A rare late finding in corrected tetralogy of Fallot: a case report

INTRODUCTION: Isolated pulmonary valve endocarditis is a rare phenomenon. Pulmonary prosthesis endocarditis is even more unusual, with only about 50 descriptions in worldwide literature, and its diagnosis and treatment is a challenge. Due to the increasing number of surgically corrected tetralogy of Fallot (TOF) patients, that often include pulmonary valve implantation, this clinical scenario is likely to become more frequent. CASE PRESENTATION: We describe a 37-year-old man with a previously implanted biologic pulmonary prosthesis after a TOF correction that presented to the emergency department with new-onset fever, orthopnoea, and lower limb oedema. Blood cultures were positive for Streptococcus mitis. Transthoracic echocardiography showed a large mobile mass in the right ventricular outflow tract, apparently originating from the pulmonary prosthesis. Transoesophageal echocardiography (TOE) showed the presence of multiple mobile structures arising from the arterial surface of the prosthesis, extending into the right pulmonary artery and causing right ventricular obstruction. Antibiogram guided treatment was administered and surgery was performed, removing a 9 cm vegetation and replacing the valve. Patient recovered well and was discharged 35 days after. DISCUSSION: In right-sided endocarditis, surgery indications and its timing are much less clear than in left-sided infections, but current literature describes it as associated with a significant morbidity, mortality, and high likelihood of requiring surgery. Large vegetations and clinical signs of haemodynamic impact should prompt consideration of early surgical intervention. The combination of transthoracic and TOE allowed a correct diagnosis and a timely treatment.