JP2022048021A - Foreign body suction catheter - Google Patents

Abstract

To provide a foreign body suction catheter capable of suppressing back flow of a sucked foreign body.SOLUTION: A foreign body suction catheter, which is a foreign body suction catheter capable of sucking a foreign body in the body, includes a tubular catheter body part for partitioning a suction flow passage, and a check valve positioned in the suction flow passage. The check valve includes multiple film parts in which, when a suction pressure below a prescribed value is applied to the suction flow passage, a mutually abutting closed state is maintained, and when a suction pressure equal to or higher than the prescribed value is applied to the suction flow passage, an open state is acquired by mutual separation in an orthogonal direction orthogonal to the extension direction of the catheter body part.SELECTED DRAWING: Figure 1

Description

The present disclosure relates to a foreign body suction catheter.

Conventionally, a foreign body suction catheter for sucking a foreign body such as a substance causing stenosis in a blood vessel (for example, a thrombus) has been known. Patent Document 1 describes a thrombus suction catheter as this type of foreign body suction catheter. The thrombus suction catheter described in Patent Document 1 includes a catheter body having a central lumen.

JP-A-2017-64067

In the thrombus suction catheter as a foreign body suction catheter described in Patent Document 1, the catheter body may be deformed while sucking a foreign body such as a thrombus due to the movement of the heart or the movement of the thrombus suction catheter. There is. When the catheter body is deformed, the central lumen, which is the suction flow path, is also deformed, which may cause a decrease in the suction pressure in the central lumen. If a foreign body in the central lumen flows back due to a decrease in suction pressure, the foreign body may leak from the thrombus suction catheter. Therefore, the thrombus suction catheter described in Patent Document 1 still has room for improvement from the viewpoint of suppressing the backflow of the sucked foreign matter.

It is an object of the present disclosure to provide a foreign body suction catheter capable of suppressing the backflow of a sucked foreign body.

The foreign matter suction catheter as the first aspect of the present disclosure is a foreign matter suction catheter capable of sucking foreign matter in a living body, and has a tubular catheter main body portion for partitioning a suction flow path and an inverse position located in the suction flow path. The check valve is provided with a stop valve, and the check valve is maintained in a closed state in which it abuts against each other when a suction pressure of less than a predetermined value is applied to the suction flow path, and suction of the predetermined value or more is performed on the suction flow path. It is provided with a plurality of membrane portions that are opened by being separated from each other in a direction orthogonal to the extending direction of the catheter main body when pressure is applied.

As one embodiment of the present disclosure, the catheter main body portion includes an inner diameter increasing portion having a larger inner diameter of the suction flow path than the distal side and the proximal side in the extending direction, and each membrane of the plurality of membrane portions. At least a part of the portion is located in the enlarged diameter space defined by the inner diameter increasing portion in the suction flow path.

As one embodiment of the present disclosure, each of the membrane portions is separated from another membrane portion of the plurality of membrane portions in the orthogonal direction in the open state, and abuts on the other membrane portion in the closed state. The tip portion on the proximal side in the extending direction is provided, and the tip portion of each of the film portions is located in the enlarged diameter space.

As one embodiment of the present disclosure, each of the film portions has the tip end portion between a position where the tip portion abuts on the other film portion and a position where the tip end portion is separated from the other film portion. The deformation starting point portion that supports the portion in a deformable manner is provided, and the deformation starting point portion of each of the film portions is located in the enlarged diameter space.

As one embodiment of the present disclosure, the bending rigidity of the tip portion is smaller than the bending rigidity of the deformation starting portion.

As one embodiment of the present disclosure, a reinforcing body for reinforcing the strength of the inner diameter increasing portion of the catheter main body portion in the extending direction is further provided.

According to the present disclosure, it is possible to provide a foreign body suction catheter capable of suppressing the backflow of a sucked foreign body.

It is a figure which shows the foreign body suction catheter as the 1st Embodiment. In the foreign body suction catheter shown in FIG. 1, it is a cross-sectional view along the extending direction of the catheter main body at the position where the check valve is provided, and is the figure which shows the check valve in a closed state. 2 is a cross-sectional view of the catheter body at the position of line I-I in FIG. 2A. In the foreign body suction catheter shown in FIG. 1, it is a cross-sectional view along the extending direction of the catheter main body at the position where the check valve is provided, and is the figure which shows the check valve in an open state. FIG. 3 is a cross-sectional view of the catheter body at the position of line II-II in FIG. 3A. It is sectional drawing along the extending direction of the catheter main body part at the position where the check valve is provided in the foreign body suction catheter as a 2nd Embodiment, and is the figure which shows the check valve in a closed state. FIG. 4 is a cross-sectional view of the foreign body suction catheter shown in FIG. 4 along the extending direction of the catheter main body at a position where a check valve is provided, and is a diagram showing a check valve in an open state. It is a figure which shows the modification of the foreign body suction catheter shown in FIG. It is sectional drawing along the extending direction of the catheter main body part at the position where the check valve is provided in the foreign body suction catheter as a 3rd Embodiment, and is the figure which shows the check valve in a closed state. It is sectional drawing which is orthogonal to the extending direction of the catheter main body part at the position of the check valve in the foreign body suction catheter as 4th Embodiment.

