Treatment of ischemic wounds with noncontact, low-frequency ultrasound: the Mayo clinic experience, 2004-2006

Application of dual-frequency ultrasound for reduction of perilesional edema and ecchymosis after rhinoseptoplasty

OBJECTIVES

Biological aspect and clinical research demonstrated that dual-frequency ultrasound (local dynamic micro-massage, LDM) waves of very high frequency can significantly modify cellular signaling providing anti-inflammatory and anti-fibrotic effects. During the recent past, these waves were successfully applied for the treatment of various inflammatory skin conditions, hypertrophic scars, and chronical wounds. Since the main complications after rhinoseptoplasty are caused by excessive inflammatory reactions and development of fibrosis along nasal implants which can lead to a revision rhinoseptoplasty, in this retrospective multicenter blinded study we have evaluated the efficacy of LDM ultrasound for the treatment of the postoperative perilesional ecchymosis and edema in patients after rhinoseptoplasty.

METHODS

Twenty-four patients received daily LDM treatment (study group) for 5 days starting from the first day postoperative, whereas 24 patients (control group) were treated with conventional ice packs. Dynamic reduction of the postoperative perilesional ecchymosis and edema was followed up, and the total duration of these side effects was determined within specific paranasal anatomical areas.

RESULTS

Post-rhinoseptoplasty ecchymosis and edema were observed in the areas of anterior cheek, lower eyelids, and upper eyelids. Duration of the postoperative perilesional edema was significantly reduced in the group treated with LDM (1.9 ± 0.9 days) compared with control group (4.5 ± 2.1 days). Duration of the ecchymosis was also significantly reduced in LDM group (2.8 ± 1.4 days) compared with controls (7.4 ± 2.8 days). Postoperative patient satisfaction in LDM-treated and control groups was 3.1 ± 1.3 and 1.5 ± 0.7, respectively, demonstrating significantly higher satisfaction in LDM-treated group.

CONCLUSIONS

This study proved that the post-rhinoseptoplasty group treated with LDM ultrasound showed a significantly shorter duration of the postsurgical perilesional ecchymosis and edema, with no substantial adverse effects other than those observed in the control group. It can be suggested that ultrasound treatment can serve as an alternative option for the noninvasive management of postoperative perilesional ecchymosis and edema.

Electromechanical therapy in diabetic foot ulcers patients: A systematic review and meta-analysis

Purpose

Diabetic foot ulcer (DFU) is one of the most devastating and troublesome consequences of diabetes. The current therapies are not always effective because of the complicated aetiology and interactions of local and systemic components in DFU. However, adjunctive therapy (electromechanical therapy) has become the latest modality in recent years, although there is a lack of significant research to support its utilization as a treatment standard. The purpose of this systematic research was to review the literature on the application of electromechanical therapies in the healing of DFUs.

Methods

For this systematic review, we searched PubMed, Medline, EmBase, the Cochrane library, and Google Scholar for the most current research (1990-2022) on electromechanical therapies for DFUs. We used the PICO method (where P is population, I is intervention, C is comparator/control, and O is outcome for our study) to establish research question with the terms [Electromechanical therapy OR Laser therapy OR photo therapy OR Ultrasound therapy OR Shockwave therapy] AND [diabetic foot ulcers OR diabetes] were used as search criteria. Searches were restricted to English language articles only. Whereas, Cochrane handbook of "Systematic Reviews of Interventions" with critical appraisal for medical and health sciences checklist for systematic review was used for risk of bias assessment. There were 39 publications in this study that were deemed to be acceptable. All the suitably selected studies include 1779 patients.

Results

The meta-analysis of 15 included research articles showed the overall effect was significant (P = 0.0002) thus supporting experimental groups have improvement in the DFUs healing in comparison to the control group.

Conclusion

This systematic review and meta-analysis revealed electromechanical treatments are significantly viable options for patients with DFUs. Electromechanical therapy can considerably reduce treatment ineffectiveness, accelerate healing, and minimize the time it takes for complete ulcer healing.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40200-023-01240-2.

Effect of ultrasound-supported wound debridement in subjects with diabetic foot ulcers: A meta-analysis

A meta-analysis study to assess the effect of ultrasound-supported wound debridement (USSD) in subjects with diabetic foot ulcer (DFU). A comprehensive literature examination till January 2023 was implemented and 1873 linked studies were appraised. The picked studies contained 577 subjects with DFUs in the studies' baseline, 282 of them were using USSD, 204 were using standard care, and 91 were using a placebo. Odds ratio (OR) in addition to 95% confidence intervals (CIs) were used to calculate the consequence of USSD in subjects with DFUs by the dichotomous styles and a fixed or random effect model. The USSD applied to DFU caused a significantly higher wound healing rate compared with the standard care (OR, 3.08; 95% CI, 1.94-4.88, P < .001) with no heterogeneity (I2  = 0%) and the placebo (OR, 7.61; 95% CI, 3.11-18.63, P = .02) with no heterogeneity (I2  = 0%). The USSD applied to DFUs caused a significantly higher wound healing rate compared with the standard care and the placebo. Though precautions should be taken when commerce with the consequences as all of the picked studies for this meta-analysis was with low sample sizes.

Low-Intensity Ultrasound Reduces Brain Infarct Size by Upregulating Phosphorylated Endothelial Nitric Oxide in Mouse Model of Middle Cerebral Artery Occlusion

OBJECTIVE

There have been attempts to use therapeutic ultrasound (US) for the treatment of both experimental and clinical stroke. We hypothesized that low-intensity US has direct beneficial effects on the brain independent of cerebral blood flow (CBF) during middle cerebral artery occlusion (MCAO).

METHODS

Three groups of mice were studied. Group I included 84 mice with MCAO undergoing US treatment/no treatment at two US frequencies (0.25 and 1.05 MHz) with three different acoustic pressures at each frequency in which infarct size (IS) was measured 24 h later. Group II included 11 mice undergoing treatment based on best US results from group I animals in which the IS/risk area (RA) ratio was measured 24 h later. Group III included 38 normal mice undergoing US treatment/no treatment for assessment of CBF, tissue metabolite and protein expression and histopathology.

DISCUSSION

Ultrasound at both frequencies and most acoustic pressures resulted in reduction in IS in group I animals, with the best results obtained with 0.25 MHz at 2.0 MPa: IS was reduced 4-fold in the cerebral cortex, 1.5-fold in the caudate putamen and 3.5-fold in the cerebral hemisphere compared with control. US application in group III animals elicited only a marginal increase in CBF despite a 2.6-fold increase in phosphorylated endothelial nitric oxide synthase (p-eNOS)-S1177 and a corresponding decrease in p-eNOS-T494. Histopathology revealed no evidence of hemorrhage, inflammation or necrosis.

CONCLUSION

Low-intensity US at specific frequencies and acoustic pressures results in marked neuroprotection in a mouse model of stroke by modulation of p-eNOS independent of its effect on CBF.

