JP4388180B2 - Laser fiber guide catheter - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a laser fiber guide catheter suitably used for PDT (Photodynamic Therapy) after PTCA (percutaneous angioplasty), for example.
[0002]
[Prior Art and Problems to be Solved by the Invention]
Twenty years have passed since the start of PTCA (percutaneous angioplasty), but the phenomenon of vascular restenosis is the biggest problem. Possible causes of vascular restenosis after PTCA are remodeling and neointimal proliferation mainly composed of smooth muscle cells. RePTCA and stent placement have been established as effective treatments for remodeling, but as a method for preventing restenosis after stent placement, only neointimal proliferating cells (media cells) can be selectively killed. I know it would be good.
Conventional radiotherapy has been reported as a treatment method for vascular restenosis.
(1) Intracoronary radiation therapy using γ-ray A method in which a ¹⁹² Ir wire as a γ-ray source is inserted and fixed in a stenosis portion of a blood vessel and irradiated with 20 to 25 Gy.
(2) Intracoronary radiation therapy using β rays (A) A method of performing 4 Gy radiation irradiation by inserting and fixing a 90 Y (90Sr / Y) wire of a β ray source into a stenosis portion of a blood vessel.
(B) A method in which ³⁰ P of β-ray source is attached to a PS stent, and the PS stent is inserted and fixed in a stenosis portion of a blood vessel to perform irradiation.
(C) A method in which a liquid containing ¹⁸⁸ Re as a β-ray source is injected into a PTCA balloon, and the balloon is inserted and fixed in a stenosis of a blood vessel to perform radiation irradiation.
However, the above-mentioned radiotherapy method (a) causes restenosis of blood vessels even after radiotherapy, and is not fully satisfactory for prevention of restenosis after PTCA.
(B) In addition, gamma rays are likely to cause exposure to other organs of the patient and medical staff.
(C) Furthermore, the problem of the optimum dose for both γ and β rays has not been solved.
There were problems such as. Therefore, as a result of intensive studies to solve the above problems, the present inventors have reached the following invention.
[0003]
[Means for Solving the Problems]
[1] The present invention has a lumen (4) into which a laser fiber (LF) can be inserted at least inside the shaft (2),
The shaft (2) is made of a laser transmissive material,
The shaft (2) forms a stopper (3) of a laser fiber (LF) inside the front,
At least a laser fiber insertion opening (7) is formed at the rear end of the shaft (2),
The interior of the shaft (2) is partitioned by the lumen of the rear laser fiber (4) and the lumen of the front guide wire (5) by the stopper (3),
A guide wire insertion opening (6) is formed on the side wall of the shaft (2) in the vicinity of the stopper (3),
A positioning marker (8) is formed outside the vicinity of the tip of the shaft (2),
When the laser fiber (LF) is inserted into the laser fiber lumen (4), the laser fiber is formed so that the tip of the laser fiber (LF) can stop at a position where it hits the stopper (3). A guide catheter (1) is provided.
[2] The present invention has a lumen (24) into which a laser fiber (LF) can be inserted at least inside the shaft (22),
The shaft (22) is made of a material that can transmit laser,
The shaft (22) forms a stopper (23) of a laser fiber (LF) inside the front,
At least a laser fiber insertion opening (27) is formed at the rear end of the shaft (22),
The interior of the shaft (22) is partitioned by the stopper (23) by a rear laser fiber lumen (24) and a front guidewire lumen (25),
A guide wire insertion opening (26) is formed on the side wall of the shaft (22) in the vicinity of the stopper (23),
Forming a first positioning marker (28a) outside the vicinity of the tip of the shaft ( 22 ), and forming a second positioning marker (28b) outside the front of the shaft (22);
The first end of the laser fiber (LF) can be stopped at the middle (C) between the first positioning marker (28a) and the second positioning marker (28b). Provided is a laser fiber guide catheter (21) in which a stopper (23) is disposed at an intermediate position (C) between a positioning marker (28a) and the second positioning marker (28b).
[0004]
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 is a schematic view of a catheter 1 showing an embodiment of a laser fiber guiding catheter (hereinafter referred to as “catheter”) of the present invention. The catheter 1 includes at least a shaft 2 having a lumen 4 into which a laser fiber LF can be inserted. The shaft 2 is formed of a material that can transmit laser.
A stopper 3 for the laser fiber LF is formed inside the front of the shaft 2, and a positioning marker 8 is formed outside the vicinity of the tip of the shaft 2. The inside of the shaft 2 is partitioned by the stopper 3 by the lumen 4 of the laser fiber and the lumen 5 of the guide wire, and the guide wire GW insertion port 6 and the cleaning solution or contrast medium are led into and out of the side wall of the shaft 2 near the stopper 3. Side holes 9 are formed.
