JPH0546418Y2 - - Google Patents

Description

[Detailed description of the invention] "Industrial application field" This invention is used to temporarily stop the flow of blood in blood vessels, for example, when an aneurysm or varicose vein ruptures or when there is intracerebral hemorrhage. Concerning blood duct obstruction devices.

"Prior Art" For example, when an artery or vein ruptures or when there is intracerebral hemorrhage, it may not be possible to immediately provide treatment due to the amount of bleeding. In such cases, treatment is performed after temporarily stopping the blood flow using a blood duct occluding device.

As such a blood duct occluding device, one is known that is made of a metal coil, and when inserted into a blood vessel, the device tangles randomly to occlude the blood duct. This type of blood duct occluding device can be inserted by simply inserting a guide tube such as a catheter into the blood vessel, inserting the occluding device into the guide tube and pushing it out with a pusher, etc., and can stop the blood flow quickly and reliably. It has the advantage of being able to stop bleeding.

As an example of such a blood duct obturator, one is known in which a metal wire is formed into a coil shape, and the coil is further formed into a randomly entwined state. When inserting such a blood vessel obturator into a blood vessel, the coils, which are formed in a randomly tangled state, are manually pulled into a straight coil, and in this state, the device is inserted into the blood vessel through a guide tube.

In this case, as shown in FIG. 7, the coil 41 is directly inserted into the catheter 21 and the pusher 25
If you try to push it out with
Frictional resistance between the coil 41 and the catheter 21 increases, and the catheter 21 is easily bent, making it difficult to push it out.

Therefore, as shown in FIG. 8, after pulling the bent coil into a straight coil 41, it is inserted into a cylindrical cartridge 23, and this cartridge 23 is inserted into the catheter 21. There is. A stopper 22 is provided on the inner periphery of the distal end of the catheter 21, and a stopper 22 is provided on the inner periphery of the distal end of the catheter 21.
A protrusion 24 is provided on the rear outer periphery of 3.
When the cartridge 23 is inserted into the catheter 21, the protrusion 24 abuts against the stopper 22 and is locked therein. In this state, the pusher 25 pushes the coil 41 inside the cartridge 23 from behind,
It is pushed out into the blood vessel 31. blood vessel 31
The coil (blood duct occluding device) 41 that has been pushed out is
Due to its elastic force, it returns to the randomly entangled state, and as a result, the inside of the blood vessel 31 is occluded and blood flow is temporarily stopped.

"Problem to be solved by the invention" However, even when inserting the coil (blood duct occluding device) 41 using the method shown in FIG. 8, the frictional resistance between the cartridge 23 and the coil 41 is large.
Cartridge 23 must be straight. For this reason, there was a problem that it was difficult to insert it into a curved blood vessel.

Furthermore, if the cartridge 23 is made longer, it becomes even more difficult to insert it, so the length of the coil 41 cannot be made too long. For this reason, even if the coil 41 returns to its shape within the blood vessel, it is difficult to become entangled tightly enough to stop the blood flow, so Dacron fiber or the like is entangled between the pitches of the coil 41 to enhance the occlusion effect. The need arose.

Furthermore, when conventional blood duct occlusion devices are pushed into a blood vessel, they instantly return to their shape in a random tangled state, meaning there is no time to correct the placement of the vascular occlusion device, and insertion errors are likely to occur. There were also problems.

Therefore, an object of the present invention is to provide a blood vascular occlusion device that has good insertability and operability, can be inserted into a catheter without using a guide tube, and has a length sufficient to occlude the blood channel within a blood vessel. The aim is to provide the tools.

"Means for Solving the Problems" In order to achieve the above object, the blood duct obturator of the present invention has a metal wire formed into a coil shape to form a primary coil, and this primary coil further formed into a coil shape. This secondary coil has a tapered metal coil whose coil diameter gradually decreases, and a metal coil inserted inside the primary coil, which has a glass transition point at a temperature lower than body temperature. It is characterized by being made of a shape memory resin wire rod.

The present invention will be explained in more detail below.

In this invention, a metal wire is formed into a coil to form a primary coil, and this coil is further formed into a secondary coil, forming a so-called double coil. In this case, the secondary coil is
The coil diameter gradually decreases to form a tapered shape. The outer diameter of the primary coil is preferably 2 mm or less, so that it can be inserted into a tubular organ such as a blood vessel through a catheter, etc. The outer diameter of the secondary coil is preferably 3 to 8 mm, so that it can fully occlude the blood vessel.
The wire of this coil may be a normal metal wire such as stainless steel, but is more preferably a wire made of a shape memory alloy such as a TiNi alloy.
The wire may be in any shape, such as round, rectangular or flat.

