JPH09131348A - Blood vessel obliteration therapeutic/cancer therapeutic device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To sharply shorten the time required for dissolving a thrombus and open a clogged blood vessel in a short time by providing a bubble feeding device sticking bubbles to the thrombus and a shock wave generating device applying shock waves to the bubbles stuck to the thrombus. SOLUTION: This device used for the therapy of blood vessel obliteration caused by a thrombus or an embolus generated from an organism (referred to as the thrombus hereafter) such as cerebral embolism or the therapy of cancer is constituted of a bubble feeding device sticking bubbles to the thrombus and a shock wave generating device applying shock waves to the bubbles stuck to the thrombus. The thrombus is pierced and broken by a liquid jet formed when the bubbles interfere with the shock waves and are broken, or the area of the thrombus kept in contact with a thrombus dissolving agent is increased. A device having a micro-pump is used for the bubble feeding device, and an underwater spark discharge type shock wave generating device or a shock wave generating device via the light convergence of a laser is used for the shock wave generating device.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention is used for treatment of vascular embolism such as cerebral embolism due to thrombus or embolus generated from a living body (hereinafter simply referred to as thrombus), and also used for cancer treatment. Related to devices that can

[0002]

2. Description of the Related Art When a blood vessel is occluded by an embolus or the like and blood circulation is obstructed, the tissue to which blood is fed becomes deficient in nutrients and oxygen, and the tissue is necrotic. When cerebral embolism occurs because a blood clot in the brain suddenly occludes a blood vessel in the brain, compared to thrombotic occlusion due to arteriosclerosis, the development of the accessory blood circulation is poorer, and a serious and widespread ischemic lesion occurs Formed and brain tissue is prone to necrosis.

There are surgical treatments and medical treatments for the treatment of blood vessel blockages such as cerebral embolism and myocardial infarction, and thrombolytic agents such as TPA and urokinase are generally used for medical treatments. On the other hand, as a method of treating cancer, physical therapy such as radiation therapy is used in addition to surgical therapy and medical therapy.

[0004]

SUMMARY OF THE INVENTION In order to prevent necrosis of living tissues to which the blood is sent due to blood vessel obstruction,
There is an urgent need to rebuild the blood flow in the blocked blood vessels. Especially cerebral infarction and myocardial infarction are urgent tasks. In order to reconstruct the blood circulation of the blood vessel blocked by medical therapy, it is desirable to penetrate and crush the thrombus etc. to remove the thrombus etc. When using a thrombolytic agent, once the thrombus begins to dissolve Since the area of the thrombus portion in contact with the dissolving agent is accelerated, the dissolution is accelerated, and therefore, in order to quickly eliminate the blockage of the blood vessel, a treatment method such as increasing the area of the thrombus portion in contact with the dissolving agent Is desired.

The present invention has been made in view of the above points, and a first object thereof is to penetrate a thrombus or the like which blocks a blood vessel,
An object of the present invention is to provide a device for increasing the area of thrombus or the like that is crushed or comes into contact with a lysing agent. On the other hand, the radiation treatment used for cancer treatment is to irradiate the cancer tissue with radiation to cause necrosis of the cancer tissue. Living tissue is also easily necrotic.

When the anticancer drug is administered by medical therapy, it is desirable to increase the area of the cancer tissue in contact with the anticancer drug in order to increase the efficacy of the anticancer drug. A second object of the present invention is to provide a device which enhances the efficacy of an anticancer agent and can selectively treat a limited cancer occurrence site, for example, a gastric inner wall polyp or a tumor site in the brain. It is a thing.

[0007]

A device for achieving the first object comprises a bubble supply device for adhering bubbles to a thrombus or the like and a shock wave generator for applying a shock wave to the bubbles adhering to the thrombus or the like. A liquid jet formed when air bubbles interfere with a shock wave and collapses penetrates or crushes thrombus or the like, or mechanically increases the area of the thrombus or the like in contact with the thrombolytic agent due to penetration.

