JPS6282976A - Tubular organ dilator - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a medical device used to dilate a stenosis formed in a hollow organ such as a blood vessel or trachea.

[Prior Art] As is well known, living bodies are composed of many hollow organs such as blood vessels and tracheas, and lesions such as stenosis often occur in these organs, and many diseases are caused by this. It is provided. Traditionally, surgical treatment has been used to treat stenosis.

[Problems to be Solved by the Invention] Since surgery is highly invasive to patients, the risk of some diseases is high, and there are cases where surgery cannot be performed or patients do not recover even after surgery.

An object of the present invention is to provide an instrument that can easily treat stenosis of a hollow organ without surgery.

[Means for Solving the Problems] The present invention provides a luminal organ expansion device in which a coil formed by spirally winding a shape memory alloy is deformed and reduced in diameter at a temperature below the transformation temperature of the shape memory alloy. It is.

The shape memory alloy used in the present invention is an alloy that has the property of restoring its shape before deformation when heated above the transformation temperature even if it is deformed below the transformation temperature.
More than 10 types are known, such as i-Ti alloys and copper alloys. Among them, Ni-Ti alloys are preferably used.

[Function] The instrument of the present invention is used as follows. That is,
Select the instrument of the present invention whose outer diameter when restored to a coil is approximately the same as or slightly larger than the inner diameter of the hollow organ, and insert it into the hollow organ using a catheter or the like while maintaining it below the transformation temperature. The narrowed portion is heated above the transformation temperature to restore the coil shape. This dilates the stenosis and restores it to its normal state.

Since it is difficult to insert a coil as it is into a hollow organ, in the present invention, a coil with a reduced diameter is inserted by deforming the coil. As for the mode of deformation, it is easy and preferable to stretch it in a straight line, but it may be deformed into other forms. Shape memory alloys have the property of becoming relatively soft at temperatures below their transformation temperature, so they can be easily deformed.

In the present invention, it is preferable to use body temperature to heat the shape memory alloy to a temperature higher than its transformation temperature.

In other words, if we use a shape memory alloy whose transformation temperature is slightly lower than 37°C, insert it into an organ while cooling it in a catheter, and take it out from the catheter at the narrowed area, the transformation temperature will automatically change due to body temperature. Since the coil is heated to a higher level, it is restored to its original state. Therefore, the transformation temperature of the shape memory alloy is preferably slightly lower than 37°C. When the transformation temperature is higher than 37° C., heating is performed by high frequency induction heating or contact with warm physiological saline.

[Example] Hereinafter, the present invention will be explained in more detail with reference to the drawings.

FIG. 1 is a perspective view of a helically wound coil made of a shape memory alloy. In one example of the luminal organ expansion device of the present invention, this coil is stretched in a straight line as shown in FIG. When stretched in this way, the diameter becomes smaller than that of a coil, so it can be easily inserted into small hollow organs.

FIG. 3 is a diagram showing a procedure for dilating a stenotic region using the luminal organ dilating device 1 of the present invention. First, the instrument 1 of the present invention, which has been stretched in a straight line to reduce its diameter, is inserted into the catheter 2, held with grasping forceps (not shown), and then inserted into the vicinity of the constricted part 4 of the hollow organ 3. Figure 3A). At this time, physiological saline (in the case of blood vessels) or air (in the case of the trachea) at a temperature lower than the transformation temperature of the shape memory alloy is continuously injected into the catheter to prevent transformation from occurring. Next, the device 1 is pushed out of the catheter and positioned at the stenosis 4 (FIG. 3B). The device 1 is heated by body temperature and undergoes metamorphosis, restoring to its original coil shape and at the same time pushing and widening the stenosis (Fig. 3C).

In the example described above, the coil is stretched linearly, but it may be deformed into other shapes (for example, a coil with a smaller diameter). The point is to make the diameter small so that it can be easily inserted into a hollow organ.

The device of the present invention may use the shape memory alloy as is, or the surface may be coated with a flexible material. Examples of flexible materials used at this time include woven or knitted fabrics made of polyester fibers, porous polytetrafluoroethylene membranes, and coatings of silicone, polyurethane, and poly(meth)acrylate esters. Since these materials have excellent blood compatibility or tissue compatibility, they can be left in the endoluminal device for a long period of time. Also, to prevent blood clotting,
It is also possible to use a blood anticoagulant such as heparin or urokinase applied to the surface of the shape memory alloy or the surface of the coating material.

[Effects of the Invention] By using the luminal organ dilation device of the present invention, it is possible to dilate a stenotic region without surgery, which is less invasive to the patient and is preferable as a treatment method. And the equipment is
Since the diameter is reduced before use, it is easy to insert into a hollow organ. After insertion, it is possible to restore the coil shape and dilate the stenotic region by simply heating it above the transition temperature. In particular, the transition temperature of shape memory alloy is 37
If you choose a temperature slightly lower than ℃, it will be heated by body temperature and transition will occur automatically, making it extremely convenient to use.

[Brief explanation of drawings]

FIG. 1 is a perspective view of a helically wound coil made of a shape memory alloy. FIG. 2 is a front view of one embodiment of the luminal organ expansion device of the present invention, in which the coil shown in FIG. 1 is stretched linearly. Furthermore, FIG. 3 is a partial cross-sectional view showing a procedure for dilating a stenotic region using the luminal organ dilating device of the present invention. 1. Luminal organ expansion device 2. Catheter 2, luminal organ 4. stricture

Claims (8)

[Claims] (1) A coil made of a shape memory alloy spirally wound,
A luminal organ expansion device characterized by being deformed and reduced in diameter at a temperature below the transformation temperature of a shape memory alloy. (2) The luminal organ expansion device according to claim 1, which is formed by stretching a coil linearly to reduce its diameter. (3) The luminal organ expansion device according to claim 1 or 2, wherein the transformation temperature of the shape memory alloy is slightly lower than 37°C. (4) The luminal organ expansion device according to claim 1 or 2, wherein the surface of the shape memory alloy is coated with a flexible material. (5) The luminal organ expansion device according to claim 4, wherein the flexible material is a polyester woven fabric or a knitted fabric. (6) The luminal organ expansion device according to claim 4, wherein the flexible material is a porous polytetrafluoroethylene membrane. (7) The luminal organ expansion device according to claim 4, wherein the flexible material is a coating of silicone, polyurethane, or poly(meth)acrylate. (8) The luminal organ expansion device according to any one of claims 1 to 7, which has a surface coated with a blood anticoagulant.