When making a shape memory alloy wire into a coil, after forming it into a double coil by primary forming and secondary forming as described above, it is heated for 400 to 500 minutes while maintaining this shape.
It is possible to memorize its shape by subjecting it to a restrained aging treatment for a predetermined period of time at around ℃, and after deforming it at a low temperature, when the temperature rises above the transformation point,
It is possible to impart the property of returning to the memorized shape. Note that this transformation point is preferably set at a temperature that easily undergoes plastic deformation when working at room temperature, and that when inserted into a blood vessel, it reliably returns to its shape due to body temperature. Preferably, the range is within the range.

The blood duct obturator of the present invention includes a wire made of shape memory resin inserted into the primary coil. The wire made of shape memory resin is preferably a round wire that loosely fits or fits into the inner diameter of the primary coil. In addition, in order to prevent damage to the inside of the tubular organ, the end of the wire made of shape memory resin is
As shown in the embodiments described below, it is preferable to make it protrude from the end of the primary coil and fix it so as to cover the end of the primary coil. Furthermore, the shape memory resin wire protrudes from one end of the primary coil and extends long, and when it returns to its shape, it continues to the end where the diameter of the secondary coil becomes smaller, and its diameter becomes even smaller. Preferably, a spiral is formed.

Generally speaking, shape memory resin is a substance that changes into resin at room temperature and rubber at a temperature slightly above room temperature, and its glass transition point (Tg) is slightly higher than room temperature. At temperatures below the glass transition point, it exhibits the property of plastic deformation like a resin, and when the glass transition temperature is exceeded, it has the property of returning to its memorized shape like a rubber.

Shape memory resins include trinorbornene (manufactured by Nippon Zeon Co., Ltd.), styrene-butadiene copolymer (manufactured by Asahi Kasei Industries, Ltd.), and polyurethane (manufactured by Mitsubishi Heavy Industries, Ltd.).
Among these, those having a glass transition point lower than body temperature can be used in the present invention.

A wire made of shape memory resin has relatively high rigidity and plastic deformation at room temperature, and when placed in a blood vessel, it softens like rubber due to body temperature, so its glass transition point is lower than body temperature. It is preferable to set the temperature to 0 to 20℃, more preferably
It is said that Further, it is more preferable to carry out a memory treatment so that the coil returns to the same shape as a metal coil when it is placed in a blood vessel and exceeds the glass transition point due to body temperature.

"Operation" Shape memory resin deforms plastically like a resin at a temperature lower than the glass transition point, and has high rigidity. On the other hand, when the glass transition temperature is exceeded, the rigidity decreases and the material has the property of returning to its memorized shape like rubber.

In the blood duct obturator of the present invention, a shape memory resin wire rod with a glass transition point lower than body temperature is inserted into the metal coil, so at room temperature, the shape memory resin wire has high rigidity and plasticity. transform. Therefore, at room temperature, the rigidity of the shape memory resin wire can be used to stretch the metal coil.
It can be maintained in a straight-lined shape.
If the shape is maintained in a straight line, the slip resistance will be extremely small when inserted into the catheter, so the obturator can be inserted directly into the catheter and pushed out into the blood vessel, eliminating the need for a guide tube, etc. .

Since the catheter can be bent relatively freely,
Easy to insert into curved areas of blood vessels. Therefore, if the obturator of the present invention is used, the catheter can be freely inserted into a desired location in a bent blood vessel through a catheter, and it can be inserted into a location where the hemostasis effect is highest.

When the obturator of the present invention is inserted into a tubular organ in a linearly extended shape, the rigidity of the wire made of shape memory resin decreases due to body temperature. As a result, the elastic force of the metal coil overcomes the rigidity of the shape memory resin and returns to its original bent state, occluding the inside of the tubular organ and temporarily stopping bleeding.

When the metal coil is made of shape memory alloy,
Due to the shape-returning force and superelasticity of the shape memory alloy, the original randomly entangled state can be easily restored.
Further, if the shape memory resin wire is memorized into a shape similar to the shape when the metal coil is restored, the shape restoring force of the shape memory resin also contributes to the restoration of the coil.

Note that since the shape memory resin wire has low thermal conductivity, even if it is placed inside a tubular organ, the temperature does not rise immediately, and its rigidity decreases and shape recovery is relatively slow. Therefore, there is a certain amount of time lag for the metal coil to restore its bent shape, and there is also the advantage that the position of the obturator can be easily corrected after insertion. This becomes even more effective when a shape memory alloy and a shape memory resin are combined.

That is, FIG. 3 shows the relationship between temperature and load of the shape memory alloy and shape memory resin. In the figure, M indicates the characteristics of the shape memory alloy, and P indicates the characteristics of the shape memory resin. In this way, shape memory alloys have a characteristic that their rigidity is low at low temperatures, and their rigidity increases rapidly when the temperature exceeds the transformation point. Shape memory resins also have a characteristic that they have high rigidity at low temperatures and decrease in rigidity when the temperature exceeds the glass transition point.

