b'Scientific Session Abstracts SUNDAY APRIL 21, 2024 28: MULTICENTER EXPERIENCE OF PHYSICIAN-MODIFIED FENESTRATED-BRANCHED ENDOVASCULAR AORTIC REPAIR FOR FAILED COMPLEX ENDOVASCULAR AORTIC ANEURYSM REPAIRHerbert James, III, Sukgu M Han, Alexander D. DiBartolomeo, Alyssa Pyun, Gregory Magee 1 , Michael C. Soult, Carlos F. Bechara 21 University of Southern California,2 Loyola UniversityObjectives: Type 1A endoleak after complex endovascular aortic aneurysm repairs (CEVAR) can be challenging to fix. We report a multicenter experience of physician-modified fenestrated- branched endovascular aortic repair(PM-FBEVAR) to rescue failed previous CEVAR.Methods: A retrospective review of consecutive patients who underwentPM-FBEVAR for failed CEVAR at two high-volume aortic centers from 2018 to 2022 was performed. Patient characteristics, operative metrics, and outcomes were evaluated.Results: Among 469 patients who underwent PM-FBEVAR during the study period, 10 were included in the study. Previous CEVAR included Zenith Fenestrated Commercial Endograft (ZFEN) (4), parallel grafting (3), and PM-FBEVAR (3). Median interval between the initial CEVAR and rescue PM-FBEVAR was 8.5 months (3-48 months). Type 1A endoleak was identified shortly after the initial CEVAR due to gutter leak (2) and infolding of ZFEN (1), and delayed after the initial CEVAR due to caudal migration (3) and seal zone dilation (4). CEVAR targeted a median of 3 vessels per patient, while rescue PM-FBEVAR targeted all available renal mesenteric vessels (median=4). Mean operative time was 261 min, fluoroscopy time was 67 min, and contrast use was 107 ml. Technical success was achieved in 80% of patients. There were no perioperative mortalities. The only perioperative major adverse event was acute kidney injury seen in 1 patient. Mean follow- up was 18 months, during which 5 patients (50%) underwent reinterventions for endoleak (3) and branch stenosis/thrombosis (2) (Table I). All-cause mortality was 20% due to non-aortic causes.Conclusions: The relatively short interval between initial CEVAR and subsequent PM-FBEVAR in our study suggests that CEVAR techniques that incorporate 4 target vessels may be susceptible for early failure. PM-FBEVAR is a feasible option to repair failed CEVAR, albeit with a high rate ofreintervention during follow-up.74SOUTHERN CALIFORNIA VASCULAR SURGICAL SOCIETY'