The efficacy of low-frequency ultrasound as an added treatment for chronic wounds: A meta-analysis

We performed a meta-analysis to evaluate the effect of low-frequency ultrasound as an added treatment for chronic wounds. A systematic literature search up to May 2022 was performed and 838 subjects with chronic wounds at the baseline of the studies; 412 of them were using the low-frequency ultrasound (225 low-frequency high-intensity contact ultrasound for diabetic foot wound ulcers, and 187 low-frequency low-intensity non-contact ultrasound for a venous leg wound ulcers), and 426 were using standard care (233 sharp debridements for diabetic foot wound ulcers and 193 sham treatments for venous leg wound ulcers). Odds ratio (OR), and mean difference (MD) with 95% confidence intervals (CIs) were calculated to assess the effect of low-frequency ultrasound as an added treatment for chronic wounds using the dichotomous, and contentious methods with a random or fixed-effect model. The low-frequency high-intensity contact ultrasound for diabetic foot wound ulcers had significantly lower non-healed diabetic foot wound ulcers at ≥3 months (OR, 0.37; 95% CI, 0.24-0.56, P < .001), a higher percentage of diabetic foot wound ulcers area reduction (MD, 17.18; 95% CI, 6.62-27.85, P = .002) compared with sharp debridement for diabetic foot wound ulcers. The low-frequency low-intensity non-contact ultrasound for a venous leg wound ulcers had a significantly lower non-healed venous leg wound ulcers at ≥3 months (OR, 0.31; 95% CI, 0.15-0.62, P = .001), and higher percentage venous leg wound ulcers area reduction (MD, 18.96; 95% CI, 2.36-35.57, P = .03) compared with sham treatments for a venous leg wound ulcers. The low-frequency ultrasound as an added treatment for diabetic foot wound ulcers and venous leg wound ulcers had significantly lower non-healed chronic wound ulcers at ≥3 months, a higher percentage of chronic wound ulcers area reduction compared with standard care. The analysis of outcomes should be with caution because of the low sample size of all the 17 studies in the meta-analysis and a low number of studies in certain comparisons.

High-frequency noncontact low-intensity pulsed ultrasound modulates Ca2+-dependent transcription factors contributing to cell migration

Chronic wounds have negative physical and psychological effects on patients and increase the health care burden. Consequently, chronic wound in the elderly population is an important issue. Ultrasound can be a great modality for treating chronic wounds because of its noninvasive and safety characteristics; it can accelerate in vitro and in vivo wound healing. In this study, we developed a novel noncontact ultrasound for wound treatment. We stimulated human epidermal keratinocyte migration using low-intensity pulsed ultrasound (LIPUS) with a noncontact transducer to avoid direct contact with the wound. We also compared the effects of 15-min contact and noncontact transducer stimulation, where a 1-MHz contact transducer (intensity = 40 or 200 mW/cm²) and a 0.45-MHz noncontact transducer (intensity = 30 mW/cm²) were used. Both contact and noncontact LIPUS considerably increased cell migration and activated the calcium (Ca²⁺)-dependent transcription factors cAMP-responsive element-binding protein (CREB) and nuclear factor of activated T cells (NFAT). Furthermore, noncontact transducer stimulation did not cause cell death or affect cell proliferation but significantly increased the Ca²⁺ influx-mediated intracellular Ca²⁺ levels. Ca²⁺-free medium and Ca²⁺ channel blockers effectively inhibited LIPUS-induced Ca²⁺-dependent transcription factor activation and cell migration.

Non-surgical treatment for arterial leg ulcers: a narrative review

Objectives:

Arterial leg ulcers (ALUs) pose a considerable burden on patients and health services. The cornerstone of treatment is revascularisation; however, this is not always possible and does not necessarily guarantee ulcer healing. Alternative treatment options are therefore also important. This narrative review aims to summarise the evidence available for non-surgical treatment of ALUs, including topical therapy, pharmacological agents, therapeutic angiogenesis and devices.

Methods:

A literature search was performed in November 2020 to identify studies reporting data on the non-surgical management of ALUs. Prospective randomised controlled trials (RCTs), controlled clinical trials and meta-analyses that investigated conservative or medical interventions on patients with intractable ALUs, and which provided quantitative data on ulcer healing were included. Following screening, studies that met the inclusion criteria underwent a data extraction process and findings were synthesised and categorised narratively.

Results:

In total, 14 controlled trials were selected for inclusion and analysed based on experimental protocol and outcome measures.

Conclusion:

There is some evidence available for the use of short-term systemic prostanoids, ultrasound therapy and pneumatic compression. There are limitations to these options including side effects, patient tolerance due to pain and availability in clinical practice. Further research is needed to improve treatment options for this complex group.

Ultrasound-Assisted Wound (UAW) Debridement in the Treatment of Diabetic Foot Ulcer: A Systematic Review and Meta-Analysis

A systematic review and meta-analysis were carried out to investigate the effect of ultrasound-assisted wound (UAW) debridement in patients with diabetic foot ulcers (DFUs). All selected studies were evaluated using the Cochrane risk of bias tool to assess the risk of bias for randomized controlled trials. PubMed and Web of Science were searched in October 2021 to find randomized clinical trials (RCT) assessing the effect of UAW debridement on DFUs. RevMan v5.4. was used to analyze the data with the Mantel-Haenszel method for dichotomous outcomes. A total of 8 RCT met our inclusion criteria, with 263 participants. Concerning the healing rate comparing UAW versus the control group, a meta-analysis estimated the pooled OR at 2.22 (95% CI 0.96-5.11, p = 0.06), favoring UAW debridement, with low heterogeneity (x² = 7.47, df = 5, p = 0.19, I² = 33%). Time to healing was similar in both groups: UAW group (14.25 ± 10.10 weeks) versus the control group (13.38 ± 1.99 weeks, p = 0.87). Wound area reduction was greater in the UAW debridement group (74.58% ± 19.21%) than in the control group (56.86% ± 25.09%), although no significant differences were observed between them (p = 0.24). UAW debridement showed higher healing rates, a greater percentage of wound area reduction, and similar healing times when compared with placebo (sham device) and standard of care in patients with DFUs, although no statistically significant differences were observed between groups.

Point-of-Care Ultrasound as a Tool to Assess Wound Size and Tissue Regeneration after Skin Grafting

Chronic wounds can be difficult to heal and are often accompanied by pain and discomfort. Multiple skin substitutes or cellularized/tissue-based skin products have been used in an attempt to facilitate closure of complex wounds. Allografts from cadaveric sources have been a viable option in achieving such closure. However, early assessment of graft incorporation has been difficult clinically, often with delayed evidence of failure. Visual cues to assess graft integrity have been limited and remain largely superficial at the skin surface. Furthermore, currently used optical imaging techniques can penetrate only a few millimeters deep into tissue. Ultrasound (US) imaging offers a potential solution to address this limitation. This work evaluates the use of US to monitor wound healing and allograft integration. We used a commercially available dual-mode (US and photoacoustic) scanner operating only in US mode. We compared the reported wound size from the clinic with the size measured using US in 45 patients. Two patients from this cohort received an allogenic skin graft and underwent multiple US scans over a 110-d period. All data were processed by two independent analysts; one of them was blinded to the study. We measured change in US intensity and wound contraction as a function of time. Our results revealed a strong correlation (R² = 0.81, p < 0.0001) between clinically and US-measured wound sizes. Wound contraction >91% was seen in both patients after skin grafting. An inverse relationship between wound size and US intensity (R² = 0.77, p < 0 .0001) indicated that the echogenicity of the wound bed increases as healthy cells infiltrate the allograft matrix, regenerating and leading to healthy tissue and re-epithelization. This work indicates that US can be used to measure wound size and visualize tissue regeneration during the healing process.

