Near-infrared spectroscopic assessment of tissue hydration following surgery

Near-infrared reflectance spectroscopy and imaging were used to assess tissue hydration following elevation of reverse McFarlane dorsal rat skin flaps (N = 6). A quantitative measure of tissue water content was derived using the integrated intensities of the strong absorption bands of water centered at 970 and 1450 nm. Near-infrared spectroscopy monitored tissue hydration at discrete locations, while imaging provided hydration maps of cutaneous tissues. Both methods were rapid and noninvasive. The near-infrared results were compared to laser Doppler flux measurements. Significant changes in tissue hydration were observed upon surgical elevation with substantial regional variation along the skin flap. These results indicate the potential of near-infrared spectroscopy and imaging to monitor tissue hydration changes in the skin following surgery.