血管外支架预防CABG术后吻合口狭窄的研究

Experimental study of external stents preventing stenosis of porcine saphenous vein grafts′ anastomosis

目的采用猪大隐静脉-颈总动脉旁路移植动物模型，观察涤纶血管外支架支持对静脉桥血管吻合口部位内、中膜增生的作用。方法25-30 kg普通长白猪10只，行双侧大隐静脉-颈总动脉旁路移植（端侧吻合），实验侧静脉桥放置涤纶外支架，完全覆盖而不压迫吻合口。术后35 d取出桥血管，观察吻合口部位内、中膜增生情况。结果近端吻合口对照组内膜增生较实验组明显增加[（0.698 1±0.085 9）mm vs（0.376 0±0.064 5）mm，P〈0.01]，对照组中膜增生亦较实验组增加[（0.827 5±0.127 0）mm vs（0.640 4±0.058 8）mm，P〈0.01）]；远端吻合口对照组内膜增生较实验组明显增加[（0.619 7±0.145 8）mm vs（0.413 0±0.097 2）mm，P〈0.01）]，对照组中膜增生亦较实验组增加[（0.822 4±0.136 3）mm vs（0.578 6±0.146 4）mm，P〈0.01）]。结论非限制性涤纶血管外支架可以显著减轻大隐静脉桥血管近、远端吻合口部位内膜及中膜增生，能够预防大隐静脉桥吻合口狭窄。

Objective To evaluate the effect of external stents on preventing anastomotic intimal hyper-plasia and medial thickening with non-restrictive end-to-side anastomoses. Methods Studies were kg. All the animals underwent bilateral saphenous of reversed saphenous vein was beveled to about macro-porous polyester stent around porcine vein grafts with performed using ＂white race＂ pigs （n = 10） weight 25 -30 vein into carotid artery bypass grafting. The end of a segment 45 degree and then anastomosed to the carotid artery by an end-to-side anastomotic technique. In each animal,a macroporous stent was placed around a graft on one side and an unstented graft on the opposite side as control. The polyester stent was long enough to cover both anastomoses completely. The size of the stent allowed unrestricted expansion of the graft in initial response to arterial pressure, and the stent did not oppress the anastomosis. After 35 days of surgery, 10 animals were taken to remove grafts. Anastomosis dimensions were measured on histological sections. Results All the grafts were patent when they were removed. 35 days after surgery, stents significantly reduced proximal anastomotic neointimal thickening [ （0. 698 1 ± 0. 085 9）mm vs （0.376 0 ± 0.064 5 ）mm, P 〈 0.01 ）] and medial thickening [ （0.827 5 ±0. 127 0）mm vs （0.640 4 ±0. 058 8） mm,P 〈0.01 ） ]. Stents also significantly reduced distal anastomotic neointimal thickening [ （0.619 7 ± 0. 145 8 ） mm vs （ 0.413 0 ± 0.097 2 ） mm, P 〈 0.01 ） ] and medial thickening [ （0. 822 4 ± 0.136 3 ）mm vs （ 0. 578 6 ± 0. 146 4 ） mm, P 〈 0.01 ） ]. Conclusion External non-restrictive polyester stent can inhibit anastomosis （end-to-side anastomoses） neointimal formation and medial thickening, and prevent late vein grafts restenosis.