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

Abstract

Background We developed a novel pedicled DIEP flap model in rat to explore the possible remedy for the distal necrosis of the flap. Methods A 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 (TcPO 2 ) and transcutaneous carbon dioxide pressure (TcPCO 2 ) were measured immediately after flap elevation, protein level of Hif-1a was measured 48 hours later, and flap survival was assessed 7 days postoperatively. Results Blockade of artery led to significantly lower TcPO 2 , higher TcPCO 2 , 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 plusmn; 5.7%) and group IV (78.4 ± 6.5%), compared to observed in group I (97.2 plusmn; 3.0%) and group II (94.2 plusmn; 6.2%). Conclusions It 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.