JP2021145934A - catheter - Google Patents

Abstract

To provide a low-cost catheter capable of preventing adhesion between the catheter and a blood vessel and having a simple configuration.SOLUTION: A catheter including a base body having a liquid embolic agent supply part, and a tube part 10 connected to the base body to be inserted into a living body, includes an adhesion prevention film 40 with hydrophilic nature and biocompatibility, preventing adhesion of the embolic agent to an external periphery area, at the external periphery area in the length area at least including the base body and an opposite-side tip end T of the tube part 10. The catheter is configured to tear off or shear off the embolic agent stuck to the adhesion prevention film 40 and hardened, by the tube part 10 retracting in the direction of the base body.SELECTED DRAWING: Figure 4

Description

The present invention relates to a catheter.

For example, in the treatment of abnormal blood vessels (Nidas Nidus) such as cerebral arteriovenous malformation (AVM), Nidus is occluded using solid particles or medical adhesives. Such endovascular treatment is not limited to those aiming at curative treatment alone, but is also used as embolization before radiotherapy such as gamma knife or before surgical resection.
In such endovascular treatment, a catheter is percutaneously inserted into the blood vessel from outside the body, and a medical adhesive is discharged from the tip of the catheter at the affected area. The medical adhesive is a liquid that is smoothly discharged from the tip of the catheter at the time of discharge, and over time, it becomes an individual that embolizes the affected area and can occlude Nidus. Such an embolic treatment device is described in, for example, Patent Document 1.

By the way, in endovascular treatment using a medical adhesive, there is a concern that the medical adhesive discharged from the tip of the catheter adheres the tip of the catheter to the blood vessel and prevents the catheter from being pulled out. .. In Patent Document 1 described above, in order to prevent adhesion between the catheter and the blood vessel, a cap that expands the diameter when the medical adhesive is discharged and is placed in the blood vessel after the catheter is pulled out is provided at the tip of the catheter. Have been described. Further, the embolization treatment device described in Patent Document 1 is provided with an expansion operation unit for attaching a cap to the tip of the catheter and expanding the diameter of the cap. Patent Document 1 describes that the expansion operation unit is composed of four wires, and the wires are bent and deformed by applying a push force to the wires by an operator's operation.

JP 2015-167572

Since the catheter is a disposable instrument, it is preferable that the structure is simple and the cost is low.
However, it can be said that the embolization treatment device described in Patent Document 1 has a large number of parts and a complicated structure as compared with known embolization treatment instruments.
The present invention has been made in view of the above points, and relates to a catheter having a simple structure and a low cost, which prevents the catheter from being adhered in a blood vessel and does not increase the number of parts.

The catheter of the present invention is a catheter including a base portion having a supply portion of a liquid embolic agent and a tube portion connected to the base portion and inserted into a living body, and the base portion in the tube portion. The embolic agent is provided with an adhesion-preventing film that is hydrophilic and biocompatible and prevents the embolic agent from adhering to the outer peripheral region in the outer peripheral region in the length region including at least the tip portion on the opposite side to the above. The adhesion-preventing film to which the film has adhered and hardened is broken or sheared off by the tube portion retracting in the direction of the substrate portion.

INDUSTRIAL APPLICABILITY The present invention can provide a low-cost catheter having a simple structure without increasing the number of parts while preventing the catheter from being adhered in a blood vessel.

It is an overall view of the catheter of one Embodiment of this invention. It is a cross-sectional view of the catheter along the arrow line II-II shown in FIG. It is a vertical cross-sectional view of the catheter along the arrow line III-III shown in FIG. It is a figure which shows the state which the adhesion prevention film is formed in the tip region of the tube part shown in FIG. (A) shows a state in which the embolic agent is attached on the adhesion prevention film. (B) shows a state in which the adhesion prevention film shown in (a) is peeled off from the tube portion. It is a figure which shows the modification of the adhesion prevention film in this embodiment. It is a figure which shows the other modification of the adhesion prevention film in this embodiment.

