JPH10127647A - Embolus member pusher and embolic member-extruder assembly - Google Patents

Abstract

PROBLEM TO BE SOLVED: To ensure the smooth movement of vascular embolus member in a catheter by forming a hydrophilic resin coating layer which exhibits a surface moistening property when wet on at least part of the surface of the wire base body of an extruder of the vascular embolus member for indwelling the vascular embolus member in the desired section in a blood vessel system. SOLUTION: This embolus member-extruder assembly has the extruder 10 formed with the hydrophilic resin coating layer 20 in part of the surface of the wire base body 11 and the coiled vascular embolus member 40 connected via a rod-shaped connecting member 30 to the front end of this extruder 10. The extruder 10 is a guiding element for introducing the vascular embolus member 40 into the desired section. The extruder 10 has a contrast medium part 12 at its front end and has a terminal part 13 at its rear end. At the time of forming the hydrophilic resin coating layer 20, the wire base body 11 is first treated with the soln. of a compd. having a reactive functional group to form a ground substrate layer (adhesive layer). The wire base body is then treated with the soln. of a water-soluble resin material and the hydrophilic resin coating layer is formed by the reaction of the reactive functional group and the water-soluble resin material.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an embolus member pusher and an embolus member-extruder assembly.

[0002]

2. Description of the Related Art In recent years, vascular embolization in which a vascular embolization member is placed in an aneurysm has attracted attention as a less invasive treatment for an aneurysm and the like (for example, US Pat.
Nos. 884,579 and 4,739,768). In this vascular embolization, the vascular embolus member placed in the aneurysm becomes a physical obstacle to blood flow,
The formation of a thrombus within the aneurysm can be promoted to reduce the risk of aneurysm rupture. Here, a coil-shaped member made of platinum or the like is known as a vessel embolization member to be placed at a predetermined site in a vascular structure such as an aneurysm.

[0003] Such a coil-shaped vascular embolus member is introduced into an aneurysm via an appropriate catheter by a wire-like pusher (inductor) detachably connected to its end (for example, JP-T 5-500322,
JP-T 8-501015, JP-T 7-50267
No. 4). Specifically, a coil-shaped vascular embolus member (hereinafter referred to as an “embolic member-extruder assembly”) to which an extruder is connected is inserted into a catheter which has been inserted into a living body in advance so that the distal end opening is located in the aneurysm. ) Is inserted with the vascular embolus member at the top. As a result, the vascular embolus member advances in the catheter while being pressed by the pusher, and is pushed out of the distal end opening of the catheter into the aneurysm. Then, when the entire length of the vascular embolus member is extruded from the distal end opening, that is, when the connecting portion with the pushing tool reaches the distal end opening, the vascular embolus member is mechanically or electrolyzed. Cut off the extruder. As a result, only the embolization member is placed in the aneurysm.

[0004]

However, when the embolic member-extrusion device assembly is inserted into a wet catheter into which physiological saline or blood is flowing, the embolic member-extrusion device assembly receives the embolic member-extrusion device assembly. The frictional resistance (frictional resistance with the catheter inner wall) is extremely large. Also,
The frictional resistance received by the vascular embolus member tends to increase over time due to thrombus formed in the gap between the coils. For this reason, in the catheter in the wet state, the embolus member-extruder assembly cannot be smoothly advanced, and the embolic member cannot be pushed out from the distal end opening of the catheter, or the distal end opening of the catheter is displaced. Thus, the embolization member cannot be placed at a target site.

To cope with such a problem, it is conceivable to provide lubrication by coating the surface of the extruder with a fluororesin or a silicone resin. However, even by coating with a fluororesin or a silicone resin, the effect of reducing frictional resistance (providing lubricity) in a wet catheter is small, and the above-mentioned problem has not been solved.

