Department of Clinical Sciences and Community Health, Università di Milano, Milan, Italy.
Unità Operativa di Chirurgia Vascolare, Fondazione I.R.C.C.S. Cà Granda Ospedale Maggiore Policlinico, Milan, Italy.
Ann Biomed Eng. 2019 Apr;47(4):1129-1140. doi: 10.1007/s10439-019-02201-8. Epub 2019 Jan 18.
This study explored the potential of hemodynamic disturbances and geometric features to predict long-term carotid restenosis after carotid endarterectomy (CEA). Thirteen CEA for carotid diameter stenosis > 70% were performed with patch graft (PG) angioplasty in nine cases, and primary closure (PC) in four cases. MRI acquisitions within one month after CEA were used for hemodynamic and geometric characterization. Personalized computational hemodynamic simulations quantified the exposure to low and oscillatory wall shear stress (WSS). Geometry was characterized in terms of flare (the expansion at the bulb) and tortuosity. At 60 months after CEA, Doppler ultrasound (DUS) was applied for restenosis detection and intima-media thickness determination. Larger flares were associated to larger exposure to low WSS (Pearson R values up to 0.38, P < 0.05). The two cases characterized by the highest flare and the largest low WSS exposure developed restenosis > 50% at 60 months. Linear regressions revealed associations of DUS observations of thickening with flare variables (up to R= 0.84, P < 0.001), and the exposure to low (but not oscillatory) WSS (R= 0.58, P < 0.05). Our findings suggest that arteriotomy repair should avoid a large widening of the carotid bulb, which is linked to restenosis via the generation of flow disturbances. Hemodynamics and geometry-based analyses hold potential for (1) preoperative planning, guiding the PG vs. PC clinical decision, and (2) stratifying long-term restenosis risk after CEA.
本研究探讨了血流动力学紊乱和几何特征在预测颈动脉内膜切除术（CEA）后颈动脉再狭窄的长期预后中的潜力。对 13 例颈动脉直径狭窄>70%的患者进行了 CEA，其中 9 例采用补片血管成形术（PG），4 例采用直接缝合（PC）。CEA 后一个月内进行 MRI 采集，用于血流动力学和几何特征分析。个体化计算血流动力学模拟量化了低壁切应力（WSS）和振荡壁切应力的暴露程度。几何特征采用膨大部扩张（flare）和迂曲度来描述。CEA 后 60 个月，应用多普勒超声（DUS）检测再狭窄并测量内膜中层厚度。较大的膨大部扩张与低壁切应力暴露程度较大有关（Pearson R 值高达 0.38，P<0.05）。两个膨大部扩张最大、低壁切应力暴露最大的病例在 60 个月时发展为再狭窄>50%。线性回归分析显示，DUS 观察到的增厚与膨大部扩张变量之间存在相关性（最高 R 值为 0.84，P<0.001），以及与低壁切应力（但非振荡壁切应力）暴露之间存在相关性（R=0.58，P<0.05）。我们的研究结果表明，动脉切开修复应避免颈动脉膨大部过度扩张，这会通过产生血流紊乱导致再狭窄。基于血流动力学和几何特征的分析具有（1）术前规划，指导 PG 与 PC 临床决策，以及（2）分层 CEA 后长期再狭窄风险的潜力。