Hereinafter, embodiments of the foreign body suction catheter according to the present disclosure will be exemplified with reference to the drawings. The same reference numerals are given to the configurations common to each figure.

[First Embodiment]
FIG. 1 is a diagram showing a foreign body suction catheter 1 as an embodiment of the foreign body suction catheter according to the present disclosure. The foreign body suction catheter 1 can be introduced percutaneously into the living body. The foreign body suction catheter 1 introduced percutaneously into the living body can suck a foreign body in the living body such as a thrombus in a blood vessel. The foreign matter in the living body sucked by the foreign matter suction catheter 1 is removed from the living body.

As shown in FIG. 1, the foreign body suction catheter 1 includes a tubular catheter main body 2, a hub 3, a coated tube 4, and a check valve 5.

<Catheter body 2>
The catheter body 2 is an insertion portion to be inserted into the living body. On the other hand, the hub 3 and the coated tube 4 are non-insertion portions that are not inserted into the living body. The hub 3 and the covering tube 4 are located outside the living body with the catheter main body 2 inserted in the living body, and are operated by an operator. Hereinafter, for convenience of explanation, in the longitudinal direction A of the foreign body suction catheter 1, the direction from the non-insertion portion to the insertion portion will be referred to as “distal side” or “distal direction A1”. Further, in the longitudinal direction A of the foreign body suction catheter 1, the direction from the inserted portion to the non-inserted portion is described as "proximal side" or "proximal direction A2".

The tubular catheter body 2 separates the suction flow path 2a and the guide wire insertion hole 2b. The diameter of the guide wire insertion hole 2b of the present embodiment is smaller than the diameter of the suction flow path 2a and has a small diameter.

The suction flow path 2a is from the suction port 2a1 located at the distal end of the catheter body 2 (hereinafter referred to as “distal end”) to the proximal end of the catheter body 2. (Hereinafter referred to as "proximal end"), it extends to the communication port 2a2 connected to the in-hub flow path 3a of the hub 3.

Although the details will be described later, the check valve 5 is located in the suction flow path 2a.

The guide wire insertion hole 2b extends from the distal opening 2b1 on the distal side to the proximal opening 2b2 on the proximal side. The guide wire insertion hole 2b is a so-called rapid exchange type, and is formed so as to follow only a part of the suction flow path 2a on the distal side. That is, the proximal opening 2b2 of the guide wire insertion hole 2b is located on the distal side of the communication port 2a2 of the suction flow path 2a.

The catheter main body 2 of the present embodiment includes a main body tubular portion 11 and an adjacent tubular portion 12 adjacent to the main body tubular portion 11. The adjacent tubular portion 12 of the present embodiment is adjacent on the radial outer side of the main body tubular portion 11. The suction flow path 2a of the present embodiment is partitioned in the main body tubular portion 11. Further, the guide wire insertion hole 2b of the present embodiment is partitioned in the adjacent tubular portion 12. The suction flow path 2a partitioned in the main body tubular portion 11 and the guide wire insertion hole 2b partitioned in the adjacent tubular portion 12 do not communicate with each other, but are adjacent to each other and parallel to each other. The main body tubular portion 11 and the adjacent tubular portion 12 of the present embodiment are formed by fixing another pipe material to be the adjacent tubular portion 12 to the radial outer side of the pipe material to be the main body tubular portion 11. Therefore, the adjacent tubular portion 12 of the present embodiment projects radially outward with respect to the main body tubular portion 11. However, the configuration of the catheter body 2 is not limited to this configuration. That is, the catheter main body 2 may have a configuration in which the outer diameter does not fluctuate between the region where the guide wire insertion hole 2b is located and the region where the guide wire insertion hole 2b is not located in the longitudinal direction A.

The main body tubular portion 11 of the present embodiment includes a proximal tube portion 13 and a distal tip 14. A distal tip 14 is attached to the distal side of the proximal tube portion 13. A hub 3 and a covering tube 4 are attached to the proximal side of the proximal tube portion 13. The suction flow path 2a described above is from the distal end of the distal tip 14 (hereinafter referred to as “distal end”) to the proximal end of the proximal tube portion 13 (hereinafter referred to as “proximal”). It is described as "end".) Therefore, the suction port 2a1 of the suction flow path 2a described above is provided at the distal end of the distal tip 14. Further, at the proximal end of the proximal tube portion 13, the communication port 2a2 of the suction flow path 2a described above is provided.

The suction port 2a1 formed at the distal end of the distal tip 14 is provided so as to be inclined with respect to the longitudinal direction A. As a result, the suction port 2a1 is easily opposed to the inner wall of the blood vessel, and foreign matter such as a thrombus is easily sucked. Further, the bending rigidity of the distal tip 14 is smaller than the bending rigidity of the proximal tube portion 13. As a result, the flexibility of the distal end of the catheter body 2 can be increased, and the distal end of the catheter body 2 can be prevented from being caught on the inner wall of the blood vessel.

The adjacent tubular portion 12 of the present embodiment includes an X-ray contrast metal coil tube. The coil tube is made of a material having X-ray (radiation) impermeable material such as gold and platinum. Thereby, the position of the distal end portion of the catheter main body portion 2 in the living body can be visually recognized by X-ray contrast imaging.

