The effect of pannus and weight gain in mitral stenosis after mitral ring annuloplasty.

Pannus formation is a known complication of valve replacement surgery. However, few cases describe pannus formation in the mitral position, and they are mostly associated with prosthetic valves rather than only annuloplasty. We describe the case of a 62-year-old woman who first underwent reductive annuloplasty using a Carpentier-Edwards 28 mm ring prosthesis in 2009 that performed well on regular follow-up for 5 years. In 2014, the patient presented with significant weight gain, shortness of breath (New York Heart Association functional class III) and signs of severe mitral stenosis. Echocardiography demonstrated the formation of a pannus and increased pressure gradients. Removal of the ring prosthesis and pannus-like fibrotic tissue was performed. The native valve was left in place as it had supple leaflets and performed well once properly debrided. The patient remained well throughout a 24-month follow-up. <Learning objective: This case report presents a rare phenomenon that will help familiarize readers with this complication type. Pannus formation of this type is rarely documented and encountered.>.