Flap monitoring using infrared spectroscopy

We report results of clinical trials on flap monitoring in 65 plastic surgeries. Hemoglobin oxygen saturation of flap tissue (StO 2 ) was monitored non-invasively by using ODISsey TM tissue oximeter, an infrared spectroscopic device. StO 2 measurements were conducted both intra-operatively and post-operatively. From the intra-operative measurements, we observed that StO 2 values dropped when the main blood vessels supplying the flap were clamped in surgery, and that StO 2 jumped after anastomosis to a value close to its pre-operative value. From post-operative monitoring measurements for the 65 flap cases, each lasted two days or so, we found that the StO 2 values approach to a level close to the baseline if the surgery was successful, and that the StO 2 value dropped to a value below 30% if there is a perfusion compromise, such as vascular thrombosis.