Further, the adjacent tubular portion 12 of the present embodiment protrudes distally from the main body tubular portion 11. Further, the adjacent tubular portion 12 of the present embodiment projects radially outward from the main body tubular portion 11 at a position straddling both the proximal tube portion 13 and the distal tip 14 of the main body tubular portion 11 in the longitudinal direction A. ing.

Examples of the material for forming the catheter body 2 include a polyolefin (for example, polyethylene and polypropylene), a polyolefin elastomer (for example, an elastomer using a polyethylene elastomer, a polypropylene elastomer, an ethylene-propylene copolymer, etc.), a polyvinyl chloride, and the like. Thermoplastic resins such as ethylene-vinyl acetate copolymers, polyamide elastomers, polyurethanes and fluororesins, silicone rubbers and the like can be used, and polyethylene, polyamide elastomers or polyurethanes are preferable.

<Hub 3>
As shown in FIG. 1, the hub 3 includes a cylindrical main body portion 21, a tubular distal connection portion 22, two wing portions 23, and a proximal connection portion 24. The distal connection 22 is connected to the distal end of the body 21 and is pushed into the proximal end of the proximal tube 13 of the catheter body 2. The two wing portions 23 project radially outward from the outer peripheral surface of the main body portion 21. The proximal connection portion 24 is connected to the proximal end of the main body portion 21 and can be connected to a suction device such as a syringe directly or via a medical tube. The hub 3 is divided into a hub inner flow path 3a that penetrates the main body portion 21, the distal connection portion 22, and the proximal connection portion 24 in the longitudinal direction A. The in-hub flow path 3a partitioned by the hub 3 is partitioned by the catheter body 2 by inserting the distal connection portion 22 of the hub 3 into the proximal tube portion 13 of the catheter body 2 and fitting it tightly. It communicates with the suction flow path 2a in a liquid-tight manner. Further, the proximal connection portion 24 of the hub 3 can be liquid-tightly connected to a suction device or a medical tube provided with a luer lock type connector portion.

Examples of the material for forming the hub 3 include polyolefins such as polyethylene, polypropylene, and ethylene-propylene copolymer; ethylene-vinyl acetate copolymer (EVA); polyvinyl chloride; polyvinylidene chloride; polystyrene; polyamide; polyimide; polyamide. Imid; Polycarbonate; Poly- (4-methylpentene-1); Ionomer; Acrylic resin; Polymethylmethacrylate; Acrylonitrile-butadiene-styrene copolymer (ABS resin); Acrylonitrile-styrene copolymer (AS resin); butadiene- Styrene copolymer; polyesters such as polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polycyclohexane terephthalate (PCT); polyether; polyetherketone (PEK); polyetheretherketone (PEEK); polyetherimide; Polyacetal (POM); Polyphenylene oxide; Modified polyphenylene oxide; Polysulfone; Polyethersulfone; Polyphenylene sulfide; Polyallylate; Aromatic polyester (liquid crystal polymer); Polytetrafluoroethylene, Polyfluorinated vinylidene, and other fluororesins; Examples include resin materials. Further, a blend containing one or more of these, a polymer alloy, or the like may be used. In addition, various glass materials, ceramic materials, and metal materials may be used.

<Coated tube 4>
As shown in FIG. 1, the coated tube 4 covers the proximal end of the catheter body 2. More specifically, the covering tube 4 of the present embodiment includes a proximal covering portion 31 that covers a portion of the proximal tube portion 13 of the catheter main body 2 into which the distal connecting portion 22 of the hub 3 is inserted. It includes a distal covering portion 32 that covers a portion of the proximal tube portion 13 of the catheter body portion 2 distal to the portion into which the distal connecting portion 22 of the hub 3 is inserted. By providing such a covering tube 4, it is possible to suppress the kink of the proximal tube portion 13 of the catheter main body portion 2 at the position of the distal end of the distal connection portion 22 of the hub 3.

As the forming material of the covering tube 4, for example, the same material as the above-mentioned forming material exemplified as the forming material of the catheter main body 2 can be mentioned.

<Check valve 5>
As shown in FIG. 1, the check valve 5 is located in the suction flow path 2a of the catheter main body 2. 2A and 3A are cross-sectional views taken along the longitudinal direction A of the catheter main body 2 at the position where the check valve 5 is provided. FIG. 2B is a cross-sectional view of the catheter body 2 at the position of line II in FIG. 2A. FIG. 3B is a cross-sectional view of the catheter body 2 at the position of line II-II in FIG. 3A. 2A and 2B show the check valve 5 in the closed state. Further, FIGS. 3A and 3B show a check valve 5 in an open state.

