Key result
Simplified UNICORN TAVI technique achieves ~86% technical success without coronary obstruction in high-risk patients.
Why the study?
Coronary obstruction during TAVI for degenerated surgical or transcatheter aortic valves is life-threatening, prompting evaluation of a simplified UNICORN leaflet modification technique with self-expanding platforms.
Does leaflet modification using a simplified UNICORN technique prevent coronary obstruction in high-risk patients undergoing TAVI for degenerated bioprosthetic valves with self-expanding platforms?
Does leaflet modification using a simplified UNICORN technique prevent coronary obstruction in high-risk patients undergoing TAVI for degenerated bioprosthetic valves with self-expanding platforms?
The simplified UNICORN technique is a feasible method to prevent coronary obstruction during TAV-in-SAV and TAV-in-TAV procedures using self-expanding platforms, though it carries risks of hemodynamic instability and ventricular perforation.
May warrant consideration in high-risk TAVI with self-expanding valves to avoid obstruction; hypothesis-generating and should not yet change practice.
Background Coronary obstruction during transcatheter aortic valve implantation (TAVI) for degenerated surgical (SAV) or transcatheter aortic valves (TAV) is a life-threatening complication. Several techniques have been proposed to overcome this issue. The aim of this study was to evaluate the efficacy and safety of leaflet modification using a simplified version of the undermining iatrogenic coronary obstruction using radiofrequency needle (UNICORN) technique, originally described for balloon-expandable platforms. Methods This study included consecutive patients undergoing TAVI with self-expanding platforms for degenerated SAV or TAV at our Heart Valve Clinic between 2023 and 2025 who were deemed at high risk of coronary obstruction and received coronary protection with the simplified UNICORN technique. The simplified UNICORN technique involves electrosurgical traversal of the target leaflet with a straight 0.035-inch guidewire supported by a microcatheter. After successful traversal, the wire is exchanged for a stiff 0.035-inch wire and the leaflet is directly ballooned with large balloons prior to laceration and subsequent TAV implantation. Procedural and in-hospital outcomes according to Valve Academic Research Consortium (VARC-3) criteria were evaluated. Results Seven patients were included in this study. Mean age was 76 years and 5/7 were female, presenting with symptomatic bioprosthetic valve failure. The degenerated index valve was SAV in 6/7 and TAV in 1/7 cases. The left coronary artery was at risk in all cases, and the left neo-cusp was the target of all the UNICORN procedures. Additionally, 2/7 of patients received coronary protection for the right coronary artery by means of chimney stenting. A cerebral protection device was used in 3/7 cases. The implanted TAV was Evolut R/PRO (Medtronic) in 6/7 cases and ALLEGRA (Biosensors) in 1/7 cases. VARC-3 technical success was achieved in 6/7 (85.7%) patients, with 1 procedure-related death related to ventricular perforation. Hemodynamic instability after leaflet laceration was observed in 2/7 (28.5%) cases. No peri-procedural coronary obstruction events occurred. Conclusion Leaflet modification using a simplified UNICORN technique for TAV-in-SAV and TAV-in-TAV using self-expanding platforms is feasible and effective in preventing coronary obstruction. Further data are needed to confirm these findings.
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Beneduce et al. (2026) studied this question. The simplified UNICORN technique for TAVI with self-expanding platforms achieved 85.7% technical success with no peri-procedural coronary obstruction events in seven high-risk patients.
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