FIG. 4 shows the temperature rise over time when a shape memory alloy and a shape memory resin are placed in a certain high temperature atmosphere, for example inside the body. In the figure, M indicates a shape memory alloy, and P indicates a shape memory resin. In this way, since the shape memory alloy and the shape memory resin have different thermal conductivity, the temperature of the shape memory resin increases more slowly even if they are placed at the same temperature.

FIG. 5 shows the load generated when a shape memory alloy and a shape memory resin are combined. In the figure, M+P represents the load generated when a shape memory alloy and shape memory resin are combined, and M represents the load generated when the shape memory alloy is used alone. In this way, in the case of the shape memory alloy alone (M), a load is generated immediately and the shape is restored in an extremely short time _t1 . but,
When a shape memory alloy and a shape memory resin are combined (M+P), a load is generated at time _t2 , which is delayed from time _t1 , and the shape is restored at time _t3 , which is further delayed.

In this way, the time t ₃ required for the shape to recover when shape memory alloy and shape memory resin are combined (M+P) is significantly greater than the time t ₁ when shape memory alloy is used alone (M). I will be late,
Since the blood vessel obturator is maintained in a straight shape during that time, the position can be easily corrected.

"Embodiment" FIGS. 1 and 2 a and 2b show an embodiment of the blood duct obturator according to the present invention.

This obturator 11 has a double coil shape in which a wire 12 made of a shape memory alloy is formed into a primary coil 12a, and this primary coil 12a is further formed into a secondary coil 12b. However, the secondary coil 12b is formed in a tapered shape such that the coil diameter gradually decreases. The diameter of the primary coil 12a is such that it can be easily inserted into a catheter or the like described later, and the diameter of the secondary coil 12b is such that it can effectively occlude the inside of a tubular organ. Specifically, the diameter of the primary coil 12a is 2 mm or less, and the diameter of the secondary coil is 3 to 8 mm.
Preferably, it is about mm. Then, the wire rod 12 formed into a coil shape is subjected to a shape memory treatment by being subjected to a restraint aging treatment at approximately 400 to 500° C. for a predetermined time while maintaining this shape. In addition, the transformation point is a temperature lower than body temperature, preferably 0 to 20
It is said to be around ℃.

Furthermore, as shown in FIG. 2a, the inside of the primary coil 12a made of the above-mentioned coiled wire 12 is made of a shape memory resin having a glass transition temperature lower than body temperature, preferably about 0 to 20°C. Wire rod 13
is inserted. In this embodiment, the wire 13 is a round wire that fits the inner diameter of the primary coil 12a. Then, as shown in FIG. 2b, the wire rod 13
Both ends of the coil protrude from the end of the primary coil 12a and cover the end of the coil 12a. Thereby, the wire 13 is fixed to the coil 12a, and the end portion of the coil 12a can prevent tissue inside the tubular organ from being damaged. Note that it is preferable that the wire rod 13 made of a shape memory resin is heated in the above state to a temperature above the glass transition point and cooled as it is, so that it is memorized into a helical shape that follows the shape of the secondary coil 12b.

FIG. 6 shows a method of occluding the blood vessel 31 using the blood vessel occluding device 11 of the present invention shown in FIG.

The catheter 21 is inserted into a predetermined location of the blood vessel 31 by a known working means, the blood path occlusion device 11 is inserted into the catheter 21, and the blood path occlusion device 11 is pushed out of the catheter 21 by the pusher 25. In this case, since the blood path obturator 11 is in an atmosphere at room temperature before being inserted into the catheter 21, the wire 13 made of shape memory resin is plastically deformed with relatively strong rigidity. For this purpose, the secondary coil 12b shown in FIG. 1 is stretched so that only the primary coil 12a extends linearly, and the linear shape is maintained by the rigidity of the wire rod 13 made of shape memory resin. be able to. Therefore, the blood path occlusion device 11 is brought into a straight state to reduce sliding resistance, and can be directly inserted into the catheter 21 and pushed out into the blood vessel.

When the blood vessel obturator 11 is pushed out into the blood vessel 31 by the pusher 25, the wire rod 13 made of shape memory resin gradually heats up, its rigidity gradually weakens, and it tries to return to the pre-memorized shape. . Further, the coiled wire 12 made of a shape memory alloy tends to return to the shape shown in FIG. 1 due to shape restoring force due to reverse transformation and/or superelasticity. Therefore, the blood path obturator 11 is restored to the shape shown in FIG. 1, and can effectively occlude the inside of the tubular organ.

When inserting the blood duct occluding device 11, it is made straight as described above to reduce slipping resistance, and can be inserted directly through the catheter without using a straight cartridge, so even a relatively long one can be inserted. The shape when the secondary coil 12b is formed can be made dense, and the hemostasis effect can be enhanced. However, the hemostatic effect may be further improved by intertwining Dacron fiber or the like between the pitches of the coiled wire 12.