As shown in FIGS. 2A, 2B, 3A and 3B, the check valve 5 includes a plurality of (two in this embodiment) film portions 41. The plurality of film portions 41 maintain a closed state in which they are in contact with each other when a suction pressure of less than a predetermined value is applied to the suction flow path 2a (see FIGS. 2A and 2B). Further, the plurality of film portions 41 maintain a closed state in which they are in contact with each other even when the suction pressure does not act (see FIGS. 2A and 2B). On the other hand, the plurality of membrane portions 41 are in the extending direction of the catheter main body portion 2 (in the present embodiment, the same direction as the longitudinal direction A) when a suction pressure of a predetermined value or more acts on the suction flow path 2a. It is in an open state by being separated from each other in the orthogonal orthogonal direction B (see FIGS. 3A and 3B). Here, "separation from each other in the orthogonal direction B" is not limited to the separation due to the movement of only the orthogonal direction B, but includes the separation due to the movement including the component of the orthogonal direction B. That is, the plurality of membrane portions 41 of the present embodiment are configured to be separated from each other by moving only in the orthogonal direction B orthogonal to the extending direction of the catheter main body portion 2, but the configuration is not limited to this. The plurality of membrane portions 41 may be separated from each other by movement including a component in the orthogonal direction B orthogonal to the extending direction of the catheter main body portion 2. Hereinafter, in the present embodiment, for convenience of explanation, the extending direction of the catheter main body 2 is simply referred to as “longitudinal direction A of the catheter main body 2”.

Further, the check valve 5 may be provided with at least the plurality of film portions 41 described above, and is not limited to this configuration. Therefore, the check valve 5 may include another portion in addition to the plurality of membrane portions 41.

The foreign matter suction catheter 1 is provided with such a plurality of membrane portions 41, so that the backflow of the sucked foreign matter can be suppressed.

Further, in the foreign body suction catheter 1, the suction pressure of the suction flow path 2a does not have to be excessively increased in order to suppress the backflow due to the presence of the plurality of membrane portions 41 described above. Therefore, in the foreign matter suction catheter 1 of the present embodiment, the foreign matter can be sucked by applying a suction pressure of 100 Pa or less to the suction flow path 2a. In other words, the plurality of film portions 41 of the present embodiment are configured to be openable and closable with a predetermined value of 100 Pa or less as a threshold value. By realizing such a low suction pressure, it is possible to suppress the occurrence of damage to the living tissue due to the suction of foreign substances. The threshold value is preferably 60 Pa or more. By doing so, it is possible to prevent the plurality of film portions 41 from unintentionally opening and closing regardless of suction.

Further, each film portion 41 of the present embodiment includes a tip portion 41a on the proximal side in the longitudinal direction A, which abuts and separates from another film portion 41. More specifically, the tip portion 41a of each film portion 41 is separated from the tip portion 41a of another film portion 41 in the film thickness direction C in the orthogonal direction B in the open state (see FIGS. 3A and 3B), and is in a closed state. (See FIGS. 2A and 2B), it comes into contact with the tip portion 41a of another film portion 41. Here, the "thickness direction C" is one aspect of the orthogonal direction B, and is the membrane portion in the cross section of the membrane portion 41 (see FIGS. 2B and 3B) orthogonal to the longitudinal direction A of the catheter main body portion 2. It means the thickness direction of 41.

As shown in FIG. 2A, in the plurality of film portions 41 of the present embodiment, the length L1 in the longitudinal direction A of the tip portions 41a that are in contact with each other in the closed state is 1 of the total length L2 in the longitudinal direction A of the film portion 41. It is preferably /4 or more, more preferably 1/3 or more, and particularly preferably 1/2 or more. By doing so, it is possible to increase the frictional force between the tip portions 41a of the plurality of film portions 41 in the closed state. As a result, when the suction pressure of the suction flow path 2a is less than a predetermined value, the plurality of membrane portions 41 can be more reliably maintained in the closed state.

Further, each film portion 41 of the present embodiment includes a deformation starting point portion 41b that supports the tip portion 41a in a deformable manner. More specifically, the deformation starting point portion 41b has a position where the tip portion 41a abuts on the tip portion 41a of another film portion 41 and a position where the tip portion 41a is separated from the tip portion 41a of the other film portion 41. In between, the tip portion 41a is deformably supported.

As shown in FIGS. 2A and 3A, the deformation starting point 41b of the present embodiment includes a distal starting point 41b1 located distal to the tip 41a. Further, as shown in FIGS. 2B and 3B, the deformation starting point portion 41b of the present embodiment is laterally located on both sides of the tip portion 41a in the film width direction D in the region where the tip portion 41a is located in the longitudinal direction A. A starting point portion 41b2 is provided. The deformation starting point 41b of the present embodiment is continuous from the lateral starting point 41b2 on one side in the film width direction D to the lateral starting point 41b2 on the other side in the film width direction D via the distal starting point 41b1. There is. Here, the "membrane width direction D" is an aspect of the orthogonal direction B, and is a membrane portion in a cross section of the membrane portion 41 (see FIGS. 2B and 3B) orthogonal to the longitudinal direction A of the catheter main body portion 2. It means the extending direction of 41 (the direction orthogonal to the film thickness direction C).

As shown in FIGS. 2A and 3B, the distal starting point 41b1 of the deformation starting point 41b of each film portion 41 is in a closed state in which the tip portions 41a of the plurality of film portions 41 are in contact with each other, and the plurality of film portions 41. In any case of the open state in which the tip portions 41a of the above are separated from each other, they are separated from another film portion 41. On the other hand, as shown in FIG. 2B, the lateral starting point 41b2 of the deformation starting point 41b of each film portion 41 is another film portion in the closed state where the tip portions 41a of the plurality of film portions 41 are in contact with each other. The deformation starting point 41b of 41 is in contact with the side starting point 41b2. Then, as shown in FIG. 3B, the lateral starting point portion 41b2 of the deformation starting point portion 41b of each film portion 41 is deformed by another film portion 41 in an open state in which the tip portions 41a of the plurality of film portions 41 are separated from each other. It is separated from the side starting point portion 41b2 of the starting point portion 41b.

