BackgroundFenestrated/branched endovascular aneurysm repair (F/BEVAR) volume has increased rapidly, with favorable outcomes at centers of excellence. We evaluated changes over time in F/BEVAR complexity and associated outcomes at a single-center complex aortic disease program. MethodsProspectively collected data of all F/BEVAR (definition: requiring ≥1 fenestration/branch), procedures performed in an institutional review board-approved registry and/or physician-sponsored investigational device exemption trial (IDE# G130210), were reviewed (11/2010-2/2019). Patients were stratified by surgery date into thirds: early experience, mid experience, and recent experience. Patient and operative characteristics, aneurysm morphology, device types, perioperative and midterm outcomes (survival, freedom from type I or III endoleak, target artery patency, freedom from reintervention), were compared across groups. ResultsFor 252 consecutive F/BEVARs (early experience, n = 84, mid experience, n = 84, recent experience, n = 84), 194 (77%) company-manufactured custom-made devices, 11 (4.4%) company-manufactured off-the-shelf devices, and 47 (19%) physician-modified devices, were used to treat 5 (2.0%) common iliac, 97 (39%) juxtarenal, 31 (12%) pararenal, 116 (46%) thoracoabdominal, and 2 (0.8%) arch aneurysms. All patients had follow-up for 30-day events. The mean follow-up time for the entire cohort was 589 days (interquartile range, 149-813 days). On 1-year Kaplan-Meier analysis, survival was 88%, freedom from type I or III endoleak was 91%, and target vessel patency was 92%. When stratified by time period, significant differences included aneurysm extent (thoracoabdominal, 33% early experience, 40% mid experience, and 64% recent experience; P < .001) and target vessels per case (four-vessel case, 31% early experience, 39% mid experience, and 67% recent experience; P < .0001). There was no difference, but a trend toward improvement, in composite 30-day events (early experience, 39%; mid experience, 23%; recent experience, 27%; P = .05). On Kaplan-Meier analysis, there was no difference in survival (P = .19) or target artery patency (P = .6). There were differences in freedom from reintervention (P < .01) and from type I or III endoleak (P = .02), with more reinterventions in the early experience, and more endoleaks in the recent period. ConclusionsDespite increasing repair complexity, there has been no significant change in perioperative complications, overall survival, or target artery patency, with favorable outcomes overall. Type I or III endoleaks remain a significant limitation, with increased incidence as the number of branch arteries incorporated into the repairs has increased.