A Simple Way to Measure Glucose and Lactate Values During Free Flap Head and Neck Reconstruction Surgery

Purpose: Evaluation of flap blood flow is necessary to detect flap blood flow abnormalities and perform salvage surgery. This study determined whether intra-flap blood glucose and lactate values measured with a simple instrument could detect impaired blood flow during head and neck reconstruction.

Materials and methods: We prospectively analyzed 82 cases of head and neck cancer reconstruction (62 men and 20 women; mean age, 64.0 years [range, 20 to 88 years]), of which 74 had impeded blood flow. Glucose and lactate levels were regularly measured over a period of 48 hours, from the time of flap elevation, as predictor variables. Blood flow obstruction was the outcome variable. Other study variables included primary site, flap type, gender, age at operation, height, weight, body mass index, presence or absence of diabetes, ischemia time, and operative time. Logistic analysis, using glucose and lactate values at the time of blood flow failure, was performed. Cutoff values were calculated using a receiver operating characteristic analysis.

Results: The breakdown of the flaps was as follows: 20 free jejunum, 19 anterolateral thigh, 12 fibular, 11 radial forearm, 8 rectus abdominis myocutaneous, and 4 other flaps. Congestion was observed in 8 of the 82 flaps, including 3 anterolateral thigh flaps, 3 radial forearm flaps, 1 free jejunum flap, and 1 rectus abdominis myocutaneous flap. The intra-flap blood glucose values in the normally progressing cases gradually decreased until 16 hours postoperatively and thereafter recovered to normal levels. Intra-flap blood lactate values increased until 8 hours postoperatively and subsequently decreased. The odds ratio during congestion was only significantly different for lactate (odds ratio, 2.55, P = .014), and the cutoff values for sensitivity and specificity were 4.2 mmol/L and 6.7 mmol/L, respectively.

Conclusions: Intra-flap blood glucose and lactate values may reflect the transition of the postoperative circulation of free flaps. During congestion, lactate values change more sensitively than blood glucose values.