The membrane portion 41 of the present embodiment is fixed to the inner wall of the catheter main body portion 2. Then, in the membrane portion 41 of the present embodiment, the tip portion 41a is elastically deformed in the orthogonal direction B starting from the portion fixed to the inner wall of the catheter main body portion 2. Therefore, as shown in FIGS. 2A, 2B, 3A, and 3B, the deformation starting point 41b of the membrane portion 41 of the present embodiment depends on the portion of the membrane portion 41 that is fixed to the inner wall of the catheter main body portion 2. It is configured.

Further, as shown in FIG. 2A, in the closed state where the plurality of membrane portions 41 are in contact with each other, the angle of the tangent line on the distal side surface of each membrane portion 41 with respect to the longitudinal direction A is the position of the tip portion 41a (FIG. 2A). It becomes larger at the position of the distal starting point 41b1 (not shown because it is parallel to the longitudinal direction A and the angle is 0 degrees in FIG. 2A) than the position of the distal starting point 41b1 (see “θ1”). In other words, each film portion 41 of the present embodiment is convexly curved in the direction toward another film portion 41 in the closed state. The distal side surface of each film portion 41 is a surface of each film portion 41 located on the distal side in the film thickness direction C, and means a surface that abuts on another film portion 41. With such an angular relationship, the plurality of membrane portions 41 can more reliably maintain the closed state at a suction pressure of less than a predetermined value, and are easily separated from each other at a suction pressure of a predetermined value or more.

Further, in the film portion 41 of the present embodiment, the bending rigidity of the tip portion 41a is smaller than the bending rigidity of the deformation starting point portion 41b. By doing so, when the suction pressure of the suction flow path 2a changes from a predetermined value or more to a predetermined value, the tip portions 41a of the plurality of membrane portions 41 are mutually moved by the elastic force in the vicinity of the deformation starting portion 41b. It is possible to more reliably return from the position separated from the position to the position where they are in contact with each other.

The film portion 41 of the present embodiment is made of the same forming material. In the film portion 41 of the present embodiment, the thickness of the tip portion 41a is thinner than the thickness of the deformation starting point portion 41b. In the present embodiment, the relationship between the bending rigidity of the above-mentioned tip portion 41a and the deformation starting point portion 41b is realized by doing so. Further, in the present embodiment, the thickness of the tip portion 41a is made thinner than the thickness of the distal starting point portion 41b1 of the deformation starting point portion 41b, but the present invention is not limited to this configuration. In addition to or in place of making the thickness of the tip portion 41a thinner than the thickness of the distal starting point portion 41b1 of the deformation starting point portion 41b, the thickness may be made thinner than the thickness of the lateral starting point portion 41b2 of the deformation starting point portion 41b. Further, the relationship between the bending rigidity of the tip portion 41a and the deformation starting point portion 41b described above is not limited to the adjustment by the thickness of the film portion 41 of the present embodiment. The relationship between the bending rigidity of the tip portion 41a and the deformation starting point 41b may be realized by another means such as different forming materials of the tip portion 41a and the deformation starting point portion 41b.

Further, in the foreign body suction catheter 1 of the present embodiment, a plurality of check valves 5 having the same configuration are arranged at different positions in the longitudinal direction A (two in the present embodiment), but the number of check valves 5 is large. Not particularly limited. Therefore, only one check valve 5 may be provided in the suction flow path 2a, or three or more check valves 5 may be provided.

Further, as in the present embodiment, it is preferable that the check valve 5 is arranged in the suction flow path 2a at least at the position of the distal end portion of the catheter main body portion 2. In the present embodiment, one check valve 5 is arranged in the space of the suction flow path 2a where the distal tip 14 of the catheter main body 2 is partitioned. By arranging the check valve 5 at the position of the distal end portion of the catheter main body 2, the foreign matter once sucked from the suction port 2a1 immediately moves to the proximal side of the check valve 5. Therefore, even if the suction pressure of the suction flow path 2a decreases, foreign matter once sucked from the suction port 2a1 into the suction flow path 2a is less likely to flow back from the suction port 2a1 by the check valve 5. Further, by arranging the check valve 5 at the distal end on the proximal side rather than at the distal end of the catheter main body 2, damage to the check valve 5 can be prevented, and the check valve 5 can be prevented from being damaged. Maintain the opening and closing function.

Examples of the material for forming the plurality of film portions 41 of the check valve 5 of the present embodiment include the same materials as the above-mentioned forming material exemplified as the forming material for the catheter main body portion 2.

