Estimulação elétrica de alta voltagem como alternativa para o tratamento de úlceras crônicas de membros inferiores

Effects of High-Voltage Electrical Stimulation in Improving the Viability of Musculocutaneous Flaps in Rats

BACKGROUND

The musculocutaneous flap of the transverse rectus abdominis muscle is a technique used for breast reconstruction, and one of the complications of this procedure is tissue necrosis. The objective of the study is to determine the effect of high-voltage electrical stimulation (HVES) in the transverse rectus abdominis muscle flap in rats.

METHODS

Fourteen rats underwent surgery for obtaining the flap. The rats were distributed into 2 homogeneous groups: group 1 underwent both surgery and the use of HVES, whereas group 2 underwent just the surgery (control). Electrical stimulation was applied immediately after surgery and for 2 consecutive days. The percentage of necrotic area was analyzed using the Image J software, and blood flow was assessed by infrared thermography in different regions of the flap, divided into 4 zones according to the proximity of the pedicle of the inferior epigastric artery.

RESULTS

The results were analyzed using a Student t test, where group 1 experienced a necrotic area of 26.2%, and group 2 had an area of 54.5%. Regarding the temperature, the 2 groups showed increase in the minimum and maximum temperature on the fourth postoperative day.

CONCLUSION

The HVES appeared to have a positive influence on the viability of the flap.

High voltage pulsed current in collagen realignment, synthesis, and angiogenesis after Achilles tendon partial rupture

Objective

To verify the efficacy of high voltage pulsed current in collagen realignment and synthesis and in angiogenesis after the partial rupturing of the Achilles tendon in rats.

Method

Forty male Wistar rats were randomized into four groups of 10 animals each: sham, cathodic stimulation, anodic stimulation, and alternating stimulation. Their Achilles tendons were submitted to direct trauma by a free-falling metal bar. Then, the treatment was administered for six consecutive days after the injury. In the simulation group, the electrodes were positioned on the animal, but the device remained off for 30 minutes. The other groups used a frequency of 120 pps, sensory threshold, and the corresponding polarity. On the seventh day, the tendons were removed and sent for histological slide preparation for birefringence and Picrosirius Red analysis and for blood vessel quantification.

Results

No significant difference was observed among the groups regarding collagen realignment (types I or III collagen) or quantity of blood vessels.

Conclusion

High voltage pulsed current for six consecutive days was not effective in collagen realignment, synthesis, or angiogenesis after the partial rupturing of the Achilles tendon in rats.

Polarized currents inhibit in vitro growth of bacteria colonizing cutaneous ulcers

Infections caused by Staphylococcus aureus, Pseudomonas aeruginosa, and Escherichia coli are among the microorganisms that often lead to infection in pressure ulcers. Polarized current has emerged as a possible intervention to limit bacterial proliferation. We analyzed the effect of fixed diphasic - Bernard (FD-B) and high voltage monophasic pulsed (HVMP) currents on bacteria S. aureus ATCC 25923 (Gram +), P. aeruginosa ATCC 27853 (Gram -), and E. coli ATCC 25922 (Gram -). After the bacterial strains were activated the bacteria were suspended in physiological solution (0.9%) and the concentration adjusted to 1.5 × 10(3) CFU/mL. The cultures were stimulated with FD-B current at (3, 6, and 9 mA, 100 Hz, 15 and 30 minutes) and HVMP (32, 64, and 95 V, 100 Hz, 30 and 60 min) while monitoring the pH and temperature. After the stimulation, the suspensions were plated and incubated for 24 hours at 37°C. Then the counts were made of colony forming units (CFU). Data were submitted to normality Shapiro-Wilk test followed by nonparametric ANOVA test and post hoc Tukey test with p < 0.05. There was a decrease in the CFU for the two currents, but the most effective reduction was in FD-B. The temperature remained constant and the pH measured alkaline at the negative pole and acid at the positive pole during stimulation. The application of FD-B and HVMP currents promoted inhibition of bacterial proliferation when stimulated in vitro, acting as an adjuvant resource in the healing process.