Early Outcomes of the t-Branch Off-the-Shelf Multibranched Stent-Graft in Urgent Thoracoabdominal Aortic Aneurysm Repair

PURPOSE: To assess the short-term outcomes of the multibranched off-the-shelf t-Branch stent-graft for urgent thoracoabdominal aortic aneurysm (TAAA) repair and to evaluate the impact on outcomes of the learning curve and adherence to the instruction for use (IFU).

METHODS: Between 2014 and 2017, 42 patients (mean age 73.3±7 years; 26 men) underwent urgent TAAA treatment using the t-Branch stent-graft [18 in the early (2014-2015) period and 24 in the late (2016-2017) period]. Nearly half the patients were symptomatic (n=18) and 12 had contained rupture. Aneurysm diameter >80 mm was present in 12 (mean diameter 77.7±13.2 mm). Nineteen patients did not meet the IFU for the t-Branch due to target vessel anatomy. The primary endpoints were spinal cord ischemia (SCI), renal function impairment, and 30-day mortality. Target vessel patency and endoleak incidence were assessed at 30 days. Multivariate analyses examined associations between perioperative variables and outcomes; the results are presented as the odds ratio (OR) and 95% confidence interval (CI).

RESULTS: The technical success rate was 93% (39/42). Successful catheterization was achieved in 150/155 target vessels (97%). The postoperative SCI rate was 21% (5 paraplegia/4 transient paraparesis) and was correlated with age (OR 1.26, 95% CI 1.01 to 1.56, p=0.04). The renal function impairment rate was 23% (10/42; 2 temporary, 2 permanent dialysis) and was correlated with early experience (OR 7.74, 95% CI 1.3 to 43.9, p=0.019). The 30-day mortality was 14% (no intraoperative deaths); no factor was associated with mortality. During the first month, the incidences of type I, II, and III endoleaks were 0%, 43%, and 0%, respectively; branch patency was 99% (150/151). Procedure time decreased in the later experience (479±333 vs 407±25 minutes, p=0.09), though it was increased in cases outside the IFU (497±135 vs 389±118 minutes, p=0.009), along with fluoroscopy time (121±48 vs 92±33 minutes, p=0.036).

CONCLUSION: Endovascular repair of urgent TAAA using the t-Branch is a feasible treatment option with acceptable 30-day mortality and morbidity in terms of SCI and renal function impairment. Adherence to the IFU prolonged procedure time but had no effect on outcomes. Increased experience of such cases over time may improve outcomes.