Introduction
The aortic valve (AV) is a semilunar valve and is derived from endocardial cushions of the primitive heart tube. The right and left cusps stem from conotruncal cushions, whereas the non-coronary cusp originates from right-posterior intercalated cushions. Cavitation of the cushions leads to separation of the cusps with formation of a lumen, and this is followed by elongation and thinning of the cusps. Dysregulation of extracellular matrix remodeling for instance, can lead to valve malformations, and thus different valve phenotypes 1.
The normal AV-phenotype is tricuspid, but we know that AVs can range from unicuspid (UAV) to quadricuspid valves, with even further variability beyond this spectrum 2. Nonetheless, UAVs are rare congenital heart valve malformations, with an estimated prevalence of 0.02% 3. Although there is no official classification for UAVs, possibly due to its’ rarity, we generally distinguish between an acommissural- and unicommissural phenotype(Figure1A,B) .
UAVs can be repaired through biscuspidization. This is generally achieved through patch augmentation of both cusps (e.g. butterfly patch), with or without realignment of the commissural angle or aortic annuloplasty 4, 5. As in other AV-phenotypes, there is a spectrum of UAV morphologies. However, the commissure is usually positioned posteriorly (Figure1B) and the height of the two raphae is generally lower (5-15mm) than the level of the commissure6, as in bicuspid AVs 6, 7. Nonetheless, there is no one technique fits all approach for UAV-repair, and herein we are presenting our original technique for bicuspidization of a regurgitant UAV without the usual patch augmentation of the cusps.