Intraoperative optical imaging of tissue hemodynamic variations in mastectomy skin flaps for identifying ischemic/hypoxic tissues

Mastectomy skin flap necrosis (MSFN) occurs in 5% to 30% of cases due to insufficient tissue blood flow and oxygenation. We report an innovative, inexpensive, dye-free, depth-sensitive, multiple wavelength speckle contrast diffuse correlation tomography (MW-scDCT) technology that enables noninvasive, noncontact, and continuous imaging of blood flow and oxygenation distributions in mastectomy skin flaps during surgery. Six female patients undergoing mastectomies were imaged sequentially by the dye-free MW-scDCT and dye-based commercial fluorescence angiography (SPY-PHI). Hemodynamic images obtained by the MW-scDCT and SPY-PHI in 6 patients were generally consistent. However, several challenging issues limit the wide acceptance of dye-based fluorescence angiography in clinical settings, including allergic reaction, short time-window for observation, and high cost for equipment and supplies. With further optimization and validation in large populations, MW-scDCT may ultimately be utilized as a noninvasive and inexpensive imaging tool for intraoperative assessment of skin flap viability to predict and prevent MSFN.