Prediction of Flap Survival Using Flap Blood Glucose Level

Background: Flap viability is crucial for reconstructive surgery success, with vascular compromise being the main cause of failure. Postoperative monitoring, including glucose measurement, provides an objective, cost-effective method to detect ischemia early. Optimal glucose levels support metabolism and healing, while low or high levels predict flap compromise and necrosis. Methods: Flap blood glucose was measured from the distal margin using a glucometer immediately postoperatively and at 0, 4, 8, 12, 24, and 48 hours. Clinical parameters were assessed concurrently. Suspected congestion prompted frequent glucose monitoring and corrective measures, with persistent deterioration leading to surgical re-exploration for compromise. Results: The study included 25 patients (mean age 33.6 ± 9.8 years; 52% males). Urban residents comprised 64% while 36% were rural residents. 56% were smokers. Most were American Society of Anesthesiologists (ASA) I (88%), with a mean BMI of 29.46 ± 0.3 kg/m². Free flaps were performed in 6 patients (24%), pedicled flaps in 10 (40%) which included 2 cases (8%) had both abdominoplasty and mastopexy, abdominoplasty alone in 8 (32%), revascularization in 1 (4%). Glucose monitoring detected flap compromise significantly earlier than clinical signs (7.3 ± 7.8 h vs. 26 ± 6 h; p = 0.0038). The flap-to-systemic RBS ratio declined in congested or failed flaps after 4 hours (all p < 0.02). ROC analysis showed highest diagnostic accuracy at 48 hours (100% sensitivity, 100% specificity). Conclusion: Flap glucose monitoring provides a rapid, cost-effective method for early flap failure detection. Persistent low flap-to-systemic RBS ratios predict compromise and guide timely intervention.