Real-time Quantitative Optical Perfusion Imaging in Surgery

Surgeons are nowadays unable to visualize and quantitatively evaluate microvascularisation in real-time during surgery. Complications due to vascular compromise are a major problem, especially in reconstructive surgery. Poor blood perfusion leads to ischemia and even tissue necrosis. If, however, perfusion and ischemia could be monitored during surgery, then surgeons could change their reconstructive design and the anaesthesiologists could improve perfusion with fluids, inotropes or vasopressors, if necessary. Surgeons therefore need a tool that is able to image in high resolution (microvascularisation), direct, intra-operative, in 3D (to image thrombosis, luminal narrowing or distinct overlaying vessels) and that produces quantitative data to objectify image interpretation. Optical techniques, based on the interaction of light with tissue, are able to image tissue at high resolution and in real-time. These techniques are FDA-approved and have emerged as powerful diagnostic tools in different departments of medicine, such as ophthalmology for visualizing retina vascularisation and dermatology for skin diagnostics. In this study, investigators hypothesize that four novel optical technologies: Fluorescence Imaging, Laser Speckle Contrast Imaging, Optical Coherence Tomography and Sidestream Darkfield Microscopy are able to quantitatively image perfusion in real-time during surgery.