|Budget Amount *help
¥2,300,000 (Direct Cost: ¥2,300,000)
Fiscal Year 2004: ¥800,000 (Direct Cost: ¥800,000)
Fiscal Year 2003: ¥1,500,000 (Direct Cost: ¥1,500,000)
First examination was carried out to determine principles of the interventional vascular occlusion treatment in acute and sub-acute phases. The epigastric vein in a pig was exposed, and a catheter and a laser fiber were inserted. Laser irradiation was performed from diaphragm level to insertion part. Venograms and pulmonary angiograms were obtained before and after treatment. Arterial blood pressure and arterial blood gas were measured repeatedly during examination. The treated vein was examined pathologically. The vein was blocked right after the irradiation. Arterial blood pressure and arterial blood gas did not change during examination, and pulmonary embolism was not recorded. Pathologically, destruction of vessel wall, perivascular edema and intravascular thrombotic occlusion were observed just after the irradiation. Two weeks later, vessel occlusion, degeneration of thrombus, change from granulation tissue to fibrous tissue, loss of elastic fiber and smooth muscle in vessel wall
were observed. By this examination, the maneuver to insert a catheter and a laser fiber was established, and followings were confirmed ; local safety, no risk of pulmonary embolism, strong thrombotic occlusion of the vessel.
Next examination was carried out to observe a natural course after the treatment up to 6 months, and to assess the effect of elastic bandage to prevent re-canalization of the treated vessel Continuation of vascular occlusion was confirmed for two months in pilot experiments, while remodeling of experimental protocol was needed because of high activity of the animal, difficulty to wear the elastic bandage continuously, and validity of pathological data obtained from an animal in growth process.
On the other hand, there was a report with long-term observation from United States. On basis of this report, clinical application was started after approval by the ethical committee of our institute. Patients with varicose veins due to insufficient great saphenous vein were included in the study. Written informed consent was always obtained before the treatment. At present, complete obstruction of the great saphenous vein has been observed through all follow-up period (up to 8 months). No severe side effect, such as pulmonary embolism, was recorded.
The results was presented many times from 2003 to 2005,both in Japan and in United States (Japan Radiological Society, AJR, Japanese Society of phlebology, etc), and it will be presented in Cardiovascular and Interventional Radiological Society of Europe in 2005. Less