Ultrasound, LLLT, and the combined use of LLLT and US resulted in greater synthesis of type I collagen; US was also effective in increasing collagen organization in the early stages of the healing process.
Low-level laser therapy resulted in significantly greater amounts of type III collagen (output powers of 60 mW or more) and type I collagen (output power of 80 mW), however, no significant differences between groups were found in the realignment of collagen fibers.
Low-level laser therapy (LLLT) has been used with the aim of improving vascular perfusion of the skin and musculocutaneous flaps. This study evaluated the effect of LLLT on transverse rectus abdominis musculocutaneous flap (TRAM) viability, vascular angiogenesis, and VEGF release. Eighty-four Wistar rats were randomly divided into seven groups with 12 rats in each group. Group 1 received sham laser treatment; group 2, 3 J/cm(2) at 1 point; group 3, 3 J/cm(2) at 24 points; group 4, 72 J/cm(2) at 1 point; group 5, 6 J/cm(2) at 1 point; group 6, 6 J/cm(2) at 24 points; and group 7, 144 J/cm(2) at 1 point. All experimental groups underwent LLLT immediately after the TRAM operation and on the following 2 days; thus, animals underwent 3 days of treatment. The percentage of skin flap necrosis area was calculated on the fourth postoperative day using the paper template method, and two skin samples were collected using a 1-cm(2) punch to evaluate alpha smooth muscle actin (1A4) and VEGF levels in blood vessels. Significant differences were found in necrosis percentage, and higher values were seen in group 1 than in the other groups. Statistically significant differences were not found among groups 3 to 7 (p<0.292). Groups 5 and 7 showed significantly higher VEGF levels compared to other groups. Groups 3 and 5 had an increase in levels of blood vessels compared to other groups. LLLT at energy densities of 6 to 144 J/cm(2) was efficient to increase angiogenesis and VEGF levels and promote viability in TRAM flaps in rats.
Introduction: Transcutaneous electrical nerve stimulation (TENS) can alter the local temperature, increase skin blood flow and induce the release of vasodilator neuropeptides and growth factors. These changes may be related to the effects of TENS on the tissue repair process. Objective: To assess the effect of high-and low-frequency TENS on angiogenesis and the contraction of acute excisional wounds in rat skin. Methods: Fifty-four young adult male EPM1-Wistar rats were used in the study. An excisional wound was performed on the back of each animal using an 8mm punch. The animals were randomly assigned to three groups: the
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