Effect of high frequency transcutaneous electrical nerve stimulation on viability of random skin flap in rats1 Efeito da estimulação elétrica nervosa transcutânea em alta freqüência na viabilidade do retalho cutâneo randômico em ratos

Purpose: To determine the effect of high frequency Transcutaneous Electrical Nerve Stimulation (TENS) on viability of random skin flap in rats. Methods: The sample of this study was 75 Wistar rats. The skin flap measured 10 x 4 cm and a plastic barrier was interposed between the flap and donor site. After the operative procedure, animals of all groups were maintained anesthetized one more hour with electrodes positioned in the base of the flap and submitted to treatment according of their respective group. This procedure was repeated on the two subsequent days. G1: sham stimulation (control), G2: TENS (f = 80 Hz and I = 5 mA), G3: TENS (f = 80 Hz and I = 10 mA), G4: TENS (f = 80 Hz and I = 15 mA), G5: TENS (f = 80 Hz and I = 20 mA). Results: The average percentage of necrotic area was 43,11, 34,65, 49,44, 23,52, 45,10 in groups 1, 2, 3, 4 and 5 respectively. Conclusion: The amplitude of 15 mA presented a lower necrotic area than control group and Transcutaneous Electrical Nerve Stimulation was efficient in increasing the random skin flap viability.