Evolution of practice patterns and learning curve of aortic repair using the E-nside Off-The-Shelf Inner Branch thoracoabdominal endograft

Objective: To report the impact of the learning curve on the outcomes of branched endovascular aortic repair (BEVAR) using an off-the-shelf preloaded inner branch device (E-nside, Artivion - Kennesaw, GA-USA). Methods: Data from a physician-initiated national multicenter registry, including patients treated with E-nside endograft (INBREED) were prospectively collected (2020-2024). Endpoints were early (30-days) technical success, mortality, major adverse events (MAE), and 2-years freedom from endograft instability and target vessel instability. Patients were divided into early and late cohorts based on the median date of the procedure in each center. Results: There were 215 patients treated with the E-nside, 108 (393 target vessels) in the early and 107 (395 target vessels) in the late cohort. Most patients had a degenerative aneurysm (Early: 82%, Late: 75%; P=.326) or a chronic dissection (Early: 6%, Late:15%; P=.025). Aneurysm extent was thoracoabdominal in 53% of patients and complex abdominal in 47%; and 23% were ruptured or symptomatic and 26% had aneurysm size >70mm, without differences between groups. A narrow paravisceral aortic lumen <25 mm was more frequent in the late cohort (late: 30%, early: 18%; P=.037). From the early to the late groups, there was an increase in the use of a total transfemoral approach (late: 29% vs early: 18%; P=.042), balloon-expandable bridging stents (late: 82% vs early: 76%; P=.032), and reinforcement bridging stents (late: 26%, early: 11%; P<.001). Operating time (late: 267±131 min, early: 244±130 min; P=.230), iodinated contrast volume (late: 181±81 ml, early: 210±141 ml; P=108; P=.302), and dose area product (late: 272±110 Gycm2, early: 291±118 Gycm2; P=.277) were similar in the two groups. Intraprocedural complications decreased in the later stage of the learning curve (late: 11%, early: 23%; P=.030), while overall 30-days mortality (late: 8%, early: 6%; P=.346), technical success (late: 99%, early: 98%; P=.286), and MAEs (late: 27%, early: 29%, P=.879) remained substantially stable. There were no differences in 2-years freedom from endograft instability (late: 100±0%, early: 96±5%, P=1.00), freedom from target vessel instability (late: 98±3%, early: 94±2%;P=.090), and target vessel primary patency (late: 97±2%, early: 97±2%; P=.321). Conclusion: The increased experience with the E-nside endograft was associated with a more frequent use of a total transfemoral approach and use of balloon expandable and reinforced bridging stents. From the early to the late stages, there was a significant decrease in intraoperative complications, while most centers were learning-independent and achieved a consistent mortality, MAE, procedural metrics, and mid-term results from the start.