Exceptional Finding of Double Pannus in Aortic and Mitral Mechanical Prosthetic Valves Using Noninvasive Imaging: A Case Report.

Pannus formation is a rare but clinically important complication of mechanical prosthetic valves. The incidence of pannus in aortic prostheses is much higher than that in mitral prostheses, the latter being more prone to thrombosis. However, the presence of pannus in both prostheses is an exceptional finding. The authors present the case of a 61-year-old woman with a long history of rheumatic multivalvular disease. She had undergone three cardiac surgeries for mechanical valve prosthesis replacement in the aortic, mitral, and tricuspid positions. She was hospitalized for atypical angina and blockpnea. Transthoracic echocardiography revealed dysfunction of both the aortic and mitral mechanical prostheses due to a subvalvular mass. Transesophageal echocardiography (TEE) and CT scan showed interference from this mass, which had the appearance of pannus; this was confirmed intraoperatively, and the pannus was removed. The postoperative course was favorable. This case reports a rare clinical situation and underlines the significant role of cardiac CT and TEE in the assessment of subvalvular pannus formation in mechanical valves.