The present invention has been made based on the above circumstances. A first object of the present invention is to enable a vascular embolus member to smoothly advance in a wet catheter into which physiological saline or blood has flowed. An object of the present invention is to provide a pusher for a vascular embolus member, which can be reliably pushed out to a part to be extruded and has excellent lubricity in a wet state. A second object of the present invention is to provide a vascular embolus which can be easily inserted into a wet catheter into which physiological saline or blood has flowed, and in which a vascular embolic member can be securely placed at a target site. It is to provide a member-extrusion tool assembly.

[0007]

The pusher for a vascular embolus member according to the present invention is a pusher for a vascular embolus member for placing the vascular embolus member at a target site in a vascular system, and comprises a wire base. A hydrophilic resin coating layer which exhibits surface lubricity when wet is formed on at least a part of the surface.

[0008] The extruder for a vascular embolus member of the present invention is characterized in that a wire base is treated with a solution of a compound having a reactive functional group so that a reactive functional group is present on at least a part of the surface of the wire base. Forming a ground layer, and then treating the wire base with a solution of a water-soluble resin material, thereby reacting the reactive functional group with the water-soluble resin material to form a hydrophilic resin coating layer on the underlayer. The feature is obtained by doing. Further, the water-soluble resin material is at least one selected from the group consisting of cellulose-based polymers, nylon-based polymers, ethylene oxide-based polymers, maleic anhydride-based polymers, acrylamide-based polymers, and derivatives thereof. It is preferred that

[0009] The embolus member-extrusion device assembly of the present invention is characterized by comprising the extruder of the vascular embolus member of the present invention and a vascular embolus member connected to the distal end of the extruder via a connecting member. I do. Moreover, it is preferable that the connection member heated by the supply of the high-frequency current is cut off, so that the embolization member and the pusher are separated from each other.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail. FIG. 1 is an explanatory diagram showing an example of the embolus member-extrusion device assembly of the present invention. This embolus member-extrusion tool assembly is:
A hydrophilic resin coating layer 20 is formed on a part of the surface of the wire base 11.
Are formed, and a coil-shaped vascular embolus member 40 connected to the distal end of the pusher 10 via a rod-shaped connecting member 30.

[0011] The pusher 10 has a vascular embolus member 4 at the target site.
Inductor for introducing 0. This extruder 10 is
A hydrophilic resin coating layer 20 is formed on a part of the surface of the wire base 11.
Is formed, and has a contrast part 12 at the front end and a terminal part 13 at the rear end. Here, the outer diameter of the extruder 10 is, for example, 0.1 to 2.0 mm, and the length of the extruder 10 is, for example, 10 cm to 200 cm.
It is said.

The wire base 11 constituting the extruder 10 can be made of an elastic material such as stainless steel or Ti-Ni alloy. The imaging part 12 constituting the extruder 10 is formed by winding a metal wire such as platinum, silver, or tungsten around the surface of the wire base 11. The supply of power to the extruder 10 is performed via the terminal 13. It is sufficient that the length of the terminal portion 13 is about 1 to 3 cm.

The hydrophilic resin coating layer 20 formed on the surface of the wire base 11 exhibits surface lubricity when wet, and reduces the frictional resistance of the extruder 10 traveling in the wet catheter. Specifically, in the wet state, the coefficient of kinetic friction between the inner wall material of the catheter (eg, ethylene tetrafluoroethylene (ETFE)) and the hydrophilic resin coating layer 20 is about 0.01, and the coefficient of kinetic friction between ETFE and stainless steel ( (Approximately 0.1).

The method for forming the hydrophilic resin coating layer 20 is as follows. First, a wire base is treated with a solution of a compound having a reactive functional group, so that the reactive functional group is present on the surface of the wire base. By forming a ground layer (adhesive layer) and then treating the wire substrate having a base layer formed on the surface thereof with a solution of a water-soluble resin material, the reactive functional group reacts with the water-soluble resin material (shared). Bonding or ionic bonding) and laminating a hydrophilic resin coating layer on the underlayer.

