Background. Our study evaluates a series of video-assisted minimally invasive mitral operations, showing safe progression toward totally endoscopic techniques. Methods. Consecutive patients with isolated mitral valve disease underwent either manually directed (n = 55) or voice-activated robotically directed (n = 72) video-assisted mitral operations. Cold blood cardioplegia, a transthoracic aortic clamp, a 5-mm endoscope, and a 5-cm. minithoracotomy were used. This video-assisted minimally invasive mitral operation cohort was compared with a previous sternotomy-based mitral operation cohort (n = 100). Results. Group demographics, New York Heart Association classification, and cardiac function were similar. Repairs were performed in 61.8% manually directed (n = 34), 75.0% robotically directed (n = 54), and 54% sternotomy-based (N = 54) mitral operations. The robotically directed technique showed a significant decrease in blood loss, ventilator time, and hospitalization compared with the sternotomy-based technique. Manually directed mitral operations compared with robotically directed mitral operations had decreased arrest times (128.0 +/- 4.5 minutes compared with 90.0 +/- 4.6 minutes; p < 0.001) and decreased perfusion times (173.0 +/- 5.7 minutes compared with 144.0 +/- 4.6 minutes; p < 0.001). In the minimally invasive mitral operation cohort, complications included reexploration for bleeding (2.4%; n = 3) and one stroke (0.8%), whereas the 30-day mortality was 2.3% (n = 3). Conclusions. Video-assisted mitral surgery provides safe and effective results when compared with conventional sternal approaches. These positive results show a safe and stepwise evolution toward a totally endoscopic mitral valve operation. (C) 2001 by The Society of Thoracic Surgeons.