RS11 - Impact of the learning curve on the outcomes of thoracoabdominal aortic repair using the E-nside Off-The-Shelf Preloaded Inner Branch endograft

Objectives: 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 endograft, 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%) or a chronic dissection (Early: 6%, Late:15%) (P=.194). Aneurysm extent was thoracoabdominal in 53% of patients and complex abdominal in 47%, and 28% were treated in a urgent setting, without differences between groups. A narrow paravisceral aortic lumen < 25 mm was more frequent in the late cohort (late: 32%, early: 18%; P=.046). From the early to the late groups, there was an increase in the use of a total transfemoral approach (late: 30% vs early: 18%; P=.042), use of balloon-expandable bridging stents (late: 90% vs early: 67%; P=.028), and use of reinforcement bridging stents (late: 26%, early: 14%; P=.038). 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: 12%, early: 23%; P=.030), while overall 30-days mortality (late: 9%, early: 5%; P=.346), technical success (late: 99%, early: 97%; P=.351), and MAEs (late: 23%, early: 28%, P=.362) remained substantially stable. There were no differences in 2-years freedom from endograft instability (late: 99±1%, early: 98±3%, P=.999), freedom from target vessel instability (late: 97±2%, early: 94±2%;P=.090), and target vessel primary patency (late: 98±1%, early: 97±1%; P=.321).

Conclusions: In this multicenter experience, 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 mortality, MAEs, procedural metrics, and mid-term results remained substantially stable.