Validity of current surgical strategies for aneurysmal progression in post-subacute Stanford type B aortic...

The use of preemptive thoracic endovascular aortic repair (TEVAR) has been expanding, especially in cases where aortic enlargement is an indication for surgical intervention. Current guidelines recommend treatment for chronic type B aortic dissection (TBAD) when aortic diameter increases by ≥5 mm over a 6-month period. However, the optimal window for preemptive TEVAR is the subacute phase (up to 3 months), creating a dilemma where intervention may be delayed beyond this window. This study investigates the short- and long-term outcomes of aggressive treatment for rapidly enlarging aneurysms.

Between July 2004 and August 2024, 432 patients with acute Stanford type B aortic dissection were treated at two centers. Of these, 324 patients who completed acute best medical therapy (BMT) were included. Patients with rapid enlargement of aortic aneurysms who did not meet absolute surgical indications (aneurysm diameter <55 mm and <5 mm/month) were compared to those who continued BMT. Propensity score matching was performed between the BMT group (Group B, n = 83) and the aortic expansion group (Group E, n = 83).

Among the 324 eligible patients, 88 exhibited rapid aortic enlargement (≤5 mm in <6 months). Of these, 42 (48%) underwent surgical intervention: 12 (14%) received graft replacement, and 30 (34%) underwent TEVAR, with 28 (32%) receiving preemptive TEVAR. The BMT group continued without surgery, with 7 patients (3%) receiving graft replacement and 20 (8%) undergoing TEVAR. In Group E, aortic diameter significantly increased compared to Group B (0.4 ± 0.2 vs. 1.1 ± 0.2 mm, p < 0.001). The false lumen was thrombosed in all preemptive TEVAR patients (mean 3.2 ± 5.1 months). In addition, univariate Cox regression identified preemptive TEVAR as a significant protective factor against aorta-related events (HR: 0.03, 95% CI: 0.004-0.22, p < 0.001), highlighting its potential role in reducing adverse aortic outcomes. The aorta-related death-free survival rates at 1, 5, and 10 years were 99/99/99% vs. 99/93/88% for Groups B and E, respectively (p = 0.097). Seven deaths occurred in Group E, with six related to ruptured aortic aneurysms.

Selective preemptive TEVAR for patients with rapid aortic enlargement in the subacute and chronic phases of TBAD showed favorable outcomes. Although no significant difference in aorta-related mortality was found, the higher incidence of rupture in untreated patients suggests that preemptive TEVAR may offer a benefit. Further research is needed to identify the patients most likely to benefit from early surgical intervention.