Preoperative vein mapping for coronary artery bypass operations.

High-resolution, real-time ultrasonographic imaging of the greater saphenous veins was performed preoperatively in 100 patients undergoing coronary artery bypass grafting. Vein diameters were measured by ultrasound at four locations in the leg, and the course of the vein in the leg was marked on the overlying skin. Veins removed at operation were measured at the same locations at initial dissection and after vein preparation. The mapped and in situ vein diameters correlated closely, whereas the distended vein diameter was approximately 1.5 mm larger. When greater saphenous veins were absent or diseased, lesser saphenous veins were mapped. No differences in measurements were demonstrated for a variety of patient and operator variables. Major branches or duplications were predicted correctly in 11 patients and venous disease in 13 patients. Mapping influenced the surgeon's choice of the venectomy site in 13 patients. Vein mapping is a simple, accurate, and noninvasive method of imaging the saphenous vein preoperatively. It is useful in demonstrating areas of venous anomalies and disease, and predicts the course of the vein in the leg.