Jones D N, Rutherford R B, Ikezawa T, Nishikimi N, Ishibashi H, Whitehill T A
Department of Surgery, University of Colorado School of Medicine, Denver.
J Vasc Surg. 1991 Oct;14(4):441-8; discussion 448-51.
Lack of an endothelial surface is most often blamed for the relatively poor patency of polytetrafluoroethylene grafts used in infrageniculate bypass when compared to autogenous saphenous vein. Length, caliber, flow, and ability to withstand flexion are also acknowledged but have not been systematically examined. We report the results of our attempts to discriminate between the relative contributions of these factors and to develop a suitable canine model for evaluating small-caliber prostheses (4 mm x 10 cm thin-walled polytetrafluoroethylene). ASA/dipyridamole were given 1 week before and 4 weeks after operation. Patency was assessed by directional Doppler at frequent intervals (less than or equal to 3 days). The following were observed: (1) Iliac placement provided a useful patency reference point (40% to 50% patency at 60 days). (2) Carotid patency was not better than iliac patency. (3) Crossing a flexion crease decreased patency. (4) The low patencies were not technical but intrinsic to the graft. Iliofemoral vein grafts achieved 100% patency at 60 days. (5) External rings did not improve iliofemoral patency (equal in paired comparisons). (6) Neither baseline platelet aggregation nor platelet aggregation after ASA administration correlated with patency. This canine model is an excellent test for small caliber-low flow prostheses. It allows paired-site comparisons, which are essential, and meaningful patency data with reasonable numbers of subjects within 2 months' observation. Directional Doppler evaluation avoids need for angiography or serial postmortem analysis sacrifice.
与自体大隐静脉相比，用于膝下旁路手术的聚四氟乙烯移植物通畅率相对较低，这通常归咎于缺乏内皮表面。移植物的长度、管径、血流量以及耐受屈曲的能力也被认为是影响因素，但尚未进行系统研究。我们报告了我们为区分这些因素的相对作用并开发一种合适的犬类模型以评估小口径假体（4毫米×10厘米薄壁聚四氟乙烯）所做尝试的结果。在手术前1周和术后4周给予阿司匹林/双嘧达莫。通过定向多普勒仪定期（小于或等于3天）评估通畅情况。观察到以下几点：（1）髂动脉植入提供了一个有用的通畅参考点（60天时通畅率为40%至50%）。（2）颈动脉通畅情况并不优于髂动脉通畅情况。（3）穿过屈曲皱襞会降低通畅率。（4）低通畅率并非技术问题，而是移植物本身的问题。髂股静脉移植物在60天时通畅率达到100%。（5）外环并未改善髂股静脉的通畅情况（配对比较中相同）。（6）基线血小板聚集或服用阿司匹林后的血小板聚集均与通畅情况无关。这种犬类模型是对小口径低流量假体的极佳测试。它允许进行配对部位比较，这一点至关重要，并且在2个月的观察期内，能以合理数量的受试者获得有意义的通畅数据。定向多普勒评估避免了血管造影或系列尸检分析牺牲的必要性。
