Long-Term Outcomes of Stent Extension in Thoracic Endovascular Aortic Repair for Type B Aortic Dissection

BACKGROUND: The long-term efficacy of stent extension in thoracic endovascular aortic repair (TEVAR) for Stanford type B aortic dissection (TBAD) has not been thoroughly evaluated. METHODS: This retrospective multicentre study included patients with TBAD undergoing TEVAR between 2014 and 2021. On the basis of distal descending aorta coverage, patients were stratified into stent extension (SE) and nonstent extension (non-SE) groups. Stent extension was defined as the intentional distal placement of an additional covered stent to lengthen the repair zone within the descending aorta. After 1:1 propensity score matching (PSM) to balance baseline and perioperative characteristics, long-term outcomes were compared. Multivariate regression analysis identified risk factors. RESULTS: Among 511 enrolled patients with a median age of 56 (51-63) years, 241 patients received stent extension, and the average follow-up time was 69.4 months. After PSM (131 pairs), the groups were comparable. The SE group showed significantly lower rates of aortic-related mortality (3.8% vs 10.7%; P = 0.032), negative aortic remodelling (13.7% vs 23.7%; P = 0.039), follow-up entry flow (8.4% vs 18.3%; P = 0.018), and reoperation (3.8% vs 11.5%; P = 0.020). Stent extension was a protective factor against entry flow (odds ratio [OR], 0.67; P = 0.014) and negative remodelling (OR, 0.73; P = 0.002). Risk factors included smaller true lumen diameter and patent false lumen for entry flow and patent false lumen with multiple distal tears for negative remodelling. Entry flow independently predicted aortic-related mortality (OR, 3.54; P < 0.001) and reoperation (OR, 5.63; P < 0.001). CONCLUSIONS: Stent extension during TEVAR for TBAD is associated with improved long-term outcomes, reducing complications and reinterventions. Prospective trials are warranted for validation.