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

Background: Endovascular management of thoracoabdominal aneurysms (TAAA) is becoming more common. Tech-nological 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 endo-vascular 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 man-agement 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 1/4 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 vol-ume outcomes, as well as complex and unmeasurable surgeon-and patient-specific factors.