A Multicenter Randomized Controlled Trial Comparing Treatment of Venous Leg Ulcers Using Mechanically Versus Electrically Powered Negative Pressure Wound Therapy

Updates on Recent Clinical Assessment of Commercial Chronic Wound Care Products

Impaired wound healing after trauma, disorders, and surgeries impact millions of people globally every year. Dysregulation in orchestrated healing mechanisms and underlying medical complications make chronic wound management extremely challenging. Besides standard-of-care treatments including broad spectrum antibiotics and wound-debridement, novel adjuvant therapies are clinically tested and commercialized. These include topical agents, skin substitutes, growth factor delivery, and stem cell therapies. With a goal to overcome factors playing pivotal role in delayed wound healing, researchers are exploring novel approaches to elicit desirable healing outcomes in chronic wounds. Although recent innovations in wound care products, therapies, and devices are extensively reviewed in past, a comprehensive review summarizing their clinical outcomes is surprisingly lacking. Herein, this work reviews the commercially available wound care products and their performance in clinical trials to provide a statistically comprehensive understanding of their safety and efficacy. The performance and suitability of various commercial wound care platforms, including xenogeneic and allogenic products, wound care devices, and novel biomaterials, are discussed for chronic wounds. The current clinical evaluation will provide a comprehensive understanding of the benefits and drawbacks of the most-recent approaches and will enable researchers and healthcare providers to develop next-generation technologies for chronic wound management.

Novel home use of mechanical negative pressure wound therapy in diabetic foot ulcers

OBJECTIVE

Mechanical negative pressure wound therapy is an ultraportable, light weight and disposable single-use device that has been shown to promote wound healing. This study evaluated home use of a mechanically powered negative pressure wound therapy (NPWT) in diabetic foot wounds.

METHODS

Patients underwent revascularisation and/or debridement or amputation before starting mechanical NPWT. Wound outcomes and images of the wounds were recorded at each follow-up visit by the wound nurse. Patients were followed up until wound closure or end of therapy.

RESULTS

A total of 12 patients (each with one wound) were included in the study. Of the 12 wounds, 33.3% (n=4) of wounds achieved primary wound closure while the remaining 66.6% (n=8) of wounds demonstrated a mean wound size reduction of 37.5±0.13%. Of the closed wounds, mean time to healing was 4.75±2.50 weeks. There was 100% limb salvage with no further debridement or amputations, and no 30-day unplanned readmissions. Mean length of hospital stay before starting home NPWT was 9.75±6.31 days. Mean number of NPWT changes was 8.33±2.67 sessions, while mean duration of therapy was 4.0±1.54 weeks. Mean cost of home NWPT therapy was US$1904±731 per patient.

CONCLUSION

The home use of mechanically powered NPWT in diabetic foot wounds demonstrated excellent wound healing rates and 100% limb salvage, with no complications.