<< How to use the foreign body suction catheter 1 >>
The foreign body suction catheter 1 of the present embodiment moves the suction port 2a1 of the suction flow path 2a of the catheter main body 2 to a target site in the living body while being guided by the guide wire inserted into the guide wire insertion hole 2b. The target site in the living body is, for example, a site where a thrombus is formed in a blood vessel. In this state, a negative pressure is applied to the suction flow path 2a by a suction tool such as a syringe connected to the proximal connection portion 24 of the hub 3 located outside the living body of the foreign body suction catheter 1. As a result, it is possible to apply a suction pressure of a predetermined value or more toward the proximal direction A2 to the suction flow path 2a. By applying a suction pressure equal to or higher than a predetermined value to the suction flow path 2a, the plurality of film portions 41 of the check valve 5 change from a closed state (see FIGS. 2A and 2B) to an open state (see FIGS. 3A and 3B). The state changes. As a result, foreign matter such as a thrombus can be sucked into the suction flow path 2a from the suction port 2a1, and the sucked foreign matter can be removed from the living body.

Even if the suction pressure of the suction flow path 2a unintentionally drops to less than a predetermined value due to deformation of the catheter main body 2 or the like during the above-mentioned suction, the plurality of membrane portions of the check valve 5 41 returns from the open state (see FIGS. 3A and 3B) to the closed state (see FIGS. 2A and 2B). Therefore, it is possible to prevent the foreign matter once sucked into the suction flow path 2a from flowing back and leaking from the suction port 2a1.

[Second Embodiment]
Next, the foreign body suction catheter 101 as the second embodiment will be described with reference to FIGS. 4 and 5. The foreign body suction catheter 101 has a different configuration of the catheter main body as compared with the foreign body suction catheter 1 of the first embodiment, and has the same other configurations. Therefore, only the above differences will be described here, and the description of the common configuration will be omitted.

4 and 5 show the extending direction of the catheter main body 102 at the position where the check valve 5 is provided (in the present embodiment, the same direction as the longitudinal direction A of the foreign body suction catheter 101, and hereinafter, “ It is a cross-sectional view along the longitudinal direction A ”. FIG. 4 shows the check valve 5 in the closed state. Further, FIG. 5 shows a check valve 5 in an open state.

The catheter main body 102 of the present embodiment includes an inner diameter increasing portion 51 having a larger inner diameter of the suction flow path 102a than the distal side and the proximal side of the longitudinal direction A. Here, the "inner diameter of the suction flow path 102a" means the diameter of the perfect circle when the inner surface of the catheter main body 102 that partitions the suction flow path 102a in a cross section orthogonal to the longitudinal direction A is a perfect circle. If it is not a perfect circle, it means the maximum value of the distance connecting any two points on the inner surface of the catheter main body 102 having the same cross section.

In the catheter main body 102 of the present embodiment, the inner diameter M1 does not change in the longitudinal direction A on both sides of the distal direction A1 and the proximal direction A2 with respect to the inner diameter increasing portion 51, and the inner diameter M1 thereof is the inner diameter increasing portion 51. The thin tube portions 52 smaller than the maximum inner diameter M2 are connected. In FIGS. 4 and 5, for convenience of explanation, the boundary between the inner diameter increasing portion 51 and the thin tube portion 52 is shown by a broken line.

The outer diameter of the inner diameter increasing portion 51 of the present embodiment is larger than the outer diameter of the thin tube portion 52, but is not limited to this configuration. The outer diameters of the inner diameter increasing portion 51 and the thin tube portion 52 may be the same, for example.

As shown in FIGS. 4 and 5, each film portion 41 of the plurality of (two in the present embodiment) film portions 41 of the present embodiment is an enlarged diameter space defined by the inner diameter increasing portion 51 of the suction flow path 102a. It is located at 51a. As described above, since the film portion 41 is located in the enlarged diameter space 51a, a plurality of film portions in the open state (see FIG. 5) are compared with the case where the entire film portion 41 is not located in the enlarged diameter space 51a. It becomes easy to secure a large separation distance between 41. Therefore, it is preferable that at least a part of the film portion 41 is located in the enlarged diameter space 51a.

Further, it is particularly preferable that the entire film portion 41 of the present embodiment is located in the enlarged diameter space 51a. More specifically, the tip portion 41a of each film portion 41 is preferably located in the enlarged diameter space 51a. By doing so, as described above, it becomes easy to secure the separation distance between the tip portions 41a of the plurality of film portions 41 in the open state. Further, the tip portion 41a of each membrane portion 41 in the open state is less likely to come into contact with the inner wall of the catheter main body portion 102. As a result, it is possible to prevent each membrane portion 41 from being attached to the inner wall of the catheter main body portion 102. Further, body fluid such as blood easily enters the gap between each membrane portion 41 and the inner wall of the catheter main body portion 102 in the open state. Therefore, when the suction pressure of the suction flow path 102a drops from a predetermined value or more to a predetermined value or less, each membrane portion 41 is likely to be restored to a closed position in contact with another membrane portion 41. Therefore, it is preferable that the tip portion 41a of each film portion 41 is located in the enlarged diameter space 51a at least in an open state (see FIG. 5).

In particular, it is preferable that the position of the proximal end of the tip portion 41a of each film portion 41 in the longitudinal direction A coincides with the position in the longitudinal direction A where the inner diameter of the enlarged diameter space 51a is maximized. By doing so, the restoration performance of the film portion 41 described above from the position in the open state (see FIG. 5) to the position in the closed state (see FIG. 4) can be further enhanced.

