Australia & New Zealand Society of Vascular Surgeons

The phenomenon of entrapment of the femoro-popliteal vein bypass graft has been preveously reported. However, to the authors’ knowledge, there has been no report of femoro-distal anterior tibial vein graft entrapment. This poster describes a case of femoro-distal anterior tibial vein bypass graft entrapment demonstrated by duplex ultrasound scan. A 78 year old man with a femoro-distal anterior tibial vein bypass graft was referred to the Vascular Laboratory of the Austin Hospital for routine graft duplex ultrasound surveillance scan. An in-situ long saphenous vein was used as the graft conduit. The vein graft was anastomosed to the common femoral artery in the groin, travelled subcutaneously in the medial aspect of the thigh and calf, crossed subcutaneously over the tibia a few centimetres above the ankle and was anastomosed to the distal anterior tibial artery at the level of ankle. Graft duplex scan demonstrated normal range of peak systolic velocities throughout the vein graft when the limb was examined in supine neutral position. However, during active dorsiflexion, an increased peak systolic velocity (>450 cm/sec) was detected in the distal graft at the point where the graft crossed over the tibia. Our explanation of this phenomenon is that during active dorsiflexion, the tendon of the tibialis anterior muscle moves anteriorly compressing the vein graft against the skin. This report demonstrates that entrapment may occur in a vein bypass graft to the distal anterior tibial artery or dorsalis pedis artery. Clinicians who examine such grafts should be aware of this condition. Furthermore, modification of surgical technique for femoro-distal anterior tibial or dorsalis pedis vein bypass graft to avoid the graft crossing over the tibia may reduce the occurrence of graft entrapment.