830-nm irradiation increases the wound tensile strength in a diabetic murine model.
Stadler I, Lanzafame RJ, Evans R, Narayan V, Dailey B, Buehner N, Naim JO.
The Laser Center, Rochester General Hospital, Rochester, New York 14621, USA. Istvan.Stadler@viahealth.org
Lasers Surg Med. 2001;28(3):220-6.[PMID: 11295756]
Background and objective: The purpose of this study was to investigate the effects of low-power laser irradiation on wound healing in genetic diabetes.
Study design/materials and methods: Female C57BL/Ksj/db/db mice received 2 dorsal 1 cm full-thickness incisions and laser irradiation (830 nm, 79 mW/cm(2), 5.0 J/cm(2)/wound). Daily low-level laser therapy (LLLT) occurred over 0-4 days, 3-7 days, or nonirradiated. On sacrifice at 11 or 23 days, wounds were excised, and tensile strengths were measured and standardized.
Results: Nontreated diabetic wound tensile strength was 0.77 +/- 0.22 g/mm(2) and 1.51 +/- 0.13 g/mm(2) at 11 and 23 days. After LLLT, over 0-4 days tensile strength was 1.15 +/- 0.14 g/mm(2) and 2.45 +/- 0.29 g/mm(2) (P = 0.0019). Higher tensile strength at 23 days occurred in the 3- to 7-day group (2.72 +/- 0.56 g/mm(2) LLLT vs. 1.51 +/- 0.13 g/mm(2) nontreated; P < or = 0.01).
Conclusion: Low-power laser irradiation at 830 nm significantly enhances cutaneous wound tensile strength in a murine diabetic model. Further investigation of the mechanism of LLLT in primary wound healing is warranted.
A case report of low-intensity laser therapy (LILT) in the management of venous ulceration: potential effects of wound debridement upon efficacy.
Lagan KM, Mc Donough SM, Clements BA, Baxter GD.
Rehabilitation Sciences Research Group, School of Health Sciences, University of Ulster at Jordanstown, BT37 OQB, North Ireland.
J Clin Laser Med Surg. 2000 Feb;18(1):15-22. [PMID: 11189107]
Objective: This single case report (ABA design) was undertaken as a preliminary investigation into the clinical effects of low intensity laser upon venous ulceration, applied to wound margins only, and the potential relevance of wound debridement and wound measurement techniques to any effects observed.
Methods: Ethical approval was granted by the University of Ulster’s Research Ethical Committee and the patient recruited was required to attend 3 times per week for a total of 8 weeks. Treatments were carried out using single source irradiation (830 nm; 9 J/cm2, CB Medico, Copenhagen, Denmark) in conjunction with dry dressings during each visit. Assessment of wound surface area, wound appearance, and current pain were completed by an independent investigator. Planimetry and digitizing were completed for wound tracings and for photographs to quantify surface areas. Video image analysis was also performed on photographs of wounds.
Results: The primary findings were changes in wound appearance, and a decrease in wound surface area (range 33.3-46.3%), dependent on the choice of measurement method. Video image analysis was used, but rejected as an accurate method of wound measurement. Treatment intervention produced a statistically significant reduction in wound area using the C statistic on digitizing data for photographs (at Phase one only; Z = 2.412; p < 0.05). Wound debridement emerged as an important procedure to be carried out prior to measuring wounds. Despite fluctuating pain levels recorded throughout the duration of the study, VAS scores showed a decrease of 15% at the end of the study. This hypoalgesic effect was, however, statistically significant (using the C statistic) at Phase one only (Z = 2.554; p < 0.05).
Conclusions: Low intensity laser therapy at this dosage, and using single source irradiation would seem to be an effective treatment for patients suffering venous ulceration. Further group studies are indicated to establish the most effective therapeutic dosage for this and other types of ulceration.
Analysis of Low-Level Laser Radiation Transmission in Occlusive Dressings
de Jesus Guirro RR, de Oliveira Guirro EC, Martins CC, Nunes FR.
