Assessment of muscle flap sensibility by evoked potentials in the rat

This study investigated whether the sensory-to-motor reinervation of the mu scle flap provides a better sensory recovery of an overlying skin graft. Fi fty-four animals were studied in three groups of 18 rats each: group I (con trol): 1 cm of the gastrocnemius muscle motor nerve was excised and no repa ir was performed; group II (motor-to-motor repair): the motor nerve of the gastrocnemius flap was transected and repaired; group III (sensory-to-motor repair): the motor nerve of the gastrocnemius muscle and sural nerve were transected and their distal and proximal ends, respectively, were repaired. At follow-up periods of 6, 12, and 24 weeks, evaluation of hair growth, mu scle atrophy, and sensory evoked potentials was performed. Somatosensory ev oked potentials (SSEP) at 6 weeks in the sensory-to-motor repair (group III ) revealed a significant (P < 0.05) increase (104.4% +/- 22.9) in the relat ive response of peak-to-peak potentials when compared with group I (46.6% /- 19) and group II (51.8% +/- 14.0). Muscle flap stimulation was most prom inent at 6 weeks in sensory-to-motor reinvervated flaps (group III 133.1% /- 25.4; group I 84.9% +/- 20.2). In this study, sensory-to-motor nerve rep air significantly improved the sensibility of skin flaps at 6 weeks. Denerv ated flaps presented with 3 months of sensory recovery delay. (C) 2000 Wile y-Liss, Inc.