To evaluate the safety and efficacy of a novel, reverse thermo-sensitive polymer (LeGoo™) for its ability to provide temporary coronary occlusion and hemostasis during minimally invasive direct coronary artery bypass (MIDCAB) surgery. Between January 2009 and March 2009, 20 consecutive MIDCAB patients were studied. Ten patients received a conventional MIDCAB procedure using proximal vessel loops and CO2 blower (control group). The following 10 patients were operated by an otherwise identical procedure, except that intracoronary administration of LeGoo™ was used instead of vessel snares (LeGoo™ group). Left internal mammary artery (LIMA) bypass flow, peri- and postoperative events and perioperative creatinine kinase-MB fraction (CK-MB) release were prospectively analyzed. CO2-blower use was required in three of 10 of the LeGoo™ patients. Procedural time was identical, with a trend of shorter anastomosis time in the LeGoo™ group (12.3 vs. 10.7 min, P=0.11). LIMA-LAD flow was also not different (control 35.8 vs. LeGoo™ 42.5 ml/min, P=0.541). CK-MB values were not statistically different on postoperative days 1 and 2. However, the level of CK-MB 4 h postoperatively was lower in LeGoo™ patients (18.3±6.1 vs. 13.2±2.9 U/l, P=0.006). No major adverse cerebral or cardiovascular event occurred postoperatively and during follow-up of 317±21 days. Using LeGoo™ to achieve temporary coronary artery occlusion is easier to work with during MIDCAB due to the absence of vessel snares and less need of blowing to eliminate blood from the operative field. There were no negative postoperative events associated with the use of LeGoo™.