Flap Monitoring Using Interstitial Fluid Glucose Measurements

Background: Various flap monitoring techniques have been used in the early detection of anastomotic thrombus; however, the use of automatic and continuous monitoring methods is presently uncommon. The purpose of this study was to investigate trends in interstitial fluid glucose concentration (IFG) in flap monitoring by measuring IFG automatically and continuously. Methods: Nine patients underwent unilateral breast reconstruction using a transverse rectus abdominis myocutaneous flap with vascular anastomosis. Two IFG measuring devices were attached to each patient. One device was attached to the flap (flap IFG) and the other to the healthy breast (control IFG). In each case, flap IFG, control IFG, and IFG ratio (flap IFG/control IFG) were recorded in the initial 72 h post-surgery (first half) and also in the subsequent 72 h (second half). In all of the cases, the mean values recorded in the first half and those in the second half were compared. Results: All flaps survived. The flap IFG didn’t fall below 40 mg/dL in the first half. The minimum flap IFG and IFG ratio were 42 mg/dL and 0.55 in the first half. The flap IFG was significantly higher in the first half than in the second half in all cases, and the IFG ratio was similar in 8 cases. Furthermore, mean flap IFG and mean IFG ratio in all cases in the first half were significantly higher than in the second half. Conclusions: IFG measurements may complement conventional flap monitoring, particularly in the early postoperative period.