Burns

Bayat M, Vasheghani MM, Razavi N.

J Photochem Photobiol B. 2006 May 1;83(2):87-93.

Cell and Molecular Biology Research Center, Department of Anatomy, School of Medicine, Shaheed Beheshti University of Medical Sciences, P.O. Box 19395/4719, Tehran, Evin

This paper presents the results of a study on the effects of low-level helium-neon laser therapy (LL He-Ne LT) on the healing of burns. Seventy-eight adult male rats, having been subjected to third-degree burns, were randomly divided into four groups: two laser treated groups (n=20, each), one control group (n=19) and one nitrofurazone treated group (n=19). In the two laser treated groups, the burns were treated on a daily basis with LL He-Ne LT with an energy density of 1.2 and 2.4 J/cm(2), respectively. The response to treatment was assessed histologically at 7, 16 and 30 days after burning, and microbiologically at day 15. Analysis of variance showed that the mean of blood vessel sections in the 1.2J/cm(2) laser group was significantly higher than those in the other groups and the mean of the depth of new epidermis in the 2.4 J/cm(2) laser group on day 16 was significantly lower than in the nitrofurazone treated group (P=0.025, P=0.047, respectively). When Staphylococcus aureus and Pseudomonas aeruginosa grew in more than 50% of samples obtained from control group, there were no S. aureus and P. aeruginosa in the samples of 2.4 J/cm(2) laser group. It is concluded that LL He-Ne LT induced the destruction of S. aureus and P. aeruginosa in third-degree burns of rats, yet at the same time our histological findings showed that LL He-Ne LT caused a significant increase in the mean of blood vessel sections on day 7 after third degree burns and a decrease in the mean of the depth of new epidermis on day 16 after the same burns in rats.

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Al-Watban FA, Delgado GD.

Photomed Laser Surg. 2005 Jun;23(3):245-50.

Laser Medicine Section, Biological and Medical Research, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia.

OBJECTIVE: A study on burn healing in rats was initiated using a diode laser at varied doses for determination of optimum dosimetry and treatment schedule.

MATERIALS AND METHODS: A number of male Sprague-Dawley rats were randomly assigned to several groups. Anesthesia (a mixture of ketamine HCl and Xylocaine) was administered intraperitoneally. Burn on both flanks was created using a preheated metal probe and measured daily using a caliper. The right side of the treated rats was irradiated five times and three times per week. Slopes from the actual burn areas were obtained and compared against the control with the healing rate calculated and expressed in percent.

RESULTS: In reference to the control group, no significant difference in healing was observed. In comparing both treatment schedules, there was likewise no significant difference at any day in both age-groups. Notably in younger rats, accelerated healing was observed with the highest rate in the lower range of doses (1 and 5 J/cm2), 12.4% and 11.6%, respectively.

CONCLUSION: This experiment affirms that the beneficial effect on burn healing in rats is indeed affected by an interplay of several factors.

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Bayat M, Vasheghani MM, Razavi N, Taheri S, Rakhshan M.

J Photochem Photobiol B. 2005 Feb 1;78(2):171-7.

Anatomy Department, Medical Faculty, Cell and Molecular Biology Research Center, Shaheed Beheshti University of Medical Sciences, P.O. Box 19395/4719, Tehran, Iran.

This paper presents the results of a study on the effects of two different doses of low-level laser therapy on healing of deep second-degree burns. Sixty rats were randomly allocated to one of four groups. A deep second-degree burn was inflicted in each rat. In the control group burns remained untreated; in two laser treated groups the burns were irradiated daily with low-level helium-neon laser with energy densities of 1.2 and 2.4 J/cm2, respectively. In the fourth group the burns were treated topically with 0.2% nitrofurazone cream every day. The response to treatments was assessed histologically at 7, 16 and 30 days after burning, and microbiologically at Day 15. The number of macrophages at day 16, and the depth of new epidermis at day 30, was significantly less in the laser treated groups in comparison with control and nitrofurazone treated groups (P=0.000). Staphylococcus epidermidis was found in the 70% of rat wounds in the laser treated groups in comparison with 100% of rats in the control group. S. aureus was found in the 40% rat wounds in the nitrofurazone treated group, but there was not found in the wounds of laser treated, and control groups. It is concluded that low-level laser therapy of deep second-degree burn caused significant decrease in the number of macrophage and depth of new epidermis. In addition, it decreased incidence of S. epidermidis and S. aureus.

