur. Therefore, it is desired to reduce the risk of kinking of the tubular body. On the other hand, in order to ensure a sufficient blood circulation flow rate, it is necessary to reduce the pressure loss, and it is also required to make the lumen as large as possible.

For this reason, it is conceivable to provide a reinforcing body such as a braided body made of metal or the like inside the tubular body to prevent kinks from occurring. However, once a kink occurs in the tubular body at the punctured portion or the meandering portion, the reinforcing member is bent due to plastic deformation, making it impossible to secure the lumen. In addition, the edge of the broken reinforcing member may break through the outer layer resin of the tubular body to form a small hole. This may result in reduced circulatory flow and invasion of the inner wall of the blood vessel.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a percutaneous catheter that can reduce the risk of kinking of a tubular body and suppress the occurrence of problems due to a reinforcing body. do.

A percutaneous catheter according to the present invention for achieving the above objects comprises a tubular body having a lumen along its entire length, the tubular body having a distal end, and a proximal end extending from the proximal end of the distal end to the proximal side, and having an outer diameter of and a proximal end portion extending from the proximal end of the inclined portion toward the proximal end side and having an outer diameter larger than that of the distal end portion, and the proximal end portion is a reinforcing body. The reinforcement layer has a distal end position on the proximal side of the inclined portion.

In the percutaneous catheter configured as described above, the reinforcing layer reduces the risk of kinking of the tubular body, and even if a kink occurs on the distal end side of the tubular body, the reinforcing layer does not break through the tubular body. can be prevented. In addition, since the outer diameter of the distal end is smaller than that of the proximal end, the contact area with the vascular wall can be reduced when inserted into the body, and the risk of thrombus generation is reduced by reducing the chance of inflammation of the vascular wall. can be reduced.

The reinforcing layer may be composed of wires made of stainless steel or nickel-titanium alloy. Thereby, the rigidity of the tubular body can be sufficiently ensured.

The reinforcing layer may be composed of a braided body. This effectively prevents kinking of the tubular body.

The reinforcing layer may be composed of a coil body. This effectively prevents kinking of the tubular body.

The reinforcing layer may have a repeating structure, and at least a part of the repeating structure may have a pitch changing portion in which the pitch increases toward the tip side. As a result, sudden changes in the physical properties of the tubular body can be mitigated, and kinks can be prevented more reliably.

The tubular body may have a side hole that communicates the lumen with the outside, and the side hole may be arranged in a gap portion of the repeating structure in the pitch change portion. Thereby, the side hole can be arranged at the proximal end without interfering with the reinforcement layer.

The lumen of the tubular body may have an enlarged diameter portion whose inner diameter increases from the distal end side to the proximal end side. As a result, the inner diameter of the tubular body can be prevented from changing discontinuously, and turbulence can be suppressed when blood flows from the distal end to the proximal end, thereby reducing pressure loss.

At least a portion of the enlarged diameter portion may be positioned within the range of the inclined portion in the length direction. As a result, it is possible to prevent the thickness of the tubular body from becoming too thin from the distal end portion to the proximal end portion.

1 is a front view of a medical device system according to this embodiment; FIG. 2 is an enlarged view of a tubular body of the percutaneous catheter; FIG. 4 is a partially enlarged cross-sectional view of a tubular body; FIG. FIG. 4 is a partially enlarged front view of the braided body; FIG. 4 is a partially enlarged view of a tubular body provided with a braided body having pitch variation. It is a partially enlarged front view of a coil body. FIG. 10 is an enlarged cross-sectional view of the vicinity of the inclined portion when the inclined portion and the enlarged diameter portion are displaced from each other in the longitudinal direction;

Hereinafter, embodiments of the present invention will be described with reference to the drawings. Note that the dimensional ratios in the drawings may be exaggerated for convenience of explanation and may differ from the actual ratios. Also, in this specification, the side of the medical device system 10 that is inserted into a living body cavity is referred to as the "distal end" or "distal side", and the proximal side for manipulation is referred to as the "proximal end" or "proximal side".

A medical device system 10 in the following embodiments is a blood removal cannula used in ECMO, and is composed of a percutaneous catheter 20 and a dilator 30. The dilator 30 is used as a core material that is passed through the percutaneous catheter 20 when it is inserted into the living body and that imparts rigidity to the percutaneous catheter 20 . The medical device system 10 is inserted from the patient's femoral vein, and the distal end is left in the vena cava via the iliac vein.

As shown in FIG. 1, the percutaneous catheter 20 of the medical device system 10 has an elongate tubular body 40 having a lumen over its entire length. The percutaneous catheter 20 has a base portion 42 on the proximal end side of the tubular body 40 , and a connector portion 44 is provided at the proximal end portion of the base portion 42 .

The dilator 30 has a long tubular main body 50 and a dilator hub 52 provided at the proximal end of the main body 50 . The body portion 50 has an outer diameter that allows it to be inserted through the lumen of the percutaneous catheter 20 . Moreover, the inner diameter of the body portion 50 has an inner diameter through which a guide wire can be inserted. The dilator hub 52 is formed so as to be able to engage with the connector portion 44 of the percutaneous catheter 20 .