Further, the deformation starting point portion 41b of each film portion 41 is preferably located in the enlarged diameter space 51a. More specifically, it is preferable that both the distal starting point 41b1 and the lateral starting point 41b2 (see FIGS. 2B and 3B) of the deformation starting point 41b are located in the enlarged diameter space 51a. By locating the distal origin 41b1 in the enlarged diameter space 51a, the distal origin 41b1 is located distal in the longitudinal direction A as compared with the case where the distal origin 41b1 is located in the space of the suction flow path 102a in which the capillary portion 52 is partitioned. At the position of the starting point portion 41b1, it is possible to prevent the suction flow path 102a from becoming thin or narrow, and it is possible to improve the suction efficiency of foreign matter. Further, since the lateral starting point 41b2 is located in the enlarged diameter space 51a, the tip portions 41a are located in the space of the suction flow path 102a where the thin tube portion 52 is partitioned. The cross-sectional area of the valve inner flow path 42 (see FIG. 5) formed so as to be separated from each other in the cross section orthogonal to the longitudinal direction A can be widened, and the suction efficiency of foreign matter can be improved.

Further, it is preferable that the outer wall of the inner diameter increasing portion 51 is coated with a lubricating material. By doing so, it is possible to suppress the frictional force between the outer wall of the inner diameter increasing portion 51 and the inner wall of the blood vessel when the catheter main body 102 is inserted into the blood vessel. As a result, it is possible to suppress excessive stimulation of blood vessels.

Examples of the lubricating material to be coated include a lubricating material composed of a hydrophilic material. The hydrophilic materials that can be used include, for example, a cellulose-based polymer substance, a polyethylene oxide-based polymer substance, and a maleic anhydride-based polymer substance (for example, a copolymer of maleic anhydride such as a methylvinyl ether-maleic anhydride copolymer). Polymers), acrylamide-based polymer substances (for example, polyacrylamide, block copolymer of polyglycidyl methacrylate-dimethylacrylamide (PGMA-DMAA)), water-soluble nylon, polyvinyl alcohol, polyvinylpyrrolidone and the like.

Further, when blood enters between the inner wall of the inner diameter increasing portion 51 and the membrane portion 41 when the foreign matter is sucked, the blood tends to stay there. Therefore, it is preferable that an anticoagulant layer composed of an anticoagulant is laminated on the inner wall of the inner diameter increasing portion 51 and the surface of the membrane portion 41 facing at least the inner wall of the inner diameter increasing portion 51. Examples of the anticoagulant include heparin, EDTA-2K, sodium citrate, sodium fluoride, warfarin and the like, and heparin or EDTA-2K is particularly preferable.

Further, the foreign body suction catheter 101 preferably includes a reinforcing body that reinforces the strength of the inner diameter increasing portion 51 of the catheter main body 102 in the longitudinal direction A. FIG. 6 is a diagram showing a modified example of the foreign body suction catheter 101 of the present embodiment. The foreign body suction catheter 201 shown in FIG. 6 differs from the foreign body suction catheter 101 shown in FIGS. 4 and 5 only in the presence or absence of the reinforcing body 61. As shown in FIG. 6, when the foreign body suction catheter 201 is provided with the reinforcing body 61, it is possible to suppress the collapse of the inner diameter increasing portion 51 due to the suction pressure. The reinforcing body 61 of the present embodiment is composed of coil bodies arranged on the distal side and the proximal side of the check valve 5, but is not limited to this configuration. The reinforcing body 61 may be arranged only on either the distal side or the proximal side of the check valve 5. Further, the reinforcing body 61 may have a different configuration such as a net-like body instead of the coil body. Further, although the reinforcing body 61 of the present embodiment is arranged so as to abut on the inner wall of the inner diameter increasing portion 51, it may be embedded in the wall of the inner diameter increasing portion 51.

As the material for forming the reinforcing body 61, for example, stainless steel wire, amorphous alloy wire and the like are preferable, and as the amorphous alloy wire, iron-silicon-boron alloy, cobalt-silicon-boron alloy, iron-cobalt-chromon-molybdenum are preferable. An amorphous alloy wire formed by using a silicon-boron alloy or the like can be preferably used.

[Third Embodiment]
Next, the foreign body suction catheter 301 as the third embodiment will be described with reference to FIG. 7. The foreign body suction catheter 301 has a different check valve configuration as compared with the foreign body suction catheter 101 of the second embodiment, and has the same other configurations. Therefore, only the above differences will be described here, and the description of the common configuration will be omitted.

FIG. 7 shows the extending direction of the catheter main body 102 at the position where the check valve 305 is provided (in the present embodiment, the same direction as the longitudinal direction A of the foreign body suction catheter 301, and hereinafter, “longitudinal direction A”. It is a cross-sectional view according to). FIG. 7 shows the check valve 305 in the closed state.

The check valve 305 shown in FIG. 7 includes a plurality of film portions 341. The plurality of film portions 341 maintain a closed state in which they are in contact with each other when a suction pressure of less than a predetermined value acts on the suction flow path 102a. Further, when a suction pressure of a predetermined value or more acts on the suction flow path 102a, the plurality of film portions 341 are opened by being separated from each other in the orthogonal direction B orthogonal to the longitudinal direction A.