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Gaida K, Koller R, Isler C, Aytekin O, Al-Awami M, Meissl G, Frey M.

Burns. 2004 Jun;30(4):362-7.

Department of Reconstructive and Plastic Surgery, Burn Unit, Division of Surgery, University of Vienna, Austria.

Burn scars are known to be difficult to treat because of their tendency to worsen with hypertrophy and contracture. Various experimental and clinical efforts have been made to alleviate their effects but the problem has not been solved. Since patients keep asking for Low Level Laser Therapy (LLLT) and believe in its effectiveness on burn scars, and since former studies show contradictory results of the influence of LLLT on wound healing, this prospective study was designed to objectify the effects of LLLT on burn scars. Nineteen patients with 19 burn scars were treated with a 400 mW 670 nm Softlaser twice a week over 8 weeks. In each patient a control area was defined, that was not irradiated. Parameters assessed were the Vancouver Scar Scale (VSS) for macroscopic evaluation and the Visual Analogue Scale (VAS) for pruritus and pain. Photographical and clinical assessments were recorded in all the patients. Seventeen out of 19 scars exhibited an improvement after treatment. The average rating on the VSS decreased from 7.10+/-2.13 to 4.68+/-2.05 points in the treated areas, whereas the VSS in the control areas decreased from 6.10+/-2.86 to 5.88+/-2.72. A correlation between scar duration and improvement through LLLT could be found. No negative effects of LLLT were reported. The present study shows that the 400 mW 670 nm softlaser has a positive, yet sometimes limited effect on burn scars concerning macroscopic appearance, pruritus, and pain.

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Ribeiro MS, Da Silva Dde F, De Araujo CE, De Oliveira SF, Pelegrini CM, Zorn TM, Zezell DM.

J Clin Laser Med Surg. 2004 Feb;22(1):59-66.

Center for Lasers and Applications, IPEN-CNEN/SP, Cidade Universitaria, Sao Paulo, Brazil. mribeiro@ipen.br

OBJECTIVE: This study was carried out to investigate the influence of low-intensity polarized visible laser radiation on the acceleration of skin wound healing. Background Data: Low-level laser therapy (LLLT) at adequate wavelength, intensity, and dose can accelerate tissue repair. However, there is still unclear information about light characteristics, such as coherence and polarization. Some studies indicate that linearly polarized light can survive through long propagation distance in biological tissue.

MATERIALS AND METHODS: Three burns about 6 mm in diameter were created on the back of rats with liquid N(2). Lesion "L(//)" was irradiated by He-Ne laser (lambda = 632.8 nm), D= 1.0 J/cm(2), with linear polarization parallel to the spinal column of the rat. Lesion "L(inverted v)" was irradiated using the same laser and dose, but the light polarization was aligned perpendicularly to the relative orientation. Lesion "C" was not irradiated in order to be considered as control. The animals were sacrificed at day 3-17 after lesion creation. Samples were collected and prepared for histological analysis.

RESULTS: Histological analysis showed that the healing of irradiated wounds was faster than that of non-irradiated wounds. Moreover, it was observed that skin wound repair is dependent on polarization orientation with respect to a referential axis as the animal's spinal column. Consequently, "L(//)" was completely healed after 17 days, whereas "L (perpendicular) " showed a moderate degree of healing after the same period.

CONCLUSIONS: These results indicate that the relative direction of the laser polarization plays an important role in the wound healing process when highly coherent He-Ne laser is used.