Hereinafter, an embodiment of the present invention will be described. In the drawings used in the present embodiment, the same members may be designated by the same reference numerals, and a part of the description thereof may be omitted. Further, the drawings explain the function, configuration, and technical idea of the catheter of the present invention, and do not specify the specific shape such as the aspect ratio and the thickness of the member.
1, FIG. 2 and FIG. 3 are diagrams for explaining the catheter 1 of the present embodiment. FIG. 1 is an overall view of the catheter 1, and FIG. 2 is a cross-sectional view of the catheter 1 along the arrow lines II-II shown in FIG. FIG. 3 is a vertical cross-sectional view of the catheter 1 along the arrow lines III-III shown in FIG.
The catheter 1 of the present embodiment is an inactive catheter that does not have an operation line or an operation unit, but is not limited to this, and is provided with an operation line or an operation unit to operate the catheter 1. It may be an active catheter in which the tube portion bends at the same time.

As shown in FIG. 1, the catheter 1 includes a base portion 90 having a hub 96 which is a supply portion of a liquid embolic agent, and a tube portion 10 which is connected to the base portion 90 and inserted into a living body. There is. Then, the tube portion 10 is hydrophilic and biocompatible and prevents the embolic agent from adhering to the outer peripheral region of the outer peripheral region of the length region L including at least the tip portion T on the opposite side of the base portion 90. It is provided with an adhesion prevention film (see FIG. 4).
Of the above, "liquid" may be in a state of having fluidity and surface tension, and is not limited to the degree of viscosity thereof. Further, the embolic agent may be liquid before being discharged from the tube portion 10, and after discharge, the embolic agent is sometimes hardened and solidified or semi-solidified.
"Hydrophilic" refers to the property of being easily dissolved in water or easily mixed with water by forming a hydrogen bond with water. "Biocompatibility" refers to the property, or the degree to which, when the material is attached or transplanted, it is recognized as a foreign substance by the living body and becomes familiar without being eliminated.

The embolic agent is a medical adhesive and may be either a polymerization type or a precipitation type. Examples of such embedding agents include cyanoacrylate adhesives, polyvinyl alcohol adhesives, polyurethane adhesives, gelatin adhesives, fibrin adhesives (fibrin glues) and the like. Of these, the cyanoacrylate-based adhesive can be satisfactorily applied because it exerts an embolic effect immediately after being discharged from the tube portion 10. Examples of the cyanoacrylate-based adhesive include NBCA (N-butyl-2-cyanoacrylate) and Onex (registered trademark).
Hereinafter, the basic configuration of the catheter 1 will be described prior to the description of the adhesion prevention membrane by the embolic agent.

(Catheter body)
The hub 96 provided in the base portion 90 is provided so as to communicate with the main lumen 20 which is a hollow portion of the tube portion 10. A syringe 100 is attached to the hub 96. The hub 96 is provided at the rear end of the main body case 94 of the base portion 90, and the syringe 100 is mounted from the rear of the hub 96. An embolic agent is contained in the syringe 100, and by injecting the liquid embolic agent into the hub 96 by the syringe 100, the embolic agent is injected through the main lumen 20 (FIGS. 2 and 3) of the tube portion 10. Can be supplied to blood vessels and the like.
However, the catheter 1 of the present embodiment injects a liquid embolic agent, a contrast agent, a liquid anticancer agent, a physiological saline solution, and a chemical solution such as NBCA (n-butyl-2-cyanoacrylate) used as an instant adhesive. It can also be used as a medical device.

The tube portion 10 shown in FIG. 1 is also called a sheath, and is a hollow tubular and long member having a main lumen 20 formed therein. More specifically, the tube portion 10 is formed to have an outer diameter that allows it to enter the blood vessel. The tube portion 10 is connected to the tip of the main body case 94 with respect to the rear end connected to the hub 96, the connection point with the main body case 94 is the base end portion F, and the peripheral portion of the discharge port 25 for discharging the embolic agent. Is the tip portion T, and the length region L is defined between the base end portion F and the tip portion T.

As shown in FIGS. 2 and 3, the tube portion 10 has a laminated structure. The tube portion 10 is configured by laminating an inner layer (main tube) 24 and an outer layer 50 in order from the inner diameter side, centering on the main lumen 20. The inner layer 24 and the outer layer 50 are made of a flexible resin material, and each has a circular tubular shape and a substantially uniform thickness in the circumferential direction.

