Effect of low-frequency transcutaneous electrical nerve stimulation (TENS) on the viability of ischemic skin flaps in the rat: an amplitude study.

The purpose of this study was to determine the effect of low-frequency (2 Hz) transcutaneous electrical nerve stimulation (TENS) on the viability of ischemic skin flaps in the rat. Seventy-five EPM1-Wistar rats were used. The random skin flap measuring 10 x 4 cm was raised and a plastic barrier was placed between the flap and its bed. After the surgical procedure, animals in all groups were kept anesthetized for 1 hour, with electrodes placed at the base of the flap, and received the assigned treatment. The animals were randomized into five groups (G1-G5) and each group was subjected to the following procedures, which were repeated on the 2 subsequent days: G1-sham stimulation (control); G2-transcutaneous electrical nerve stimulation, TENS (f=2 Hz, I=5 mA), G3-TENS (f=2 Hz, I=10 mA), G4-TENS (f=2 Hz, I=15 mA), G5-TENS (f=2 Hz, I=20 mA). Seven days after treatment, the percentage of flap necrosis was determined. For each group, the mean+/-SEM percentage of flap necrosis was as follows: G1 group (control), 43.88+/-2.02%; G2 group, 39.20+/-3.17%; G3 group, 38.57+/-4.08%; G4 group, 32.14+/-2.89%; and G5 group, 44.13+/-2.98%. The G4 group had the smallest necrotic area compared with the control group. The low-frequency TENS treatment was effective in improving the viability of ischemic skin flap.