摘要Background:Free flap transplantation has emerged as a prevalent technique in reconstructive surgery for patients with oral cancer.Postoperative monitoring of flap perfusion is critical for flap survival,necessitating early detection and timely intervention.Developing a monitoring approach that is highly sensitive,specific,non-invasive,continuous,and cost-effective is crucial for accurately assessing flap perfusion and informing clinical decisions.Methods:From April 2024 to December 2024,20 patients with oral tumors requiring flap transplantation were enrolled at the Ninth People's Hospital affiliated to Shanghai Jiao Tong University School of Medicine.Contin-uous monitoring of various free flaps was performed utilizing a transcutaneous blood gas analyzer,both before and after surgery.This approach allowed for real-time measurement of transcutaneous partial pressure of oxygen(TcPO2)and transcutaneous partial pressure of carbon dioxide(TcPCO2),facilitating the evaluation of perfusion dynamics across various free flap types.Results:After free flap transplantation,a reduction in blood supply resulted in a rapid decline in TcPO2(to below 10 mmHg),accompanied by a gradual increase in TcPCO2,peaking at 135 mmHg.Following vascular anastomosis and blood flow restoration,TcPO2 and TcPCO2 exhibited opposite trends.Statistical analysis revealed no sig-nificant differences in TcPO2 and TcPCO2 measurements among the various flap types(P＜0.05),indicating a consistent pattern of change across all flaps.Conclusion:The transcutaneous blood gas analyzer proves to be a reliable method for monitoring free flap perfusion.Dynamic changes in TcPO2 and TcPCO2 effectively reflect blood supply status,enabling early detection of vascular compromise and potentially enhancing flap preservation outcomes.