At the rear end of the shaft 2, a connector 10 having at least a laser fiber insertion port 7 (a liquid outlet 11 for a cleaning liquid, a contrast medium or the like as necessary) is mounted.
A contrast agent or the like is led out from the side hole 9 through a space S formed between the outer periphery of the laser fiber LF inserted into the lumen 4 of the shaft 2 and the inner wall surface of the shaft 2 from the outlet 11.
[0005]
FIG. 2 is a schematic view of a catheter 21 showing another embodiment of the laser fiber guide catheter (hereinafter referred to as “catheter”) of the present invention. The catheter 21 has two markers 28a and 28b formed near the front end of the shaft 22 and outside the front, and the front end of the laser fiber LF can be stopped at the middle C between the marker 28a and the marker 28b. The rear end of the stopper 23 is arranged at an intermediate position C. For this reason, positioning of the laser fiber LF becomes easy.
The other constituent members of the laser fiber guide catheter 21 are substantially the same as those of the catheter 1, and thus detailed description thereof is omitted.
[0006]
Next, an example of how to use the catheter 1 will be described.
For example, the femoral artery is secured by the Seldinger method, and the photosensitive substance PF is administered to the target stenosis of the blood vessel using a drug administration catheter. A guiding catheter is inserted up to the vicinity of the stenosis with a guide wire GW.
Subsequently, the catheter 1 is inserted into the lumen of the guiding catheter, and positioning is performed so that the marker 8 is positioned in the vicinity of the target stenosis while being seen through with X-rays. The laser fiber LF is inserted into the lumen 4 until the tip of the laser fiber LF hits the stopper 3. The target cell is killed by irradiating a laser beam from the tip of the laser fiber LF to activate the photosensitive substance PF.
The catheter 21 is used in the same manner as the catheter 1, but in the catheter 21, the two markers 28a and 28b are formed as described above so that the tip of the laser fiber LF can be positioned so as to be surely positioned at the target stenosis. Therefore, laser irradiation can be performed reliably and efficiently.
[0007]
3 is a schematic view showing a catheter 41 of a reference example (FIG. 4 is an enlarged view of the vicinity of the balloon 52 in FIG. 3, and FIG. 5 is a cross-sectional view taken along the line AA in FIG. 4).
In the catheter 41, the balloon 52 is disposed at the distal end of the outer tube 54 of the shaft 42, and the inner tube 55 of the shaft 42 is disposed from the rear of the outer tube 54 to the distal end of the balloon 52 through the inside of the balloon 52. A connector 50 having an insertion port 47 for a guide wire GW and a laser fiber LF and an introduction port 58 for a balloon expansion fluid is arranged at the rear end.
The insertion port 47 communicates with the distal end opening 59 of the inner tube 55 through the inside of the inner tube 55 (the guide wire GW and the lumen 45 of the laser fiber LF), and the introduction port 58 is located at the inner end of the connector 50 and the outer tube 54. It communicates with the inside of the balloon 52 through the opening 60.
The photosensitive substance PF is a substance that is activated by laser irradiation and kills the target cell. For example, photofrin is used. The photosensitive substance PF can be fixed to the outer periphery of the balloon 52 by, for example, gelation.
In addition to the outer periphery of the balloon 52, the photosensitive substance PF may be administered locally by, for example, a local injection catheter, or can be administered intravenously and accumulated in the lesion.
One positioning marker 48 may be provided on the outer periphery of the inner tube 55 in the center of the balloon 52, or two markers may be provided on the outer periphery of the inner tube 55 on both sides of the balloon 52 at equal intervals from the center of the balloon 52. . Further, a stopper 43 of the laser fiber LF may be provided on the inner periphery of the inner tube 55 at the center of the balloon 52 so that the tip of the laser fiber LF stops at the center of the balloon 52.
Next, an example of how to use the catheter 41 of the reference example will be described.
For example, the femoral artery is secured by the Seldinger method, and the guiding catheter is inserted to the vicinity of the target stenosis using a guide wire. Subsequently, the catheter 41 is inserted into the lumen of the guiding catheter, and the balloon 52 is positioned at the stenosis and inflated. As a result, the blood flow can be blocked, the local physical adhesion and absorption of the photosensitive substance PF can be increased, and the laser beam transmission can be ensured.
The laser fiber is inserted to the tip of the balloon 52, and the laser is irradiated to activate the photosensitive substance PF to kill the target cell.
[0008]
As the material for the shaft 2 (22) of the catheter 1 (21) of the present invention, any material can be used as long as it can transmit laser.
Further, the shaft 42 (outer tube 54, inner tube 55) of the catheter 41 and the balloon 52 are permeable so that the laser can pass through and the laser can activate the photosensitive substance PF which is administered to the outer periphery or the local area of the balloon 52 or intravenously. Any material can be used.
The laser transmission performance depends on the transparency, thickness, etc. of the material, but it can be freely set according to the treatment purpose of the stenosis, etc., taking into account various conditions such as the type of laser, output, and irradiation time. Can do.
