[Left Ventricular Outflow Tract Obstruction After Transcatheter Aortic Valve Replacement due to Pannus Formation].

We experienced a case of surgical aortic valve re-replacement due to structural valve deterioration caused by pannus formation 4 years after transcatheter aortic valve replacement( TAVR). The patient underwent surgery because the mean transvalvular pressure gradient increased to 48 mmHg on echocardiography. Contrast-enhanced computed tomography (CT) was useful for predicting the site of adhesion to surrounding tissue preoperatively and exploring the presence of the pannus. Intraoperative findings showed the TAVR valve was covered with neointima except around the origins of the left and right coronary arteries and was firmly adhered to the surrounding tissues. As residual pannus was present in the subvalvular tissues, it was carefully removed. The explanted TAVR valve functioned well with good opening and closure. The postoperative course was uneventful. Pannus formation can result from mechanical stress. TAVR valves put significantly greater stress on the left ventricular outflow tract than surgical valves and may be more likely to cause pannus formation.