Department of Biomechanics, Medicine and Rehabilitation of the Locomotor System, School of Medicine of Ribeirã o Preto, University Sã o Paulo, Brazil
Photomed Laser Surg. 2009 Oct 9. [PMID: 19817516]
Objective: The purpose of this study is to analyze the power transmitted by low-level laser therapy (LLLT) into occlusive dressings using different wavelengths for the treatment of cutaneous lesions.
Background data: LLLT has been largely used to treat several cutaneous lesions commonly associated with occlusive dressings to accelerate the healing process.
Materials and methods: Radiation transmission was measured by a digital power analyzer connected to a laser emitter with wavelengths of 660, 830, and 904 nm and mean levels of 30, 30, 6.5 mW, respectively, previously calculated. Thirteen different occlusive dressings were analyzed and interposed between the laser emitter and the power analyzer sensor, with 15 measurements made for each dressing. Statistics were provided by the analysis of variance (ANOVA), followed by Student’s t-test (p < 0.05).
Results: The power transmitted ranged between 98.6% and 0%, depending on the material and wavelength. The dressings tested were BioFill, Hydrofilm, Confeel Plus 3533, Confeel 3218, DuoDERM Extra Thin, Hydrocoll, Micropore Nexcare, CIEX tape, Emplasto Sábia, CombiDERM, Band-aid, Actisorb Plus, in addition to polyvinylchloride (PVC) film, and transmitted power higher than 40% of the incident power, independently from the wavelength indicated for the association with LLLT.
Conclusion: The results showed that LLLT transmission depends on the occlusive dressing material and the wavelength irradiated.
Effect of low-level laser therapy (830 nm) with different therapy regimes on the process of tissue repair in partial lesion calcaneus tendon
Oliveira FS, Pinfildi CE, Parizoto NA, Liebano RE, Bossini PS, Garcia EB, Ferreira LM.
Department of Plastic Surgery, Sã o Paulo Federal University-UNIFESP, Sã o Paulo, SP 04024-900, Brazil.
Lasers Surg Med. 2009 Apr;41(4):271-6. [PMID: 19347936]
Background and objective: Calcaneous tendon is one of the most damaged tendons, and its healing may last from weeks to months to be completed. In the search after speeding tendon repair, low intensity laser therapy has shown favorable effect. To assess the effect of low intensity laser therapy on the process of tissue repair in calcaneous tendon after undergoing a partial lesion.
Study design/materials and methods: Experimentally controlled randomized single blind study. Sixty male rats were used randomly and were assigned to five groups containing 12 animals each one; 42 out of 60 underwent lesion caused by dropping a 186 g weight over their Achilles tendon from a 20 cm height. In Group 1 (standard control), animals did not suffer the lesion nor underwent laser therapy; in Group 2 (control), animals suffered the lesion but did not undergo laser therapy; in Groups 3, 4, and 5, animals suffered lesion and underwent laser therapy for 3, 5, and 7 days, respectively. Animals which suffered lesion were sacrificed on the 8th day after the lesion and assessed by polarization microscopy to analyze the degree of collagen fibers organization.
Results: Both experimental and standard control Groups presented significant values when compared with the control Groups, and there was no significant difference when Groups 1 and 4 were compared; the same occurred between Groups 3 and 5.
Conclusion: Low intensity laser therapy was effective in the improvement of collagen fibers organization of the calcaneous tendon after undergoing a partial lesion.
Effect of low-level laser therapy (830 nm) with different therapy regimes on the process of tissue repair in partial lesion calcaneus tendon.
Oliveira FS, Pinfildi CE, Parizoto NA, Liebano RE, Bossini PS, Garcia EB, Ferreira LM.
Department of Plastic Surgery, São Paulo Federal University-UNIFESP, São Paulo, SP 04024-900, Brazil.
Lasers Surg Med. 2009 Apr;41(4):271-6. [PMID: 19347936]
Background and objective: Calcaneous tendon is one of the most damaged tendons, and its healing may last from weeks to months to be completed. In the search after speeding tendon repair, low intensity laser therapy has shown favorable effect. To assess the effect of low intensity laser therapy on the process of tissue repair in calcaneous tendon after undergoing a partial lesion.