Furthermore, for the reasons mentioned above, the shape of the blood occlusion device 11 after being pushed out into the blood vessel 31 is relatively slow to return to its original shape. , the position of the blood vessel obturator 11 can be determined accurately.

FIGS. 9 and 10 show still another embodiment of the blood duct occluding device according to the present invention.

As shown in FIG. 9, in this embodiment, the end 13a of the wire 13 made of shape memory resin protrudes from the end of the primary coil 12a. The length a of this protruding portion is preferably 10 to 20 mm. Then, as shown in FIG. 10, when the shape is restored and the secondary coil 12b is formed, the end 13a of the wire 13 is continuous with the end of the secondary coil 12b where the diameter becomes smaller. , the shape is memorized to form a spiral shape whose diameter becomes smaller.

In this way, by elongating one end 13a of the shape memory resin wire 13 and forming an even smaller spiral, the gap in the center of the secondary coil 12b can be eliminated, thereby further enhancing the blood duct occlusion effect. . In addition, if an attempt is made to further reduce the coil diameter at the center of the secondary coil 12b to completely block the secondary coil 12b using a metal coil, the coil pitch of the primary coil 12a will be widened and a gap will be created.

"Effects of the Invention" As explained above, according to the blood duct obturator of the present invention, since the shape memory resin wire is inserted inside the metal coil, the shape memory resin wire maintains a straight shape at room temperature due to its rigidity. can be maintained,
Frictional resistance when inserted into a blood vessel through a catheter or the like can be reduced. Therefore, it can be easily inserted into bent and narrow blood vessels without requiring an auxiliary tool such as a cartridge. When inserted into a blood vessel, the rigidity of the shape memory resin wire is weakened, and the metal coil returns to its bent shape, allowing the blood vessel to be effectively occluded. Further, the length of the entire coil can be made sufficiently long so that the density of the coil becomes high when the metal coil returns to its shape. Furthermore, since the thermal conductivity of shape memory resin is low, it is possible to slowly restore the shape after it has been placed inside a blood vessel, and during this time the blood duct obstruction device can be inserted while checking its position with an endoscope, etc. The position of can be corrected.

[Brief explanation of the drawing]

Fig. 1 is a perspective view of the blood duct obturator of the present invention, Fig. 2a is a partial cross-sectional view of the intermediate portion showing a shape memory resin wire inserted into a coil-shaped shape memory alloy wire; b is a partial sectional view of the tip of the shape memory resin wire inserted into the coil-shaped shape memory alloy wire, and Figure 3 shows the relationship between the temperature and load of the shape memory alloy and shape memory resin. Figure 4 shows the temperature rise over time when a shape memory alloy and shape memory resin are placed in a predetermined temperature atmosphere, and Figure 5 shows the temperature rise when a shape memory alloy and shape memory resin are combined. Figure 6 is a diagram showing the load over time, Figure 6 is a diagram showing a method for occluding the inside of a blood vessel using the blood vessel occlusion device of the present invention, and Figure 7 is a diagram showing the state when a conventional blood vessel occlusion device is inserted into a catheter. Fig. 8 is a diagram showing a method of occluding the inside of a blood vessel using a conventional blood duct occluding device, and Fig. 9 is a partial sectional view showing another embodiment of the vascular occluding device of the present invention.
FIG. 0 is a front view of the blood duct obturator. In the figure, 11 is a blood path obturator, 12 is a wire made of a shape memory alloy, 12a is a primary coil, 12b is a secondary coil, 13 is a shape memory resin wire, 13a is an end, 21 is a catheter, 25 is a pusher, 3
1 is a blood vessel.

Claims (1)

[Claims for Utility Model Registration] (1) A metal wire is formed into a coil shape to form a primary coil, this primary coil is further formed into a coil form to form a secondary coil, and this secondary coil has a coil diameter. It is characterized by comprising a metal coil having a tapered shape such that the temperature gradually decreases, and a wire rod made of a shape memory resin having a glass transition point lower than body temperature, which is inserted inside the primary coil. Blood duct obturator. (2) The blood duct obturator according to claim 1, wherein the metal coil is made of a shape memory alloy having a transformation point lower than body temperature. (3) The blood duct occlusion device according to claim 1 or 2, wherein the wire of the shape memory resin is memorized into a shape that follows the shape of the metal coil. (4) The blood duct obturator according to any one of claims 1 to 3, wherein the shape memory resin wire protrudes from an end of the primary coil and covers the end of the primary coil. (5) The shape memory resin wire protrudes from one end of the primary coil and extends long, and when it returns to its shape, continues to the end of the secondary coil where the diameter becomes smaller, and further extends. The blood duct obturator according to any one of claims 1 to 4, which forms a spiral whose diameter becomes smaller.