A recent prospective, multicentre cohort study provides insights into early and late aortic-related mortality and rupture after fenestrated and branched endovascular aneurysm repair (F/BEVAR) of thoracoabdominal aortic aneurysms (TAAAs). Researchers claim these are likely to represent the most comprehensive data on the topic for the foreseeable future, citing the unworkable nature of a randomised study.
Gustavo Oderich, Ying Huang (both University of Texas Health Science Center at Houston–McGovern Medical School, Houston, USA) and colleagues, on behalf of the US Aortic Research Consortium (ARC), write in Circulation that F/BEVAR has been used as a minimally invasive alternative to open surgical repair to treat patients with TAAAs.
The authors explain that, despite the widespread use of fenestrated and branched aortic devices worldwide, they are not currently commercially approved by the US Food and Drug Administration (FDA). Access to these devices, they continue, is limited to those centres with ongoing physician-sponsored investigational device exemption (PS-IDE) studies. The researchers detail that the US ARC has been collecting prospective data from these studies since 2018.
The aim of the present study, the authors note, was to evaluate aortic-related mortality and aortic aneurysm rupture after F/BEVAR of TAAAs. In order to do so, the research team analysed patients enrolled in eight prospective, non-randomised, PS-IDE studies between 2005 and 2020 who underwent elective F/BEVAR of asymptomatic intact TAAAs.
The primary endpoints of the study, Oderich, Huang et al detail, were aortic-related mortality, defined as any early mortality (30-day or in-hospital) or late mortality from aortic rupture, dissection, organ or limb malperfusion attributable to aortic disease, complications of reinterventions, or aortic rupture. Secondary endpoints were early major adverse events, TAAA life-altering events—defined as death, permanent spinal cord injury, permanent dialysis, or stroke—all-cause mortality, and secondary interventions.
Oderich, Huang and colleagues share in Circulation that 1,109 patients were analysed in the study, noting that 589 (53.1%) had extent I–III and 520 (46.9%) had extent IV TAAAs. The patients had a median age of 73.4 years and just under one-third were women.
The investigators report that early mortality was 2.7% and that congestive heart failure was associated with early mortality. Furthermore, they reveal that the incidence of early aortic rupture was 0.4% and that the incidence of early major adverse events and TAAA life-altering events was 20.4% and 7.7%, respectively.
Oderich, Huang et al continue that there were 30 late aortic-related mortalities; the five-year cumulative incidence was 3.8%; and older age and extent I–III TAAAs were independently associated with late aortic-related mortality.
Furthermore, the authors report that 14 late aortic ruptures occurred; the five-year cumulative incidence was 2.7%; extent I–III TAAAs were associated with late aortic rupture; five-year all-cause mortality was 45.7%; and five-year cumulative incidence of secondary intervention was 40.3%.
In the conclusion of their findings, Oderich, Huang and colleagues write that aortic-related mortality and aortic rupture are “uncommon” after elective F/BEVAR of asymptomatic intact TAAAs. They add that half of the aortic-related mortalities within the study occurred early, and that most of the late deaths were not aortic related.
Oderich, Huang et al reiterate that five-year all-cause mortality was high—45.7%—mostly due to non-aortic-related causes, “likely reflecting selection of higher-risk subgroups compared with historical reports of [open surgical repair]”.
The final conclusion the authors make is that secondary interventions were needed in one of four patients. They do stress, however, that three-quarters of these were minor procedures.
The authors recognise several limitations of their study, including possible patient selection bias due to a need to adhere to PS-IDE inclusion and exclusion criteria, the frequency of cause of death being unknown, and the reason for aortic rupture and the aortic diameter at the time of rupture not being available for all patients, among others.
Despite these limitations, the authors underline the significance of the present study. “Given a perceived lack of clinical equipoise to justify a randomised controlled trial,” they comment, “these data are likely to be the most reliable and obtainable to validate the role of F/BEVAR for the treatment of TAAA.”
On the clinical implications, Oderich, Huang and colleagues remark: “Rigorous surveillance after F/BEVAR is required because the need for secondary interventions was high among patients undergoing F/BEVAR of TAAAs, and identifying the need for secondary interventions will paradoxically be higher with better surveillance.”