Study design/materials and methods: Experimentally controlled randomized single blind study. Sixty male rats were used randomly and were assigned to five groups containing 12 animals each one; 42 out of 60 underwent lesion caused by dropping a 186 g weight over their Achilles tendon from a 20 cm height. In Group 1 (standard control), animals did not suffer the lesion nor underwent laser therapy; in Group 2 (control), animals suffered the lesion but did not undergo laser therapy; in Groups 3, 4, and 5, animals suffered lesion and underwent laser therapy for 3, 5, and 7 days, respectively. Animals which suffered lesion were sacrificed on the 8th day after the lesion and assessed by polarization microscopy to analyze the degree of collagen fibers organization.
Results: Both experimental and standard control Groups presented significant values when compared with the control Groups, and there was no significant difference when Groups 1 and 4 were compared; the same occurred between Groups 3 and 5.
Conclusion: Low intensity laser therapy was effective in the improvement of collagen fibers organization of the calcaneous tendon after undergoing a partial lesion.
Effects of a single near-infrared laser treatment on cutaneous wound healing: biometrical and histological study in rats.
Rezende SB, Ribeiro MS, Núñez SC, Garcia VG, Maldonado EP.
Center for Lasers and Applications, IPEN-CNEN/SP, São Paulo, SP, Brazil.
J Photochem Photobiol B. 2007 Jun 26;87(3):145-53. Epub 2007 Mar 19. [PMID: 17475503]
Background: Low intensity laser therapy has been recommended to support the cutaneous repair; however, so far studies do not have evaluated the tissue response following a single laser treatment. This study investigated the effect of a single laser irradiation on the healing of full-thickness skin lesions in rats.
Methods: Forty-eight male rats were randomly divided into three groups. One surgical lesion was created on the back of rats using a punch of 8mm in diameter. One group was not submitted to any treatment after surgery and it was used as control. Two energy doses from an 830-nm near-infrared diode laser were used immediately post-wounding: 1.3 J cm(-2) and 3 J cm(-2). The laser intensity 53 m W cm(-2) was kept for both groups. Biometrical and histological analyses were accomplished at days 3, 7 and 14 post-wounding.
Results: Irradiated lesions presented a more advanced healing process than control group. The dose of 1.3 J cm(-2) leaded to better results. Lesions of the group irradiated with 1.3 J cm(-2) presented faster lesion contraction showing quicker re-epithelization and reformed connective tissue with more organized collagen fibers.
Conclusions: Low-intensity laser therapy may accelerate cutaneous wound healing in a rat model even if a single laser treatment is performed. This finding might broaden current treatment regimens.
Low-level laser therapy in oral mucositis: a pilot study.
Cauwels RG, Martens LC.
Dept of Paediatric Dentistry, University Hospital, De Pintelaan 158, B 9000 Ghent, Belgium. rita.cauwels@ugent.be
Eur Arch Paediatr Dent. 2011 Apr;12(2):118-23. [PMID: 21473845]
Aim: The goal of this pilot study was to investigate the capacity of pain relief and wound healing of low level laser therapy (LLLT) in chemotherapy-induced oral mucositis (OM) in a paediatric oncology population group.
Study design and methods: 16 children (mean age 9.4 years) from the Gent University Hospital – Department Paediatric Oncology/haematology, suffering from chemotherapy-induced OM were selected. During clinical investigations, the OM grade was assessed using the WHO classification. All children were treated using a GaAlAs diode laser with 830 nm wavelength and a potency of 150 mW. The energy released was adapted according to the severity of the OM lesions. The same protocol was repeated every 48 hrs until healing of each lesion occurred. Subjective pain was monitored before and immediately after treatment by an appropriate pain scale and functional impairment was recorded. At each visit, related blood cell counts were recorded.
Results: After 12 mths, records were evaluated and information about treatment sequence, treatment sessions and frequencies related to the pain sensation and comfort were registered. Immediately after beaming the OM, pain relief was noticed. Depending on the severity of OM, on average, 2.5 treatments per lesion in a period of 1 week were sufficient to heal a mucositis lesion.
