Mechanical Characterization and Ex Vivo Evaluation of a Novel Constraining Device for Safe Endovascular Endograft...

Open surgical conversion after EVAR is morbid and performed without disease-specific instruments. We evaluated the feasibility, and mechanical characteristics of the EVAx, a novel single-use device designed to disengage, collapse, and constrain suprarenal aortic fixation barbs during open endograft explantation.

Slide and constrainment testing was performed across five endograft configurations spanning three platforms: Endurant II (25, 36 mm), Treo (28 mm), and Zenith (28, 36 mm). Endografts were embedded in a silicone aortic model (25 mm inner diameter), and three operators each performed five trials per configuration (n = 150). The EVAx was compared with the modified syringe technique in bovine aortic specimens across three operators, with the primary objective of evaluating macroscopic intimal injury after aortic endograft explant. Additionally, constraining arms underwent uniaxial compression to failure on an Instron load frame in intended- and reverse-loading orientations.

The EVAx successfully advanced over the Endurant and Treo platforms in all trials (100%) and the Zenith platform in 90%, with the 36 mm Zenith showing the lowest slide success (80%). Constrainment success was 100% for the Endurant 36 mm and Treo, 80% for the Endurant 25 mm, and 80% and 47% for the Zenith 28 mm and 36 mm. The EVAx produced no macroscopic intimal injury across all operators, whereas one specimen removed with a syringe showed barb puncture sites. Constraining arms failed at a peak force of 25 N.

The EVAx demonstrates early feasibility in ex vivo testing for safe suprarenal endograft constrainment, with reproducible benchtop performance and reduced aortic wall trauma compared with the modified syringe technique. These results offer promise of reduced aortic wall trauma utilizing the EVAx, a disease-specific device for endograft removal.