Endovascular Aneurysm Repair Devices as a Use Case for Postmarketing Surveillance of Medical Devices

Abstract

The US Food and Drug Administration (FDA) is building a national postmarketing surveillance system for medical devices, moving to a "total product life cycle" approach whereby more limited premarketing data are balanced with postmarketing surveillance to capture rare adverse events and long-term safety issues. To assess the methodological requirements and feasibility of postmarketing device surveillance using endovascular aneurysm repair devices (EVARs), which have been the subject of safety concerns, using clinical data from a large health care system. This retrospective cohort study included patients with electronic health record (EHR) data in the Veterans Affairs Corporate Data Warehouse. Implantation of an AFX Endovascular AAA System (AFX) device (any of 3 iterations) or a non-AFX comparator EVAR device from January 1, 2011, to December 21, 2021. The primary outcomes were rates of type III endoleaks and all-cause mortality; and rates of these outcomes associated with AFX devices compared with non-AFX devices, assessed using Cox proportional hazards regression models and doubly robust causal modeling. Information on type III endoleaks was available only as free-text mentions in clinical notes, while all-cause mortality data could be extracted using structured data. Device-specific information required by the FDA is ascertained using unique device identifiers (UDIs), which include factors such as model numbers, catalog numbers, and manufacturer-specific product codes. The availability of UDIs in EHRs was assessed. In total, 13 941 patients (mean [SD] age, 71.8 [7.4] years) received 1 of the devices of interest (AFX with Strata [AFX-S]: 718 patients [5.2%]; AFX with Duraply [AFX-D]: 404 patients [2.9%]; or AFX2: 682 patients [4.9%]), and 12 137 (87.1%) received non-AFX devices. The UDIs were not recorded in the EHR for any patient with an AFX device, and partial UDIs were available for 19 patients (0.1%) with a non-AFX device. This necessitated the development of advanced natural language processing tools to define the cohort of patients for analysis. The study identified a significantly higher risk of type III endoleaks at 5 years among patients receiving any of the AFX device iterations, including the most recent version, AFX2 (11.6%; 95% CI, 8.1%-15.1%) compared with that among patients with non-AFX devices (5.7%; 95% CI, 2.2%-9.2%; absolute risk difference, 5.9%; 95% CI, 2.3%-9.4%). However, there was no significantly higher all-cause mortality for any of the AFX device iterations, including for AFX2 (19.0%; 95% CI, 16.0%-22.0%) compared with non-AFX devices (18.0%; 95% CI, 15.0%-21.0%; absolute risk difference, 1.0%; 95% CI, -2.1% to 4.1%). The findings of this cohort study suggest that clinical data can be used for the postmarketing device surveillance required by the FDA. The study also highlights ongoing challenges to performing larger-scale surveillance, including lack of consistent use of UDIs and insufficient relevant structured data to efficiently capture certain outcomes of interest.