Effects Of Hyperbaric Oxygen And Normalbaric Oxygen On The Survival Rate, CD105 Expressin Level And Cell Ultra-Structure Of Random-pattern Flaps In Rats.

Objective: To study the effect of hyperbaric oxygen and normalbaric oxygen on the survival rate of random-pattern flaps in rats and measure the expression level of CD105 in flap tissue and the change of the microstructures of the tissue cells to discover the probable mechanism.Methods: Forty-five Wister rats were assigned to three groups equal in number randomly. A random pattern flap was elevated in the central part of the rachis. Group A was left as controls. In group B, all the rats received normalbaric oxygen twice a day until postoperative day 5. In group C, hyperbaric oxygen was applied to the rats twice a day lasting for five days. On the seventh day, survival rates of all the flaps were calculated. And the expression levels of CD105 were also measured. Then a tissue of 1 mm×1 mm×1 mm in volume three-centimetres away from the pedicle was picked up and made into extra-thin slice. The changes of the mitochondrion were observed through Transmission Electron Microscope.Results:1. On the seventh day, the survival rates were as follows: control team, 48.6±8.0%; normal baric oxygen team, 51.7±7.1%; hyperbaric oxygen team, 89.1±3.7%. The difference was significant among the three, while the difference between the normal baric oxygen team and control team is not significant.2. Expression levels of CD105 is much higher in the hyperbaric oxygen team than the left two. And there is no significant difference between team normalbaric oxygen and control.3. Five grades were set for each mitochondrion as follows: grade zero: normal mitochondrion; grade one: matrix granule disappears; grade two: mitochondrion swells and matrix goes transparent; grade three: crista ruptures and matrix fuses; grade four: crista ruptures, matrix fuses and membrane breaks. The scan of Transmission Electron Microscope show that changes of mitochondrion in group C are chiefly Grade one and two (in a proportion of 92%), while in group A and B, that are mainly Grade three and four (in a proportion of 87%). There has a significant difference of the proportion of Grade one and two among the three groups, while the difference between the normal baric oxygen team and control team is not significant. Conclusions: Hyperbaric oxygen used in this study significantly increases flap survival in rat random-pattern flap model, while normalbaric oxygen as a treatment does not have a corresponding beneficial effect. The mechanism that hyperbaric oxygen can increase flap survival rate may rely on that it can activate new blood vessel formation and give relatively adequate oxygen supply.Postgraduate student: Ji-zhen Ren (Plastic surgery)Directed by Associate: associate prof. Zhen-yu Chert...