Examples of the water-soluble resin material used to form the hydrophilic resin coating layer 20 include cellulosic polymers such as carboxymethylcellulose, methylcellulose, hydroxyethylcellulose, and hydroxypropylcellulose; nylon-based polymers; Ethylene oxide polymer such as glycol; maleic anhydride homopolymer, maleic anhydride polymer such as methyl vinyl ether-maleic anhydride copolymer; acrylamide polymer; 2-vinylpyridine; N-vinylpyrrolidone; polyethylene glycol Acrylates; hydrophilic acrylates; acrylic acid; acrylonitrile; polymers formed from acrylamidomethylpropanesulfonic acid or its salts; and derivatives thereof It can be-option.

The derivatives of the polymer include esters, salts, amidates, anhydrides, halides, ethers obtained by condensation reaction, addition reaction, substitution reaction, oxidation reaction, reduction reaction and the like of the polymer. Compound, hydrolyzate, acetal compound, formal compound, alkylol compound, quaternary compound, diazo compound, hydrazide compound, sulfonated compound, nitrated compound, ion complex, reactive functional group (for example, diazonium group, azide group, isocyanate group, Acid chloride group, acid anhydride group, imino carbonate group, amino group, carboxyl group, epoxy group, hydroxyl group,
Cross-linked product with a substance having two or more of allyl groups, unsaturated compounds (vinyl compound, acrylic acid, methacrylic acid,
And diene compounds).
No. 81 and Japanese Patent Publication No. 4-14991.

By interposing an aqueous solution of the above-mentioned water-soluble resin material (polymer and derivative thereof) between certain objects, the frictional resistance between the objects can be remarkably reduced, and is effectively used as a lubricant. be able to. Also,
By bonding (covalent bond or ionic bond) of these water-soluble resin materials to a reactive functional group present in the underlayer, a hydrophilic resin coating layer supported on a wire substrate can be obtained. The coating layer can obtain continuous surface lubricity without being dissolved in water.

The compound having a reactive functional group used for forming the underlayer is not particularly limited as long as it has reactivity with a water-soluble resin material. Adduct or prepolymer of isocyanate and polyol, polyamine, polyaldehyde, polyepoxide, etc.
Compounds described in JP-A-33181 and JP-B-4-14991 can be exemplified.
4'-diphenylmethane diisocyanate is preferred.

When an underlayer is formed on the surface of a wire substrate made of stainless steel or the like, the treatment is preferably performed using a solution of an organic polymer resin material together with a solution of a compound having a reactive functional group. Examples of such organic polymer resin materials include polyvinyl chloride resin, polyurethane resin, polyamide resin, polyester resin, latex resin, and the like.
Polyurethane resins are preferred.

The solvent for dissolving the compound having a reactive functional group for forming the underlayer is preferably a solvent capable of dissolving both the compound having a reactive functional group and the organic polymer resin material. By using such a solvent, the adhesive strength between the surface of the wire substrate and the underlayer is improved, and the durability of the hydrophilic resin coating layer formed on the underlayer can be improved. Specific examples of such a solvent include methyl ethyl ketone (MEK),
Examples thereof include cyclohexanone, tetrahydrofuran (THF), xylene, and methyl alcohol.

As a specific treatment method for forming the underlayer, a wire substrate is immersed in a solution of a compound having a reactive functional group, and the solution is applied to the surface of the wire substrate. A method for drying the membrane is exemplified. Here, drying conditions are room temperature to about 80 ° C. for 5 minutes to
It is about 48 hours.

The wire substrate having the underlayer formed on the surface is then treated with a solution of a water-soluble resin material, whereby a hydrophilic resin coating layer is formed on the underlayer. Here, the solvent for dissolving the water-soluble resin material is selected from those that do not react with the reactive functional group present in the underlayer. For example, methyl ethyl ketone (ME
K), tetrahydrofuran (THF), acetone and the like. The concentration of the water-soluble resin material in the solution used for the treatment is usually 0.1 to 15% by weight,
Preferably it is 0.5 to 10% by weight.