Ultrasound in the Modern Management of the Diabetic Foot Syndrome: A Multipurpose Versatile Toolkit

Ultrasound (US) is a noninvasive and versatile technology that in recent years found acceptance in almost all the medical specialties, with diagnostic and interventional applications. In the diabetic foot syndrome (DFS), US found specific indications mainly in the screening, quantification, and follow-up of the vascular component of the pathology, but also in the study of the deformities and structural modifications induced by neuropathy and in the diagnosis and surgical management of infections, especially those that induce anatomical changes, like abscesses and fasciitis. This review will summarize all these application of US, giving special attention to the vascular aspects, and on the predominant role that US gained in recent times to guide the indication to revascularization, on the new standardized approach to the study of the arterial tree of the limb and the foot, the so-called duplex ultrasound arterial mapping, which significantly increased the utilization of US to plan the revascularizations in this complex pathology. Outside the vascular fields, the diagnosis of neuropathy and infection and the intraoperative use of US in the surgical management of abscesses and fasciitis will be discussed, leaving the last part to the new and interesting applications of US in the management of DFU, a field that is still in evolution, offering new possibilities to the health care professionals involved in the management of these chronic wounds. The variety of applications both in diagnostic and operative fields makes US a rather versatile technology-a toolkit-that should have a special place among those at reach of the specialists of DFS care.

Ultrasound Devices to Treat Chronic Wounds: The Current Level of Evidence

Chronic wounds cause considerable morbidity and utilize significant health care resources. In addition to addressing wound etiology and treating infection, regular debridement is a key component of wound care with a proven ability to accelerate healing. In this regard, a significant innovation in wound care has been the development of ultrasound debridement technology. The purpose of this review is to evaluate the current evidence behind the technology with an emphasis on noncontact low-frequency (NCLF) ultrasound. A number of studies, especially those evaluating NCLF technology, have demonstrated the potential of ultrasound debridement to effectively remove devitalized tissue, control bioburden, alleviate pain, and expedite healing. However, most of the studies are underpowered, involve heterogeneous ulcer types, and demonstrate significant methodological limitations making comparison between studies difficult; there is a paucity of data on cost-effectiveness. Future clinical trials on ultrasound debridement technology must address the design issues prevalent in current studies, and report on clinically relevant endpoints before adoption into best-practice algorithms can be recommended.

Peripheral arterial disease: Scoping review of patient-centred outcomes

Peripheral arterial disease (PAD) impairs patients' quality of life (QOL), walking and ulcer healing, increasing patient pain, costs, and risks of amputation or mortality. A literature appraisal described PAD treatment capacity to improve validated patient-centred outcomes in controlled clinical studies. The PUBMED database was searched from 1 January 1970 to 21 June 2018, for original and derivative controlled clinical trial references addressing MeSH terms for 'ischemia' AND 'leg ulcer'. Non-ischemic ulcer treatment references were excluded. Frequencies of improved (P < .05) outcomes were reported. Eighty-eight studies on 4153 patients were summarized. Walking, pain or QOL improved mainly for interventions administered before PAD became severe. Amputation incidence, pain and ulcer healing were more frequently reported in those with severe PAD. Independent of PAD severity, patients experienced more likely improved walking, QOL, or pain reduction in response to structured walking interventions or those increasing calf muscle activity. Those with more severe PAD were more likely to report amputation reduction, mainly in response to invasive interventions. Those with PAD experienced more consistently improved patient-centred outcomes if they received multidisciplinary PAD management with supervised walking or calf muscle activity, with more likely amputation risk reduced for those with more severe PAD.

Ultrasound-assisted debridement of neuroischaemic diabetic foot ulcers, clinical and microbiological effects: a case series

OBJECTIVE

To evaluate the clinical and microbiological effects of sequential wound debridement in a case series of neuroischaemic diabetic foot ulcers (DFUs) using an ultrasound-assisted wound debridement (UAW) device.

METHOD

A prospective, single-centre study, involving a case series of 24 neuroischaemic DFUs, was conducted to evaluate sequential wound debridement with UAW during a six-week treatment period. Soft tissue punch biopsies were taken every second week of treatment, both before and after wound debridement sessions. Qualitative and quantitative microbiological analysis was performed and wounds were assessed at patient admission, and before and after each debridement procedure.

RESULTS

Wound tissue quality scores improved significantly from a mean score of 2.1±1.3 points at patient inclusion, to 5.3±1.7 points (p=0.001). Mean wound sizes were 4.45cm² (range: 2-12.25cm²) at week zero, and 2.75cm² (range: 1.67-10.70cm²) at week six (p=0.04). The mean number of bacterial species per culture determined at week zero and at week six was 2.53±1.55 and 1.90±1.16, respectively (p=0.023). Wound debridement resulted in significant decreases in bacterial counts (1.17, 1.31 and 0.77 log units in colony forming units (CFU) for week zero, three and six, respectively). The average bacterial load in tissue samples before and after wound debridement after the six-week treatment was Log 5.55±0.91CFU/g and Log 4.59±0.89CFU/g, respectively (p<0.001).

CONCLUSIONS

The study results showed a significant bacterial load reduction in DFU tissue samples as a result of UAW debridement, independent of bacterial species, some of which exhibited antibiotic-resistance. Significant bacterial load reduction was correlated with improved wound conditions and significant reductions of wound size.

Efficacy and Safety of Low-Frequency, Noncontact Airborne Ultrasound Therapy (Glybetac) For Neuropathic Diabetic Foot Ulcers: A Randomized, Double-Blind, Sham-Control Study

The diabetic foot ulcer (DFU) healing rates remain dismally low. Therefore, many adjunctive therapies have been evaluated including ultrasound therapy. The prior studies with noncontact, low-frequency ultrasound were retrospective, single arm, unblinded, or with historical controls. The aim of the present study was to compare the efficacy of noncontact, low-frequency airborne ultrasound (Glybetac) therapy with sham therapy added to standard treatment in patients with neuropathic, clinically infected, or noninfected DFU (wound size >2 cm²), Wagner grades 2 and 3. Patients received ultrasound or sham therapy for 28 days dosed daily for first 6 days followed by twice a week for next 3 weeks along with standard of care. The primary outcome was percentage of patients with at least >50% decrease in wound area at 4 week of intervention. Fifty-eight patients completed the study protocol. The duration of wound was 15.8 ± 11.2 weeks and 12.1 ± 10.9 weeks and wound area of 11.3 ± 8.2 cm² and 14.8 ± 13.8 cm² ( P = .507) in the ultrasound and sham groups, respectively. A >50% reduction in wound area was observed in 97.1% and 73.1% subjects ( P = .042) in ultrasound and sham groups, respectively. Wound contraction was faster in the first 2 weeks with ultrasound therapy, 5.3 cm², compared with 3.0 cm² ( P = .025) with sham treatment. Overall, wound area reduction of 69.4 ± 23.2% and 59.6 ± 24.9% ( P = .126) was observed at 4 weeks in the ultrasound and sham groups, respectively. We conclude that the airborne low-frequency ultrasound therapy improves and hastens the healing of chronic neuropathic DFU when combined with standard wound care.

Diagnostic and Therapeutic Ultrasound on Venous and Arterial Ulcers: A Focused Review

GENERAL PURPOSE

To provide information about the use of ultrasound for diagnostic and therapeutic treatment of venous and arterial ulcers.

TARGET AUDIENCE

This continuing education activity is intended for physicians, physician assistants, nurse practitioners, and nurses with an interest in skin and wound care.

LEARNING OBJECTIVES/OUTCOMES

After completing this continuing education activity, you should be able to: ABSTRACT: To review the diagnostic and therapeutic use of ultrasound on venous and arterial ulcers.

METHODS

PubMed was searched for peer-reviewed articles using the search terms "ultrasound for venous ulcers" and "ultrasound for arterial ulcers." The search yielded 282 articles on ultrasound for venous ulcers and 455 articles for ultrasound on arterial ulcers. Data from 36 articles were selected and included after abstract review.