The present device can be generally used for cerebral embolism, myocardial infarction and other vascular occlusion due to thrombosis. A device for achieving the second object comprises a bubble supply device for adhering bubbles to the cancer tissue and a shock wave generator for imparting a shock wave to the bubbles adhering to the cancer tissue. The bubbles interfere with the shock waves. It is intended to penetrate the cancer tissue with a liquid jet formed when it collapses and destroy the cancer tissue, and mechanically increase the area of the cancer tissue in contact with the anticancer agent.

The air bubble supplying device used in each of the above-mentioned devices comprises, for example, a catheter that is passed through a blood vessel or an organ and a drop connected to the end of the catheter. A device that uses a micropump instead of the device and the spoid,
It is possible to use a device that consists of a syringe and directly attaches air bubbles to the thrombus or cancer tissue by piercing the blood vessel or organ with an injection needle. Among these, a certain size of air bubble is supplied to the thrombus or cancer tissue. What consists of a catheter and a micropump that can be done is desirable.

As the shock wave generator, for example, an underwater spark discharge type shock wave generator, a shock wave generator by condensing a laser, a shock wave generator using a piezo element, an electromagnetic drive type shock wave generator, and a micro explosive are used. A shock wave generator or the like can be used.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION The present inventors pay attention to the mutual interference between an underwater shock wave and a bubble and focus on a thrombus or the like of a liquid jet or a cancer tissue which is formed when the bubble interferes with the underwater shock wave and collapses. Aiming to develop a therapeutic method using penetration, gelatin, which has an acoustic impedance almost equal to that of blood, blood vessels, living tissues, etc., and is considered to be close to a thrombus, is used. The interference and the interference of air bubbles attached to gelatin injected into a Teflon tube used as a blood vessel simulating material and shock waves in water were investigated.

FIG. 1 shows an experimental apparatus used for this investigation. A pressure transducer meter 2 (natural frequency 10 MHz) manufactured by Imotech is provided on one side of a water tank 1 filled with water.
On the horizontal extension, a silver azide pellet 3 (10 mg) manufactured by Chugoku Kayaku Co., Ltd. is set as a shock wave source at a position apart from the pressure transducer 2 by L = 50 mm. And the detonation is Y
0.4 mm inside diameter from the laser light emitted from the AG laser light source 4
The silver azide pellet 3, the YAG laser light source 4, the glass fiber 5 and the like constitute a shock wave generator. 6 is a diffuser.

The experiment was carried out by using the gelatin (1
A 10% by weight aqueous solution was poured into a Teflon tube 7 having an inner diameter of 2 mm, an outer diameter of 3 mm and an inner diameter of 3.9 mm, and an outer diameter of 6 mm, and cooled slowly. After solidification, the Teflon tube 7 was immersed vertically in water, and one bubble 13 (radius of curvature 2r) was attached to the gelatin interface using a commercially available syringe as a bubble supply device.
Next, at the open end of the Teflon tube 7, a Mylar film (material: polyethylene terephthalate, thickness: 25 μm) was attached and sealed to prevent entrapment of liquid particles when a shock wave was generated. The test was repeated such that the silver azide pellets 3 were set right above the silver azide pellets 3 at a distance of L = 50 mm and the silver azide pellets 3 were detonated. And the appearance of the bubble collapse in each test flash time 4
John Hadland with Xe Flash 9 of 00 μs as light source
An image was taken by a transmission method through an observation window 11 using an image converter camera 10 (Model 790) manufactured by the company, and the maximum penetration depth 1 of the jet advancing inside the gelatin was measured.
The change over time in the penetration depth of the jet when the size of the bubbles is constant is shown by a black circle in FIG. 2 in which the vertical axis represents the jet penetration depth 1 and the horizontal axis represents time. Further, the relationship between the bubble size and the penetration depth of the jet is represented by the ratio of the maximum penetration depth 1 of the jet to the bubble curvature diameter 2r on the vertical axis, and the bubble curvature diameter and the tube inner diameter D on the horizontal axis.
It is shown by a black circle in FIG. 3 in which the ratio with i is taken.

