Development and Evaluation of a Remote Patient Monitoring System in Autologous Breast Reconstruction

Background: Flap monitoring after a deep inferior epigastric perforator flap breast reconstruction is crucial to detect complications in time. A novel and innovative wireless device has been developed and tested in a feasibility study. This study describes our experience with remote patient monitoring via this device in postoperative monitoring of deep inferior epigastric perforator flaps. Methods: Following a deep inferior epigastric perforator breast reconstruction, the "Free Flap Patch" was adhered to the flap, continuously measuring temperature and tissue saturation. Data were stored locally on the patch and analyzed in a retrospective manner. Raw analog-digital-conversion values from the red- and infrared sensors, delta muscle saturation (dSmO(2)), and estimated tissue oxygenation (StO(2)) were assessed and compared with clinical records. Results: No adverse events related to the device were recorded. One patient suffered flap loss; a decrease in estimated tissue oxygenation was measured with the device in situ. No deviations in clinical variables were recorded in the uncompromised flaps. Conclusions: A wearable patient monitoring device was successfully utilized in clinical practice. In one patient, a flap failure was recorded where the PPG-derived StO(2) parameter was indicatory for this event. The Free Flap Patch has the potential of automatically predicting blood supply issues in an early stage. More data are needed for clinical validation.