利用兔颈动脉旁路移植模型评价新型全生物化小口径移植血管

摘要

目的 建立兔双侧颈动脉旁路移植模型,以模拟冠状动脉旁路移植术,并在此模型上对经脱细胞联合肝素处理的犬颈动脉进行体内实验,以评价其作为小口径血管移植物的可行性.方法 犬10只,取双侧颈动脉,先经过去污剂-酶消化法脱除管壁细胞,脱细胞后的血管分为两组,肝素结合联合脱细胞组(A组)对脱细胞血管材料再进行肝素结合处理;仅脱细胞组(B组).测量两组血管的管径,并与同期手术患者的乳内动脉进行比较.兔20只作自身对照,左侧颈动脉移植A组血管,右侧移植B组血管,以建立双侧颈动脉旁路移植模型.实验同期测量20只兔双侧颈动脉的管径,并与20例冠心病患者的冠状动脉进行比较.移植后3周和3个月分别经过超声观察移植血管的通畅性及血流动力学.3个月后处死20只兔,取双侧移植血管,经HE染色及电镜观察血管重塑情况.结果 A组和B组的管径与患者乳内动脉比较差异无统计学意义(P＞0.05),兔颈动脉的管径与人的冠状动脉比较差异也无统计学意义(P＞0.05).犬颈动脉经过去污剂-酶消化法脱细胞处理后,细胞去除完全而且基质保存完整,肝素可以成功结合于管壁全层;术后超声发现,两组中均有部分血管内可见血栓形成,3周时A组的通畅率(95%)高于B组(40%)(P<0.05),3个月时 A组(90%)也高于B组(30%)(P<0.05);3个月后的HE染色、电镜显示两组中未形成血栓的血管可以发生较满意的血管重塑.结论 兔双侧颈动脉旁路移植模型建立简便,可以用于冠状动脉旁路移植术中对小口径血管移植材料的探索和评价;肝素结合联合脱细胞处理的犬颈动脉可能作为新型的全生物化小口径移植血管材料.%Objective To evaluate the feasibility of the new graft small - caliber vascular graft developed with canine carotid arteries.Methods Canine bilateral carotid arteries(n= 20) were decellularized by enzymatic and detergent extraction procedures.Then the arteries were randomly divided into two groups: Group A (decellularized and heparin treatment) and group B (only decellularized).The diameter of the arteries of the two groups were measured and compared with human's internal mammary arteries during operation.Self - controlled study was carried on the 20 rabbits to establishing a bilateral carotid artery bypass graft model.The grafts in group A were transplanted into the left carotid arteries,while that in group B were transplanted into the right side.The diameter of the bilateral carotid arteries was measured and compared with the coronary arteries of 20 patients with coronary heart disease (CHD).The potency of the grafts of the two groups was observed with B - type ultrasonography after 3 weeks and 3 months.The rabbits were sacrificed after 3 months,and the remolding situation of the graft artery was observed by HE stain and electron microscope.Results There was no statistical significance in diameter of the grafts in group A,group B and human's internal mammary artery(P＞0.05).The diameter of the carotid arteries of the rabbits and the coronary arteries in patients was no statistical significance.After the enzymatic and detergent treatments, the cells of the grafts were removed completely and the matrix were protected well.The whole vascular wall was treated with heparin.Thrombus was found in some grafts in both sides.Overall,the potency rate was found significantly better in group A than that in group B.The potency rate in group A and group B was 95.0％ versus 40％ at 3 weeks(P＜0.05) ,and the thrombosis rate in group A and group B was 10.0％ versus 85.0％ at 3 months(P＜0.05).The grafts without thrombus formation showed a satisfactory cellular reconstruction.Conclusion The bilateral carotid artery bypass model on the rabbits was easy to establish and could be used to explore and evaluate the small - caliber bypass vascular grafts for coronary bypass grafting.Canine common carotid artery treated by detergent, enzymatic extraction and heparin might become a new complete biological small- caliber vascular xenograft.