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

Abstract

ImportanceThe 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.ObjectiveTo 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.Design, Setting, and ParticipantsThis retrospective cohort study included patients with electronic health record (EHR) data in the Veterans Affairs Corporate Data Warehouse.ExposureImplantation 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.Main Outcomes and MeasuresThe 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.ResultsIn 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%).Conclusions and RelevanceThe 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.

Periodontitis and the risk of all‐cause and cause‐specific mortality among US adults with diabetes: A population‐based cohort study

“…Details of the missing rates for covariates and the method of multiple imputation are shown in Table S1 and Appendix S1. Adjusted absolute risk differences for 5 and 10 years based on the cumulative incidence information were used to summarize the association between PD and all-cause mortality (Elhence et al, 2023;Wang et al, 2023;Weinberg et al, 2023).…”

Doubly Robust Causal Modeling to Evaluate Device Implantation

“…Using doubly robust estimation, Wang et al aimed to estimate average treatment effects (AFX device minus non-AFX devices) for type III endoleaks and all-cause mortality while protecting against model misspecification. Notably, this protection can extend to the proportional hazards assumption often made with Cox models by modeling baseline hazards stratified by treatment group .…”

“…In the October 2023 issue of JAMA Internal Medicine , Wang et al used electronic health record data of 13 941 patients who had received an implanted endovascular aneurysm repair device (EVAR) to evaluate associations of specific devices with rates of type III endoleaks and all-cause mortality. The authors used doubly robust causal modeling to evaluate endovascular graft devices used to treat an abdominal aortic aneurysm (AAA).…”

“…The authors used doubly robust causal modeling to evaluate endovascular graft devices used to treat an abdominal aortic aneurysm (AAA). Wang et al found that devices in the AFX Endovascular AAA Graft System (AFX; Endologix) were independently associated with higher rates of type III endoleaks but not all-cause mortality compared with non-AFX devices. Notably, the authors’ findings differed somewhat from secondary analyses that estimated hazard ratios using conventional Cox models.…”

Unique Device Identifiers—Missing in Action

“…The investigation by Wang and colleagues 6 comes on the heels of 2 recent studies evaluating the safety of AFX stent grafts. 7,8 Despite using methodologies with different data sources, patient populations, and analytical approaches, all 3 groups found that the AFX stent grafts were associated with higher safety risks than were other EVAR devices.…”