Predictive value of great saphenous vein mapping prior to endoscopic harvesting in coronary artery bypass surgery

OBJECTIVES The use of endoscopic vein harvesting in patients undergoing coronary artery bypass grafting is increasing, often using bedside mapping. However, data on the predictive value of great saphenous vein (GSV) mapping are scarce. This study assessed whether preoperative mapping could predict final conduit diameter. METHODS A prospective registry was created that included 251 patients. Saphenous vein mapping was performed prior to endoscopic vein harvesting at 3 predetermined sites. After harvesting and preparing the GSV, the outer diameters were measured. Appropriate graft size was defined as an outer diameter between 3 and 6 mm. RESULTS A total of 753 GSV segments were analysed. The average mapping diameter was 3.2 ± 0.7 mm. The harvested GSV had a mean diameter of 4.7 ± 0.8 mm. Mapping diameters were significantly positively correlated with actual GSV diameters (correlation coefficient, 0.47; P < 0.001). If the preoperative mapping diameters were between 1.5 and 5 mm, 96.6% of the GSVs had suitable dimensions after endoscopic vein harvesting. CONCLUSIONS Preoperative bedside mapping moderately predicts final GSV size after endoscopic harvesting but could not detect unsuitable vein segments. However, the majority of endoscopically harvested GSVs had diameters suitable to be used as coronary bypass grafts.