COMPARATIVE ANALYSIS OF CAPILLARY BLOOD GLUCOSE LEVELS IN FLAP AND FINGERTIP AS PREDICTORS OF POST-SURGICAL VENOUS THROMBOSIS IN PEDICLED FLAP: AN OBSERVATIONAL COHORT STUDY

Abstract

Background: Early diagnosis of venous thrombosis after surgical intervention is crucial for fruitful retrieval of pedicled flaps. Clinical evaluation remains the gold-standard conventional monitoring method, but it requires technical interpretive expertise. This study evaluated the diagnostic efficacy of the mean capillary blood glucose difference between the fingertip and pedicled flap as a principal determinant of venous thrombosis after surgery. Methods: A cohort study involving 90 adults was conducted on pedicled flap reconstruction at a tertiary care facility between November 2022 and December 2024. A portable glucometer was used to measure capillary blood glucose levels from both the fingertip and the flap over up to 5 days at specific postoperative intervals. The difference in glucose levels was calculated and examined in relation to venous thrombosis, which was confirmed through clinical evaluation. The diagnostic abilities were systematically assessed using receiver operating characteristic (ROC) curve analysis. Results: Within the first 18 post-surgical hours, venous thrombosis was detected in eight patients (8.9%) with a significantly higher (p<0.001) mean fingertip-to-flap glucose difference in normally perfused flaps (39.18 ± 7.93) in comparison to congested flaps (3.80 ± 5.62 mg/dL). ROC curve analysis shows outstanding diagnostic performance, with an AUC of 1.00. At this threshold, 100% sensitivity and 100% specificity were shown to be the ideal cut-off values for detecting venous thrombosis in the study population. Conclusions: The capillary blood glucose difference is an easy, cost-efficient, reliable, and primary additive for Postsurgical monitoring of pedicled flaps. It may increase flap salvage and facilitate earlier diagnosis of venous thrombosis when combined with standard clinical examination techniques, especially in resource-limited settings. Confirmation of these findings requires larger multicenter studies.