Non-invasive postoperative monitoring of pedicled rat skin flap using laser speckle contrast imaging

Purpose: This study used non-invasive laser speckle contrast imaging (LSCI) modality to evaluate the blood flow changes in murine flap model and to investigate the clinical feasibility of the LSCI for postoperative monitoring. Methods: Ten of 6-8 weeks old Spraque-Dawley rats with superficial inferior epigastric vessel based pedicled skin flaps were used in this experiment. The color changes of skin flap were evaluated by naked eyes and the LSCI modality 6, 24, and 48 h after surgery. Results: In vessel ligated region of skin flap, skin color began to change to a bluish color immediately postoperatively. At 24 h postoperatively, skin necrosis was detectable with the naked eye and total necrosis occurred at 48 h postoperatively. Changes in laser speckle signal were consistent with changes observed with the naked eye, and blood flow index also presented significant differences between the ligated and non-ligated region. Conclusion: These correlated laser speckle signal patterns suggest that non-invasive monitoring of perfusion by LSCI is a useful technology that may be used to identify the ischemic skin flap.