Non-Invasive Methods for Determining Lesion Depth from Vesicant Exposure

摘要

Before sulfur mustard injuries can be effectively treated, assessment of lesion depth must occur. Accurate depth assessment is important, because it dictates how aggressive treatment needs to be to minimize or prevent cosmetic and functional deficits. Depth of injury is typically assessed by physical examination. Diagnosing very superficial and very deep lesions is relatively easy for the experienced burn surgeon. Lesions of intermediate depth, however, are often problematic in determining the need for grafting. This study was a preliminary evaluation of three non-invasive bioengineering methodologies, reflectance colorimetry (RC), laser Doppler perfusion imaging (LDPI) and indocyanine green fluorescence imaging (ICGFI), to determine their ability to accurately diagnose depth of sulfur mustard lesions in a weanling swine model. Six female animals (8-12 kg) were exposed to 400 microliter of neat sulfur mustard on 6 ventral sites for 2, 8, 30, or 60 minutes. This exposure regimen produced lesions of varying depth from superficial to deep dermal. Evaluations of lesion depth using the bioengineering techniques were conducted at 24, 48, and 72 hours postexposure. Following euthanasia at 72 hours postexposure, skin biopsies were taken from each site and processed for routine H & E histological evaluation to determine the true depth of the lesion. Preliminary results demonstrated that LDPI and ICGEI were useful tools to characterize skin perfusion and provided a good estimate of HD lesion depth. The RC data are still being analyzed; however, the initial interpretation suggests that the data does not provide useful information concerning lesion depth. The novel prototype ICGFI instrument used in this study offered several advantages over LDPT and ICGFI instruments currently available including real-time imaging of blood flow through lesions, low cost, small size, portability, and not requiring the patient to be re-positioned.