As shown in FIG. 2, the tubular body 40 of the percutaneous catheter 20 includes a distal end portion 60 having a small outer diameter, and a distal end portion 60 extending proximally from the proximal end of the distal end portion 60 and having an outer diameter that increases toward the proximal end. It has an inclined portion 61 and a proximal portion 62 extending from the proximal end of the inclined portion 61 toward the proximal side and having an outer diameter larger than that of the distal portion 60 . The distal end portion 60 is provided with a plurality of side holes 64 that allow communication between the internal lumen and the outside.

As shown in FIG. 3, the tubular body 40 has a reinforcement layer 63 at the base end 62. As shown in FIG. The reinforcing layer 63 has a terminal end position on the distal end side located closer to the proximal end side than the inclined portion 61 , and does not exist in the inclined portion 61 and the distal end portion 60 . The reinforcement layer 63 is composed of wires 72 made of stainless steel or nickel-titanium alloy. A nickel-titanium alloy that exhibits superelastic properties is used.

As shown in FIG. 4, the reinforcing layer 63 is composed of a braided body 70 formed by weaving wire 72 . The braided body 70 has a repeating structure in which the same shape is repeated along the axial direction. Since the tubular body 40 has the reinforcing layer 63 made of the braided body 70, the rigidity of the tubular body 40 can be increased, and the risk of kinking when the tubular body 40 is inserted into the living body can be reduced.

The lumen 65 of the tubular body 40 has an enlarged diameter portion 66 between the distal end portion 60 and the proximal end portion 62, the inner diameter of which increases from the distal end side to the proximal end side. At least a portion of the enlarged diameter portion 66 is located within the range of the inclined portion 61 in the length direction. The lumen 65 has a smaller inner diameter on the distal side than the enlarged diameter portion 66 and a larger inner diameter on the proximal side than the enlarged diameter portion 66 . Since the lumen 65 has the enlarged diameter portion 66, the inner diameter can be prevented from changing discontinuously, and turbulence is suppressed when blood flows from the distal end to the proximal end, thereby reducing pressure loss. can be reduced.

The side hole 64 is provided to improve the fluidity of blood from the outside of the tubular body 40 into the lumen 65 . Since the side hole 64 is arranged in the tip portion 60 that does not have the reinforcement layer 63, the side hole 64 and the reinforcement layer 63 can be prevented from interfering with each other.

Since the outer diameter of the distal end portion 60 of the tubular body 40 is smaller than that of the proximal end portion 62, the contact area with the vascular wall can be reduced when the tubular body 40 is inserted into the living body, and the chance of inflammation of the vascular wall can be reduced. can reduce the risk of thrombosis. In addition, since the distal end of the reinforcing layer 63 is positioned closer to the proximal side than the inclined portion 61, even if a kink occurs on the distal end side of the tubular body 40, the wires 72 of the reinforcing layer 63 are Breaking through the tubular body 40 can be prevented.

The tubular body 40 can be made of a flexible resin material. For example, polyester elastomer, polyethylene, nylon, nylon elastomer, polyurethane, fluororesin such as PTFE and ETFE, polyetheretherketone (PEEK), polyimide, and the like can be used.

The tubular body 40 having the reinforcing layer 63 can be manufactured as follows. A pre-woven and heat-set reinforcement layer 63 is placed on the outer periphery of the inner layer member having the lumen 65, the outer layer member is placed on the outside thereof, and the outer layer member is shrunk from the outside with a shrinkable tube, so that the inner A tubular body 40 can be formed having a reinforcement layer 63 on the inside.

As shown in FIG. 5, the reinforcement layer 63 may have a pitch change portion 74 in which a part of the repeating structure has a pitch that increases toward the tip side. In the braided body 70 forming the reinforcing body layer 63 , in the portion near the inclined portion 61 , the spacing between the meshes increases toward the tip side. Therefore, a large gap 77 is formed near the tip of the reinforcing layer 63 . A side hole 64 may be provided in this gap 77 as shown in FIG.

The reinforcement layer 63 may have a structure other than the braided body 70. As shown in FIG. 6, the reinforcement layer 63 may be composed of a coil body 80 . The coil body 80 is formed by winding a wire 82 in a coil shape. Even when the reinforcing layer 63 is composed of the coil body 80 , the reinforcing layer 63 is provided at the proximal end portion 62 , and the distal end of the reinforcing layer 63 is located closer to the proximal end than the inclined portion 61 . be. Thereby, the rigidity of the base end portion 62 can be increased. The reinforcement layer 63 may be a slitted metal pipe.

The enlarged diameter portion 66 formed in the lumen 65 of the tubular body 40 may be partially positioned within the range of the inclined portion 61 in the longitudinal direction of the tubular body 40. Therefore, as shown in FIG. The position of the portion 66 in the length direction does not have to partially overlap the inclined portion 61 .

