Fig. 1From: Causes and treatment strategies of unilateral leaflet escape of bileaflet mechanical prosthetic heart valves after surgery: a case seriesPhysical drawing of a dismantled bileaflet mechanical valve. When the mechanical valve was removed, one lobe of the valve was missing, and the proliferative tissue around the valve had a complete annular structure. MMV: Mechanical mitral valve; PTV: Proliferative tissue of valveBack to article page