Conclusions: LLLT, one of the most recent and promising treatment therapies, has been shown to reduce the severity and duration of mucositis and to relieve pain significantly. In the present study similar effects were obtained with the GaAlAs 830nm diode laser. It became clear that using the latter diode device, new guidelines could be developed as a function of the WHO-OM grades i.e. the lower the grade, the less energy needed. Immediate pain relief and improved wound healing resolved functional impairment that was obtained in all cases.
Low-level laser therapy (LLLT) at 830 nm positively modulates healing of tracheal incisions in rats: a preliminary histological investigation.
Grendel T, Sokolský J, Vaščáková A, Hrehová B, Poláková M, Bobrov N, Sabol F, Gál P.
Department of Medical Biophysics, Pavol Jozef Šafárik University, Košice, Slovak Republic.
Photomed Laser Surg. 2011 Sep;29(9):613-8. Epub 2011 Apr 1.[PMID: 21456943]
Objective: The aim of the present study was to evaluate whether LLLT at 830 nm is able to positively modulate trachea incisional wound healing in Sprague-Dawley rats.
Background data: Tracheotomy may be associated with numerous complications. Development of excess granulation tissue represents a late complication that may lead to airway occlusion. Low-level laser therapy (LLLT) has been shown to have stimulatory effects on wound healing of different tissues. Therefore, it may be suggested that LLLT could be able to positively modulate trachea wound healing as well.
Materials and methods: Using general anesthesia, a median incision was performed from the second to the fifth tracheal cartilage ring in 24 rats. Animals were then randomly divided into sham-irradiated control and laser-treated groups. LLLT (power density: 450 mW/cm(2); total daily dose: 60 J/cm(2); irradiated area ∼1 cm(2)) treatment was performed daily during the first week after surgery. Samples for histological evaluation were removed 7 and 28 days after surgical procedure. Histological sections were stained with hematoxylin-eosin and van Gieson.
Results: Results from our investigation showed that LLLT was able to reduce granulation tissue formation and simultaneously increase new cartilage development at both evaluated time intervals.
Conclusions: From this point of view, LLLT at 830 nm may be a valuable tool in trachea wound healing modulation. Nevertheless, further detailed research is needed to find optimal therapeutic parameters and to test these findings on other animal models.
Treatment of Skin Ulcers with 830 nm GaAIAs Diode Laser Therapy.
Junichiro Kubota
Department of Plastic and Reconstructive Surgery, Kyorin University School of Medicine, Tokyo, Japan.
Abstract: Persistent skin ulcers are still a major problem for the plastic and reconstructive surgeon. These ulcers of various aetiologies are often resistant to conventional therapeutic methodologies, and present both patient and surgeon with severe problems. Low level laser therapy (LLLT) has been proved to accelerate wound healing by enhancing blood flow, macrophage activity and lymphatic drainage in the inflammatory stage; by increasing fibroblast proliferation and collagen deposition in the proliferative stage; by encouraging more fibroblast to myofibroblast transformation in the contractile stage; and by assisting with remodelling in the final stage of repair. It was considered that these LLLT-associated actions, coupled with others, would be of assistance in treating persistent ulcers in a painless, side-effect free and noninvasive manner. The laser used was a near infrared 830 nm gallium aluminium arsenide (GaAlAs) semiconductor laser delivering 150 mW in continuous wave. The laser was applied in the contact mode for 15 to 30 sec per point, irradiating the intact skin around the periphery of the ulcer. The incident energy density was approximately 66 J/cm2 or 132 J/cm2 per point, depending on the exposure time. Nine representative case reports are presented of persistent therapy-resistant ulcers of a variety of aetiologies which responded very well to 830 nm diode LLLT. Although further research is needed to elucidate completely the mechanisms and pathways of LLLT in wound healing enhancement, enough has been scientifically proved to date to justify the application of LLLT for persistent ulcers as a safe, effective, painless and side effect free modality, particularly when used as an adjunctive therapy together with good wound care.