What’s the remedy for the distal necrosis of DIEP flap, better venous drain or more arterial supply?

BackgroundWe developed a novel pedicled DIEP flap model in rat to explore the possible remedy for the distal necrosis of the flap.MethodsA deep inferior epigastric perforator (DIEP) flap, based on the second right cranial perforator (P2) as the main pedicle, was elevated in 48 Sprague-Dawley rats. The rats were randomized into 4 groups: group I, the left P2 remaining intact as supercharging; group II, the left P2 artery alone kept as supercharging; group III, the left P2 vein alone kept as supercharging; group IV, no supercharging. Transcutaneous oxygen pressure (TcPO2) and transcutaneous carbon dioxide pressure (TcPCO2) were measured immediately after flap elevation, protein level of Hif-1a was measured 48 hours later, and flap survival was assessed 7 days postoperatively.ResultsBlockade of artery led to significantly lower TcPO2, higher TcPCO2, and higher expression level of Hif-1a in the distal side of the flap in group III and group IV, than those of group I and group II. At 7 days post surgery, significantly lower flap survival rates were observed in group III (81.9 ± 5.7%) and group IV (78.4 ± 6.5%), compared to observed in group I (97.2 ± 3.0%) and group II (94.2 ± 6.2%).ConclusionsIt might be arterial insufficiency, not venous congestion, which mainly caused the distal necrosis of the DIEP flap in rat. Arterial instead of venous supercharging might be a more effective procedure that improves circulation to zone IV of the flap.