Learning Curve of Thoracoscopic Nonrobotic Harvest of the Left Internal Mammary Artery in Minimally Invasive Coronary Artery Bypass Grafting

Objective: Harvest of the left internal mammary artery (LIMA) is a technically demanding element of minimally invasive coronary surgery. We aimed to evaluate the learning curve of thoracoscopic, nonrobotic LIMA harvest during endoscopic coronary artery bypass (EndoCAB) surgery. Methods: Eighty patients undergoing Endo-CAB surgery were included. LIMA harvest was performed using commonly available video-assisted thoracoscopic instruments. Time from incision until heparin administration was defined as total LIMA harvest time (this includes opening of the pericardium and identification of coronary targets). LIMA harvest times (N = 80) and total procedure times for single-vessel grafting (n = 51) were analyzed. Results: The mean LIMA harvest time was 58 +/- 19 min, ranging from 15 to 113 min. The mean procedure time was 150 +/- 39 min. Significant reductions in both LIMA harvest and total Endo-CAB procedure times were observed with increasing experience (logarithmic regression Y = 109 - 14.9*log(x), P < 0.001; Y = 227 - 24.4*log(x), P < 0.001, respectively). No damage to the LIMA occurred during thoracoscopic harvesting. Conclusions: Total thoracoscopic (nonrobotic) LIMA harvest is an efficient technique with a steep learning curve using routine instruments. More patients might benefit from minimally invasive coronary surgery using thoracoscopic LIMA harvest techniques.