Effectiveness of Proximal Landing Zone 1 and 2 Thoracic Endovascular Aortic Repair for Type B Aortic Dissection by Comparing Outcomes With Thoracic Arch Aneurysm.

Purpose: Hybrid thoracic endovascular aortic repair (TEVAR) for aortic arch aneurysms is a minimally invasive procedure with improved results. This study aimed to clarify the effectiveness and expand the possibilities of zone 1 and 2 landing TEVAR for type B aortic dissection (TBAD) using our treatment strategy.

Methods: This retrospective, single-center, observational cohort study included 213 patients (TBAD, n=69; thoracic arch aneurysm [TAA], n=144; median age, 72 years; median follow-up period, 6 years) from May 2008 to February 2020. The following conditions were satisfied before performing zone 1 and 2 landing TEVAR: TBAD; proximal landing zone (LZ): diameter <37 mm, length >15 mm, and nondissection area, proximal stent-graft: size ≤40 mm and oversizing rate: 10% to 20%, and TAA; proximal LZ: diameter ≤42 mm and length >15 mm, proximal stent-graft: size ≤46 mm and oversizing rate: 10% to 20%. Of the 69 patients in the TBAD group, 34 (49.3%) had patent false lumen (PFL), and 35 (50.7%) had false lumen partial thrombosis (FLPT), including ulcer-like projections. Emergency procedures were performed in 33 (15.5%) patients.

Results: There were no significant differences in the in-hospital mortality (TBAD: 1.5% vs TAA: 0.7%, p=0.544) or the in-hospital aortic complications (TBAD: n=1 vs TAA: n=5, p=0.666). Retrograde type A dissection was not observed in the TBAD group. The aortic event-free rates at 10 years were 89.7% (95% confidence interval [CI]: 78.7%-95.3%) and 87.9% (95% CI: 80.3%-92.8%) in the TBAD and TAA groups, respectively (log-rank p=0.636). In the TBAD group, the early and late outcomes were not significantly different between the PFL and FLPT groups.

Conclusion: Satisfactory early and long-term results were obtained with zone 1 and 2 landing TEVAR. The TBAD cases had the same good results as the TAA cases. Using our strategy, we especially might reduce complications and be an effective treatment for acute complicated TBAD.

Clinical impact: This study aimed to clarify the effectiveness and expand the possibilities of zones 1 and 2 landing TEVAR for type B aortic dissection (TBAD) using our treatment strategy. Satisfactory early and long-term results in the TBAD and thoracic arch aneurysm (TAA) groups were obtained with zones 1 and 2 landing TEVAR. The TBAD cases had the same good results as the TAA cases. Using our strategy, we especially might reduce complications and be an effective treatment for acute complicated TBAD.