Conceiving MitraClip as a tool: percutaneous edge-to-edge repair in complex mitral valve anatomies.

Improvements in procedural technique and intra-procedural imaging have progressively expanded the indications of percutaneous edge-to-edge technique. To date in higher volume centres and by experienced operators MitraClip is used for the treatment of complex anatomies and challenging cases in high risk-inoperable patients. This progressive step is superimposable to what observed in surgery for edge-to-edge surgery (Alfieri's technique). Moreover, the results of clinical studies on the treatment of patients with high surgical risk and functional mitral insufficiency have confirmed that the main goal to be achieved for improving clinical outcomes of patients with severe mitral regurgitation (MR) is the reduction of MR itself. The MitraClip should therefore be considered as a tool to achieve this goal in addition to medical therapy. Nowadays, evaluation of patient's candidacy to MitraClip procedure, discussed in local Heart Team, must take into account not only the clinical features of patients but even the experience of the operators and the volume of the centre, which are mostly related to the probability to achieve good procedural results. This 'relative feasibility' of challenges cases by experienced operators should always been taken into account in selecting patients for MitraClip. Here, we present a review of the literature available on the treatment of complex and challenging lesions.