The inner layer 24 is the innermost layer of the tube portion 10, and the main lumen 20 is defined by the inner wall surface thereof. The shape of the cross section of the main lumen 20 is not particularly limited, but is circular in the present embodiment. In addition, in this specification, the wording of "the cross section of a main lumen" refers to a cross section of a shape (a cylinder long in the axial direction of the main lumen 20) defined by the outer peripheral surface of the main lumen 20. Further, in the present embodiment, the cross section of the tube portion 10 is circular, and the diameter of the circular shape differs depending on the position in the longitudinal direction (the axial direction of the main lumen 20).

Examples of the material of the inner layer 24 include a fluorine-based thermoplastic polymer resin. Specific examples of the fluorine-based thermoplastic polymer material include polytetrafluoroethylene (PTFE), polyvinylidene fluoride (PVDF), and perfluoroalkoxy alkane resin (PFA). By forming the inner layer 24 with such a fluorine-based polymer material, the deliverability when the embolic agent is supplied through the main lumen 20 is improved. Further, the sliding resistance when inserting the guide wire or the like into the main cavity 20 is reduced.

The wire reinforcing layer 30 is a protective layer that protects the inner layer 24 in the tube portion 10. The wire reinforcing layer 30 is formed by winding the reinforcing wire 32. The material of the reinforcing wire 32 includes metal materials such as tungsten (W), stainless steel (SUS), nickel-titanium alloy, steel, titanium, copper, titanium alloy or copper alloy, as well as shearing more than the inner layer 24 and the outer layer 50. High-strength resin materials such as polyimide (PI), polyamideimide (PAI) or polyethylene terephthalate (PET) can be used. In this embodiment, a thin stainless steel wire is used as the reinforcing wire 32.
The number of threads and the number of meshes of the reinforcing wire 32 are not particularly limited. Here, the number of meshes of the wire reinforcing layer 30 means the number of intersections (number of stitches) per unit length (1 inch) seen in the extending direction of the reinforcing wire.

The reinforcing wire 32 is wound diagonally around the inner layer 24. The angle formed by the extending direction of the reinforcing wire 32 with respect to the circumferential direction around the inner layer 24 is called the pitch angle of the reinforcing wire 32. When the reinforcing wire 32 is wound at a dense pitch, the pitch angle becomes a small angle. On the contrary, when the reinforcing wire 32 is wound at a shallow angle along the axis of the tube portion 10, the pitch angle becomes a large angle close to 90 degrees. The pitch angle of the reinforcing wire 32 of the present embodiment is not particularly limited, but can be 30 degrees or more, preferably 45 degrees or more, and 75 degrees or less.
The number of reinforcing wires 32 forming the wire reinforcing layer 30 is not particularly limited, but in the present embodiment, the wire reinforcing layer 30 formed by the 16 reinforcing wires 32 is shown.

FIG. 4 is a diagram showing a state in which the adhesion prevention film 40 is formed in a part of a length region (hereinafter, referred to as “tip region”) including at least the tip portion T of the tube portion 10. As shown in FIG. 4, in the present embodiment, the adhesion prevention film 40 is locally formed in a region (tip region) including the tip portion T in the outer peripheral region of the tube portion 10. The tip region of the tube portion 10 has a region A, a region B, and a region C from the side of the tip portion T. Each of the regions A, B, and C has a circular cross section, and the diameter of the cross section of the region A is the diameter Ra, the diameter of the cross section of the region B is the diameter Rb, and the diameter of the cross section of the region C is the diameter Rc. Both the diameter Ra and the diameter Rc are constant regardless of the position, and the diameter Ra is smaller than the diameter Rc. The diameter Rb is between the diameter Ra and the diameter Rc and changes with a constant inclination.

The catheter 1 of the present embodiment includes an adhesion prevention film 40 that prevents the embolic agent from adhering to the outer peripheral region of a part of the region A of the tube portion 10. The part of the region A refers to, for example, the region where the adhesion prevention film 40 shown in FIG. 4 is formed. The length of the formation region D is 1 cm or more and 20 cm or less, preferably 3 cm or more and 10 cm or less, and more preferably 5 cm or more and 10 cm or less. Further, the adhesion prevention film 40 is formed not only on the outer peripheral region of the tube portion 10 but also on the end surface 251 of the tip portion T. In this way, it is possible to cover the entire area to which the embolic agent can adhere with the adhesion prevention film 40. The end surface of the tip portion T refers to the peripheral surface of the discharge port 25.

