Leaflet Modification Technique With UNICORN in Failed Aortic Bioprosthesis

Abstract

The UNICORN (undermining iatrogenic coronary obstruction with radiofrequency needle) technique was developed in 2022 to reduce the risk for coronary obstruction during valve-in-valve transcatheter aortic valve replacement. The procedure involves traversing the target leaflet with an electrified wire, followed by serial dilation with coronary and peripheral balloons. A balloon-expandable valve is then delivered into the de novo fenestration for intraleaflet deployment. As the balloon-expandable valve expands, the target leaflet is opened and displaced away from the at-risk coronary ostium, resulting in a minimal neoskirt on the target side. Since its introduction, the technique has been adopted at numerous centers worldwide, with various modifications and adaptations. In this paper, a step-by-step description of the UNICORN procedure is provided, and troubleshooting strategies for potential challenges are discussed.