Treatment of uncomplicated acute type B aortic dissection in the endovascular era: is it time for a paradigm shift?

Abstract

Qin et al.(1) reported a multi-institutional retrospective study involving three hospitals that analyzed and compared the effects of thoracic endovascular aortic repair (TEVAR) combined with best medical treatment (BMT) versus BMT alone for treating uncomplicated acute type B aortic dissection (TBAD). The controversy regarding the actual efficacy and benefits of TEVAR in uncomplicated acute TBAD is partly attributable to study reports based on analysis over a heterogeneous population of both complicated and uncomplicated TBAD patients (2). To address this issue, Qin et al. selectively included patients diagnosed with uncomplicated acute TBAD only. The results clearly showed a greater benefit of adding TEVAR to BMT over BMT alone. Currently, TEVAR is a class II recommendation for treating uncomplicated acute TBAD, while BMT remains a class I recommendation (3,4). The lower class of recommendation for TEVAR is mostly attributable to the lack of robust data to support its routine application. Currently, BMT appears to demonstrate relatively enhanced short-term outcomes. However, the early benefits do not seem to be sustained over time, as evidenced by the time-dependent occurrence of aneurysmal degeneration and rupture or disease progression. Up to 40% of patients reportedly undergo surgery after BMT, resulting in a relatively low overall 6-year interventionfree survival rate approximating 41% (5-7). Furthermore, the reported 3-, 5-, and 6-year mortality rates are also suboptimal at 22.4%, 27.9%, and 42%, respectively (7-9).In contrast to uncomplicated TBAD, TEVAR is a class I recommendation for complicated acute TBAD (3,4). Considering the relatively poor long-term outcomes of BMT alone and the encouraging results observed with TEVAR for complicated acute TBAD, it seems reasonable to expect improved outcomes with TEVAR added to BMT for this condition. The ADSORB trial was the only prospective, randomized clinical trial aimed at collecting level A evidence for treating uncomplicated acute TBAD with TEVAR (10). Although the 1-year analysis was too short to address some of the more long-term issues, and the relatively small cohort size was limiting for an adequate statistical power of analysis, the procedural safety and significantly enhanced outcomes in terms of greater, albeit incomplete, false lumen (FL) thrombosis, decrease in FL size, and increase in true lumen (TL) size supported adding TEVAR to BMT (10). Similar to the ADSORB trial, Qin et al.(1) conducted a multi-institutional but a retrospective study. Despite its limitations, the study involved a larger cohort of 338 patients in which 184 received TEVAR plus BMT and 154 received BMT alone. Furthermore, the follow-up duration was significantly longer at 11 years. Therefore, the major strengths of this study were in the greater statistical power of analysis and the ability to provide valuable information regarding the primary endpoints over a significantly longer period of time. In this study, BMT plus TEVAR showed significantly fewer overall all-cause aorta-...