Early experience with B mode ultrasound mapping of the long saphenous vein prior to femorodistal bypass.

B mode ultrasound was used to assess and map the long saphenous vein in 20 limbs prior to femorodistal bypass. The assessment was compared with operative findings. Eighteen of 19 adequate veins and 8 of 9 anatomical abnormalities or major divisions were correctly identified. B mode ultrasound allows accurate marking of the vein, facilitating dissection, alerts the surgeon to possible difficulties and is an ideal non-invasive technique for preoperative assessment of the long saphenous vein.