The Regional Vascular Unit, Liverpool Royal Hospital, Liverpool, United Kingdom.
Institute of Ageing and Chronic Disease, University of Liverpool, Liverpool, United Kingdom.
J Vasc Surg. 2014 Aug;60(2):418-27. doi: 10.1016/j.jvs.2014.01.069. Epub 2014 Mar 20.
Meta-analysis supports patch angioplasty after carotid endarterectomy (CEA); however, studies indicate considerable variation in practice. The hemodynamic effect of a patch is unclear and this study attempted to elucidate this and guide patch width selection.
Four groups were selected: healthy volunteers and patients undergoing CEA with primary closure, trimmed patch (5 mm), or 8-mm patch angioplasty. Computer-generated three-dimensional models of carotid bifurcations were produced from transverse ultrasound images recorded at 1-mm intervals. Rapid prototyping generated models for flow visualization studies. Computational fluid dynamic studies were performed for each model and validated by flow visualization. Mean wall shear stress (WSS) and oscillatory shear index (OSI) maps were created for each model using pulsatile inflow at 300 mL/min. WSS of <0.4 Pa and OSI >0.3 were considered pathological, predisposing to accretion of intimal hyperplasia. The resultant WSS and OSI maps were compared.
The four groups comprised 8 normal carotid arteries, 6 primary closures, 6 trimmed patches, and seven 8-mm patches. Flow visualization identified flow separation and recirculation at the bifurcation increased with a patch and was related to the patch width. Computational fluid dynamic identified that primary closure had the fewest areas of low WSS or elevated OSI but did have mild common carotid artery stenoses at the proximal arteriotomy that caused turbulence. Trimmed patches had more regions of abnormal WSS and OSI at the bifurcation, but 8-mm patches had the largest areas of deleteriously low WSS and high OSI. Qualitative comparison among the four groups confirmed that incorporation of a patch increased areas of low WSS and high OSI at the bifurcation and that this was related to patch width.
Closure technique after CEA influences the hemodynamic profile. Patching does not appear to generate favorable flow dynamics. However, a trimmed 5-mm patch may offer hemodynamic benefits over an 8-mm patch and may be the preferred option.
荟萃分析支持颈动脉内膜切除术（CEA）后使用补片血管成形术；然而，研究表明实践中存在相当大的差异。补片的血流动力学效应尚不清楚，本研究试图阐明这一点并指导补片宽度的选择。
选择了四组：健康志愿者和接受 CEA 后行直接缝合、修剪补片（5mm）或 8mm 补片血管成形术的患者。从每隔 1mm 记录的横断超声图像生成颈动脉分叉的计算机生成的三维模型。快速原型生成模型用于流动可视化研究。对每个模型进行计算流体动力学研究，并通过流动可视化进行验证。使用 300mL/min 的脉动流入为每个模型创建平均壁面剪切应力（WSS）和振荡剪切指数（OSI）图。<0.4Pa 的 WSS 和>0.3 的 OSI 被认为是病理性的，易导致内膜增生的堆积。比较了得到的 WSS 和 OSI 图。
四组包括 8 个正常颈动脉、6 个直接缝合、6 个修剪补片和 7 个 8mm 补片。流动可视化发现，随着补片的增加，分叉处的流动分离和再循环增加，并且与补片的宽度有关。计算流体动力学发现，直接缝合的低 WSS 或高 OSI 区域最少，但近端吻合口处有轻微的颈总动脉狭窄，导致湍流。修剪补片在分叉处有更多的异常 WSS 和 OSI 区域，但 8mm 补片有最大的有害低 WSS 和高 OSI 区域。对四组之间的定性比较证实，补片的使用增加了分叉处的低 WSS 和高 OSI 区域，并且这与补片的宽度有关。
CEA 后的缝合技术会影响血流动力学特征。补片似乎不会产生有利的血流动力学。然而，与 8mm 补片相比，修剪的 5mm 补片可能具有更好的血流动力学效果，可能是首选。
