Many attempts have been made clinically and experimentally to improve the blood supply in an ischemic random pattern flap. There are several kinds of known pharmacological agent to increase the flap survival. Those are known to be sympatholytics, vasodilators, rheologic agents and drugs which increase the tolerance of ischemia.
Recently, Finseth proposed a new hypothesis of vasodilatation, based on precapillary arterioles to which several factors contribute such as sympathectomy, tissue ischemia and inflammatory reaction. Since then, many authors attempted to improve flap survival with pharmacological treatment which was based on the former hypothesis.
In this study, two alpha blocking agents, phenoxybenzamine and phentolamine, were tested to confirm that whether their use improved skin flap survival in rats. Cephalic based random pattern flaps were designed on the back of the rats and control group were not given any treatment. GroupⅠ rats were treated with phenoxybenzamine injection. Group Ⅱrats were treated with phentolamine injection, Group Ⅲ rats were treated with normal saline injection. Group Ⅳ rats were treated with phentolamins ointment in PEG base. Group Ⅴ rats were treated with phenoxybenzamine ointment in PEG base. Group Ⅵ rats were treated with phentolamine ointment in MC base. Group Ⅶ rats were treated with phenoxybenzamine ointment in MC base. Group Ⅷ rats were treated with phentolamine ointment in CE base. Group Ⅸ rats were treated with phenoxybenzamine ointment in CE base.
The mean survival length of the flap was calculated and following results were obtained.
The mean survival length of the flaps were 2.49±0.51cm in control, 3.24±0.50cm in group Ⅰ, 3.37±0.54cm in group Ⅱ, 2.77±0.34cm in groupⅢ, 3.24±0.49cm in group Ⅳ, 3.15±0.51cm in groupⅤ, 3.16±0.59cm in groupⅥ, 3.07±0.56cm in groupⅦ, 3.59±0.52cm in groupⅧ and 3.20±0.46cm in group Ⅸ.
The conclusions of the experiment are as follows;
1)Both phentolamine and phenoxybenzamine had significant effect increasing the flap survival. And no significant difference in effects between two agents was noted.
2)Topical ointment applications were more effective than local injection in increasing the flap survival.
3)Especially topical ointment application with cream emulsificant base was most effective.
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