A systematic review of laser therapy for venous leg ulcers

Bupivacaine-eluting soy protein structures for controlled release and localized pain relief: An in vitro and in vivo study

Burn pain is known to be excruciating, and while burn care has greatly advanced, treatment for burn-related pain is lacking. Current pain relief methods include systemic administration of analgesics, which does not provide high drug concentration at the wound site. In the present study, soy protein was used as the base material for bupivacaine-loaded hybrid wound dressings. The effect of the formulation on the drug release profile was studied using high performance liquid chromatography, and the cytotoxicity was tested on human fibroblasts. A second-degree burn model in rats was used to quantify the efficacy of the wound dressings in vivo, using the Rat Grimace Scale. All tested films exhibited high biocompatibility, and the drug release profiles showed rapid release during the initial 5 hr and a continuous slower release for another 24 hr. Significant pain relief was achieved in the animal trials, proving a decrease of 51-68% in pain levels during days 1-3 post-burn. Hence, the results indicate a safe and controlled bupivacaine release for a period of more than 24 hr, effectively treating pain caused by second-degree burns. The understanding of the formulation-properties effects, together with our in vivo study, enables to advance this field toward tailorable systems with high therapeutic potential.

WITHDRAWN: Laser therapy for venous leg ulcers

This review is being withdrawn. A new review team have registered this title and will be writing a new review which reflects current methods and up to date evidence.

The editorial group responsible for this previously published document have withdrawn it from publication.

What Is New in the Understanding of Non Healing Wounds Epidemiology, Pathophysiology, and Therapies

Chronic wounds are a growing socioeconomic problem in the western world. Knowledge on recalcitrant wounds relies on in vitro studies or clinical observations, and there is emerging evidence on the clinical impact of bacterial biofilm on skin healing. Chronic wounds are locked in the inflammatory state of wound healing, and there are multiple explanations for this arrest with the theory of exaggerated proteolysis as the most commonly accepted. Previously, there has not been enough focus on the different etiologies of chronic wounds compared to acute, healing wounds. There is an urgent need to group chronic wounds by its cause when searching for possible diagnostic or therapeutic targets. Good wound management should therefore consist of recognition of basic wound etiology, irrigation, and debridement in order to reduce microbial and necrotic load, frequently changed dressings, and appropriate antimicrobial and antibiofilm strategies based on precise diagnosis. Representative sampling is required for diagnosis and antimicrobial treatment of wounds. The present review aims at describing the impact of biofilm infections on wounds in relation to diagnosing, treatment strategies, including experimentally adjuvant approaches and animal models.

Effect of red and near-infrared wavelengths on low-level laser (light) therapy-induced healing of partial-thickness dermal abrasion in mice

Low-level laser (light) therapy (LLLT) promotes wound healing, reduces pain and inflammation, and prevents tissue death. Studies have explored the effects of various radiant exposures on the effect of LLLT; however, studies of wavelength dependency in in vivo models are less common. In the present study, the healing effects of LLLT mediated by different wavelengths of light in the red and near-infrared (NIR) wavelength regions (635, 730, 810, and 980 nm) delivered at constant fluence (4 J/cm(2)) and fluence rate (10 mW/cm(2)) were evaluated in a mouse model of partial-thickness dermal abrasion. Wavelengths of 635 and 810 nm were found to be effective in promoting the healing of dermal abrasions. However, treatment using 730- and 980-nm wavelengths showed no sign of stimulated healing. Healing was maximally augmented in mice treated with an 810-nm wavelength, as evidenced by significant wound area reduction (p < 0.05), enhanced collagen accumulation, and complete re-epithelialization as compared to other wavelengths and non-illuminated controls. Significant acceleration of re-epithelialization and cellular proliferation revealed by immunofluorescence staining for cytokeratin-14 and proliferating cell nuclear antigen (p < 0.05) was evident in the 810-nm wavelength compared with other groups. Photobiomodulation mediated by red (635 nm) and NIR (810 nm) light suggests that the biological response of the wound tissue depends on the wavelength employed. The effectiveness of 810-nm wavelength agrees with previous publications and, together with the partial effectiveness of 635 nm and the ineffectiveness of 730 and 980 nm wavelengths, can be explained by the absorption spectrum of cytochrome c oxidase, the candidate mitochondrial chromophore in LLLT.

Low-level light stimulates excisional wound healing in mice

BACKGROUND

Low levels of laser or non-coherent light, termed low-level light therapy (LLLT) have been reported to accelerate some phases of wound healing, but its clinical use remains controversial.