RESULTS

Ultrasound is an established diagnostic modality for venous and arterial disease and is indicated for wound debridement. Recent evidence continues to support its superiority over standard of care in healing venous ulcers, but findings conflict in terms of the effectiveness of low-frequency ultrasound over high-frequency ultrasound. There are currently no standardized treatment protocols for ultrasound.

CONCLUSIONS

Diagnostic ultrasound is used to assess venous and arterial disease and guide appropriate treatment for ulcers. Therapeutic low-frequency ultrasound is used to debride the wound bed, as an adjunctive topical wound treatment with standard of care, and to guide the application of other advanced therapies to chronic wounds. Better trial designs and consistent data are needed to support the effectiveness of ultrasound therapy on venous and arterial ulcers.

High-Voltage Electrical Stimulation Versus Ultrasound in the Treatment of Pressure Ulcers

OBJECTIVE

The aim of this study was to assess and compare the efficacy of high-voltage electrical stimulation (HVES) with ultrasound (US) in treating Stage II through Stage IV pressure ulcers (PrUs)* of hospitalized patients.

DESIGN

This study was designed as a prospective, controlled trial in which patients were randomly assigned to 2 groups.

PARTICIPANTS AND SETTINGS

A total of 27 patients (22 male, 5 female) hospitalized for neurologic rehabilitation in the Clinic of Physical Medicine and Rehabilitation with Stage II through Stage IV PrUs were included in this study. The patients were randomly assigned to either HVES or US treatment group, and all patients underwent standard wound care. Over 4 to 12 weeks, HVES was applied for 60 minutes 3 times per week, and US was applied 3 times per week.

MAIN OUTCOME MEASURES

Properties of the PrUs were noted during pre- and posttreatment.

RESULTS

The PrUs of patients in the HVES and US groups healed at a mean rate of 43% and 63%, respectively. There was no statistically significant intergroup difference in healing found after treatment. Regression analysis was performed for the factors that could influence the wound surface areas, and significant effects were detected among the level of ambulation, pretreatment stage, and smoking.

CONCLUSIONS

Both HVES and US are promising methods for wound healing, and both electrotherapy modalities have been demonstrated to support the healing of PrUs.

Ultrasound-based Techniques as Alternative Treatments for Chronic Wounds: A Comprehensive Review of Clinical Applications

Ultrasound (US) waves have been recently developed for the treatment of different chronic wounds with promising therapeutic outcomes. However, the clinical efficacy of these techniques is still not fully understood and standard guidelines on dose ranges and possible side effects should be determined. This paper aims to comprehensively review the recent advances in US techniques for chronic wound treatment, their therapeutic efficacies, and clinical considerations and challenges. The databases of PubMed (1985-2017), EMBASE (1985-2017), Web of Sciences (1985-2017), Cochrane central library (1990-2017), and Google Scholar (1980-2017) were searched using the set terms. The obtained results were screened for the title and abstract by two authors and the relevant papers were reviewed for further details. Preclinical and clinical studies have shown strong evidence on the therapeutic efficiency of US in chronic wounds. The main limitation on developing clinical standard protocols of US for treatment of wounds is the lack of definite dose-response for each wound. However, spatial average temporal average is the main parameter for defining US dosage in wound treatment. The range of 0.5 to 3 W/cm² is a range of dose exerting significant therapeutic outcomes and minimum adverse effects. Low-frequency US waves can accelerate the healing speed of open wounds as well as deep-tissue injuries. In addition, US waves show promising therapeutic efficacy for chronic wounds. To develop clinical US protocol for each wound type, further in vitro and in vivo preclinical and clinical trials are needed to reach an exact dose-response for each wound type.

Does noncontact low-frequency ultrasound therapy contribute to wound healing at the molecular level?

Noncontact low-frequency ultrasound (NLFU) is used to treat various types of chronic wounds including venous, diabetic, and pressure ulcers. The objective for this substudy of the IN BALANCE RCT VLU trial was to characterize and compare the NLFU treatment group and patients receiving standard of care (SOC) with respect to the effect of the assigned study treatment on content/quantity of inflammatory cytokines and fibrinogen as well as bacteria. Higher mean wound area reduction was observed in the NLFU treatment group (67.0%) compared to the SOC group (41.6%, p < 0.05). Hypertension, diabetes type II, coronary artery disease, and anemia were identified as the most common comorbidities of the Chronic venous leg ulcer (CVLU) patients included in the study. Pseudomonas, Corynebacterium, and unclassified Enterobacteriaceae were dominant in the highest number of samples. Anaerococcus, Peptoniphilus, and Finegoldia, had the highest median proportion in the samples overall. Peptoniphilus abundance decreased more in the NLFU treatment group relative to SOC; similar trends were observed for Anaerococcus and Finegoldia. Progression of mediators like TNF-alpha, IL-1beta, IL-6, IL-8, and IL-10 as well as PF4, TGF-beta, and fibrinogen was monitored and trends for several of the mediators were identified. Fibrinogen amounts were significantly reduced over time in the NLFU treatment group (p < 0.05). IL-8 levels declined in wound fluid from NLFU responders as well as SOC responders. Bacterial load (total bacterial abundance) determined local parameters of ulcer inflammation. If a bioburden of ≥ 10E⁵ was found compared to < 10E⁵ , levels of IL-1beta, IL-8, and TNF-alpha were significantly higher. In conclusion, NLFU treatment is an effective adjuvant tool for CVLU therapy. This study demonstrates that it improves wound healing by equally inhibiting abundant levels of pro-inflammatory cytokines as well as by reducing the overall bacterial burden.

Review of local wound management for scleroderma-associated digital ulcers

Digital ulcers (DU) are a common clinical problem in systemic sclerosis (SSc); however, there is no standardization of local wound care protocols for management of these lesions. There is a well-recognized need to develop and standardize non-pharmacological management of DU in patients with SSc, and to adopt these protocols in future clinical trials that focus on DU healing. The purpose of this review is to outline the types of DU that occur in SSc, and provide an update on the principles of wound management for these lesions based on the current literature and expert opinion.

Nature's Electric Potential: A Systematic Review of the Role of Bioelectricity in Wound Healing and Regenerative Processes in Animals, Humans, and Plants

Natural endogenous voltage gradients not only predict and correlate with growth and development but also drive wound healing and regeneration processes. This review summarizes the existing literature for the nature, sources, and transmission of information-bearing bioelectric signals involved in controlling wound healing and regeneration in animals, humans, and plants. It emerges that some bioelectric characteristics occur ubiquitously in a range of animal and plant species. However, the limits of similarities are probed to give a realistic assessment of future areas to be explored. Major gaps remain in our knowledge of the mechanistic basis for these processes, on which regenerative therapies ultimately depend. In relation to this, it is concluded that the mapping of voltage patterns and the processes generating them is a promising future research focus, to probe three aspects: the role of wound/regeneration currents in relation to morphology; the role of endogenous flux changes in driving wound healing and regeneration; and the mapping of patterns in organisms of extreme longevity, in contrast with the aberrant voltage patterns underlying impaired healing, to inform interventions aimed at restoring them.

Use of Noncontact Low-Frequency Ultrasound in Deep Tissue Pressure Injury: A Retrospective Analysis

PURPOSE

The purpose of this study was to examine the effect of noncontact low-frequency ultrasound (NLFU) on deep tissue pressure injury (DTPI), both hospital-acquired and those present on admission (POA).

DESIGN

Retrospective, descriptive study.