EWMA Document: Negative Pressure Wound Therapy

1. Introduction Since its introduction in clinical practice in the early 1990's negative pressure wounds therapy (NPWT) has become widely used in the management of complex wounds in both inpatient and outpatient care.¹ NPWT has been described as a effective treatment for wounds of many different aetiologies^2,3 and suggested as a gold standard for treatment of wounds such as open abdominal wounds,^4-6 dehisced sternal wounds following cardiac surgery^7,8 and as a valuable agent in complex non-healing wounds.^9,10 Increasingly, NPWT is being applied in the primary and home-care setting, where it is described as having the potential to improve the efficacy of wound management and help reduce the reliance on hospital-based care.¹¹ While the potential of NPWT is promising and the clinical use of the treatment is widespread, highlevel evidence of its effectiveness and economic benefits remain sparse.^12-14 The ongoing controversy regarding high-level evidence in wound care in general is well known. There is a consensus that clinical practice should be evidence-based, which can be difficult to achieve due to confusion about the value of the various approaches to wound management; however, we have to rely on the best available evidence. The need to review wound strategies and treatments in order to reduce the burden of care in an efficient way is urgent. If patients at risk of delayed wound healing are identified earlier and aggressive interventions are taken before the wound deteriorates and complications occur, both patient morbidity and health-care costs can be significantly reduced. There is further a fundamental confusion over the best way to evaluate the effectiveness of interventions in this complex patient population. This is illustrated by reviews of the value of various treatment strategies for non-healing wounds, which have highlighted methodological inconsistencies in primary research. This situation is confounded by differences in the advice given by regulatory and reimbursement bodies in various countries regarding both study design and the ways in which results are interpreted. In response to this confusion, the European Wound Management Association (EWMA) has been publishing a number of interdisciplinary documents^15-19 with the intention of highlighting: The nature and extent of the problem for wound management: from the clinical perspective as well as that of care givers and the patients Evidence-based practice as an integration of clinical expertise with the best available clinical evidence from systematic research The nature and extent of the problem for wound management: from the policy maker and healthcare system perspectives The controversy regarding the value of various approaches to wound management and care is illustrated by the case of NPWT, synonymous with topical negative pressure or vacuum therapy and cited as branded VAC (vacuum-assisted closure) therapy. This is a mode of therapy used to encourage wound healing. It is used as a primary treatment of chronic wounds, in complex acute wounds and as an adjunct for temporary closure and wound bed preparation preceding surgical procedures such as skin grafts and flap surgery. Aim An increasing number of papers on the effect of NPWT are being published. However, due to the low evidence level the treatment remains controversial from the policy maker and health-care system's points of view-particularly with regard to evidence-based medicine. In response EWMA has established an interdisciplinary working group to describe the present knowledge with regard to NPWT and provide overview of its implications for organisation of care, documentation, communication, patient safety, and health economic aspects. These goals will be achieved by the following: Present the rational and scientific support for each delivered statement Uncover controversies and issues related to the use of NPWT in wound management Implications of implementing NPWT as a treatment strategy in the health-care system Provide information and offer perspectives of NPWT from the viewpoints of health-care staff, policy makers, politicians, industry, patients and hospital administrators who are indirectly or directly involved in wound management.

Effectiveness of biofilm-based wound care system on wound healing in chronic wounds

A biofilm plays a crucial role in delaying wound healing. Sharp debridement, a possible effective method for eliminating biofilms, can only be applied to the wound with visible necrotic tissue; thus, no option has been available for eliminating biofilms that are not accompanied by necrotic tissue. Wound blotting was recently developed to visualize biofilm noninvasively and quickly, and ultrasonic debridement is available for biofilm removal. Therefore, the purpose of this study was to investigate the efficacy of "biofilm-based wound care system (BWCS)," a combination of wound blotting as a point-of-care testing and ultrasonic debridement, for promoting wound healing. Firstly, the cross-sectional study was conducted to examine the proportion of biofilm removal by ultrasonic debridement in pressure ulcers [Study 1]. Subsequently, the retrospective cohort study was conducted to examine the effectiveness of BWCS for healing of chronic wounds [Study 2]. The proportions of wound healing between wounds treated with BWCS and those with standard care in the home-visiting clinic were compared by Kaplan-Meier curve, and the Cox proportional hazard modeling was used to assess the effect of BWCS on wound healing. In Study 1, the median of biofilm removal proportion was 38.9% (interquartile range, 12.9-68.0%) for pressure ulcers treated with standard care and 65.2% (41.1-78.8%) for those treated with ultrasonic debridement (p = 0.009). In Study 2, the proportion of wound healing within 90 days was significantly higher in wounds treated with BWCS than in those treated with standard care (p = 0.001). The adjusted hazard ratio of BWCS for wound healing was 4.5 (95% confidence interval, 1.3-15.0; p = 0.015). In conclusion, we demonstrated that our novel approach, BWCS, can be a promising therapeutic strategy for visualizing biofilms that are not accompanied by necrotic tissue and promoting healing in chronic wounds.