METHODS

A full thickness dorsal excisional wound in mice was treated with a single exposure to light of various wavelengths and fluences 30 minutes after wounding. Wound areas were measured until complete healing and immunofluorescence staining of tissue samples was carried out.

RESULTS

Wound healing was significantly stimulated in BALB/c and SKH1 hairless mice but not in C57BL/6 mice. Illuminated wounds started to contract while control wounds initially expanded for the first 24 hours. We found a biphasic dose-response curve for fluence of 635-nm light with a maximum positive effect at 2 J/cm(2). Eight hundred twenty nanometer was found to be the best wavelength tested compared to 635, 670, and 720 nm. We found no difference between non-coherent 635+/-15-nm light from a lamp and coherent 633-nm light from a He/Ne laser. LLLT increased the number of alpha-smooth muscle actin (SMA)-positive cells at the wound edge.

CONCLUSION

LLLT stimulates wound contraction in susceptible mouse strains but the mechanism remains uncertain.

Blinding techniques in randomized controlled trials of laser therapy: an overview and possible solution

Low-level laser therapy has evidence accumulating about its effectiveness in a variety of medical conditions. We reviewed 51 double blind randomized controlled trials (RCTs) of laser treatment. Analysis revealed 58% of trials showed benefit of laser over placebo. However, less than 5% of the trials had addressed beam disguise or allocation concealment in the laser machines used. Many of the trials used blinding methods that rely on staff cooperation and are therefore open to interference or bias. This indicates significant deficiencies in laser trial methodology. We report the development and preliminary testing of a novel laser machine that can blind both patient and operator to treatment allocation without staff participation. The new laser machine combines sealed preset and non-bypassable randomization codes, decoy lights and sound, and a conical perspex tip to overcome laser diode glow detection.

Blue laser light increases perfusion of a skin flap via release of nitric oxide from hemoglobin

It has recently been shown that nitrosyl complexes of hemoglobin (NO-Hb) are sensitive to low-level blue laser irradiation, suggesting that laser irradiation can facilitate the release of biologically active nitric oxide (NO), which can affect tissue perfusion. The aim of this study was to evaluate the therapeutic value of blue laser irradiation for local tissue perfusion after surgical intervention. Blood was withdrawn from a rat, exposed to NO and infused back to the same rat or used for in vitro experiments. In vitro, an increase of NO-Hb levels (electron paramagnetic resonance spectroscopy) up to 15 microM in rat blood did not result in the release of detectable amounts of NO (NO selective electrode). Blue laser irradiation of NO-Hb in blood caused decomposition of NO-Hb complexes and release of free NO. Systemic infusion of NO-Hb in rats affected neither systemic circulation (mean arterial pressure) nor local tissue perfusion (Doppler blood flow imaging system). In contrast, a clear enhancement of local tissue perfusion was observed in epigastric flap when elevated NO-Hb levels in blood were combined with local He-Cd laser irradiation focused on the left epigastric artery. The enhancement of regional tissue perfusion was not accompanied by any detectable changes in systemic circulation. This study demonstrates that blue laser irradiation improves local tissue perfusion in a controlled manner stimulating NO release from NO-Hb complexes.

[Venous leg ulcers: no improvement of wound healing with 685-nm low level laser therapy. Randomised, placebo-controlled, double-blind study]

INTRODUCTION

Venous leg ulcers (ulcera crurum venosa) are frequently seen in elderly patients. It has been suggested that low level laser irradiation has a biostimulative and wound healing effect; however, this has not yet been clinically verified by controlled studies.

STUDY DESIGN

The difference in size reduction of leg ulcers with and without low level laser or placebo laser treatment was measured in 44 patients randomised into two treatment groups (685-nm low level laser and placebo laser) or a control group which served to quantify the effect of laser application. All patients received standardized wound care.

OBJECTIVE

The aim of the study was to compare the effectiveness of low level laser irradiation with that of a placebo "light source". The size of the ulcers was planimetrically measured at baseline (day 1), at the end of therapy (day 28) and 2 months later (day 90). The difference in wound size was evaluated.

RESULTS

There were no statistically significant differences in reduction of wound size between the three groups, thus suggesting that low level laser light does not have any stimulatory effect on wound healing in ulcera crurum venosa.

