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Published on: December 11, 2017
Leaflet Modification Technique With UNICORN in Failed Aortic Bioprosthesis: Procedural Step-by-Step, Best Practice,
Kwong-Yue Eric Chan1, Ka-Chun Un2, Ho-On Alston Conrad Chiu2
1Cardiology Division, Department of Medicine, School of Clinical Medicine, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong SAR, China; Cardiology Division, Department of Medicine, Queen Mary Hospital, Hong Kong SAR, China; Cardiac Medical Unit, Grantham Hospital, Hong Kong SAR, China.
The UNICORN technique prevents coronary obstruction during valve-in-valve transcatheter aortic valve replacement by creating an intraleaflet valve deployment. This innovative approach displaces the native leaflet, protecting coronary ostia.
Area of Science:
- Cardiovascular Surgery
- Interventional Cardiology
- Biomedical Engineering
Background:
- Coronary obstruction is a risk during valve-in-valve transcatheter aortic valve replacement (VIV-TAVR).
- Existing techniques may not fully mitigate this risk.
- Novel approaches are needed to improve VIV-TAVR safety.
Purpose of the Study:
- To describe the UNICORN technique for VIV-TAVR.
- To detail the procedural steps and potential adaptations.
- To provide troubleshooting strategies for the UNICORN procedure.
Main Methods:
- The UNICORN technique involves leaflet traversal with an electrified wire.
- Serial dilation creates a de novo fenestration for valve delivery.
- A balloon-expandable valve is deployed intraleaflet for displacement of the native leaflet.
Main Results:
- The UNICORN technique aims to displace the target leaflet away from the coronary ostium.
- This results in a minimal neoskirt on the target side, reducing obstruction risk.
- The technique has seen global adoption with modifications.
Conclusions:
- The UNICORN technique offers a method to reduce coronary obstruction during VIV-TAVR.
- Intraleaflet valve deployment is key to protecting coronary arteries.
- Further adoption and refinement of the UNICORN technique are expected.