As described above, the percutaneous catheter 20 according to this embodiment includes the tubular body 40 having the lumen 65 over the entire length. an inclined portion 61 extending toward the proximal end and having an outer diameter that increases toward the proximal end; and a proximal end portion 62 that extends from the proximal end of the inclined portion 61 toward the proximal end and has an outer diameter larger than that of the distal end portion 60; The proximal end portion 62 has a reinforcement layer 63 , and the terminal end position of the distal end side of the reinforcement layer 63 is closer to the proximal end than the inclined portion 61 . In the percutaneous catheter 20 configured in this manner, the risk of kinking of the tubular body 40 is reduced by the reinforcing layer 63, and even if a kink occurs on the distal end side of the tubular body 40, the reinforcing layer 63 will prevent the tubular body from 40 can be prevented from breaking through. In addition, since the outer diameter of the distal end portion 60 is smaller than that of the proximal end portion 62, the contact area with the vascular wall can be reduced during insertion into the living body. can reduce the risk of

The reinforcing layer 63 may be composed of wires 72 made of stainless steel or nickel-titanium alloy. Thereby, the rigidity of the tubular body 40 can be sufficiently secured.

The reinforcing layer 63 may be made of a braided body 70. Thereby, the kink of the tubular body 40 can be effectively prevented.

The reinforcement layer 63 may be composed of a coil body 80. Thereby, the kink of the tubular body 40 can be effectively prevented.

The reinforcing layer 63 may have a repeating structure, and at least a portion of the repeating structure may have a pitch changing portion 74 in which the pitch increases toward the tip side. As a result, sudden changes in the physical properties of the tubular body 40 can be mitigated, and kink can be prevented more reliably.

The tubular body 40 has a side hole 64 that communicates the lumen 65 with the outside, and the side hole 64 may be arranged in the gap of the repeated structure in the pitch change portion. As a result, the side hole 64 can be arranged at the base end portion 62 without interfering with the reinforcing layer 63 .

The lumen 65 of the tubular body 40 may have an enlarged diameter portion 66 whose inner diameter increases from the distal end side to the proximal end side. As a result, the inner diameter of the tubular body 40 can be prevented from changing discontinuously, and turbulence can be suppressed when blood flows from the distal side to the proximal side, thereby reducing pressure loss.

At least a portion of the enlarged diameter portion 66 may be positioned within the range of the inclined portion 61 in the length direction. Thereby, it is possible to prevent the wall thickness of the tubular body 40 from becoming too thin from the distal end portion 60 to the proximal end portion 62 .

It should be noted that the present invention is not limited to the above-described embodiments, and various modifications can be made by those skilled in the art within the technical concept of the present invention. The percutaneous catheter 20 described above is a blood removal cannula used in ECMO, but the present invention can also be applied to other types of medical devices.

This application is based on Japanese Patent Application No. 2021-104000 filed on June 23, 2021, and the disclosure contents thereof are incorporated by reference.

REFERENCE SIGNS LIST 10 medical device system 20 percutaneous catheter 30 dilator 40 tubular body 42 base 44 connector 50 main body 52 dilator hub 60 distal end 61 inclined portion 62 proximal end 63 reinforcing layer 64 side hole 65 lumen 66 enlarged diameter portion 70 braided body 72 wire 74 pitch change part 77 gap part 80 coil body 82 wire

Claims (8)

Equipped with a tubular body having a lumen over its entire length,
The tubular body is
a tip;
an inclined portion extending from the proximal end of the distal end portion toward the proximal side and having an outer diameter that increases toward the proximal side;
a proximal end portion extending from the proximal end of the inclined portion toward the proximal end side and having an outer diameter larger than that of the distal end portion;
A percutaneous catheter according to claim 1, wherein the proximal portion has a reinforcing layer, and the distal end of the reinforcing layer is located on the proximal side of the inclined portion. The percutaneous catheter according to claim 1, wherein the reinforcing layer is composed of wires made of stainless steel or nickel-titanium alloy. The percutaneous catheter according to claim 1 or 2, wherein the reinforcing layer is composed of a braid. The percutaneous catheter according to claim 1 or 2, wherein the reinforcing layer is composed of a coil body. The reinforcement layer has a repeating structure,
5. The percutaneous catheter according to claim 3, wherein at least a portion of the repeating structure has a pitch changing portion in which the pitch increases toward the distal end side. The tubular body has a side hole that communicates the lumen with the outside,
6. The percutaneous catheter according to claim 5, wherein the side holes are arranged in gaps of the repeating structure in the pitch change portion. The percutaneous catheter according to any one of claims 1 to 6, wherein the lumen of the tubular body has an enlarged diameter portion whose inner diameter increases from the distal side to the proximal side. The percutaneous catheter according to claim 7, wherein at least a portion of the enlarged diameter portion is located within the range of the inclined portion in the longitudinal direction.

Images