Aneurysm extent-based mortality differences in complex endovascular repair of thoracoabdominal aneurysms in the Vascular Quality Initiative and the United States Aortic Research Consortium

Abstract

Background: Endovascular management of thoracoabdominal aneurysms (TAAA) is becoming more common. Technological advances including custom devices under the Physician-Sponsored Investigational Device Exemption (PS-IDE), physician-modified endografts (PMEG), and parallel stenting techniques have expanded the extent of disease that is amenable to endovascular treatment. Patients within the PS-IDE studies are a highly selected group of patients, whereas patients treated with PMEG as captured within the Society for Vascular Surgery Vascular Quality Initiative (SVS VQI) represent a real-world experience. Research within both the SVS VQI on PMEG and the US Aortic Research Consortium (US-ARC) has demonstrated a relationship between extent of aneurysmal disease and mortality after complex endovascular TAAA repair, but no direct comparison of these cohorts has been conducted. In this study, we sought to compare outcomes of custom PS-IDE devices with off-label uses of commercially available devices for the endovascular management of TAAAs.

Methods: A retrospective review of patients presenting for elective endovascular TAAA repair for asymptomatic disease between 2011 and 2019 was conducted within both the SVS VQI registry and the US-ARC. Patients within the SVS VQI registry were treated with either PMEG or with parallel stenting techniques. Patients within the US-ARC were treated with PS-IDE custom devices. The extent of aneurysm disease was defined by the deployment zones documented for the devices entered in the registry using Crawford extents I to V. Primary outcomes were 30-day and 1-year mortality rates.

Results: A total of 3212 patients were included in the study: 1571 PMEG/parallel stenting within the VQI registry and 1641 with PS-IDE within the US-ARC database. The majority of patients presented with extent IV aneurysms (n = 1827 [57%]), with extent IV aneurysms being slightly more prevalent within the US-ARC cohort. Maximal aneurysm diameter within each extent did not vary between the US-ARC and VQI cohorts. Across all patients, the 30-day mortality was 4.4% and the 1-year mortality was 12.2%. Unadjusted mortality at 30-days was 6.7% within the VQI, and 2.2% in the US-ARC (P < .001). The unadjusted 1-year mortality was 14.3% within the VQI and 10.2% within the US-ARC (P < .001). When adjusted for aneurysm extent, similar differences in 30-day and 1-year survivals were identified.

Conclusions: Patients treated in PS-IDE studies had better 30-day and 1-year survival rates compared with those treated with a similar extent of disease using off-label approaches in a real-world registry. These differences are complex and likely associated with a number of factors, including arterial anatomy, patient comorbidities, device construct, and volume outcomes, as well as complex and unmeasurable surgeon- and patient-specific factors.

Keywords: Endovascular repair; Society for Vascular Surgery's Vascular Quality Initiative (SVS VQI); Thoracoabdominal aneurysm (TAAA); United States Aortic Research Consortium.