In the present embodiment, the "outer peripheral region" is the outer surface of the outer layer 50 which is the outermost layer of the tube portion 10, and the adhesion prevention film 40 is formed on the outer surface of the outer layer 50. The anti-adhesion film 40 functions to break or shear the embolic agent adhering to and cured on the anti-adhesion film 40 by retracting the tube portion 10 toward the substrate portion.
In the above, "breaking" refers to fracture caused by stress applied to the main surface in the substantially vertical direction, and "shearing" refers to fracture caused by stress applied to the main surface in the substantially vertical direction.

That is, when the tube portion 10 is inserted into the blood vessel and the embolic agent is discharged at the affected portion, an embolic agent vortex is formed in the vicinity of the discharge port 25, and the embolic agent adheres to the vicinity of the discharge port 25 or enters the bloodstream. It has been reported that the embolic agent returns to the discharge port 25. In such a case, as the embolic agent in the vicinity of the discharge port 25 hardens, the tip region including the tip portion T may be adhered to the inner wall of the blood vessel, which may hinder the pulling out of the tube portion 10.
In order to eliminate such a problem, in the present embodiment, the adhesion prevention film 40 is formed in advance in a part of the tip region of the tube portion 10. In this way, the embolic agent discharged from the discharge port 25 adheres to the adhesion prevention film 40 outside the tube portion 10 and hardens, and the surface of the tube portion 10 and the inner wall of the blood vessel can be directly adhered to each other. No.

When the tube portion 10 is pulled out in such a state, the adhesion prevention film 40 is broken or sheared and separated from the tube portion 10 and remains in the blood vessel, and the tube portion 10 is smoothly pulled out from the blood vessel. Further, in the present embodiment, since the main lumen 20 is hydrophilic and has biocompatibility, even if it remains in the body cavity such as a blood vessel, there is no problem in the living tissue and it is safe.
Further, in the present embodiment, since a part of the tube portion 10 which is a thin film formed on the surface of the tube portion 10 is peeled off and remains in the body, the amount of the adhesion prevention film 40 remaining in the body is very small. In this respect as well, the present embodiment can reduce the influence of the indwelling object on the living body as compared with the case where the cap having a volume that closes the blood vessel is indwelled in the body as in Patent Document 1 described above.

5 (a) and 5 (b) are schematic views for explaining the state of breakage and shearing of the adhesion prevention film 40. FIG. 5A shows a state in which the adhesion prevention film 40 is formed on the tip end portion T and the end surface 251 of the tube portion 10 and the embolic agent S is adhered on the adhesion prevention film 40. FIG. 5B shows a state in which the adhesion prevention film 40 shown in FIG. 5A is sheared and broken and peeled off from the tube portion 10.
In FIG. 5A, it is assumed that the embolic agent S is attached to a part of the tube portion 10 including the tip portion T and the end surface 251 and is cured.

When a force in the direction of the arrow Y is applied to pull out (retract) the catheter 1 in the state of FIG. 5A, the cured embolic agent S is adhered to the skin and the catheter 1 is pulled out. Hinder. At this time, the adhesion prevention membrane 40 receives the direction of the arrow line Y, which is the direction in which the tube portion 10 is pulled out, and the direction of the arrow line X, which is the direction in which the tube portion 10 is pulled out by the inner wall of the blood vessel. The directions of the arrow X and the arrow Y are substantially parallel, and shearing occurs in the layer of the adhesion prevention film 40.
As shown in FIG. 5B, the sheared anti-adhesion film 40 breaks between the sheared area and the portion not peeled from the tube portion 10. The adhesion prevention film 40 that has been sheared or broken separates from the tube portion 10 and falls.

In order to realize the above operation, in the present embodiment, the shear strength of the adhesion prevention film 40 is made lower than the breaking strength and the shear strength of the tube portion 10. In this way, when stress is applied to the adhesion prevention film 40 and the tube portion 10, the adhesion prevention film 40 is sheared and broken before the tube portion 10 is broken or sheared. Therefore, the tube portion 10 is not damaged, only the adhesion prevention film 40 is destroyed, and the tube portion 10 is not trapped by the embolic agent (hereinafter, also referred to as “trapped”).

