Stanford B型主动脉夹层动脉瘤腔内修复的实验研究

目的 探讨一种较为理想的、稳定可靠的Stanford B型主动脉夹层动脉瘤腔内修复（thoracic endovascular aortic repair,TEVAR）模型的构建方法.方法 18条犬左侧开胸后侧壁阻断降主动脉近端,环形切开外膜、中膜约1/2周径,找到动脉壁分层裂隙,沿裂隙用特制剥离子向下、侧方、向上分离.再环形剪开内膜约1/2周径,将已切开的内膜下唇双角处分别缝合固定于邻近的侧动脉壁,即内膜片双角进行缝合,然后将远端外膜及中膜缝合于近端主动脉壁上.再行下腹部正中切口,经腹主动脉前壁穿刺,用Omnipaque造影剂以10～15 mL/s速度经猪尾巴导管DSA造影及彩超跟踪检查.再经穿刺点置入覆膜支架至主动脉弓降部夹层裂口处,准确定位后释放.结果 直视下、术中彩超影像跟踪、即时DSA造影均显示动脉夹层立即形成并向远端撕裂,置入覆膜支架后夹层裂口被完全修复.结论 应用主动脉内膜片双角缝合法,可建立与人体Stanford B型主动脉夹层动脉瘤（aortic dissection,AD）病理过程相似的动物模型[1,2],经覆膜支架置入后形成腔内修复模型.

Experimental study of Stanford B type thoracic endovascular aortic repair model in canine

Objective To explore a satisfactory method for establishing Stanford B type thoracic endovascular aortic repair model in canine. Methods To-tally 18 adult dogs were used in the present study. The proximal descending aorta was clamped partially and laterally after a left thoracotomy. Half circumference of the aorta including the media and adventitia was cut open transversely, with the intima kept intact. The aortic wall was then separated inferiorly, laterally and superiorly at a special dissecting space with a unique dissecting device. Then the intima at the same site was fenestrated transversely and the two ends of the distal intimal flap were sutured to the adjacent aorta to allow blood entry. The distal adventitia and media were sutured to the proximal aorta to close the incision. An abdominal middle incision be made, puncture anterior wall of abdominal aorta. A pigtail catheter guided digital subtraction angiography （DSA） using omnipaque （10- 15 mL/s）, monitored by color Doppler ultrasound. Stent-graft was placed to the tear of descending aorta. Then it was accurately posi- tioned and deployed. Results Formation and distal extension of aortic dissections were observed immediately after the pro- cedure and were further confirmed by intra-operative color Doppler ultrasound, DSA, and endovascular repair. Conclusion The present two end intimal flap suturing method can be used for establishing Stanford B type thoracic endovascular aortic repair model in canine; which is similar to human Stanford B type aortic dissection, and could be used as endovascular repair model.