Dedicated Closure Device for Transcaval Access Closure: From Concept to First-in-Human Testing

This study sought to test safety and exploratory effectiveness of a dedicated transcaval closure device (TCD).

Transcaval access enables delivery of large-caliber devices to the aorta in patients ineligible for transfemoral arterial access. Closure of aortocaval fistulae using off-label nitinol cardiac occluders has been shown to be safe, but persistent aortocaval fistulae at exit from the catheterization lab and bleeding complications were common in a prospective study.

Preclinical testing of the TCD was performed in 24 Yorkshire swine, including 10 under good laboratory practice conditions. Subsequently, subjects undergoing transcatheter aortic valve replacement for symptomatic severe aortic stenosis, ineligible for transfemoral arterial access, were enrolled in a U.S. Food and Drug Administration-approved early feasibility study of the TCD (Transmural Systems, Andover, Massachusetts). Independently adjudicated endpoints included technical, device, and procedural success, incorporating in-hospital and 30-day clinical and imaging follow-up.

Transcaval access and closure in swine confirmed that at 30 days, TCDs were almost entirely endothelialized. Subsequently, 12 subjects were enrolled in the early feasibility study. Transcaval access, transcatheter aortic valve replacement, and aortocaval fistula closure was successful in all 12 subjects. The primary endpoint of technical success was met in 100% of subjects. Complete closure of the transcaval access tract was achieved in 75% of subjects at exit from the catheterization lab and in 100% of subjects at 30 days. There were zero modified Valve Academic Research Consortium-2 major vascular complications and zero Valve Academic Research Consortium-2 life-threatening or major bleeding complications related to transcaval access or the TCD.

The TCD achieved complete closure of the transcaval access tract in most subjects at exit from the catheterization lab and essentially eliminated transcaval-related bleeding. Dedicated devices for transcaval access and closure could enable more widespread adoption of transcaval techniques without fear of bleeding complications. (Transmural Systems Transcaval Closure Device for Transcaval Access Ports During Transcatheter Aortic Valve Replacement; NCT03432494).