The water temperature during the test was 291 K, and the atmospheric pressure was 101.5 KPa. The working pressure on the bubbles at each test was 10 when measured with the pressure converter 2 equidistant from the shock wave source. It was 0.3 ± 0.7 MPa. As can be seen from FIG. 3, the maximum penetration depth of the jet decreases slowly with increasing radius of curvature of the bubble. From other experiments, it was found that in order to effectively generate a liquid jet in a tube, the shock wave source should be set so that the bubbles can be accurately penetrated along the central axis of the tube. Further, in order to see the influence of the separation distance between the bubble and the shock wave generation source on the maximum penetration depth l of the jet, the distance H between the gelatin interface and the tube opening end is used as a parameter, and in advance for each H value, The L value of each was determined so that the acting pressure on the bubbles was constant, and the test of detonating the silver azide pellets 3 was repeated for each H value. The relationship between the separation distance between the bubble and the shock wave source and the penetration depth of the jet is shown by the ratio of the maximum penetration depth 1 of the jet to the bubble curvature diameter 2r on the vertical axis, and the distance H between the gelatin interface and the tube opening end on the horizontal axis. FIG. 4 is a graph showing the ratio of the bubble diameter to the bubble curvature diameter. As can be seen from FIG. 4, it was found that the separation distance between the bubble and the shock wave source should be about 5 times the bubble curvature diameter. Next, a gelatin wall was made from the above-mentioned gelatin, replaced with a Teflon tube, and immersed in water. The distance between the silver azide pellets and the bubbles was 50.
It was set to be mm. Then, in the same manner as above, after one bubble was attached to the gelatin wall with a syringe, the silver azide pellet 3 was detonated, and the maximum penetration depth 1 of the jet propagating inside the gelatin was measured. The change with time in the penetration depth of the jet is shown by a circle in FIG. Also, the results of examining the relationship between bubble size and jet penetration depth are shown by circles in FIG. In the case of bubbles attached to the flat wall, the length of the gelatin wall was 10 mm as Di.

In the case of a flat wall, as shown in FIG. 2, the liquid jet velocity is faster but its duration is shorter than that of a tube. The jet velocity at this time was calculated as V = 280 m / s from the slope of the plot, and the water hammer pressure P at that time was calculated.
Is from P = 1 / 2ρcv (ρ = density of water, 1000 Kg / m
³ , sound velocity in water, 1500m / s), P = 210MPa,
The jet duration was 0.6 μs. FIG.
Although the maximum penetration depth of the jet was smaller than that of the pipe as shown in Fig. 5, a sufficient penetration depth was obtained to damage the living tissue.

[0016]

The present invention is configured as described above and has the following effects. According to the apparatus of claim 1, the wet area of the thrombus or the like that forms a liquid jet and penetrates or crushes the thrombus or contacts with the lysing agent can be mechanically increased. The required time can be greatly shortened to reopen an occluded blood vessel in a short time, and thus it is suitable for treatment of urgent cerebral embolism and myocardial infarction.

Similarly, in the device according to the second aspect, the liquid jet can be selectively penetrated into the cancer tissue to damage the cancer tissue, and the area of the tissue in contact with the anticancer agent is mechanically increased. Therefore, the efficacy of anti-cancer drugs will increase.

[Brief description of the drawings]

FIG. 1 is a sectional view showing an experimental apparatus used for verifying the present invention.

FIG. 2 is a view showing a change over time in the penetration depth of a jet.

FIG. 3 is a diagram showing a relationship between bubble size and jet penetration depth.

FIG. 4 is a view showing a relationship between a separation distance between a bubble and a shock wave generation source and a penetration depth of a jet.

[Explanation of symbols]

1. ・ Water tank 2 ・ ・ Pressure transducer total 3 ・ ・ Silver azide pellets 4 ・ ・ YAG
Laser light source 5 · Glass fiber 6 · Diffuser 7 · Teflon tube 8 · Gelatin 9 · · Xe flash 10 · · Image converter camera 11 · · Observation window 13 · · Bubbles 14 · · Film

Claims (2)

[Claims] 1. A device for treating occlusion of a blood vessel, which comprises a bubble supply device for attaching bubbles to a thrombus or the like and a shock wave generator for applying a shock wave to the bubbles attached to the thrombus or the like. 2. A device for cancer treatment, comprising a bubble supply device for attaching bubbles to the cancer tissue and a shock wave generator for applying a shock wave to the bubbles attached to the cancer tissue.