Short-term augmentation of venous drainage with extra-corporeal shunt and simultaneous auto-transfusion, for salvaging a congested free flap
A 48-years-old male presented with history of road traffic accident. He had sustained head injury, fracture of right femur and Gustillo type IIIc fracture of both bones right leg. He had anterior tibial artery injury and extensive crushing of anterior compartment muscles along with a soft tissue defect spanning across upper and middle thirds of leg and extending into the upper part of lower third of leg [Figure –]. Associated head injury and patient's hemodynamic instability did not allow early surgical intervention. As the management of wound was difficult due to multiple unstable fractures, after 48 hours of injury he was taken up for a short procedure of fracture fixation. His fractures were stabilised with external fixator, spanning across the knee. Soft tissue cover was not possible at this stage because of his general condition.\nAfter getting clearance from neurosurgery and the intensive care specialists, he was taken up for elective micro-vascular free tissue transfer on the fourth post injury day. On exploration of the wound, posterior tibial artery was found intact but both accompanying deep veins of both anterior and posterior tibial vessels were found thrombosed. The short saphenous vein was injured; the great saphenous vein (GSV) was patent and uninjured. Gentle irrigation with heparin saline into the vein (GSV) was possible without much resistance and the intima appeared healthy under microscope, hence it was selected as recipient vein for anastomosis.\nAfter confirming the recipient vessels, Vastus lateralis myo-cuteneous flap of dimensions 30 × 15 cm was harvested from the left thigh and was transferred to recipient site for coverage of the fracture site. After partial insetting, anastomosis was performed. The artery was anastomosed to the posterior tibial artery in an end to side fashion with 9/0 nylon. One of the flap veins was anastomosed to the great sephanous vein in an end to end manner. Due to non-availability of recipient veins in the vicinity, the second flap vein was clipped at the end of the procedure after confirming good flow. In setting was completed and good bleeding was observed from the flap at the end of the surgery. The patient was shifted to postoperative ward.\nAn hour after the surgery, the flap became congested. Clinically, it was evident by brisk and congested bleeding on scratching the flap with needle. The flap was explored immediately suspecting some compromise in the venous flow. On exploration, after exposing the anastomotic site, the vein anastomosis was found patent. Both the anastomosed flap vein and the GSV were distended and tense. The ligated second vein was also found to be tense and distended []. The clip at the end of the second vein was released to let out some blood, in order to decongest the flap. This manoeuvre improved the flap colour and bleeding after some time. The flap drainage through a single vein was probably inadequate, so nearby areas were re-explored for another recipient vein. We could not find a suitable vessel for the second anastomosis.\nAs there was no possibility of getting a second vein for anastomosis, it was decided to let the blood out periodically to decongest the flap. The blood flow through the second vein was checked and was found to be very high (22 ml/min); letting out so much blood in a patient with multisystem injury was not a suitable option. Collecting the blood and then transfusing it was another option but had risk of contamination and sepsis. After carefully considering all the options and weighing the risks, it was decided to drain the blood through an IV catheter and auto-transfuse it to the patient simultaneously. The idea was to create a closed system with lesser risk of contamination. One IV cannula was inserted over patients forearm and the other one in the second vein of the flap through the edge of the flap. In the leg the flap vein was ligated over the cannula under appropriate pressure with 7/0 polypropylene, also the position of cannula was secured over the skin so as to prevent it from accidently getting dislodged. The cannulas were connected with an extension tubing (100 cm) as shown in . A three way system was attached at the proximal end of the extension tube through which heparin (5000U in 500 ml of normal saline) infusion was started at a rate of 20 micro-drops per minute to keep the extension tube patent [].\nThe drainage of the flap vein through the external shunt was checked every 2 hours as shown in the accompanying video []. The patient was also quite comfortable with this position and was even able to take his hand to the mouth. Considering the fact that cannulating the flap vein and transfusion of blood from the site of injury directly into systemic circulation might lead to sepsis, stringent wound hygiene was maintained. As a precautionary measure the venous cannula draining the flap vein was changed once, after 3 days of drainage. By seventh day the flap developed enough collateral venous drainage and there was no congestion on blocking the venous cannula. At this time the drainage was stopped and the second vein was ligated.\nThe flap survived, except a small area of necrosis at the distal edge []. The final insetting was completed after 2 weeks. The distal necrotic portion was debrided and the residual raw area was managed with VAC and was covered with skin graft at a later date. Complete wound healing was achieved in 4 weeks [].