Continuous Interstitial Glucose Measurement for Flap Venous Occlusion Monitoring in a Diabetic Model

Glucose has been used in the monitoring of transplanted flaps. However, few studies have focused on the effect of diabetes on the decrease in flap glucose levels. The purpose of this study was to evaluate the application of continuous interstitial glucose monitoring to detect flap venous occlusion in a diabetic rat model. The flap interstitial glucose level was measured by transcutaneous sensors in the bilateral vertical rectus abdominis myocutaneous flaps of each rat. interstitial glucose values in the bilateral flaps were recorded every 5 minutes after the venous occlusion of 1 flap. Forty-one rats were divided into the control group (n = 13), diabetic group (n = 15, established by the intraperitoneal injection of streptozotocin), and insulin-treated diabetic group (n = 13, systemic glucose well controlled by insulin before surgery). Results indicated that flap interstitial glucose decreased to the lowest level in all flaps with venous occlusion. The time from venous occlusionto the lowest interstitial glucose level was significantlylongerinthe diabetic group than the control group (120.8 ± 5.7 minutes versus 56.5 ± 6.7 min-minutes, P < 0.001), but was similar in the insulin-treated diabetic and control groups (56.5 ± 6.7 minutes versus 56.0 ± 6.6 minutes, P = 0.876). The change in interstitial glucose in both the diabetic and insulin-treated diabetic groups began with a plateau period or a slow decline before decreasing for 49.0 ± 6.4 minutes and 24.4 ± 4.3 min-minutes, respectively. in a diabetic rat model, impaired glucose metabolism prolongs the required monitoring time and dulls the reaction of flap interstitial glucose to venous congestion. Insulin restores the prolonged monitoring time, but not the reaction of flap interstitial glucose. Therefore, care is needed during application of the technique in diabetic patients.