The patient had the symptom as intermittent palpitations after the surgery of mechanical mitral valve replacement for six years later.Transthoracic echocardiography(TTE)indicated that mechanical mitral valve was stuck.Second valve replacement surgery was planned for treating with mitral valve.Preoperative anes-thetized TTE and real-time three-dimensional transesophageal echocardiography(3D-TEE)indicated the presence of an unstable stuck valve,with the instability caused by excessive pannus formation around the annulus.Finally,we choosed to clean the surrounding pannus rather than replace the mechanical mitral valve again.Follow up in 6 months,the cardiac function recovered well,and the quality of life improved significantly.