Increasing clinical experience and changes in practice protocols improved outcomes of fenestrated branched endovascular repair of complex aortic aneurysms.

Objective: To evaluate the impact of increased clinical experience and changes in practice protocols on the incidence of early major adverse events (MAEs) during fenestrated-branched endovascular aortic repair (FB-EVAR) of complex abdominal (CAAAs) and thoracoabdominal aortic aneurysms (TAAAs).

Methods: Clinical outcomes of 847 consecutive patients (72% males, median age 74 [69, 79] years) treated by the same operator in two centers were reviewed (2007-2024). Of these, 590 patients were treated under a prospective investigational device exemption study. Changes in practice protocols included routine use of fusion/cone beam computed tomography (F/CBCT, 2012), therapeutic instead of prophylactic cerebrospinal fluid drainage (T-CSFD, 2019, Q3) and preferential use of total transfemoral access (TTFA, 2020, Q4). Primary end-point was 30-day/in-hospital MAE assessment using learning curve cumulative sum (LC-CUSUM) analysis per quartiles of experience. The study period was divided into four quartiles: Q1 (2007-2014), Q2 (2014-2017), Q3 (2017-2020), and Q4 (2020-2024).

Results: There was a significant increase in the proportion of Extent I-III TAAA (16% to 58%, p<.001), chronic post-dissection aneurysms (1.9% to 21%; p<.001), symptomatic aneurysms (5.2% to 10%; p<.001), heritable thoracic aortic diseases (0.5% to 4.2%, p=.011) and prior endovascular aortic repair (8.5% to 51%, <.001) between Q1 and Q4 experience. Despite the increased aneurysm complexity, MAEs significantly decreased over time and across quartiles (p<.01). Use of F/CBCT associated with significant reduction in total operative time and radiation exposure (p<.001). Overall 30-day mortality was 1.7% (14/847). Incidence of MAEs significantly decreased for CAAAs and Extent IV TAAAs (P<.01) and remained stable for Extent I-III TAAAs after institution of T-CSFD and TTFA. LC-CUSUM analysis indicates that 32 consecutive cases were needed to reach a learning curve, 100 cases to reach plateau, with significantly improved outcomes in the 4th quartile of experience.

Conclusions: FB-EVAR was performed with low mortality (1.7%) in a large cumulative experience. Increased clinical experience and changes in practice protocol associated with significantly improved outcomes of FB-EVAR, despite a significant increase in anatomic and patient complexity. Institution of T-CSFD and TTFA had no deleterious effect on outcomes of Extent I-III TAAAs but improved outcomes in patients with less extensive aneurysms. Among CAAA patients, 21.2% had T-CSFD, and 10.7% had TTFA. For Extent IV aneurysms, 47.3% had T-CSFD, and 22.5% had TTFA.