Interventional vascular occlusion treatment for varicose veins in lower extremity : in vivo assessment and development of clinical techniques

首先检查确定急性期和亚急性期介入血管闭塞治疗的原则。暴露猪的腹壁静脉，并插入导管和激光纤维。从膜片水平到插入部位进行激光照射。治疗前后分别行静脉造影和肺血管造影。检查时反复测量动脉血压和动脉血气。对治疗后的静脉进行病理检查。照射后静脉就被堵塞了。检查时动脉血压、动脉血气无变化，无肺栓塞记录。病理上观察到辐照后血管壁破坏、血管周围水肿和血管内血栓闭塞。2周后，血管闭塞，血栓变性，肉芽组织向纤维组织转变，血管壁弹性纤维和平滑肌丧失等。通过这次检查，建立了插入导管和激光光纤的操作，并确认了以下内容：局部安全，无肺栓塞风险，强血栓性血管闭塞。下一步检查观察治疗后长达6个月的自然过程，评估弹性绷带防止治疗血管再通的效果，在中试实验中确认血管闭塞延续2个月，但由于动物活动度高，弹性绷带难以持续佩戴，以及从生长过程中动物获得的病理数据的有效性，需要对实验方案进行重构。另一方面，有一份来自美国的长期观察报告。在此报告的基础上，经我院伦理委员会批准，开始临床应用。大隐静脉不足导致的静脉曲张患者纳入研究。治疗前必须取得书面知情同意。目前，所有随访期（长达8个月）均观察到大隐静脉完全阻塞。没有严重的副作用，如肺栓塞，记录。研究结果于2003年至2005年在日本和美国（日本放射学会，AJR，日本血液学会等）多次发表，并将于2005年在欧洲心血管和介入放射学会发表。少

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 … More 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