Abstract: To explore the variation pattern of transcutaneous oxygen tension (tcPaO2) of flaps pedicled on the arterial cutaneous branch with necrotic distal end and to provide experimental evidence for clinical practice. MethodsFlaps pedicled on the cutaneous branch of the iliolumbal artery were raised on 65 male Wistar rats (400450?g) with a 12?cm×3?cm dimension. By taking a perforation point of the cutaneous branch as the proximal end, each flap was divided into four equal regions (region 1 to 4) from the proximal end to the distal end. The tcPaO2 of each region was monitored at the following time points: before the operation, immediately after the operation, at the 1st, 2nd, 4th and 7th day after the operation. ResultstcPaO2 of the four regions all significantly dropped after the operation（P＜0.01). tcPaO2 values of the proximal three regions (region 1 to 3) gradually increased from the 1st day to the 7th day after the operation. And on the 7th day, tcPaO2 values of region 1 and 2 nearly regained their normal levels. While tcPaO2 of the distal necrotic region (region 4) gradually dropped till it could not be tested on the 4th day. On the 1st and 2nd days after the operation, from proximal to distal end of the flap, tcPaO2 first increased and then gradually dropped. tcPaO2 of region 2 was significantly higher than that of region 1, 3 and 4（P＜0.05). While on the 4th and 7th days, tcPaO2 gradually dropped from proximal to distal end of the flap（P＜0.05), and differences between the proximal two regions diminished（P＞0.05）. ConclusionBy using transcutaneous oxygen tension measurement, blood circulation condition of the flap can be objectively and continuously reflected, and dysaemia of the flap can be detected in its early state. Therefore, transcutaneous oxygen tension measurement can be a promising detection method in clinical practice.

Key words: Cutaneous branches skin flap, Percutaneous oxygen partial pressure