TISSUE PERFUSION MONITOR FOR FREE-TISSUE TRANSFER

FREE TISSUE TRANSFER HAS REVOLUTIONIZED MANY AREAS OF RECONSTRUCTIVE SURGERY. AS FREE TISSUE TRANSFER IS NOW BEING DONE ROUTINELY AT INSTITUTIONS WHERE INEXPERIENCED STAFF ARE UNABLE TO ADEQUATELY MONITOR VIABILITY, THE NEED FOR A RELIABLE METHOD TO MONITOR THE PATENCY OF MICROVASCULAR ANASTOMOSES HAS BECOME INCREASINGLY EVIDENT. ACCURATE MONITORING OF BLOOD FLOW DURING AND AFTER SURGERY IS ESSENTIAL, AND EARLY RECOGNITION OF POSTOPERATIVE VESSEL THROMBOSIS IS OF UTMOST IMPORTANCE IF REEXPLORATION IS TO PROVE SUCCESSFUL. NUMEROUS MONITORING TECHNIQUES HAVE BEEN INVESTIGATED. DIRECT MONITORS OF PERFUSION HAVE PROVEN TO BE OF LITTLE OR NO VALUE. PROBES ARE BULKY, VERY EXPENSIVE, AND REQUIRE GREAT CARE IN POSITIONING AND REMOVAL. INDIRECT MONITORS RATE AHEAD OF THE DIRECT MONITORS DUE TO LOW COST, SIMPLICITY, AND EASE OF PLACEMENT AND REMOVAL. HOWEVER, THESE MONITORS LACK THE NEEDED SPECIFICITY OF THE DIRECT MONITORS FOR MEASURING TISSUE PERFUSION. THIS PROJECT SEEKS TO PRESERVE THE SIMPLICITY AFFORDED BY INDIRECT MONITORING DEVICES, WHILE PROVIDING THE SPECIFICITYFOR TISSUE PERFUSION MEASUREMENT, BY UTILIZING A SELF-CALIBRATING TISSUE PO2/PCO2PROBE, WHICH MANIPULATES THE LOCAL TISSUE GAS CONDITIONS. TISSUE PO2 AND PCO2 ARE MONITORED UNDER ALTERNATING DEPLETING AND NONDEPLETING CONDITIONS. A PHYSIOLOGICALLY BASED MATHEMATICAL RELATIONSHIP RELATES TISSUE PERFUSION TO THE PO2 AND PCO2 MEASUREMENTS. THIS RESEARCH IS DIRECTED TOWARD THE IN VIVO VALIDATION OF THE METHOD.