Redo mitral valve replacement in an adult with severe pulmonary hypertension resulting from structural valve deterioration and left ventricular outflow tract obstruction and a history of atrioventricular septal defect repair: a case report

Background Pulmonary hypertension (PH)-associated with left heart disease (Nice PH classification group II) improves when the latter is treated; however, the treatment of PH concomitant with group I PH due to congenital heart disease is difficult, and the optimal pharmacotherapy is controversial. Intervention strategies for the left-sided atrioventricular valve in partial atrioventricular septal defect (AVSD) are problematic. Case presentation A 37-year-old woman who had undergone patch closure for a partial AVSD and mitral valve replacement with a rather large bioprosthesis at the juxta-annular position for mitral regurgitation 12 years earlier was referred to our institute because of severe PH. Echocardiography revealed calcification resulting in severe stenosis of the bioprosthesis and protrusion of its stent post into the left ventricular outflow tract; therefore, redo mitral valve replacement at the supra-annular position was performed using a mechanical valve. Combined group I and II PH gradually improved with meticulous postoperative medical management. Conclusions Severe PH due to stent post protrusion and structural valve deterioration in AVSD was successfully treated with redo mitral valve replacement. The present case was complicated with group I and II PH, for which medical therapy in conjunction with surgical treatment yielded an optimal therapeutic effect. Keywords: Atrioventricular septal defect, Calcified bioprosthetic mitral valve, Pulmonary hypertension, Left ventricular outflow tract obstruction, Stent post protrusion