The smart negative pressure (SNaP) wound care system: A case series from Singapore

The Smart Negative Pressure (SNaP) wound care system is a novel device that is single-patient use, ultra-portable, and light weight and does not rely on battery or need recharging. A systematic search was performed on major databases to identify relevant articles including case reports, retrospective case series, and randomised controlled trials. Ten studies were identified, showing that the SNaP wound care system is an effective tool in treating small-sized wounds and may serve as an alternative to current electrically powered modalities. Furthermore, the system's small size and convenience leads to greater patient satisfaction and improves quality of life. Finally, we report our initial positive experiences with two cases in our institution. Although the evidence thus far has been encouraging, and patient satisfaction is higher than other wound care systems, further evidence is required to determine its superiority over current systems in terms of wound-healing outcomes.

Negative pressure wound therapy for treating leg ulcers

BACKGROUND

Leg ulcers are open skin wounds that occur between the ankle and the knee that can last weeks, months or even years and are a consequence of arterial or venous valvular insufficiency. Negative pressure wound therapy (NPWT) is a technology that is currently used widely in wound care and is promoted for use on wounds. NPWT involves the application of a wound dressing to the wound, to which a machine is attached. The machine applies a carefully controlled negative pressure (or vacuum), which sucks any wound and tissue fluid away from the treated area into a canister.

OBJECTIVES

To assess the effects of negative pressure wound therapy (NPWT) for treating leg ulcers in any care setting.

SEARCH METHODS

For this review, in May 2015 we searched the following databases: the Cochrane Wounds Group Specialised Register (searched 21 May 2015); the Cochrane Central Register of Controlled Trials (CENTRAL; The Cochrane Library 2015, Issue 4); Ovid MEDLINE (1946 to 20 May 2015); Ovid MEDLINE (In-Process & Other Non-Indexed Citations 20 May 2015); Ovid EMBASE (1974 to 20 May 2015); EBSCO CINAHL (1982 to 21 May 2015). There were no restrictions based on language or date of publication.

SELECTION CRITERIA

Published or unpublished randomized controlled trials (RCTs) comparing the effects of NPWT with alternative treatments or different types of NPWT in the treatment of leg ulcers.

DATA COLLECTION AND ANALYSIS

Two review authors independently performed study selection, risk of bias assessment and data extraction.

MAIN RESULTS

We included one study, with 60 randomized participants, in the review. The study population had a range of ulcer types that were venous arteriolosclerotic and venous/arterial in origin. Study participants had recalcitrant ulcers that had not healed after treatment over a six-month period. Participants allocated to NPWT received continuous negative pressure until they achieved 100% granulation (wound preparation stage). A punch skin-graft transplantation was conducted and the wound then exposed to further NPWT for four days followed by standard care. Participants allocated to the control arm received standard care with dressings and compression until 100% granulation was achieved. These participants also received a punch skin-graft transplant and then further treatment with standard care. All participants were treated as in-patients until healing occurred.There was low quality evidence of a difference in time to healing that favoured the NPWT group: the study reported an adjusted hazard ratio of 3.2, with 95% confidence intervals (CI) 1.7 to 6.2. The follow-up period of the study was a minimum of 12 months. There was no evidence of a difference in the total number of ulcers healed (29/30 in each group) over the follow-up period; this finding was also low quality evidence.There was low quality evidence of a difference in time to wound preparation for surgery that favoured NPWT (hazard ratio 2.4, 95% CI 1.2 to 4.7).Limited data on adverse events were collected: these provided low quality evidence of no difference in pain scores and Euroqol (EQ-5D) scores at eight weeks after surgery.

AUTHORS' CONCLUSIONS

There is limited rigorous RCT evidence available concerning the clinical effectiveness of NPWT in the treatment of leg ulcers. There is some evidence that the treatment may reduce time to healing as part of a treatment that includes a punch skin graft transplant, however, the applicability of this finding may be limited by the very specific context in which NPWT was evaluated. There is no RCT evidence on the effectiveness of NPWT as a primary treatment for leg ulcers.