Aorto-right pulmonary venous fistula after mitral valve replacement for prostheticmitral valve infective endocarditis: a case report

Background Aorto-cavitary fistula is a rare condition, and the most common underlying aetiology is infective endocarditis (IE) of the native or the prosthetic aortic valve. We report a case of aorto-right inferior pulmonary venous fistula following redo mitral valve replacement (MVR) for prosthetic mitral valve IE. Case summary A 74-year-old woman underwent urgent redo MVR for prosthetic mitral valve IE. The post-operative course was complicated with heart failure and mediastinal haematoma compressing the left atrium. The haematoma was surgically removed and laceration of the left atrial wall was suture ligated; this was attributed to the surgical trauma dissection of the adhesive tissues. One-week post-operatively, a continuous murmur emerged, which prompted an evaluation of the left to right shunt. Transthoracic echocardiography revealed an echolucent area posterior to the aorta, with continuous flow on colour Doppler. Three-dimensional computed tomography showed a fistula between the aorta and the right inferior pulmonary vein. There was a high risk involved in surgical management; therefore, she was managed medically. Fortunately, the continuous murmur and echolucent space disappeared after 6 months. The fistula was considered to be obstructed by spontaneous thrombus formation in the narrowed segment of the fistula tract. Discussion The cause of fistula was attributed to possible surgical trauma in the presence of infection. The present case was unique, as it showed spontaneous healing of an aorto-cavitary fistula, which is very rare. The patient was alive with good health status, 6 years after the MVR.