However, the breaking strength and the shear strength of the tube portion 10 are different between the formed region of the wire reinforcing layer 30 around which the wire reinforcing layer 30 is wound and the non-formed region without the wire reinforcing layer 30. In FIG. 4, a part of the region A near the tip portion T is a non-formed region without the wire reinforcing layer 30. In the present embodiment, it is preferable that the shear strength of the adhesion prevention film 40 is lower than the breaking strength and the shear strength of the formation region of the wire reinforcing layer 30 in the tube portion 10. Further, in the present embodiment, it is more preferable that the shear strength of the adhesion prevention film 40 is lower than the breaking strength and the shear strength of the formation region of the wire reinforcing layer 30 in the tube portion 10.

Further, in order to realize the operation shown in FIG. 5B, in the present embodiment, the peel strength of the adhesion prevention film 40 with respect to the outer peripheral region of the tube portion 10 is made lower than the breaking strength and the shear strength of the tube portion 10. There is. In this way, when stress is applied to the adhesion prevention film 40 and the tube portion 10, the adhesion prevention film 40 is peeled off from the outer peripheral region of the tube portion 10 before the tube portion 10 is broken or sheared. Therefore, the tube portion 10 is not damaged, only the adhesion prevention film 40 is peeled off, and the tube portion 10 is not trapped by the embolic agent.
In the present embodiment, the peel strength of the adhesion prevention film 40 with respect to the outer peripheral region of the tube portion 10 is made lower than the breaking strength and the shear strength of the forming region of the wire reinforcing layer 30 of the tube portion 10. More preferably, the peel strength of the adhesion prevention film 40 with respect to the outer peripheral region of the tube portion 10 is made lower than the breaking strength and shear strength of the non-formed region of the tube portion 10 without the wire reinforcing layer 30.

In order to realize the anti-adhesion film 40 having the above-mentioned shear strength and peel strength, the present embodiment contains the anti-adhesion film 40 containing, for example, a structural protein containing at least one of collagen, elastin, and keratin as a component. Formed from material. Such a structural protein may form an adhesion prevention film 40 as gelatin treated with an acid or an alkali after being extracted from a raw material. Further, the adhesion prevention film 40 may appropriately include a member for adjusting the hydrophilicity of gelatin within a range that does not impair biocompatibility.

As shown in FIGS. 4, 5 (a), and 5 (b), the present embodiment is limited to the adhesion prevention film 40 being formed in a part of the region including the tip of the tube portion 10. It's not something. For example, the adhesion prevention film 40 may be formed from the tip end portion T to the end portion on the base end portion F side of the outer peripheral region of the tube portion 10.

FIG. 6 is a diagram showing a modified example of the adhesion-preventing film in the present embodiment, showing an example in which another film 60 having hydrophilicity is formed on the substrate portion 90 side of the formation region of the adhesion-preventing film 40. ing. The film 60 shown in FIG. 6 is formed independently on the side of the substrate portion 90 with respect to the formation region D, and is formed so as not to have a portion overlapping with the adhesion prevention film 40. In this way, a wider range of the tube portion 10 can move smoothly in the blood vessel. Examples of such a membrane include polyvinylpyrrolidone (PVP) and maleic anhydride. The hydrophilic film formed on the side of the base portion 90 with respect to the formation region of the adhesion prevention film 40 is not intended to be peeled off in the blood vessel like the adhesion prevention film 40. Therefore, as for the hydrophilic film on the side of the substrate portion 90, it is not necessary to strictly select the material for biocompatibility as compared with the adhesion prevention film 40, and the degree of freedom in design is increased.

FIG. 7 is a diagram showing another modification of the adhesion-preventing film in the present embodiment, in which a strongly hydrophilic film 80 having a hydrophilicity stronger than that of the adhesion-preventing film 40 is formed on the surface of the adhesion-preventing film 40. An example is shown. As shown in FIG. 7, the strongly hydrophilic film 80 may be formed on the adhesion prevention film 40 and further on the side of the substrate portion 90, or may be formed so as to overlap the adhesion prevention film 40. It may not be formed on the side of the substrate portion 90.
By doing so, the hydrophilicity of the adhesion prevention film 40 can be further enhanced, and the operability of the tube portion 10 can be further enhanced.

