[The relationship between the changes in the blood flow of the exceedingly expanded skin and the viability of the flap].

Objective: To investigate the relationship between the blood flow of the exceedingly expanded skin and the viability of the flap.
Methods: The piglets were set up as the animal model. They were divided into 7 groups according to different injection volume of the tissue expander, i. e. injection to 1/2 content, 3/4 content, full content, 50% over content, 100% over content, sham-operation control and normal control. At different stages of expansion, the blood flow and the amplitude of the expanded skin were examined by laser Doppler. The survival length of the expanded flap was measured. Furthermore, statistical analysis was performed.
Results: As the expansion volume increasing, the blood flow and the amplitude of the expanded skin increased, the survival length of the expanded flap increased also. In the meantime, the amplitude instability and vessel permeability increased. When the injection volume exceeded to 100%, the blood flow and the survival length of the expanded flap decreased.
Conclusions: In soft tissue and skin expansion, increasing injection volume could increase the survival length of the expanded flap, while over-expansion to 100% content may cause blood flow disturbance.