Structural and Functional Assessment of the Condition of the Wound Bed by Microwave Dielectrometry and Laser Doppler Flowmetry

Abstract

The aim of the work was to develop and test a combined method to assess the structural and functional features of a burn wound and periwound area with the use of microwave dielectrometry and Doppler flowmetry. The study included 20 Wistar rats used to model a contact thermal injury and 10 intact rats. The wound condition was assessed 24 and 72 hours after burn injury. The dielectric properties of tissues were studied using a hardware and software complex for microwave (MW) resonant near-field probing. A sharp coordinated decrease in microcirculation intensity and dielectric permittivity was observed in wound tissues in the early post-injury period (day 1 after injury). The parameters gradually and partially restored by the end of day 3 after burning. A compensatory increase in microcirculatory blood flow was detected in the periwound area, leading to a higher degree of tissue hydration and, consequently, higher values of the two parameters. A regulatory imbalance of factors that ensure the capillary blood flow in the wound area and surrounding tissues was found to develop after a thermal injury. The imbalance was compensatory in nature and contributed to the inhibition of regeneration processes in the absence of adequate correction. Thus, a combination of the two methods used in the study may potentially provide more specific information in order to describe the structural and functional features of a tissue of interest and their dynamics, as was demonstrated with the example of an experimental burn wound.