Late Outcomes of Thoracic Endovascular Aneurysm Repair Outside Versus Inside Instruction for Use

To evaluate results of thoracic endovascular aortic repair (TEVAR) for thoracic aortic aneurysm (TAA) and to investigate outcomes based on adherence to manufacturer's instructions for use (IFUs).

Patients treated with TEVAR in 4 tertiary hospitals between 2010 and 2021 were collected. Patients with connective tissue disorders, post-dissection TAAs, aortic coarctation and intramural haematomas were excluded. Both elective and urgent procedures were considered. Primary outcome was long-term survival. Secondary outcomes were: aortic-related reinterventions and late TEVAR failure.

Out of 192 patients, 147 (76%) had endografts deployed inside IFU and 45 (24%) did not. Early outcomes were similar between groups with mortality rates of 6% inside IFU and 8.8% outside. Median follow-up was 36 months (interquartile range 20-63 months). Survival rate at 1, 3, and 5 years were 90%, 75%, and 61% for IFU group and 97%, 87%, and 66% for outside-IFU group (P = .55). Freedom from aortic-related reintervention at 1, 3, and 5 years were 94%, 87%, and 80% for IFU group and 88%, 78%, and 74% for outside IFU group (P = .04). TEVAR failure at 5 years occurred in 18 (13%) of inside IFU and 9 (22%) of outside IFU (P = .13).

TEVAR is safe and effective in the long-term. Performing TEVAR outside IFU guidelines can still be acceptable but poses a higher risk of reintervention, especially for proximal landing zone violations. Close follow-up is essential to detect late failures.