Regional intravascular sympathetic blockade for better results in flap surgery: an experimental study of free flaps, island flaps, and pedicle flaps in the rabbit ear.

Flap survival is still a major problem in reconstructive surgery. Increased flap survival after systemic administration of drugs inhibiting the adrenergic system has been reported in experimental studies. The clinical use, however, is restricted by systemic side effects. It has been demonstrated that, using guanethidine, an effective regional intravascular sympathetic (RIS) block can be obtained without systemic effects. Using this type of block, an experimental study was made on the survival and quality of different types of flaps in the rabbit ear. The results obtained in 72 flaps created in the ears of 36 rabbits were assessed by the extent of flap edema, peripheral neovascularization, flap temperature, and flap surviving area. The RIS block reduced edema and scab formation, caused higher flap temperatures, better neovascularization, and increased surviving flap area, as compared with equal flaps in the untreated contralateral ear of the same animal. The effect of RIS block may be considered as a "pharmacological delay" procedure. From the experiments as well as clinical experience, it may be concluded that this technique is a safe and effective procedure. Therefore, the RIS block method is recommended for clinical use in flap techniques in extremities of man.