Distal landing zone outcomes in thoracic endovascular aortic aneurysm repair with challenging morphology: a propensity-matched comparison of distal active fixation versus standard stent-graft

Background: To evaluate the distal landing zone (LZ) outcomes in adverse morphology after thoracic endovascular repair (TEVAR) with distal active fixation (DAF) stent-grafts compared with standard endografts. Methods: Between 2006 and the 31st December 2020, sixty-nine DAFs (study group) and sixty-nine standard stent-grafts (control group) were enrolled in a multi-center, retrospective, case-control study. The primary outcomes were the distal endoleak and reintervention. The secondary outcomes were: distal segment migration, wedge apposition and related complications. A univariate and multivariate logistic regression followed by a propensity-scored model (1:1) were performed. Results: The results were reported for the DAF vs. control group. The mean follow-up was 3.3±2.1 vs. 3.7±3.4 years. The distal endoleak rate was 7.3% vs. 27.5% (P=0.011). The freedom from distal endoleak was 95%, 95% and 91% vs. 85%, 76%, and 73% at 1, 3 and 5 years respectively (Log-rank P=0.011). Tortuosity index and distal thoracic aorta angulation were predictors of endoleak (P=0.012 and P=0.029 respectively). The distal reinterventions rate was 7.3% vs. 20.3% (P=0.026). The freedom from distal reinterventions was 95%, 95% and 91% vs. 92%, 75% and 75% at 1, 3 and 5 years respectively (Log-rank P=0.041). The wedge apposition was 5.8 vs. 13.0-mm (P<0.000). The distal segment migration was upward directed in all cases and was significant (>10-mm) in 13.0% vs. 39.1% (P=0.000). Conclusions: The DAF stent-graft showed a significant reduction of the distal endoleak rates and other specific outcomes of the distal LZ in patients with an adverse anatomy.