Prospective Assessment of Changes in Target Vessel Peak Systolic Velocity Measurements After Fenestrated-Branched Endovascular Aortic Repair.

Objective: Target vessel stenosis or occlusion is a common indication for secondary intervention after fenestrated-branched endovascular aortic repair requiring long-term imaging surveillance including duplex ultrasound (DUS). This study aimed to describe and compare longitudinal changes in peak systolic velocity (PSV) measurements for renal and mesenteric arteries targeted by directional branches (DBs) or reinforced fenestrations (RFs).

Methods: Patients enrolled in a prospective, nonrandomized study (2013-2020) had DUS of celiac axis, superior mesenteric artery, and renal arteries (RAs) obtained preoperatively, at 6 to 8 weeks, 6 months, and annually. Vessels with preprocedural stenosis were excluded. Outcomes were variations in PSV over time for target vessels incorporated by DBs or RFs, differences in balloon-expandable stent-grafts (BESGs) and self-expandable stent-grafts (SESGs), PSV measurements prior to secondary interventions related to vessel stenosis, and a predictive value of PSV for stenosis requiring secondary intervention.

Results: A total of 419 patients (292 male, mean age 74 ± 8 years old) were enrolled, with 1,311 target vessels analyzed preoperatively, including 607 mesenteric and 704 RAs. Over a median follow-up of 23 months (interquartile range [IQR], 7-36), PSV measurements decreased in the first 6 to 8 weeks after DB incorporation, remained stable, followed by a nonsignificant increase at 5 years. PSV increased in the first 6 months using RFs with postoperative velocities significantly higher (P < .05) for RFs compared to DBs. Branched mesenteric vessels stented with BESGs had higher velocities than SESGs (P < .05). Of the 23 target vessels treated by secondary intervention for stenosis, 19 (83%) had velocities above the thresholds for native, nonstented vessels. Furthermore, in RAs (n = 20) PSV effectively predicted clinically relevant stenosis, AUC was 0.98, with a 231 cm/s threshold offering 84% sensitivity with 100% specificity.

Conclusion: Longitudinal follow-up shows that velocity changes vary depending on the type of incorporation, vessel, and bridging stent. For DBs, PSV decreased initially, stabilized, and showed a nonsignificant increase at 5 years. In contrast, PSV increased with RFs and remained higher than DBs. Despite these variations, velocities remained below established thresholds for clinically significant stenosis in nonstented vessels. Criteria for in-stent stenosis may differ, and PSV alone should not be the sole indicator for reintervention.Clinical ImpactThis study provides new insight into duplex ultrasound (DUS) surveillance after fenestrated and branched endovascular aneurysm repair (FB-EVAR). Peak systolic velocity (PSV) trends differed between fenestrations and branches, and stent type influenced flow dynamics. Importantly, most vessels with secondary interventions had elevated PSVs, but many others exceeded native stenosis thresholds without clinical consequence. Despite these variations, velocities remained below established thresholds for clinically significant stenosis in non-stented vessels. Criteria for in-stent stenosis may differ, and PSV alone should not be the sole indicator for reintervention.The reported PSV measurements served as a benchmark for DUS surveillance following FB-EVAR.