JP2555393B2 - Stenosis vessel treatment tool - Google Patents

Description

TECHNICAL FIELD The present invention relates to a treatment device for stenosed blood vessels.

(B) Conventional technology Conventionally, when thrombus is formed inside the coronary artery and causes a so-called angina symptom, as a treatment method therefor, other than the method of pouring a drug that dissolves the thrombus to remove the thrombus. Insert the balloon provided at the tip of the catheter into the coronary artery,
Attention has been focused on a treatment method for expanding a thrombosed artery by expanding it by a required means. Then, a method of inserting a spiral shape memory alloy into the inside of the blood vessel is considered so that the blood vessel expanded by using the balloon does not shrink again.

(C) Problems to be Solved by the Invention However, when a spiral shape memory alloy is inserted into a blood vessel expanded by a balloon, the tip of the metal wire of the spiral shape memory alloy is sharp. Therefore, there is a risk of damaging the inner wall of the blood vessel.Because of the spiral shape, the distance between the lines is large, and the effect of expanding the inner wall of the blood vessel is not sufficient. In addition, it has a drawback that it is a metal, and it is heavy in weight, and it is easy to put a burden on blood vessels, and the treatment process is difficult. Furthermore, before inserting the spiral shape memory alloy into the blood vessel, a balloon catheter must be inserted into the blood vessel for the purpose of dilating the blood vessel and the balloon must be inflated.
Therefore, since the two operations of inserting the shape memory alloy after the inflation balloon is deflated and the catheter is sewn are involved, the work process is complicated and the treatment time is long.

(D) Means for Solving the Problems The present invention provides a balloon at the distal end of a catheter so that the balloon can be inflated and deflated, and a substantially tubular stent can be detachably mounted at a required position of the catheter. The material of
It is intended to provide a treatment tool for a stenotic blood vessel which is made of a shape memory resin which is restored to a memorized shape by heating and which can be heated by a required means.

(E) Operation In the present invention, the treatment device for a stenotic blood vessel of the present invention is inserted into a blood vessel in which a thrombus has been formed by a required means.
Before that, a tubular stent having a shape memorized to have a diameter substantially the same as the inner peripheral surface of the blood vessel is formed in a reduced diameter and mounted on a required position of the catheter, and the stent is not heated.
Then, the balloon at the tip portion of the catheter is positioned at the thrombus portion, and then the balloon is inflated by necessary means to expand the inner peripheral surface of the blood vessel at the thrombus portion. Next, the balloon is contracted by a required means, and the catheter is moved to position the stent on the expanded blood vessel portion.

Then, the stent is heated by a heater or other required means, the tubular stent is restored to a memory shape and expanded, and the stent is fitted to the inner peripheral surface of the blood vessel so that the stent can be removed from the therapeutic device. Next, the expanded stent is left, and the catheter is pulled out together with the balloon from the blood vessel, so that only the stent remains in the blood vessel and the stent is fitted to the inner peripheral surface of the blood vessel expanded by the balloon. .

(F) Effect According to the present invention, the tubular stent is made of a shape memory resin that is restored to the original memory shape by the heating of the required means, and moreover, the substantially tubular stent is removed from the catheter beforehand. Since it is removably attached, it has the effect of being able to complete all the treatments when the blood vessel is expanded and the stent is attached, and the treatment time can be shortened by inserting the catheter once.
Since it is a substantially cylindrical stent, the stent adheres to the inner peripheral surface of the expanded blood vessel, and a reliable thrombosis treatment effect can be expected,
In addition, since the material of the stent is synthetic resin, it is lightweight and easy to process and can be configured into various substantially cylindrical shapes to further improve the therapeutic effect. Further, heating is used as a means for restoring the stent to the memory shape of vasodilation. Therefore, there is an effect that the stent can be closely fitted to the inner peripheral surface of the blood vessel without difficulty.