The above embodiment includes the following technical ideas.
(1) A catheter including a base portion having a supply portion of a liquid embolic agent and a tube portion connected to the base portion and inserted into a living body, which is opposite to the base portion in the tube portion. An anti-adhesion film that is hydrophilic and biocompatible and prevents the embolic agent from adhering to the outer peripheral region is provided in the outer peripheral region in the length region including at least the tip portion of the embolic agent. A catheter in which the cured anti-adhesion film is broken or sheared off by retracting the tube portion toward the substrate portion.
(2) The catheter according to (1), wherein the shear strength in the layer of the adhesion prevention film is lower than the breaking strength and the shear strength of the tube portion.
(3) The catheter according to (1) or (2), wherein the peel strength of the adhesion prevention film with respect to the outer peripheral region is lower than the breaking strength and shear strength of the tube portion.
(4) The catheter according to any one of (1) to (3), wherein the anti-adhesion membrane contains a structural protein containing at least one of collagen, elastin, and keratin as a component.
(5) The catheter according to any one of claims 1 to 4, wherein the adhesion prevention film is locally formed in a region including the tip portion of the outer peripheral region of the tube portion.
(6) The invention according to any one of (1) to (4), wherein the adhesion prevention film is formed from the tip end portion of the outer peripheral region of the tube portion to the end portion on the side of the substrate portion. Catheter.
(7) The catheter according to any one of (1) to (6), wherein a strongly hydrophilic film having a hydrophilicity stronger than that of the anti-adhesion film is formed on the surface of the anti-adhesion film.
(8) The catheter according to any one of (1) to (7), wherein another hydrophilic film is formed on the side of the substrate portion with respect to the formation region of the adhesion prevention film.
(9) The catheter according to any one of (1) to (8), wherein the adhesion prevention film is formed not only on the outer peripheral surface of the tube portion but also on the end surface of the tip portion.

1 ... Catheter 10 ... Tube part 20 ... Main lumen 24 ... Inner layer 25 ... Discharge port 30 ... Wire reinforcing layer 32 ... Reinforcing wire 40 ... Adhesion prevention film 50 ...・ ・ Outer layer 60 ・ ・ ・ Other film 80 ・ ・ ・ Strongly hydrophilic film 90 ・ ・ ・ Base part 94 ・ ・ ・ Main body case 96 ・ ・ ・ Hub 100 ・ ・ ・ Syringe 251 ・ ・ ・ End faces A, B, C ... Region F ... Base end L ... Length region S ... Embolic agent T ... Tip

Claims (9)

A catheter including a base portion having a supply portion of a liquid embolic agent and a tube portion connected to the base portion and inserted into a living body.
Adhesion prevention that is hydrophilic and biocompatible and prevents the embolic agent from adhering to the outer peripheral region in the outer peripheral region of the tube portion in the length region including at least the tip portion on the opposite side to the substrate portion. With a membrane,
A catheter to which the anti-adhesion film to which the embolic agent has adhered and hardened is broken or sheared and removed by retracting the tube portion toward the base portion. The catheter according to claim 1, wherein the shear strength in the layer of the adhesion prevention film is lower than the breaking strength and the shear strength of the tube portion. The catheter according to claim 1 or 2, wherein the peel strength of the adhesion prevention film with respect to the outer peripheral region is lower than the breaking strength and the shear strength of the tube portion. The catheter according to any one of claims 1 to 3, wherein the anti-adhesion membrane contains a structural protein containing at least one of collagen, elastin, and keratin as a component. The catheter according to any one of claims 1 to 4, wherein the adhesion prevention film is locally formed in a region including the tip portion of the outer peripheral region of the tube portion. The catheter according to any one of claims 1 to 4, wherein the adhesion prevention film is formed from the tip end portion of the outer peripheral region of the tube portion to the end portion on the side of the base portion. The catheter according to any one of claims 1 to 6, wherein a strongly hydrophilic film having a hydrophilicity stronger than that of the anti-adhesion film is formed on the surface of the anti-adhesion film. The catheter according to any one of claims 1 to 7, wherein another hydrophilic film is formed on the side of the substrate portion with respect to the formation region of the anti-adhesion film. The catheter according to any one of claims 1 to 8, wherein the adhesion prevention film is formed not only on the outer peripheral surface of the tube portion but also on the end surface of the tip portion.

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