Balloon-Assisted Leaflet Laceration to Prevent Coronary Obstruction During TAVR: Step-by-Step Modified UNICORN.

objectivesCoronary obstruction (CO) is a life-threatening complication of transcatheter aortic valve replacement (TAVR). Undermining iatrogenic coronary obstruction with radiofrequency needle (UNICORN) has been recently described as a novel strategy to prevent CO during TAVR. We describe here the step-by-step technique of a modified version of UNICORN. KEY STEPS: First, the target leaflet is traversed using transcatheter electrosurgery with a 0.014-inch wire. After successful leaflet traversal, the leaflet is first ballooned with a noncompliant coronary balloon. Then, the wire is exchanged with a stiff 0.035-inch wire. Over a 0.035-inch wire, the leaflet is completely lacerated with a large noncompliant balloon, and finally the transcatheter heart valve is implanted. POTENTIAL PITFALLS: Electrosurgical traversal of the target aortic valve leaflet should be performed meticulously in the intended location and in front of the coronary ostium. After leaflet laceration, severe aortic regurgitation may result in hemodynamic instability. Cerebral embolic protection should always be used during leaflet modification.

conclusionsModified UNICORN is a viable alternative strategy to prevent CO during high-risk TAVR. Further data are needed to define its efficacy and safety.