SAMPLE AND SETTING

Medical records from 44 adult patients with a DTPI treated with NLFU were reviewed; 22 had a hospital-acquired DTPI (HADTPI) and 22 had DTPI POA. Their mean age was 71.3 ± 16.3 years (mean ± SD); 52% were male. The study setting was a 318-bed community hospital in the Mid-Atlantic region of the United States.

METHODS

Data were collected from the medical records including demographic and relevant clinical characteristics, DTPI measurements, and DTPI evolution/resolution. Data were summarized and examined using descriptive statistics (eg, frequencies and percentages and means and standard deviations). Differences between groups were examined using paired t tests or the Mann-Whitney U test and the chi-square test as appropriate. In addition, the heel DTPI subgroup (N = 8) was examined separately due to the small sample size.

RESULTS

All patients with HADTPI and DTPI POA treated with NLFU exhibited a statistically significant decrease in injury size from initiation to discontinuation of NLFU therapy (24.6 cm vs 14.4 cm, P = .02). No statistically significant difference in wound resolution was found between HADTPI versus DTPI POA (27% vs 18%, P = .47). Mean size of both HADTPI and DTPI POA decreased significantly from 15.9 to 13.4 cm (P = .045) by NLFU therapy. Wounds were classified as resolved at completion of treatment in 23% (10 out of 44) of all treated patients. Of all patients with the potential to be resolved (not discharged early or expired) 63% (10 out of 16) had wounds classified as resolved.

CONCLUSION

Study findings suggest that NLFU is a viable and promising treatment option for both HADTPI and DTPI POA. Future studies are needed to confirm these results and to examine efficacy and feasibility of DTPI across care settings.

Therapeutic ultrasound for venous leg ulcers

BACKGROUND

Venous leg ulcers are a type of chronic, recurring, complex wound that is more common in people aged over 65 years. Venous ulcers pose a significant burden to patients and healthcare systems. While compression therapy (such as bandages or stockings) is an effective first-line treatment, ultrasound may have a role to play in healing venous ulcers.

OBJECTIVES

To determine whether venous leg ulcers treated with ultrasound heal more quickly than those not treated with ultrasound.

SEARCH METHODS

We searched the Cochrane Wounds Specialised Register (searched 19 September 2016); the Cochrane Central Register of Controlled Trials (CENTRAL; the Cochrane Library 2016, Issue 8); Ovid MEDLINE (including In-Process & Other Non-Indexed Citations, MEDLINE Daily and Epub Ahead of Print) (1946 to 19 September 2016); Ovid Embase (1974 to 19 September 2016); and EBSCO CINAHL Plus (1937 to 19 September 2016). We also searched three clinical trials registries and the references of included studies and relevant systematic reviews. There were no restrictions based on language, date of publication or study setting.

SELECTION CRITERIA

Randomised controlled trials (RCTs) that compared ultrasound with no ultrasound. Eligible non-ultrasound comparator treatments included usual care, sham ultrasound and alternative leg ulcer treatments.

DATA COLLECTION AND ANALYSIS

Two authors independently assessed the search results and selected eligible studies. Details from included studies were summarised using a data extraction sheet, and double-checked. We attempted to contact trial authors for missing data.

MAIN RESULTS

Eleven trials are included in this update; 10 of these we judged to be at an unclear or high risk of bias. The trials were clinically heterogeneous with differences in duration of follow-up, and ultrasound regimens. Nine trials evaluated high frequency ultrasound; seven studies provided data for ulcers healed and two provided data on change in ulcer size only. Two trials evaluated low frequency ultrasound and both reported ulcers healed data.It is uncertain whether high frequency ultrasound affects the proportion of ulcers healed compared with no ultrasound at any of the time points evaluated: at seven to eight weeks (RR 1.21, 95% CI 0.86 to 1.71; 6 trials, 678 participants; low quality evidence - downgraded once for risk of bias and once for imprecision); at 12 weeks (RR 1.26, 95% CI 0.92 to 1.73; 3 trials, 489 participants; moderate quality evidence - downgraded once for imprecision); and at 12 months (RR 0.93, 95% CI 0.73 to 1.18; 1 trial, 337 participants; low quality evidence - downgraded once for unclear risk of bias and once for imprecision).One trial (92 participants) reported that a greater percentage reduction in ulcer area was achieved at four weeks with high-frequency ultrasound, while another (73 participants) reported no clear difference in change in ulcer size at seven weeks. We downgraded the level of this evidence to very low, mainly for risk of bias (typically lack of blinded outcome assessment and attrition) and imprecision.Data from one trial (337 participants) suggest that high frequency ultrasound may increase the risk of non-serious adverse events (RR 1.29, 95% CI 1.02 to 1.64; moderate quality evidence - downgraded once for imprecision) and serious adverse events (RR 1.21, 95% CI 0.78 to 1.89; moderate quality evidence downgraded once for imprecision).It is uncertain whether low frequency ultrasound affects venous ulcer healing at eight and 12 weeks (RR 3.91, 95% CI 0.47 to 32.85; 2 trials, 61 participants; very low quality evidence (downgraded for risk of bias and imprecision)).High-frequency ultrasound probably makes little or no difference to quality of life (moderate quality evidence, downgraded for imprecision). The outcomes of adverse effects, quality of life and cost were not reported for low-frequency ultrasound treatment.

AUTHORS' CONCLUSIONS

It is uncertain whether therapeutic ultrasound (either high or low frequency) improves the healing of venous leg ulcers. We rated most of the evidence as low or very low quality due to risk of bias and imprecision.

Low-Frequency Ultrasound Debridement in Chronic Wound Healing: A Systematic Review of Current Evidence

Chronic wounds are painful and debilitating to patients, pose a clinical challenge to physicians, and impose financial burden on the health-care system. New treatment options are therefore highly sought after. Ultrasound debridement is a promising technology that functions to disperse bacterial biofilms and stimulate wound healing. In this review, we focus on low-frequency ultrasound (20-60 kHz) and summarize the findings of 25 recent studies examining ultrasound efficacy. Ultrasound debridement appears to be most effective when used 3 times a week and has the potential to decrease exudate and slough, decrease patient pain, disperse biofilms, and increase healing in wounds of various etiology. Although current studies are generally of smaller size, the results are promising and we recommend the testing of low-frequency ultrasound therapy in clinical practice on a larger scale.

Preliminary Treatment of Achilles Tendinopathy Using Low-Intensity Pulsed Ultrasound

BACKGROUND

Achilles tendinopathy is a degenerative process of the tendon associated with diminished vascularity, microtrauma, and aging. Nonoperative treatments such as activity modification, immobilization, night splints, and physical therapy have good outcomes for the majority of patients. However, there are cohorts of patients that remain symptomatic despite use of all nonoperative measures that eventually require surgical intervention. The present study reports the preliminary short-term clinical outcomes of low-intensity pulsed ultrasound (LIPUS) for treatment for Achilles tendinopathy.

MATERIALS AND METHODS

Fourteen patients with clinically diagnosed Achilles tendinopathy who failed previous nonoperative treatments underwent LIPUS stimulation directly over the area of maximum tendon tenderness for 20 min/d for 8 weeks total. No other treatment modalities were used during the period of LIPUS stimulation. All patients had serial clinical exams and evaluations with an average follow-up of 12 months (range, 6-50 months).

RESULTS

Excellent clinical outcomes with complete resolution of pain and other symptoms were obtained in 7 patients (50%). Two patients (14%) had good outcomes with mild tendon irritation and stiffness not requiring further intervention. Five patients (36%) had minimal benefit with continued pain, swelling, and tenderness over the Achilles and functional deficits. No patients had worsening pain or progression of disability requiring surgery.

