Division of Vascular Surgery, Stanford University, Stanford, Calif.
Division of Vascular Surgery, Stanford University, Stanford, Calif.
J Vasc Surg. 2019 Oct;70(4):1048-1055. doi: 10.1016/j.jvs.2018.12.050. Epub 2019 Jul 18.
The use of duplex ultrasound (DUS) examinations for surveillance after fenestrated endovascular aneurysm repair (FEVAR) is not well-studied. Our objective was to further characterize normal and abnormal duplex findings in renal branch grafts after FEVAR.
We retrospectively reviewed a single-center experience involving consecutive patients treated with Cook ZFEN devices between 2012 and 2017. Postoperative imaging consisted of a computed tomography (CT) scan at 1 month, 6 months, 1 year, and annually thereafter. As experienced progressed, DUS examination with or without concurrent CT scans were obtained in a nonstandardized protocol, particularly for patients with decreased renal function. Renal patency loss was defined as occlusion or stenosis of greater than 50% evaluated on 3-day renal artery center-line imaging.
A total of 116 patients were treated with FEVAR, of which 60 (51.7%) had concurrent CT and renal DUS images available for review. Six patients (10%) had limited ultrasound studies owing to bowel gas and were excluded. The study cohort therefore included 54 patients receiving of 94 renal fenestrated stents with a mean follow-up of 23 months. Twelve cases of renal patency loss in 10 patients (9 stenoses, 3 occlusions) were found on CT scanning, 11 (91.6%) of which had concurrent abnormalities found on ultrasound examination. Stents with compression at the junction of the main body exhibited significantly elevated mean Peak systolic velocities (PSV) compared with nonstenosed stents (349.2 cm/s vs 115.3 cm/s; P = .003). Stenosis in the most proximal portion of the stent (ie, within the main body) showed no difference in proximal PSV (86.0 cm/s vs 131.9 cm/s; P = .257); however, dampened PSV showed significant differences in the mid (17.5 cm/s vs 109.9 cm/s; P = .027) and distal (19.0 cm/s vs 78.3 cm/s; P = .028) segments compared with nonstenosed stents. All occluded stents demonstrated no flow detection. Proximal PSV served as a strong classifier for junctional stenosis (area under the curve, 0.98). A combined criterion of proximal PSV of greater than 215 cm/s or distal PSV of less than 25 cm/s resulted in a sensitivity of 91.6% and specificity of 85.3% for detecting patency loss. All stents that were compromised underwent successful secondary reintervention and restoration of patency.
DUS imaging is a clinically useful modality for surveillance of renal branch grafts after FEVAR. Patterns of segmental velocity elevation (proximal PSV, >215 cm/s) and dampening in the distal renal indicate potential hemodynamic compromise and should prompt more aggressive workup or imaging and likely be considered for secondary intervention.
对经开窗血管内动脉瘤修复术（fenestrated endovascular aneurysm repair，FEVAR）后进行双功超声（duplex ultrasound，DUS）检查的应用尚未进行深入研究。我们的目的是进一步描述 FEVAR 后肾分支移植物中正常和异常 DUS 结果。
我们回顾性分析了 2012 年至 2017 年期间在单中心接受 Cook ZFEN 装置治疗的连续患者的经验。术后影像学检查包括术后 1 个月、6 个月、1 年和此后每年进行一次计算机断层扫描（CT）检查。随着经验的不断积累，我们按照非标准方案进行 DUS 检查（包括或不包括同时进行 CT 扫描），特别是对于肾功能下降的患者。肾闭塞损失定义为在 3 天的肾动脉中心线成像上评估的大于 50%的闭塞或狭窄。
共对 116 例患者进行了 FEVAR 治疗，其中 60 例（51.7%）同时有 CT 和肾 DUS 图像可供复查。由于肠气的影响，有 6 例（10%）患者的超声研究受限并被排除。因此，本研究队列包括 54 例患者，共接受了 94 个肾开窗支架的治疗，平均随访 23 个月。在 CT 扫描中发现 10 例患者中有 12 例（9 例狭窄，3 例闭塞）出现肾闭塞，其中 11 例（91.6%）在超声检查中同时发现了异常。在主支架体交界处受压的支架显示出明显升高的收缩期峰值速度（Peak systolic velocity，PSV），与未狭窄的支架相比（349.2 cm/s 比 115.3 cm/s；P =.003）。支架最靠近近端的狭窄（即位于主体内）近端 PSV 无差异（86.0 cm/s 比 131.9 cm/s；P =.257）；然而，中（17.5 cm/s 比 109.9 cm/s；P =.027）和远（19.0 cm/s 比 78.3 cm/s；P =.028）段的 PSV 差异明显，与未狭窄的支架相比。所有闭塞的支架均未检测到血流。近端 PSV 是区分支架交界处狭窄的有力指标（曲线下面积为 0.98）。近端 PSV 大于 215 cm/s 或远端 PSV 小于 25 cm/s 的联合标准可使检测闭塞的灵敏度达到 91.6%，特异性为 85.3%。所有受损的支架均成功进行了二次再介入治疗并恢复了通畅。
DUS 成像对于 FEVAR 后肾分支移植物的监测是一种有临床应用价值的方法。节段性速度升高（近端 PSV，>215 cm/s）和远端肾的衰减模式表明存在潜在的血流动力学障碍，应促使进行更积极的检查或影像学检查，并可能需要考虑进行二次介入治疗。