As a specific treatment method for forming the hydrophilic resin coating layer, a wire substrate having an underlayer formed on the surface thereof is immersed in a solution of a water-soluble resin material to form a surface of the wire substrate. A method of applying the above solution to the coating solution and drying the coating film is exemplified. Here, the immersion treatment temperature is set to about normal temperature to about 80 ° C., and the treatment time is set to about 1 second to about 48 hours. The drying conditions are from room temperature to about 80 ° C. for about 5 minutes to about 48 hours. Thereby, the reactive functional group present in the underlayer reacts with the water-soluble resin material,
A hydrophilic resin coating layer is formed on the underlayer.

The hydrophilic resin coating layer thus formed is preferably subjected to a water treatment, whereby a hydrophilic effect is exhibited in a short time. The water treatment is usually performed by immersing the wire substrate on which the hydrophilic resin coating layer is formed in water and then drying.
Here, the immersion treatment temperature is set to a normal temperature to about 60 ° C., and the treatment time is set to about 10 minutes to 2 hours. The drying conditions are from room temperature to about 80 ° C. for about 30 minutes to about 48 hours.

As described above, the extruding tool 10 in which the hydrophilic resin coating layer 20 is formed on the surface of the wire base 11
Is a vascular embolus member 4 in a wet catheter.
0 can proceed smoothly, and this vascular embolus member 4
0 can be reliably pushed out from the distal end opening of the catheter. In addition, as shown in FIG.
May be formed on the surface of the contrast section 12,
It may be formed on the entire region of the pusher including the terminal portion.
Since the hydrophilic resin coating layer is provided on the surface of the contrast portion constituting the distal end portion of the pusher, the ease of insertion into a wet catheter can be further improved.

In the embolus member-extrusion device assembly shown in FIGS. 1 and 2, the tip of the extrusion device 10 (contrast unit 12) is
A coil-shaped vascular embolus member 40 is connected via the connection member 30. The vascular embolization member 40 is a helical secondary coil body formed by further winding a coil formed by winding a wire made of a metal (for example, platinum, gold, tungsten) that can be observed by X-ray projection or the like. It is.
Here, the diameter of the wire is about 0.02 to 0.12 mm. In addition, the primary coil diameter is usually 0.1 to 1.
0 mm, preferably 0.2 to 0.5 mm, and the secondary coil diameter is usually 2 to 40 mm, preferably 2 to 2 mm.
0 mm. A spherical tip 41 is fixed to the distal end of the embolization member 40.

The material of the connecting member 30 interposed between the vascular embolus member 40 and the pusher 10 does not adversely affect the living body,
Any polymer that can be melt-cut by heating may be used. Specifically, a polyvinyl alcohol-based polymer that melts when heated is preferable. The material of the connection member 30 is not limited to this, and for example, a material that is deformed by heating, such as a shape memory alloy or a shape memory resin, can be used. Here, the fixing means between the pushing tool 10 and the connecting member 30 and the fixing means between the connecting member 30 and the vascular embolus member 40 are not particularly limited. For example, fixing by an adhesive, welding, connection by physical force, and the like. , Other means can be used.

The embolic member-extrusion device assembly having the above-described structure is easily inserted into a wet catheter into which physiological saline or blood has flowed, smoothly advances through the catheter, and is inserted into the catheter. The vascular embolus member is reliably pushed out from the distal end opening. Specifically, as shown in FIG.
With the coil-shaped vascular embolus member at the top, the embolic member-extrusion tool assembly is inserted from the hand operation unit 63 into the catheter 62 inserted beforehand so that the distal end opening is located at the target site P of the living body 61. . Thereby, the vascular embolus member,
While being stretched linearly while being pressed by the extruder having excellent lubricating properties, it smoothly advances in the wet state of the catheter 62, and is pushed into the target site P from the distal end opening of the catheter 62. Then, when the connecting member reaches the distal end opening of the catheter 62, the ground electrode 64 is attached to an appropriate skin surface of the living body 61, and the high-frequency power supply device 65 is connected to the terminal portion of the pushing tool. To the extrusion means. As a result, the connecting member interposed between the vascular embolus member and the pusher is heated by the high-frequency current and melts, the connecting member is cut, and the vascular embolus member and the pusher are separated, whereby Placement of the vaso-embolic member is achieved.