CONCLUSIONS

LIPUS is an additional noninvasive treatment modality for chronic Achilles tendinopathy that may potentially help improve clinical symptoms and delay and/or prevent the need for surgical intervention. While LIPUS is easy to use, well-tolerated, and has promising early clinical results, further research is needed to determine the long-term benefits, disadvantages, and cost-effectiveness of this alternative treatment for tendinopathy.

LEVELS OF EVIDENCE

Therapeutic, Level IV: Case series.

Challenges in the Treatment of Chronic Wounds

Significance: Chronic wounds include, but are not limited, to diabetic foot ulcers, venous leg ulcers, and pressure ulcers. They are a challenge to wound care professionals and consume a great deal of healthcare resources around the globe. This review discusses the pathophysiology of complex chronic wounds and the means and modalities currently available to achieve healing in such patients. Recent Advances: Although often difficult to treat, an understanding of the underlying pathophysiology and specific attention toward managing these perturbations can often lead to successful healing. Critical Issues: Overcoming the factors that contribute to delayed healing are key components of a comprehensive approach to wound care and present the primary challenges to the treatment of chronic wounds. When wounds fail to achieve sufficient healing after 4 weeks of standard care, reassessment of underlying pathology and consideration of the need for advanced therapeutic agents should be undertaken. However, selection of an appropriate therapy is often not evidence based. Future Directions: Basic tenets of care need to be routinely followed, and a systematic evaluation of patients and their wounds will also facilitate appropriate care. Underlying pathologies, which result in the failure of these wounds to heal, differ among various types of chronic wounds. A better understanding of the differences between various types of chronic wounds at the molecular and cellular levels should improve our treatment approaches, leading to better healing rates, and facilitate the development of new more effective therapies. More evidence for the efficacy of current and future advanced wound therapies is required for their appropriate use.

Polarized currents inhibit in vitro growth of bacteria colonizing cutaneous ulcers

Infections caused by Staphylococcus aureus, Pseudomonas aeruginosa, and Escherichia coli are among the microorganisms that often lead to infection in pressure ulcers. Polarized current has emerged as a possible intervention to limit bacterial proliferation. We analyzed the effect of fixed diphasic - Bernard (FD-B) and high voltage monophasic pulsed (HVMP) currents on bacteria S. aureus ATCC 25923 (Gram +), P. aeruginosa ATCC 27853 (Gram -), and E. coli ATCC 25922 (Gram -). After the bacterial strains were activated the bacteria were suspended in physiological solution (0.9%) and the concentration adjusted to 1.5 × 10(3) CFU/mL. The cultures were stimulated with FD-B current at (3, 6, and 9 mA, 100 Hz, 15 and 30 minutes) and HVMP (32, 64, and 95 V, 100 Hz, 30 and 60 min) while monitoring the pH and temperature. After the stimulation, the suspensions were plated and incubated for 24 hours at 37°C. Then the counts were made of colony forming units (CFU). Data were submitted to normality Shapiro-Wilk test followed by nonparametric ANOVA test and post hoc Tukey test with p < 0.05. There was a decrease in the CFU for the two currents, but the most effective reduction was in FD-B. The temperature remained constant and the pH measured alkaline at the negative pole and acid at the positive pole during stimulation. The application of FD-B and HVMP currents promoted inhibition of bacterial proliferation when stimulated in vitro, acting as an adjuvant resource in the healing process.

Prospective Randomized Controlled Trial Comparing the Effects of Noncontact Low-Frequency Ultrasound with Standard Care in Healing Split-Thickness Donor Sites

BACKGROUND

Skin graft donor sites are notoriously painful, with potential complications of fluid loss, delayed healing, infection, and hypertrophic scarring, particularly in patients with burns or traumatic injury. In this population, rapid epithelialization is critical to reducing morbidity and cost.

STUDY DESIGN

This prospective, randomized controlled trial compared the effects of 40-kHz noncontact low-frequency ultrasound (NLFU) in addition to standard care (SC) with SC alone in subjects with split-thickness donor sites of 20 to 200 cm(2). Standard care consisted of cleansing and moist wound dressings. Outcomes measured were time to healing, defined as absence of drainage and full epithelialization; pain and itching scores; and recidivism rates.

RESULTS

Of 33 patients enrolled; 27 were randomized and received a minimum of 4 study treatments. Median age was 49 years, 69% were male, and 84% were burn patients. Comorbidities included hypertension (31%), coronary artery disease (22%), pulmonary disease (38%), anemia (31%), and diabetes (16%). Median donor site area was 136.0 cm(2). Noncontact low-frequency ultrasound and SC compared with SC demonstrated a mean time to heal of 12.1 days vs 21.3 days (p = 0.04). All NLFU+SC subjects had epithelialized by 4 weeks compared with only 71% in SC. Recidivism rates were 8% for NLFU+SC compared with 45% for SC. Pain scores were reduced and significant differences in itching were observed.

CONCLUSIONS

Noncontact low-frequency ultrasound and SC compared with SC alone in the treatment of split-thickness donor sites demonstrated significant accelerated healing and reduced pain and itching. Noncontact low-frequency ultrasound subjects experienced a better quality of healing with less incidence of infection and recidivism.

Wound management of chronic diabetic foot ulcers: from the basics to regenerative medicine

BACKGROUND

Hospital-based studies have shown that mortality rates in individuals with diabetic foot ulcers are about twice those observed in individuals with diabetes without foot ulcers.

OBJECTIVE

To assess the etiology and management of chronic diabetic foot ulcers.

STUDY DESIGN

Literature review.

METHODS

Systematic review of the literature discussing management of diabetic foot ulcers. Since there were only a few randomized controlled trials on this topic, articles were selected to attempt to be comprehensive rather than a formal assessment of study quality.

RESULTS

Chronic nonhealing foot ulcers occur in approximately 15% of patients with diabetes. Many factors contribute to impaired diabetic wound healing. Risk factors include peripheral neuropathy, peripheral arterial disease, limited joint mobility, foot deformities, abnormal foot pressures, minor trauma, a history of ulceration or amputation, and impaired visual acuity. With the current treatment for nonhealing diabetic foot ulcers, a significant number of patients require amputation.

CONCLUSION

Diabetic foot ulcers are optimally managed by a multidisciplinary integrated team. Offloading and preventative management are important. Dressings play an adjunctive role. There is a critical need to develop novel treatments to improve healing of diabetic foot ulcers. The goal is to have wounds heal and remain healed.

CLINICAL RELEVANCE

Diabetic neuropathy and peripheral arterial disease are major factors involved in a diabetic foot ulcer. Despite current treatment modalities for nonhealing diabetic foot ulcers, there are a significant number of patients who require amputations. No known therapy will be effective without concomitant management of ischemia, infection, and adequate offloading.

Non-contact low-frequency ultrasound therapy compared with UK standard of care for venous leg ulcers: a single-centre, assessor-blinded, randomised controlled trial

‘Hard‐to‐heal’ wounds are those which fail to heal with standard therapy in an orderly and timely manner and may warrant the use of advanced treatments such as non‐contact low‐frequency ultrasound (NLFU) therapy. This evaluator‐blinded, single‐site, randomised controlled trial, compared NLFU in addition to UK standard of care [SOC: (NLFU + SOC)] three times a week, with SOC alone at least once a week. Patients with chronic venous leg ulcers were eligible to participate. All 36 randomised patients completed treatment (17 NLFU + SOC, 19 SOC), and baseline demographics were comparable between groups. NLFU + SOC patients showed a −47% (SD: 38%) change in wound area; SOC, −39% (38%) change; and difference, −7·4% [95% confidence intervals (CIs) −33·4–18·6; P = 0·565]. The median number of infections per patient was two in both arms of the study and change in quality of life (QoL) scores was not significant (P = 0·490). NLFU + SOC patients reported a substantial mean (SD) reduction in pain score of −14·4 (14·9) points, SOC patients' pain scores reduced by −5·3 (14·8); the difference was −9·1 (P = 0·078). Results demonstrated the importance of high‐quality wound care. Outcome measures favoured NLFU + SOC over SOC, but the differences were not statistically significant. A larger sample size and longer follow‐up may reveal NLFU‐related improvements not identified in this study.

