A Study of Flap Capillary Blood Glucose Monitoring as a Predictor of Flap Survival

Background: Monitoring glucose levels in flap tissues can be a valuable indicator of flap viability and early detection of flap failure. This study aimed to analyze the utility of intra-flap glucose monitoring in predicting flap outcomes. Materials & Methods: It was a single centre, single arm, non-comparative longitudinal observational study done from May 2019 to October 2020. Thirty (31) patients, operated for reconstruction with various flap incorporating skin in the department of plastic and reconstructive surgery after taking informed written consent. Flap blood glucose levels have been measured at scheduled times by glucometer. At the same time blood glucose levels has been measured from adjacent normal skin (control site). In addition to blood glucose assessment simultaneous clinically findings have been noted and correlated. In the event of any indication of impending/frank ischemic changes appropriate measures have been taken by the surgeon in-charge. Capillary blood sample has been taken by pin prick method at the distal most part of flap. At the same time patient blood glucose level has been measured from normal skin adjacent to flap. Samples were taken in immediate postoperative period then after 1hr, 12 hr, 24 hr, 48 hr and 72 hr after operation. Results: Out of thirty-five patients, thirty were male and five were female. Among four free flaps, three were antero-lateral (ALT) fascio-cutaneous flap and one was free latissimus dorsi (LD) musculocutaneous flap. We have measured flap blood glucose and body blood glucose from control site simultaneously and then calculated flap blood glucose as a percentage of body blood glucose. Out of 35 flaps, 21 flaps have done well and no sign of ischemia was found in these flaps. Blood Glucose levels of these flaps were taken at regular intervals as per study schedule. Total 63 values have been recorded from clinically ischemic flaps. Blood glucose values of ischemic flaps were significantly low with a mean value of 35.81% of body glucose. At the intervals of immediate, 1hour, 6-hour, 24-hour, 48-hour, 72 hour, 5 days the mean values of glucose are lower in necrosed flap than survived flaps. It was found to be statistically significant (p<0.05). Conclusion: Intra-flap glucose monitoring is a reliable method for predicting flap viability. Higher glucose levels are associated with flap survival, providing a potential tool for early intervention in cases of impending flap failure.