Optionen des Debridements in der Therapie chronischer Wunden. Options for debridement in the therapy of chronic wounds

Debridement is defined as the removal of non-vital tissue from wounds. In chronic wounds, debridement means the elimination of necrosis as well as the clearing away of wound dressings, foreign bodies, and other non-vital substances. Sufficient debridement represents one basic prerequisite for a non-delayed wound-healing process. In addition to treating the causal factors for delayed wound healing, debridement should be the first step in an adequate phase-adapted wound-bed preparation for chronic wounds. This report aims to review the different options available in the execution of debridement in chronic wounds. The following therapeutic measures are available for the debridement of chronic wounds: surgery, maggot therapy, laser, ultrasound, hydrotherapy, wet-to-dry method, autolysis, proteolytic enzymes, osmotic or chemical debridement. There is no single correct debridement for all patients! Patients are individuals and therefore different methods of debridement may make sense. Which therapeutic option is chosen is determined by multiple factors. Moreover, depending on the wound milieu, the successive application of different methods can be useful.

Low-level laser irradiation attenuates production of reactive oxygen species by human neutrophils

OBJECTIVE

The aim of this study was to examine the effects of low-level laser therapy (LLLT) on production of reactive oxygen (ROS) species by human neutrophils.

BACKGROUND DATA

LLLT is an effective therapeutic modality for inflammatory conditions.

MATERIALS AND METHODS

The laser device used was the infrared diode laser (GaAlAs), 830-nm continuous wave (150 mW/cm(2)). After irradiation, ROS production by neutrophils was measured using luminol-dependent chemiluminescence (LmCL) and expression of CD11b and CD16 on neutrophil surface was measured by flow cytometry.

RESULTS

The LmCL response of neutrophils was reduced by laser irradiation at 60 min prior to the stimulation with opsonized zymosan and calcium ionophore. The attenuating effect of LLLT was larger in neutrophils of smokers than non-smokers, while the amount of produced ROS was larger in neutrophils of smokers. Expression of CD11b and CD16 on neutrophil surface was not affected by LLLT.

CONCLUSION

Attenuation of ROS production by neutrophils may play a role in the effects of LLLT in the treatment of inflammatory tissues. There is a possible usage of LLLT to improve wound healing in smokers.

Advances in wound care and healing technology

Wounds are unique in so far as no disease process other than wounds would have existed from the beginning of mankind. Over the years, the management of wounds, especially that of chronic wounds, has had enormous social and economic implications worldwide. With an aging population, this impact is likely to increase. In recent years, this has been reflected by the birth and rapid growth of the new speciality of 'wound healing'. Continuous advances made in the study of the wound microenvironment, an ever-broadening understanding of the pathophysiology of wounds, and improved techniques in monitoring the response of healing have led to continuing developments in the treatment of chronic wounds. Current research focuses on growth factors and human skin substitutes that provide promising results. This article reviews advances made in wound care management over the years. Despite all these advances, it must be borne in mind that basic principles of wound care in a multidisciplinary team setting still remain the backbone of wound management.

Laser therapy for venous leg ulcers

OBJECTIVES

To assess the effectiveness of low level laser therapy in the treatment of venous leg ulcers.

SEARCH STRATEGY

Searches of 19 databases, hand searching of journals and conference proceedings from 1948 onwards, and examination of bibliographies.

SELECTION CRITERIA

Randomised controlled trials comparing low level laser therapy with: sham laser; no laser; non-coherent light. There was no restriction on date or language. The main outcome measure used was complete healing of the ulcers.

DATA COLLECTION AND ANALYSIS

Data extraction was done by one reviewer and checked by a second. Meta analysis was used to combine the results of trials where the interventions and outcome measures were sufficiently similar.

MAIN RESULTS

There were 4 eligible trials. Two RCTs compared laser therapy with sham, 1 with ultraviolet therapy and 1 with non-coherent, unpolarised red light. Neither of the two RCTs comparing laser with sham found a significant difference in healing rates; there was no significant of laser evident when the trials were pooled. A three-arm study compared: - laser therapy alone - laser therapy plus infrared light - non-coherent, unpolarised red light. Significantly more ulcers completely healed in the group receiving a combination of laser and infrared light compared with non-coherent, unpolarised red light. A fourth trial compared laser and ultraviolet light and found no difference.

REVIEWER'S CONCLUSIONS

We have found no evidence of any benefit associated with low level laser therapy on venous leg ulcer healing. One small study suggests that a combination of laser and infrared light may promote the healing of venous ulcers, however more research is needed.