Transcutaneous CO2 Pressure Monitoring Increases Salvage Rates after Free Tissue Transplantation for Extremity Reconstruction.

Although free tissue transplantation (FTT) is an essential technique in extremity functional reconstruction, postoperative blood flow disturbance is one of the critical complications leading to transplanted tissue necrosis. Early detection of this complication may prevent tissue failure by prompt improvement of blood flow. The aim of this study was to determine whether transcutaneous carbon dioxide pressure (TcPCO2) monitoring increases the salvage rates after FTT. Methods: We retrospectively reviewed 75 consecutive patients who underwent FTT for extremity reconstruction with TcPCO2 monitoring postoperatively between December 2016 and September 2021. Results: Extremity reconstruction was performed in 53 cases due to trauma, 20 cases due to infection, and two cases due to tumor resection for tissue defects. The overall success rate of the FTT was 98.7%, with 13 complications. Of the 11 patients who underwent reoperation, nine had thrombosis and two had vascular strangulation. However, when reoperation was decided, none of the reoperation cases still exhibited any deterioration in the Doppler or clinical assessment. All reoperated cases were salvaged. Of the two patients who did not undergo reoperation, one had failed flaps and one had partial skin necrosis. With a TcPCO2 cutoff value of 70 mm Hg, the sensitivity and specificity for detecting complications due to impaired blood flow were 100% and 93.5%, respectively. Conclusions: TcPCO2 monitoring was performed after FTT for extremity reconstruction, and all cases of reoperation were salvaged. TcPCO2 monitoring can detect impaired postoperative blood flow critically earlier than clinical assessments and may increase salvage rates of transplanted tissue.