BACKGROUND: To investigate if ultrasonic therapy is effective in avoidance of incisional hernia (IH), once the ideal technique for repair of IH is still a non-solved problem, in spite of prostheses usage. METHODS: IH was created by linea alba opening over 20 male Wistar rats, distributed in two groups: one group received ultrasound over the wound, during 14 days (5 animals) and the other for 28 days (5 animals), each one with the same number of animals as controls. The ultrasound was applied using a small probe, 1:5 pulse mode, 3.0MHz frequency and 0.5W/cm² intensity, for 5 minutes daily, from the first postoperative day. The width of the linea alba scar or the hernia ring was measured at the end of every period. The IH was defined when these openings were over 2mm wide. Some specimens from hernia sac or linea alba scar were obtained for the analysis of vessels, fibroblasts, and colagen fibers density. Standard deviation and medians were obtained by variation analysis and Tukey-Kramer multi-comparison test. RESULTS: The ultrasound group showed a linea alba scar in 60%. The other 40% presented the hernia ring smaller than the non treated group (p<0.0001). The ultrasound increased density of blood vessels (p=0,0031), fibroblasts (p<0,0001), and collagen fibers (p=0,0015). There was no difference between the two treated groups. CONCLUSION: The ultrasound avoided the IH to appear or reduced its width. Fourteen days of treatment were sufficient for this purpose.
Hernia; Abdomen; Ultrasonic therapy; Wound healing; Rats, Wistar
