Significant transaortic gradient after direct flow aortic valve implantation

A patient with severe aortic valve disease and high surgical risk underwent Direct Flow (DF) valve implantation. Anatomical assessment (Trans-esophageal echocardiography (TEE) and CT scan) revealed a 3-leaflet aortic valve (annulus diameter 23.4 mm) that was functionally bicuspid because of complete and linearly calcified fusion of noncoronary and right cusps. The valve had severe stenosis (peak/mean gradients of 70/45 mm Hg) and moderate to severe regurgitation. A balloon valvuloplasty (semicompliant 23 mm × 45 mm balloon, 2 inflations) was performed with persistence of balloon waist. A 25 DF valve was positioned in the aortic annulus, with both rings well expanded. A mild deformity in the vertical supporting tubes was observed but considered nonrelevant because valve function (peak/mean gradients of 25/12 mm Hg respectively and no aortic regurgitation) was acceptable. Then the polymer was injected and the valve released from its attachments. Postoperative course was uneventful without clinical complications; nevertheless 3 days later Doppler peak/mean transaortic gradients were 80/45 mm Hg. These high gradients were confirmed by direct invasive measurements while CT scan documented a severe geometrical deformation of the valve cuff. Since patient was in good clinical condition, a conservative strategy was adopted. Eight months later, patient functional status had improved (NYHA class II), left ventricular dimensions decreased, left ventricular ejection fraction (LVEF) increased, and valve gradients remained unchanged; therefore surgical aortic valve replacement has been deferred until clinical indication. Such a favorable course can be explained by disappearance of aortic regurgitation. Patient anatomical and procedural features that conditioned this very rare phenomenon are discussed as well as clues to prevent it.