Comparison of endoscopic versus conventional internal mammary harvesting regarding unligated side branches

In an effort to minimise access in cardiac surgery, endoscopic vessel harvesting has become more popular. The endoscopic approach, however, allows for only the harvest of the mid to distal internal mammary artery (IMA), leaving the more proximal branches of the conduit available for collateral flow away from the coronary bed. To compare the number and anatomic variation of remaining side branches in thoracoscopic vs. conventional IMA harvesting. 199 fresh cadavers were randomly divided into two groups. Group A (n = 100) underwent endoscopic IMA harvesting. In Group B (n = 99), IMAs were harvested using an open conventional approach. In both groups during surgery, side branches of the IMA were isolated and identified. The two groups were comparable with regard to mean age and age distribution, male sex (56% vs. 63%, respectively), cause of death and coronary risk factors including smoking, diabetes, dyslipidaemia and hypertension. 24 of 199 cadavers(12%) had a lateral costal branch. The left IMA arose from the third part of the subclavian artery in 6%, and from the thyrocervical trunk in 7% of the cadavers. There were significantly more unligated side branches in Group B compared to Group A (14 branches vs. 3 branches, p < 0.01). The first intercostal artery and lateral costal artery were found unligated in 3% and 5% of cadavers in Group B, whereas no side branch remained unligated in Group A. There was no subclavian artery or IMA injury in either group. Internal mammary vein was damaged in 2% of cadavers in Group B. Thoracoscopic left IMA harvesting is more accurate in finding and ligating the side branches of IMA.