In the present invention, for example, polycarbonate, polyacrylate, polymethylpentene, polyethylene terephthalate, polyethylene, polyamide, nylon or the like can be used as a constituent material that can transmit laser.
In addition, the shaft 2 (22) of the catheter 1 (21) of the present invention is basically the portion where the tip of the laser fiber LF abuts against the stopper 3 (23), and the shaft 42 (outer tube 54, inner tube 55) of the catheter 41. ) And the balloon 52 only need to be formed of a material that can transmit the laser at the tip of the laser fiber LF. It may be formed of a material which can be formed and can transmit a laser.
The marker 8 (28a, 28b, 48) is made of an X-ray opaque material such as gold or platinum.
[0009]
【Example】
Photofrin 5 mg was administered intravascularly as a photosensitive substance PF to a beagle femoral artery using a drug administration catheter. The outer diameter of the shaft 2 that can be inserted into the human coronary artery is 4 Fr. Catheter with an outer diameter of 7 Fr. And inserted through the guiding catheter to the site of photofrin administration. A laser fiber LF made of silica was passed through the transparent portion at the tip of the guide wire 1 and a Yag-OPO laser was irradiated at 2 mj / pulse (50 Hz) for 20 minutes or 10 minutes to perform PDT. Arteriography was performed before, immediately after and 1 week after PDT, and the same site was examined histologically. The tip temperature of the laser fiber LF during irradiation was 37 degrees. In addition, the fresh frozen section | slice of the photofurin administration site | part was observed with the fluorescence microscope, and the accumulation property of the same substance was confirmed.
[0010]
Fluorescence microscopy showed red fluorescence of photofrin in the vascular media, indicating the effectiveness of photofrin administration with a drug administration catheter. Arteriography showed no abnormalities in the blood vessels undergoing PDT throughout the course. In the histological findings of the PDT site, the medial cells were necrotic and extinct in all cases, and the number of medial cell fractions was significantly reduced as compared with the site where PDT was not performed. A part of the intima side of the intima disappeared and disappeared after 20 minutes of irradiation, but the same findings were not observed after 10 minutes of irradiation.
PDT was able to selectively necrotize mesothelial cells, suggesting the effectiveness of this method for preventing restenosis.
[0011]
[Effects of the invention]
The laser-irradiated portion of the laser fiber LF can be reliably fixed to the affected area, and the photosensitive substance PF can be activated to reliably treat the target stenosis.
[Brief description of the drawings]
FIG. 1 is a schematic view of a catheter 1 showing an embodiment of the laser fiber guide catheter of the present invention. FIG. 2 is a schematic view of a catheter 21 showing another embodiment of the laser fiber guide catheter of the present invention. a schematic diagram Figure 4 is an enlarged view of the vicinity of the balloon 52 of FIG. 3 and FIG. 5 a-a sectional view of FIG. 4 showing the guide catheter in the laser fiber of reference example

Claims (2)

At least a lumen (4) into which a laser fiber (LF) can be inserted inside the shaft (2);
The shaft (2) is made of a laser transmissive material,
The shaft (2) forms a stopper (3) of a laser fiber (LF) inside the front,
At least a laser fiber insertion opening (7) is formed at the rear end of the shaft (2),
The interior of the shaft (2) is partitioned by the lumen of the rear laser fiber (4) and the lumen of the front guide wire (5) by the stopper (3),
A guide wire insertion opening (6) is formed on the side wall of the shaft (2) in the vicinity of the stopper (3),
A positioning marker (8) is formed outside the vicinity of the tip of the shaft (2),
When the laser fiber (LF) is inserted into the lumen (4) of the laser fiber, the laser fiber (LF) is formed so that the tip of the laser fiber (LF) can stop at a position where it hits the stopper (3). A laser fiber guiding catheter (1). A lumen (24) into which a laser fiber (LF) can be inserted at least in the shaft (22);
The shaft (22) is made of a material that can transmit laser,
The shaft (22) forms a stopper (23) of a laser fiber (LF) inside the front,
At least a laser fiber insertion opening (27) is formed at the rear end of the shaft (22),
The interior of the shaft (22) is delimited by the rear laser fiber lumen (24) and the front guide wire lumen (25) by the stopper (23),
A guide wire insertion opening (26) is formed on the side wall of the shaft (22) in the vicinity of the stopper (23),
Forming a first positioning marker (28a) outside the vicinity of the tip of the shaft ( 22 ), and forming a second positioning marker (28b) outside the front of the shaft (22);
The first end of the laser fiber (LF) can be stopped at the middle (C) between the first positioning marker (28a) and the second positioning marker (28b). A laser fiber guide catheter (21), wherein a stopper (23) is arranged at an intermediate position (C) between the positioning marker (28a) and the second positioning marker (28b).

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