As described above, the extruding tool (the extruding tool of the present invention) constituting the embolus member-extrusion tool assembly of the present invention is formed with the hydrophilic resin coating layer exhibiting surface lubricity when wet. Therefore, in a wet catheter into which physiological saline or blood has flowed, the embolic member-extruder assembly has a low frictional resistance, and even if the catheter has a meandering shape, the blood vessel in the catheter is The embolus member can be advanced smoothly. Further, since the embolic member-extruder assembly receives a small frictional resistance, when the embolic member-extruder assembly advances in the catheter, the distal end opening of the catheter is not displaced. The vascular embolus member can be securely placed at a target site.

[0030]

【Example】

<Example 1> Made of stainless steel having a front-end outer diameter (d) of 0.05 mm, a rear-end outer diameter (D) of 0.35 mm, and a total length of 180 cm. A fine metal wire is wound around the front end to form an image. After immersing the wire base on which the part is formed in a mixed solution of 1 part by volume of a THF solution (5%) of a polyurethane resin and 1 part by volume of a MEK solution (2%) of 4,4′-diphenylmethane diisocyanate By drying at 60 ° C. for 1 hour, an underlayer (adhesive layer) was formed on the surface of the wire base and the tip contrast portion. Next, the wire base was placed in a MEK solution (2.5%) of a methyl vinyl ether-maleic anhydride copolymer “GAMTREZ AN-169” (manufactured by GAF, Mw = 1,500,000).
After immersing for 3 minutes at 60 ° C., the wire substrate was dried at 60 ° C. for 30 minutes.
By drying for 4 hours, a hydrophilic resin coating layer was formed on the surface of the wire substrate (excluding the range of 30 cm from the rear end) and the surface of the front contrast portion.
The extrusion tool of the present invention having the structure shown in FIG.

A test piece having a hydrophilic resin coating layer formed thereon (for measuring dynamic friction coefficient) was prepared by treating under the same conditions as described above, and the kinetic friction between the hydrophilic resin coating layer and ETFE was measured in a wet state. When the coefficient was measured using a surface property measuring device “HEIDON 14DR” (manufactured by Shinto Kagaku Co., Ltd.) under the conditions of a load of 200 g and a speed of 300 mm / min, an extremely small value of 0.02 was shown.

Comparative Example 1 A silicone oil "MDX4-4" was applied to the surface of the same wire base as used in Example 1.
159 "(manufactured by Dow Corning Asia Co., Ltd.) to produce a comparative extruder by applying an acetone diluted solution (3%).

<Comparative Example 2> A wire base similar to that used in Example 1 was prepared and used as an extruder for comparison.

<Evaluation of Extruder> (1) Production of Embolus Member-Extruder Assembly: At the tip of each extruder obtained in Example 1 and Comparative Examples 1-2,
0.2 m diameter made of polyvinyl alcohol copolymer
m, a rear end portion of a cylindrical rod-shaped connecting member having a length of 10 mm is bonded with an adhesive, and further, a secondary coil diameter of 8 m formed of a platinum alloy wire is attached to a front end portion of the connecting member.
The rear end portion of the embolization member composed of a secondary coil having a length of 20 cm and a coil length of 20 cm was adhered with an adhesive, thereby producing an embolus member-extrusion device assembly.

(2) Preparation of meandering blood vessel model: tube made of polyvinyl chloride (inner diameter 2.0 mm, length 150 cm)
Was bent in a meandering shape from the one end side opening to the other end side opening so that the bent part to the bent part shown below were continuous to prepare a meandering blood vessel model.