Noncontact, low-frequency ultrasound therapy enhances neovascularization and wound healing in diabetic mice

BACKGROUND

Chronic wounds are a major source of morbidity for patients and represent a significant health burden. Implementing noninvasive techniques that accelerate healing of these wounds would provide great benefit. Ultrasound appears to be an effective modality for the treatment of chronic wounds in humans. MIST Therapy is a noncontact, low-frequency ultrasound treatment delivered through a saline mist. A variety of mechanisms have been proposed to explain the efficacy of ultrasound therapy, but the underlying molecular and cellular pathways impacted by this technique remain unclear. The in vivo effect of noncontact, low-frequency ultrasound was therefore examined in a humanized excisional wound model.

METHODS

The treatment group received noncontact, low-frequency ultrasound therapy three times per week, whereas the control group received a standard dressing change. Wounds were photographed at regular intervals to calculate healing kinetics. Wound tissue was harvested and processed for histology, quantitative polymerase chain reaction, and enzyme-linked immunosorbent assay.

RESULTS

The MIST group demonstrated significantly accelerated wound healing, with 17.3 days to wound closure compared with 24 days in the controls (p < 0.05). This improvement became evident by day 9, with healing evidenced by significantly decreased mean wound area relative to original size (68 percent versus 80 percent; p < 0.01). Expression of markers of neovascularization (stromal cell-derived factor 1, vascular endothelial growth factor, and CD31) was also increased in the wound beds of noncontact, low-frequency ultrasound-treated mice compared with controls.

CONCLUSION

Noncontact, low-frequency ultrasound treatment improves neovascularization and wound closure rates in excisional wounds for diabetic mice, likely because of the stimulated release of angiogenic factors.

Antimicrobial effect of an ultrasonic levitation washer disinfector with silver electrolysis and ozone oxidation on methicillin-resistant Staphylococcus aureus

Methicillin-resistant Staphylococcus aureus (MRSA) has rapidly emerged as a cause of severe and intractable skin infection. At present, there are no effective topical treatments, and infection or colonization by MRSA of the skin raises serious medical problems. We developed an ultrasonic levitation washer that generates silver ions (Ag(+)) and ozone (O3) to clean and sterilize medical devices. We report the effect of ultrasonic levitation (levitation) with Ag(+) and O3 on MRSA in vitro and in vivo. Antimicrobial effect against six MRSA strains of all agr types was examined under three in vitro conditions; cells floating in a water tank, cells infiltrating-, and cells forming a biofilm on an atelocollagen membrane. In the in vivo studies, we assayed the number of MRSA organisms that survived treatment on murine skin ulcers and evaluated the ulcer size. Levitation with Ag(+) dramatically decreased the survival of MRSA floating in a water tank. Levitation with Ag(+) and O3 significantly decreased the viability of MRSA that had infiltrated or formed a biofilm on atelocollagen membranes regardless of the level of biofilm production. In vivo studies showed that the number of MRSA on murine skin ulcers was significantly decreased when 15-min treatment was performed for 7 consecutive days and that the ulcer size was significantly decreased after the seventh treatment course. Levitation with Ag(+) and O3 may be a valuable tool for treating MRSA infestation of the skin and for accelerating wound healing.

Noncontact, low-frequency ultrasound as an effective therapy against Pseudomonas aeruginosa-infected biofilm wounds

Bacterial biofilms, a critical chronic wound mediator, remain difficult to treat. Energy-based devices may potentially improve healing, but with no evidence of efficacy against biofilms. This study evaluates noncontact, low-frequency ultrasound (NLFU) in the treatment of biofilm-infected wounds. Six-millimeter dermal punch wounds in rabbit ears were inoculated with 10(7) colony-forming units of Pseudomonas aeruginosa or left as sterile controls. A biofilm was established in vivo using our published model. NLFU treatment was carried out every other day or every day, with contralateral ear wounds acting as internal, untreated controls. Wounds were harvested for several quantitative endpoints and scanning electron microscopy to evaluate the biofilm structure. The P. aeruginosa biofilm consistently impaired wound epithelialization and granulation. NLFU, both every other day and every day, improved healing and reduced bacterial counts relative to untreated controls (p < 0.05). Scanning electron microscopy confirmed a qualitative decrease in bacteria after both treatments. NLFU also reduced inflammatory cytokine expression (p < 0.05). Our study suggests that NLFU is an effective therapy against P. aeruginosa wound biofilm. This represents the first in vivo evidence of energy-based modalities' impact on wound biofilm, setting the foundation for future mechanistic studies. Continued wound care technology research is essential to improving our understanding, and treatment, of biofilm-infected chronic wounds.

New techniques for wound debridement

Debridement is a crucial component of wound management. Traditionally, several types of wound debridement techniques have been used in clinical practice such as autolytic, enzymatic, biodebridement, mechanical, conservative sharp and surgical. Various factors determine the method of choice for debridement for a particular wound such as suitability to the patient, the type of wound, its anatomical location and the extent of debridement required. Recently developed products are beginning to challenge traditional techniques that are currently used in wound bed preparation. The purpose of this review was to critically evaluate the current evidence behind the use of these newer techniques in clinical practice. There is some evidence to suggest that low frequency ultrasound therapy may improve healing rates in patients with venous ulcers and diabetic foot ulcers. Hydrosurgery debridement is quick and precise, but the current evidence is limited and further studies are underway. Debridement using a monofilament polyester fibre pad and plasma-mediated bipolar radiofrequency ablation are both very new techniques. The initial evidence is limited, and further studies are warranted to confirm their role in management of chronic wounds.

Wound care: biofilm and its impact on the latest treatment modalities for ulcerations of the diabetic foot

Biofilm is an increasingly important topic of discussion in the care of the chronic diabetic foot wound. Treatment modalities have focused on biofilm reduction or eradication through debridement techniques, topical therapies, negative pressure therapy, and ultrasound. In addition, advanced wound healing modalities, such as bioengineered alternative tissues, require optimal wound bed preparation with specific consideration of biofilm reduction before their application. Although fundamental principles of diabetic wound care still apply, critical thought must be given to biofilm before implementing a treatment plan for the closure of these complex wounds.