The check valve 305 shown in FIG. 7 further includes a tubular base end portion 343 connected to the distal ends of all of the plurality of membrane portions 341. The proximal end 343 extends in the longitudinal direction A and is connected to the distal ends of the plurality of membrane portions 341 at its proximal end. Further, the proximal end of the proximal end portion 343 connected to the distal end of the plurality of membrane portions 341 is located in the enlarged diameter space 51a. On the other hand, the distal end of the proximal end portion 343 is located in the capillary portion 52 and is fixed to the inner wall of the capillary portion 52.

The deformation starting point portion 341b of the film portion 341 of the present embodiment is the proximal end of the tubular base end portion 343. The tip portion 341a of the film portion 341 can be deformed in the orthogonal direction B starting from the proximal end of the base end portion 343 as the deformation starting point portion 341b. As described above, the deformation starting points 341b of the plurality of film portions 341 of the check valve 305 shown in FIG. 7 do not have to be fixed to the inner wall of the catheter main body portion 102.

[Fourth Embodiment]
Finally, the foreign body suction catheter 401 as the fourth embodiment will be described with reference to FIG. The foreign body suction catheter 401 is different from the foreign body suction catheter 101 of the second embodiment only in the number of membrane portions, and has the same other configurations. Therefore, only the above differences will be described here, and the description of the common configuration will be omitted.

FIG. 8 is a cross-sectional view at the position of the check valve 405, orthogonal to the longitudinal direction A. The check valve 405 shown in FIG. 8 includes three film portions 441. FIG. 8 shows three membrane portions 441 in a closed state. As described above, the number of the film portions 441 included in the check valve 405 is not particularly limited, and may be two or four or more as in the first to third embodiments.

The foreign body suction catheter according to the present disclosure is not limited to the specific configuration shown in the first to fourth embodiments described above, and can be variously modified and modified as long as it does not deviate from the scope of claims. Further, a foreign body suction catheter configured by combining various configurations shown in the first to fourth embodiments also belongs to the technical scope of the present disclosure.

The present disclosure relates to a foreign body suction catheter.

1, 101, 201, 301, 401: Foreign matter suction catheter 2, 102: Catalyst body 2a, 102a: Suction flow path 2a1: Suction port 2a2: Communication port 2b: Guide wire insertion hole 2b1: Distal opening 2b2: Proximal Opening 3: Hub 3a: In-hub flow path 4: Covered tube 5, 305, 405: Check valve 11: Main body tubular part 12: Adjacent tubular part 13: Proximal tube part 14: Distal tip 21: Main body part 22: Distal connection 23: Wing 24: Proximal connection 31: Proximal covering 32: Distal covering 41, 341, 441: Membrane 41a, 341a: Tip 41b, 341b: Deformation starting point 41b1: Far Positioning point 41b2: Lateral starting point 42: Valve inner flow path 51: Inner diameter increasing part 51a: Diameter expansion space 52: Thin tube part 61: Reinforcing body 343: Base end part A: Foreign matter suction catheter longitudinal direction (in the embodiment) Same as the extending direction of the catheter body)
A1: Distal direction A2: Proximal direction B: Orthogonal direction orthogonal to the extending direction of the catheter body C: Membrane film thickness direction D: Membrane width direction L1: Tip in contact in a closed state Length in the longitudinal direction of the portion L2: Total length in the longitudinal direction A of the membrane portion M1: Inner diameter of the capillary portion M2: Maximum inner diameter of the inner diameter increasing portion

Claims (6)

A foreign body suction catheter that can suck foreign substances in the living body.
The tubular catheter body that separates the suction flow path and
A check valve located in the suction flow path is provided.
The check valve is maintained in a closed state in which it abuts against each other when a suction pressure of less than a predetermined value acts on the suction flow path, and when a suction pressure of a predetermined value or more acts on the suction flow path, the check valve is said to be in contact with each other. A foreign body suction catheter having a plurality of membrane parts that are opened by being separated from each other in an orthogonal direction orthogonal to the extending direction of the catheter main body. The catheter main body portion includes an inner diameter increasing portion in which the inner diameter of the suction flow path is larger than that on the distal side and the proximal side in the extending direction.
The foreign body suction catheter according to claim 1, wherein at least a part of each of the plurality of membrane portions is located in an enlarged diameter space defined by the inner diameter increasing portion in the suction flow path. Each of the membrane portions is separated from another membrane portion of the plurality of membrane portions in the open state in the orthogonal direction, and is in contact with the other membrane portion in the closed state, on the proximal side in the extending direction. Equipped with a tip,
The foreign body suction catheter according to claim 2, wherein the tip portion of each membrane portion is located in the enlarged diameter space. Each of the film portions is a deformation starting point that deformably supports the tip portion between a position where the tip portion abuts on the other film portion and a position where the tip portion is separated from the other film portion. Equipped with a part
The foreign body suction catheter according to claim 3, wherein the deformation starting point of each membrane portion is located in the enlarged diameter space. The foreign body suction catheter according to claim 4, wherein the bending rigidity of the tip portion is smaller than the bending rigidity of the deformation starting portion. The foreign body suction catheter according to any one of claims 2 to 5, further comprising a reinforcing body for reinforcing the strength of the inner diameter increasing portion of the catheter main body portion in the extending direction.

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