Bending portion: (radius of curvature 20 mm, intersection angle of radius 180 °) Bending portion: (radius of curvature 18 mm, intersection angle of radius 180 °) Bending portion: (radius of curvature 16 mm, intersection angle of radius 180 °) Part: (radius of curvature 14 mm, intersection angle of radius 180 °) ・ Bent part: (radius of curvature 12 mm, intersection angle of radius 180 °) ・ Bent part: (radius of curvature 10 mm, intersection angle of radius 180 °) ・ Bent part: (radius of curvature 8mm, radius intersection angle 180 °) ・ Bend: (curvature radius 6mm, radius intersection angle 180 °)

(3) Evaluation of ease of insertion: In the meandering blood vessel model prepared in the above (2), a microcatheter “Shirasukon Navigator III” manufactured by Kaneka Medix Co., Ltd. (this is referred to as “microcatheter A”) .)
After filling the inside of the microcatheter A with physiological saline, each of the embolic member-extrusion tool assembly manufactured in the above (1) is inserted into the microcatheter A.
The vascular embolus member was inserted from one end side, and the ease of insertion was evaluated. The ease of insertion was also evaluated when blood was filled instead of physiological saline, and the same evaluation was performed using a different type of microcatheter (hereinafter referred to as “microcatheter B”). .

The evaluation criteria are as follows: "O" indicates that the vascular embolus member can be smoothly advanced in the microcatheter and the entire length of the vascular embolus member can be pushed out from the distal end opening of the catheter. The frictional resistance during the advancement of the embolic member is large, and the case where only a part of the vascular embolus member can be pushed out from the distal end opening of the catheter is “△”. The case where the vascular embolus member could not be pushed out from the opening at the distal end of the catheter was evaluated as “x”. The evaluation results are shown in Table 1 below.

[0039]

[Table 1]

[0040]

The extruder according to the present invention has excellent lubricity in a wet state, and can smoothly advance a vascular embolus member in a wet catheter into which physiological saline or blood has flowed. The vascular embolus member can be reliably pushed out to the target site from the distal end opening of the catheter. INDUSTRIAL APPLICABILITY The vascular embolus member-extrusion device assembly of the present invention can be easily inserted into a wet catheter into which physiological saline or blood has flowed, and the vascular embolus member constituting the embolic member can be securely inserted into a target site. Can be detained.

[Brief description of the drawings]

FIG. 1 is an explanatory view showing an example of an embolus member-extrusion device assembly of the present invention.

FIG. 2 is an explanatory view (partial sectional view) showing another example of the embolus member-extrusion device assembly of the present invention.

FIG. 3 is a schematic explanatory view showing a case where the assembly of the present invention is applied to a cerebral aneurysm in a living body.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Extruder 11 Wire base 12 Contrast part 13 Terminal part 20 Hydrophilic resin coating layer 30 Connection member 40 Vascular embolus member 41 Chip 61 Living body 62 Catheter 63 Hand operation part 64 Earth electrode 65 High frequency power supply

Claims (5)

[Claims] 1. A pusher for a vasoembolic member for placing a vasoembolic member at a target site in a vascular system, wherein at least a part of the surface of a wire substrate exhibits surface lubricity when wet. An extruder for a vascular embolus member, comprising a hydrophilic resin coating layer formed thereon. 2. Treating a wire substrate with a solution of a compound having a reactive functional group to form an underlayer in which a reactive functional group is present on at least a part of the surface of the wire substrate. By treating the wire substrate with a solution of a resin material, the reactive functional group reacts with the water-soluble resin material, and is obtained by forming a hydrophilic resin coating layer on the underlayer. The pusher for a vascular embolus member according to claim 1. 3. At least one water-soluble resin selected from the group consisting of cellulose-based polymers, nylon-based polymers, ethylene oxide-based polymers, maleic anhydride-based polymers, acrylamide-based polymers, and derivatives thereof. The device for extruding a vascular embolus member according to claim 2, wherein the device is obtained by treating a wire base with a solution of a material. 4. A vascular embolus member according to any one of claims 1 to 3, and a vascular embolus member connected to a distal end of the embolic member via a connecting member. Embolic member-extrusion assembly. 5. The embolus according to claim 4, wherein the connection member heated by the supply of the high-frequency current is cut off, so that the embolization member and the pusher are separated from each other. Member-extrusion tool assembly.