A pilot study evaluating non-contact low-frequency ultrasound and underlying molecular mechanism on diabetic foot ulcers

Non-contact low-frequency ultrasound (NCLF-US) devices have been increasingly used for the treatment of chronic non-healing wounds. The appropriate dose for NCLF-US is still in debate. The aims of this pilot study were to evaluate the relationship between dose and duration of treatment for subjects with non-healing diabetic foot ulcers (DFUs) and to explore the correlation between wound healing and change of cytokine/proteinase/growth factor profile. This was a prospective randomised clinical study designed to evaluate subjects with non-healing DFUs for 5 weeks receiving standard of care and/or NCLF-US treatment. Subjects were randomly assigned to one of the three groups: application of NCLF-US thrice per week (Group 1), NCLF-US once per week (Group 2) and the control (Group 3) that received no NCLF-US. All subjects received standard wound care plus offloading for a total of 4 weeks. Percent area reduction (PAR) of each wound compared with baseline was evaluated weekly. Profiles of cytokines/proteinase/growth factors in wound fluid and biopsied tissue were quantified to explore the correlation between wound healing and cytokines/growth factor expression. Twelve DFU patients, 2 (16·7%) type 1 and 10 (83·3%) type 2 diabetics, with an average age of 58 ± 10 years and a total of 12 foot ulcers were enrolled. Average ulcer duration was 36·44 ± 24·78 weeks and the average ABI was 0·91 ± 0·06. Group 1 showed significant wound area reduction at weeks 3, 4 and 5 compared with baseline, with the greatest PAR, 86% (P < 0·05); Groups 2 and 3 showed 25% PAR and 39% PAR, respectively, but there were no statistically significant differences between Groups 2 and 3 over time. Biochemical and histological analyses indicated a trend towards reduction of pro-inflammatory cytokines (IL-6, IL-8, IL-1β, TNF-α and GM-CSF), matrix metalloproteinase-9 (MMP-9), vascular endothelial growth factor (VEGF) and macrophages in response to NCLF-US consistent with wound reduction, when compared with control group subjects. This proof-of-concept pilot study demonstrates that NCLF-US is effective in treating neuropathic diabetic foot ulcers through, at least in part, inhibiting pro-inflammatory cytokines in chronic wound and improving tissue regeneration. Therapeutic application of NFLU, thrice (3) per week, renders the best wound area reduction.

Low-frequency ultrasound (20-40 kHz) as an adjunctive therapy for chronic wound healing: a systematic review of the literature and meta-analysis of eight randomized controlled trials

Ultrasound as a therapeutic agent in chronic wound healing has been studied extensively. This systematic review and meta-analysis specifically examines low-frequency (20-30 kHz) ultrasound delivered at either low or high intensity. The objective of this review was to determine whether low-frequency ultrasound used as an adjunctive therapy improves the outcomes of complete healing and reduction of size of chronic lower limb wounds. PubMed, Cochrane/CENTRAL, technical assessment, relevant wound-related journals, and clinical guidelines were searched along with contacting manufacturers and authors of relevant randomized controlled trials were completed. Searches focused on the use of low-frequency ultrasound in randomized controlled trials. Data were collected via a data collection form and was adjudicated independently via coauthors. Meta-analyses and heterogeneity checks were performed using Mantel-Haenszel and inverse variance (fixed and random effects) statistical methods on studies with similar outcomes (complete healing and percent wound area reduction) over similar time periods. Single study results were reported via the statistical methods used in the study. Eight randomized controlled trials were identified. Results demonstrated that early healing (at ≤5 months) in patients with venous stasis and diabetic foot ulcers was favorably influenced by both high- and low-intensity ultrasound delivered at a low frequency-either via contact or noncontact techniques. However, the quality of the data may be suspect, especially for low-frequency low-intensity noncontact ultrasound because of significant biases. In patients presenting with either venous stasis or diabetic foot ulcers (Wagner classification 1-3), early healing appears to be facilitated by either low-frequency low-intensity noncontact ultrasound or low-frequency high-intensity contact ultrasound.

Therapeutic modalities--an updated review for the hand surgeon

The number of therapeutic modalities available to the hand surgeon has greatly increased over the past several decades. A field once predicated only on heat, massage, and cold therapy now uses electrical stimulators, ultrasound, biofeedback, iontophoresis, phonophoresis, mirror therapy, lasers, and a number of other modalities. With this expansion in choices, there has been a concurrent effort to better define which modalities are truly effective. In this review, we aim to characterize the commonly used modalities and provide the evidence available that supports their continued use.

A prospective pilot study of ultrasound therapy effectiveness in refractory venous leg ulcers

Venous insufficiency is the most common cause of leg ulcers in the United States. Venous leg ulcers cost the health care system billions of dollars annually, and healing rates are less than 70% with standard of care; therefore, new therapies are needed to increase healing times and minimize associated costs. Non contact ultrasound therapy has been used to treat a variety of chronic wounds including venous leg ulcers, and it is thought that ultrasound has an effect on decreasing the bacterial count in wounds, although the exact mechanism of action of ultrasound is yet to be determined. We conducted an open labelled pilot study of 10 refractory venous ulcers of large size to determine the effect of non contact ultrasound on wound closure, bacterial counts, expression of inflammatory cytokines and pain reduction. We lacked a sham control group but we compared the baseline and end of treatment assessments and noted the differences. We found a significant reduction in wound area (P = 0·0039) over the 4-week treatment period. We also found a decline in individual and total bacterial counts; however, these differences were not significant. For all patients, there was also a trend toward reduced inflammatory cytokine expression compared with baseline levels; however, this reduction did not reach statistical significance. Interestingly, there was a correlation between healing and change in cytokine expression, which showed statistically significance for tumour necrosis factor (TNF)-αP = 0·0395, IL-1a P = 0·0351, IL-6 P = 0·0508, IL-8 P = 0·0990. Pain as measured by the visual analogue scale (VAS) was reduced from 4 at the baseline to 2·7 by the end of the study. In conclusion, we found that patients treated with ultrasound therapy and compression therapy show clinical improvement over the course of 4 weeks and had a decrease in inflammatory cytokines, bacterial counts and pain.

Effects of low-frequency ultrasound on microcirculation in venous leg ulcers

Background:

Therapeutic low-frequency ultrasound (US) has been used for many years to improve wound healing in chronic wounds like venous leg ulcers. No human data are available for the possible effects of single US applications on microcirculation and their frequency-dependency.

Aims:

To investigated the role of therapeutic low-frequency US on microcirculation of venous leg ulcers in vivo.

Patients and Methods:

This is a pilot study on an inpatient basis. We use a newly developed low-frequency continuous-wave US-equipment composed of a US transducer based on piezo-fiber composites that allow the change of frequency. In this study, we apply US of 34 kHz, 53.5 kHz, and 75 kHz respectively. Twelve patients with chronic venous leg ulcers are analyzed. As an adjunct to good ulcer care, therapeutic US is applied, non-contacting, once a day, in a subaqual position for 10 minutes. Microcirculation is assessed in the ulcers adjacent to skin before US-therapy, immediately after the treatment and 30 minutes later. We use a micro-light guide spectrophotometer (O2C, LEA Medizintechnik GmbH, Gieίen, Germany) for calculation of blood flow velocity, hemoglobin oxygen saturation (SCO₂) and relative hemoglobin concentration (rHb) in 2 and 8 mm depth. Contact-free remission spectroscopy (SkinREM3, Color Control Chemnitz GmbH, Chemnitz, Germany) allows contact free measurements in the VIS-NIR range of the spectrum (400 ± 1600 nm).

Results:

It is seen that therapeutic US is well tolerated. One patient dropped out from a treatment series since he developed erysipelas responding to standard antibiotic. Effects were seen at 34 kHz only. The SO₂ values increased after single US application. The values for rHb were higher in the superficial layer of the wound bed (depth 2 mm) compared to deeper parts (8 mm depth). US treatment did not result in significant changes of rHb and blood cell velocity. The data obtained by remission spectroscopy disclose an increase of oxygenized hemoglobin.

Conclusions:

The major findings are that continuous-wave low-frequency US of 34 kHz, but not, 53.5 kHz or 75 kHz, has a temporary stimulatory effect on microcirculation mainly due to an improved oxygenation. Further studies with treatment series are necessary.