[Open mitral commissurotomy. Experience of the Ignacio Chávez National Institute of Cardiology].

From 1970 to 1979 open mitral commissurotomy (OMC) was indicated in 167 patients. In 22 cases a valvular prosthesis was inserted. In the 145 patients subjected to OMC there was one hospital and one late death. Four late systemic emboli (SE) in three patients. In 92% there was improvement in functional class. Poor post-op course in 8% due to mitral regurgitation (MR) added to mitral stenosis or iatrogenic MR subjected to annuloplasty with poor results and eventual mitral prosthetic implantation. Pre-op SE in 35%, intracavitary thrombosis (IT) in 23% and in 13% of cases without history of SE. IT found as often in atrium as in left auricular appendage. The vast majority of patients with IT were in atrial fibrillation (AF), this arrhythmia was present in 34% of the 145 cases. In hospitals where all cases of predominant mitral stenosis (MS) cannot be operated by OMC because of logistics, cases of MS with AF and surgical indication should be operated by OMC because of the correlations between AF and IT. Other indications for OMC are reviewed. The excellent post-op results with scarce late complications re-enforce the convenience of retaining the human mitral valve and avoiding valve replacement when repair is possible.