EXPANSION DEVICE FOR OPENING VALVE PERIMETER IN CARDIAC SURGERY

A tissue expander/retractor tool works within a narrow cavity/tunnel to access a deeper structure (e.g., the mitral valve) without consuming a significant amount of space either within the small through-hole or in the vicinity of the entrance to the port. The tool provides the user with direct control of the expansion and separation of a target area. The moving parts of the tool have a closed configuration with a narrow profile for insertion/removal and an open configuration obtained using a remotely-controlled, compact pivot mechanism that provides a broad enlargement capability for the retraction jaws. A pantograph mechanism with input pivots and output pivots is coupled between the retraction jaws and a compound cable (e.g., Bowden cable). A handle is coupled to the other end of the compound cable for displacing the inner wire along the outer tube.