超声多普勒血流速度诊断肾动脉支架植入术后支架内再狭窄

目的 分析超声多普勒血流速度诊断支架植入术治疗重度粥样硬化性肾动脉狭窄（ARAS）术后支架内再狭窄的价值。方法 回顾性分析85例（94条肾动脉）肾动脉支架植入术后重度ARAS患者,根据术后12个月超声造影（CEUS）所示支架内径狭窄比判定狭窄程度,以<30%为无再狭窄,30%~50%为轻度再狭窄,51%~70%为中度再狭窄,>70%为重度再狭窄;对比其支架内收缩期峰值血流速度（PSV）及肾动脉PSV与腹主动脉PSV比值（RAR）。采用受试者工作特征（ROC）曲线分析PSV、RAR对支架内再狭窄的诊断价值。结果 94条植入支架后肾动脉中,术后12个月2条支架闭塞。92条未闭塞动脉中,58条无再狭窄,15条轻度再狭窄,11条中度再狭窄,8条重度再狭窄。不同程度再狭窄肾动脉支架内PSV及RAR差异均有统计学意义（P均<0.01）,且PSV、RAR随狭窄程度增高而逐渐加大（P均<0.05）。以PSV>162.50 cm/s作为判断支架内径狭窄比>30%的阈值,其敏感度、特异度均为100%;以RAR>2.28作为阈值,敏感度为100%,特异度为96.60%。对于支架内径狭窄比>50%,以PSV>219.55 cm/s作为诊断阈值,其敏感度为100%,特异度为98.60%;以RAR>3.17作为阈值,敏感度为100%,特异度为94.50%。以PSV>310.53 cm/s作为支架内径狭窄比>70%的诊断阈值,敏感度为100%,特异度为100%;以RAR>4.33作为阈值,敏感度为100%,特异度为100%。结论 超声多普勒血流速度对于诊断肾动脉支架植入术治疗重度ARAS术后支架内再狭窄的效能较高。

Doppler flow velocity in diagnosis of in-stent restenosis after renal artery stenting

Objective To explore the value of ultrasonic Doppler flow velocity in diagnosis of stent restenosis after stent implantation for treating severe atherosclerotic renal artery stenosis (ARAS). Methods Eighty-five patients (94 renal arteries) with severe ARAS after renal artery stenting were retrospectively analyzed. According to the ratio of stent diameter stenosis measured with contrast-enhanced ultrasound (CEUS) 12 months after stenting, the patients were divided into non-restenosis (<30%), mild restenosis (30%-50%), moderate restenosis (51%-70%) and severe restenosis (>70%), respectively. The peak systolic velocity (PSV) in stent and ratio of renal artery PSV to abdominal aortic PSV (RAR) were compared among renal arteries with different restenosis degrees. Receiver operating characteristic (ROC) curve was used to analyze the diagnostic value of PSV and RAR for in-stent restenosis. Results Twelve months after stenting, CEUS showed stent occlusion in 2 renal arteries. Totally 92 renal arteries were enrolled in the study, including 58 with restenosis, 15 with mild restenosis, 11 with moderate restenosis and 8 with severe restenosis. There were statistically significant differences of PSV and RAR among renal arteries with different restenosis degrees (all P<0.01). PSV and RAR increased gradually with the development of stenosis degrees (all P<0.05). Taken PSV >162.50 cm/s as the diagnostic threshold of intra-stent diameter stenosis ratio >30%, the sensitivity and specificity were both 100%, while taken RAR >2.28 as the diagnostic threshold, the sensitivity was 100%, and specificity was 96.60%. For diagnosing intra-stent diameter stenosis ratio >50%, taken PSV >219.55 cm/s as the diagnostic threshold, the sensitivity was 100% and specificity was 98.60%; while taken RAR >3.17 as the threshold, the sensitivity was 100% and specificity was 94.50%. Taken PSV>310.53 cm/s as the diagnostic threshold of intra-stent diameter stenosis ratio >70%, the sensitivity and specificity were both 100%, while taken RAR >4.33 as the threshold, the sensitivity and specificity were both 100%. Conclusion Ultrasonic Doppler flow velocity had high efficacy in diagnosing in-stent restenosis after renal artery stenting in patients with severe ARAS.