Utility of arteriovenous loops before free tissue transfer for post-traumatic leg defects

Crush injuries of severe magnitude involving lower limbs require complex bone and soft tissue reconstructions in the form of microvascular free tissue transfers. However, satisfactory recipient vessels are often unavailable in the leg due to their vulnerability to trauma and post traumatic vessel disease (PTVD), which extends well beyond the site of original injury. In such situations, healthy recipient vessels for free flap anastomosis can be made available by constructing temporary arteriovenous loops with saphenous vein grafts, anastomosed to corresponding free flap vessels. Our study included 7 patients with severe crush injuries of leg due to rail and road traffic accidents. Long and short saphenous vein grafts were anastomosed to Femoral artery in the subsartorial canal in 2 cases and to large muscular branches and accompanying veins in rest of the cases. Free flap transfers were performed in the same sitting in 6 cases. One case showed insufficient dilatation of the vein loop and hence free flap transfer was staged. Free Latissimus dorsi, Gracilis and Rectus abdominis flaps were performed. There were two cases of flap necrosis - one in the case of a pathologic vein graft with staged flap transfer which showed vein thrombosis on re exploration. The other case of flap failure was caused by a hematoma underneath the flap. In another patient, secondary haemorrhage occurred on day 18, without any consequence to the flap. All the other cases had complete free flap survival. We consider the use of single stage arteriovenous loops, a valuable tool to increase the applications of free flap, whenever healthy recipient vessels are not available in the periphery of the trauma.