121 Laser Speckle Perfusion Imaging of Wound Healing in a Porcine Model

Abstract

A Laser Speckle Perfusion Imaging (LSPI) system has been developed to achieve rapid, high-resolution, noninvasive imaging of tissue blood flow. This study was designed to evaluate LSPI for monitoring dermal blood flow during the wound healing process in a well-established porcine model. Full-thickness excisional wounds (2 × 2 cm) were created on the dorsal skin of 11 juvenile female red Duroc pigs. The skin wounds were imaged weekly with the LSPI system until day 49 postwounding. Blood flow values for the wounds were normalized using the values from the surrounding healthy skin to account for variations in systemic perfusion from one scan date to the next. An average normalized perfusion value was obtained from the scans of all animals for each time point. Wound perfusion at the time of reepithelialization reached ∼165% of the surrounding skin (p < 0.001). This elevation in wound perfusion slowly and steadily decreased over time, until day 49 postwounding, at which time the values returned to normal. This trend toward decreased wound perfusion over time has previously been reported in human burn wounds using the LSPI instrument. Further, the LSPI data from this study and from other human studies correlates well with data generated using the more widely established Laser Doppler Imaging (LDI) technique. The faster scan time and higher resolution of the LSPI method provides a distinct clinical advantage, both in terms of patient comfort and for reliably matching perfusion characteristics to their associated anatomical features. The fast temporal response of the LSPI instrument could be used to monitor vascular responses to mechanical or pharmacological interventions to study dynamic vascular changes to damaged tissues. This study validates LSPI as a tool to measure blood flow in skin wounds and further supports the use of the juvenile female pig as a model of excisional wound healing, yielding results comparable to healing in humans. Acknowledgments: Funding provided by CIHR, AHFMR, and NSERC