(G) Example To explain the example of the present invention in detail with reference to the drawings, FIG. 1 (A) shows a treatment device for a stenotic blood vessel according to the present invention, which is configured as follows. That is, a balloon (2) is provided at the distal end of the catheter (1) so as to be expandable and contractible, and a stent (4) described later is heated on the catheter peripheral surface located in the front part as a vicinity of the balloon (2). A heater (3) used as a required means for is installed.

The heater (3) has a mechanism in which a nichrome wire generates heat due to electric resistance.

A tubular stent (4) is attached to the outer circumference of the heater (3) at a position where the thermal effect of the heater (3) is exerted.

As a method of heating the stent by the required means,
In addition to the heater, there is a method of heating a heated fluid by directly or indirectly acting on the stent.

The stent (4) is formed in a net-like tubular body, and is made of a shape memory resin that restores to a memory shape by heating. As the memory shape, a blood vessel of a thrombus is expanded. It has a cylindrical shape with an outer diameter substantially the same as the inner diameter.

The stent (4) may have various mesh shapes other than the ordinary mesh-like tubular shape, and as shown in FIG. 3, the peripheral surface is substantially C-shaped with a part notched in the longitudinal direction. It can also be in the form of. It is also possible to make a spirally wound sheet-like one, and it is also possible to give a perforated shape to the tubular body instead of the mesh, and in a substantially tubular stent,
Includes all of these stent structures.

Therefore, the stent (4) can be closely fitted to the inner peripheral surface of the blood vessel expanded by the balloon (2) by being heated by the heater (3) and other required means.

(5) is a guide wire provided at the tip of the catheter (1), that is, at the tip of the balloon (2), (6) is an electric wire connected to the heater (3), (8) is a blood vessel, and (M) is a thrombus. Indicates.

The embodiment of the present invention is configured as described above, and at the time of use, the stenosis vessel treatment tool (A) of the present invention is inserted into the blood vessel (B) by a predetermined means and pushed to the thrombus (M) portion. To go. Then, when the balloon (2) is located at the thrombus (M) portion, required means, for example, physiological saline is supplied to inflate the balloon (2) and expand the blood vessel (B) for thrombus formation. Next, the balloon (2) is contracted by removing the physiological saline, and the catheter (1) is further moved, and the stent (4) is placed on the portion of the blood vessel (B) that has been expanded.
Is positioned and the heater (3) is energized in this state to heat the stent (4). As described above, the heating method may be a method other than the heater (3), for example, a method of supplying heated saline, or a method of heating from outside the human body.

The stent (4) is restored to its original memory shape by heating, and is closely fitted to the inner peripheral surface of the expanded blood vessel (B) to form a blood vessel (3) in which a thrombus (M) is generated in a normal inner diameter state. Can be held at.

The catheter (1) and the deflated balloon (2) are pulled out from the hollow portion of the stent (4) having a large diameter by heating and removed from the blood vessel.

By making the catheter (1) a net-like substantially tubular body,
The inner peripheral surface of the blood vessel (B) is easy to be fitted, and the inner diameter of the blood vessel can be surely maintained while being intimately contacted and expanded.

[Brief description of drawings]

FIG. 1 is an explanatory view of a treatment device for a stenotic blood vessel according to the present invention. FIG. 2 is an explanatory view showing (1), (2), (3), and (4) processes in use. FIG. 3 is an explanatory view showing an embodiment of a stent. (1): Catheter (2): Balloon (3): Stent

Continuation of the front page (56) Reference JP-A-1-94837 (JP, A) JP-A 64-83251 (JP, A) JP-A 62-231657 (JP, A) JP-A 62-82976 (JP , A) Japanese Patent Sho 61-6655 (JP, B2)

Claims (1)

(57) [Claims] 1. A balloon (2) is provided at the distal end of a catheter (1) so as to be expandable and contractible, and a substantially tubular stent (4) is detachably mounted at a required position of the catheter (1), A therapeutic device for a stenotic blood vessel, wherein the material of the stent (4) is a shape memory resin that restores to a memorized shape by heating, and the stent (4) can be heated by a required means.