Monitoring of Myocutaneous Flaps by Measuring Capillary Glucose and Lactate Levels: Experimental Study.

INTRODUCTION: In surgery, certain defects require reconstruction with a microsurgical flap. The free flap failure rate varies between 2% and 5%. Vascular thrombosis is the most frequent complication and represents 15% to 73% of failures. The success rate of salvage therapy is greater when salvage surgery is early. Currently, clinical monitoring is the criterion standard but many noninvasive or minimally invasive techniques have been developed to improve early diagnosis of complications of vascular thrombosis. The aim of our experimental study was to compare clinical assessments with measurements of capillary glycemia and lactatemia during the monitoring of free flaps.

MATERIALS AND METHODS: Myocutaneous latissimus dorsi flaps with skin paddles were created in pigs under general anesthesia. For each animal, 2 flaps were created (right and left) using the same technique. Four groups were made: group 1 (no flap ligation: control group), group 2 (flap with permanent ligation of the artery), group 3 (flap with permanent ligation of the two veins), group 4 (flap with transient ligation of the artery and 2 veins for 1 hour). The postoperative monitoring protocol consisted of monitoring the clinical, biological (glucose and lactate), and histological parameters.

RESULTS: Eight animals were operated on and sixteen flaps were created. Each flap was clinically and biologically tested 25 times. Clinical, biological, and histological monitoring showed significant variations between the groups. The analysis of variance of capillary glycemia and lactatemia showed statistically significant difference between control group and group 2 (P < 0,0001), group 3 (P < 0,0001), or group 4 (P < 0,0001). There were no histological abnormalities after transient ligature at different times contrary to permanent ligature.

DISCUSSION-CONCLUSION: Measuring capillary levels of lactate and glucose associated with clinical monitoring may shorten the time to diagnosis of flap failure. Ultimately, this will save lives and achieve better functional and aesthetic results.