Minimally Invasive Mitral Valve Surgery: a 6-year Experience with 714 Patients

Background: This study analyzes a single institutional experience with minimally invasive mitral valve operations of 6 years, reviewing short-term morbidity and mortality and long-term echocardiographic follow-up data.

Methods: Seven hundred fourteen consecutive patients had minimally invasive mitral valve procedures between November 1995 and November 2001; concomitant procedures included 91 multiple valves and 18 coronary artery bypass grafts. Of these 714 patients, 561 patients had isolated mitral valve operations (375 repairs, 186 replacements). Mean age was 58.3 years (range, 14 to 96 years; 30.1% > 70 years), and 15.4% of patients had previous cardiac operations. Arterial cannulation was femoral in 79.0% and central in 21%, with the port access balloon endo-occlusion used in 82.3%. Cardioplegia was transjugular retrograde (54.1%) or antegrade (29.4%). Right anterior minithoracotomy was used in 96.6% and left posterior minithoracotomy in 2.2%.

Results: Hospital mortality for primary isolated mitral valve repair was 1.1% and 5.8% for isolated mitral valve replacement. Overall hospital mortality was 4.2% (30 of 714). Mean cross-clamp time was 92 minutes and mean cardiopulmonary bypass time was 127 minutes. Postoperatively, median ventilation time was 11 hours, intensive care unit time was 19 hours, and total hospital stay was 6 days. Complications for all patients included permanent neurologic deficit (2.9%), aortic dissection (0.3%); there was no mediastinal infection (0.0%). Follow-up echocardiography demonstrated 89.1% of the repair patients had only trace or no residual mitral insufficiency.

Conclusions: This study demonstrates that the minimally invasive port access approach to mitral valve operations is reproducible with low perioperative morbidity and mortality and with late outcomes that are equivalent to conventional operations.