Randomized Clinical Trial Comparing a Thermosensitive Polymer (LeGoo) With Conventional Vessel Loops for Temporary Coronary Artery Occlusion During Off-Pump Coronary Artery Bypass Surgery

Background. During off-pump coronary artery bypass graft (OPCABG) surgery, a bloodless surgical field is mandatory for visualization and construction of optimal coronary anastomoses. Presently used temporary vascular occluders are known to cause endothelial dysfunction and vessel injury. The present prospective multicenter randomized clinical trial evaluates safety and efficacy of a novel thermosensitive polymer (LeGoo) as an atraumatic temporary vascular occluder. Methods. Between July 2008 and February 2010, 110 patients undergoing OPCABG were randomized between LeGoo (LG) and conventional vessel loops (VL) for coronary artery occlusion during construction of the distal anastomosis. A semiquantitative 4-point scale was used to evaluate the degree of bloodless surgical field and surgical comfort. Duration of coronary artery occlusion was also recorded. Safety during the operation and ensuing 30 days was evaluated by a composite endpoint of major adverse cardiac events that consisted of death from all causes, graft occlusion, myocardial infarction, and low cardiac output. Results. Fifty-six patients (117 distal anastomoses) were randomly assigned to LG and 54 patients (122 anastomoses) to VL. There were 2 anastomoses crossed over from LG to the control arm, and 3 from control to LG. Five anastomoses in LG patients were treated with an alternative device (shunts). Satisfactory hemostasis was achieved in 88.0% of LG anastomoses (103 of 117) compared with 60.7% of VL anastomoses (74 of 122; p <0.001). Mean total anastomotic time was 12.8 minutes in the LG group and 15.1 minutes in the VL group (p <0.001). This difference was more pronounced for arteries on the posterior and lateral than on the anterior walls of the heart. Composite adverse events were similar in the two groups: 3 of 48 LG patients and 3 of 46 VL patients. There was 1 death in the LG group. One patient in the LG group and 1 in the VL arm had a myocardial infarction. No operation was converted from OPCABG to CABG with cardiopulmonary bypass. Conclusions. LeGoo is a safe and effective temporary coronary occluder during OPCABG. It provided a dry surgical field for visualization of the anastomotic field and surgical comfort more frequently than conventional vessel loops. In addition, anastomotic times were shorter with LG. Major cardiac adverse events were similar in the LG and VL arms. (Ann Thorac Surg 2011;92:2177-83)