[Correlation between endothelin, nitric oxide and microcirculation in super-thinned skin flap in pig]

To investigate the influence of the endothelin (ET) and the nitric oxide (NO) on the microcirculation of a super-thinned skin flap.

With pig, a super-thinned skin flap, only including subdermal vascular networks, was raised and sutured back on its bed on one flank of each pig, and on the other flank a traditional skin flap was also formed for the controlled group. A laser Doppler Flowmeter was used for evaluation of the blood circulation before and after the operation. The endothelin and the nitric oxide of the flap were examined after certain times of the operation. Furthermore, the necrosis of each flap was decided 7 days after the operation.

The ET and NO were significantly increasing after 1 hour of the operation in both of the groups (the peak value of ET at 6 hours and NO at 3 hours after the operation). However, the ET in the super-thinned flap group was significantly lower at 1, 3, 6 hours after the operation, compared with the centrolled group (P < 0.05), but the NO measured meantime was significantly higher than the control (P < 0.05). The blood flow of the super-thinned flap was significantly higher than the control flap separately at 1, 3, 6 hours after the operation (P < 0.01). The survival of the super-thinned flap increased about 35% more than the control. There was a negative correlation existed between the ET and the blood flow, as well as a positive correlation between the NO and the blood flow.

This study has indicated that the changes of the ET and NO in the flaps, especially in the super-thinned flap, have strongly correlated with their microcirculation. The highter survival rate of the super-thinned flap might owes to the mechanism which the ET in the flap produces less while the NO more, Compared with the traditional skin flap.