Dressings and topical agents for arterial leg ulcers

Dressings and topical agents for arterial leg ulcers

BACKGROUND

It is estimated that up to 1% of people in high-income countries suffer from a leg ulcer at some time in their life. The majority of leg ulcers are associated with circulation problems; poor blood return in the veins causes venous ulcers (around 70% of ulcers) and poor blood supply to the legs causes arterial ulcers (around 22% of ulcers). Treatment of arterial leg ulcers is directed towards correcting poor arterial blood supply, for example by correcting arterial blockages (either surgically or pharmaceutically). If the blood supply has been restored, these arterial ulcers can heal following principles of good wound-care. Dressings and topical agents make up a part of good wound-care for arterial ulcers, but there are many products available, and it is unclear what impact these have on ulcer healing. This is the third update of a review first published in 2003.

OBJECTIVES

To determine whether topical agents and wound dressings affect healing in arterial ulcers. To compare healing rates and patient-centred outcomes between wound dressings and topical agents.

SEARCH METHODS

The Cochrane Vascular Information Specialist searched the Cochrane Vascular Specialised Register, Cochrane Central Register of Controlled Trials, MEDLINE, Embase, Cumulative Index to Nursing and Allied Health Literature and Allied and Complementary Medicine databases, the World Health Organization International Clinical Trials Registry Platform and ClinicalTrials.gov trials register to 28 January 2019.

SELECTION CRITERIA

Randomised controlled trials (RCTs), or controlled clinical trials (CCTs) evaluating dressings and topical agents in the treatment of arterial leg ulcers were eligible for inclusion. We included participants with arterial leg ulcers irrespective of method of diagnosis. Trials that included participants with mixed arterio-venous disease and diabetes were eligible for inclusion if they presented results separately for the different groups. All wound dressings and topical agents were eligible for inclusion in this review. We excluded trials which did not report on at least one of the primary outcomes (time to healing, proportion completely healed, or change in ulcer area).

DATA COLLECTION AND ANALYSIS

Two review authors independently extracted information on the participants' characteristics, the interventions, and outcomes using a standardised data extraction form. Review authors resolved any disagreements through discussion. We presented the data narratively due to differences in the included trials. We used GRADE to assess the certainty of the evidence.

MAIN RESULTS

Two trials met the inclusion criteria. One compared 2% ketanserin ointment in polyethylene glycol (PEG) with PEG alone, used twice a day by 40 participants with arterial leg ulcers, for eight weeks or until healing, whichever was sooner. One compared topical application of blood-derived concentrated growth factor (CGF) with standard dressing (polyurethane film or foam); both applied weekly for six weeks by 61 participants with non-healing ulcers (venous, diabetic arterial, neuropathic, traumatic, or vasculitic). Both trials were small, reported results inadequately, and were of low methodological quality. Short follow-up times (six and eight weeks) meant it would be difficult to capture sufficient healing events to allow us to make comparisons between treatments. One trial demonstrated accelerated wound healing in the ketanserin group compared with the control group. In the trial that compared CGF with standard dressings, the number of participants with diabetic arterial ulcers were only reported in the CGF group (9/31), and the number of participants with diabetic arterial ulcers and their data were not reported separately for the standard dressing group. In the CGF group, 66.6% (6/9) of diabetic arterial ulcers showed more than a 50% decrease in ulcer size compared to 6.7% (2/30) of non-healing ulcers treated with standard dressing. We assessed this as very-low certainty evidence due to the small number of studies and arterial ulcer participants, inadequate reporting of methodology and data, and short follow-up period. Only one trial reported side effects (complications), stating that no participant experienced these during follow-up (six weeks, low-certainty evidence). It should also be noted that ketanserin is not licensed in all countries for use in humans. Neither study reported time to ulcer healing, patient satisfaction or quality of life.

AUTHORS' CONCLUSIONS

There is insufficient evidence to determine whether the choice of topical agent or dressing affects the healing of arterial leg ulcers.

Biofabrication of thick vascularized neo-pedicle flaps for reconstructive surgery

Wound chronicity due to intrinsic and extrinsic factors perturbs adequate lesion closure and reestablishment of the protective skin barrier. Immediate and proper care of chronic wounds is necessary for a swift recovery and a reduction of patient vulnerability to infection. Advanced therapies supplemented with standard wound care procedures have been clinically implemented to restore aberrant tissue; however, these treatments are ineffective if local vasculature is too compromised to support minimally-invasive strategies. Autologous "flaps", which are tissues equipped with their own hierarchical vascular supply, can be harvested from one region of the patient and transplanted to the wound where it is reperfused upon microsurgical anastomosis to appropriate recipient vessels. Despite the success of autologous flap transfer, these procedures are extremely invasive, incur obligatory donor-site morbidity, and require sufficient donor-tissue availability, microsurgical expertise, and specialized equipment. 3D-bioprinting modalities, such as extrusion-based bioprinting, can be used to address the clinical constraints of autologous flap transfer, primarily addressing donor-site morbidity and tissue availability. This advancement in regenerative medicine allows the biofabrication of heterogeneous tissue structures with high shape fidelity and spatial resolution to generate biomimetic constructs with the anatomically-precise geometries of native tissue to ensure tissue-specific function. Yet, meaningful progress toward this clinical application has been limited by the lack of vascularization required to meet the nutrient and oxygen demands of clinically relevant tissue volumes. Thus, various criteria for the fabrication of functional tissues with hierarchical, patent vasculature must be considered when implementing 3D-bioprinting technologies for deep, chronic wounds.

Genetic Deletion of Galectin-3 Does Not Impair Full-Thickness Excisional Skin Healing

Galectin-3 has been linked to the regulation of several molecular processes essential during acute cutaneous wound healing, but a comprehensive study of the role of galectin-3 has yet to be performed. With known roles in macrophage polarization, myofibroblast differentiation, re-epithelialization, and angiogenesis, we hypothesized that genetic deletion of galectin-3 would significantly impair healing of excisional skin wounds in mice. In wild-type mice, galectin-3 expression correlated temporally with the inflammatory phase of healing. Conversely, genetic deletion of galectin-3 did not alter gross wound healing kinetics even though it resulted in delayed re-epithelialization. Wound composition was not altered up to 15 days after wounding in knockout mice, and isolated dermal fibroblast function in vitro was unchanged. We further explored, spatially, the expression of galectin-3 in human chronic wound tissue in relation to the immune cell infiltrate. We show a decreased mRNA and protein abundance in the wound edge tissue, whereas markers of neutrophils, M1 and M2 macrophages are expressed abundantly. Both transforming growth factor-β1 and tumor necrosis factor-α decrease galectin-3 mRNA abundance in chronic wound edge dermal fibroblasts in vitro, providing a potential mechanism for this decreased expression in chronic wounds.

Dressings and topical agents for arterial leg ulcers

BACKGROUND

It is estimated that people in industrialised countries have a 1% chance of suffering from a leg ulcer at some time in their life. The majority of leg ulcers are associated with circulation problems; poor blood return in the veins causes venous ulcers (around 70% of ulcers) and poor blood supply to the legs causes arterial ulcers (around 22% of ulcers). Treatment of arterial leg ulcers is directed towards correcting the poor arterial blood supply, for example by correcting arterial blockages (either surgically or pharmaceutically). If the blood supply has been restored, these arterial ulcers can heal following principles of good wound care. Dressings and topical agents make up a part of good wound care for arterial ulcers but there are many products available and it is unclear what impact these have on ulcer healing. This is an update of a review first published in 2003.

OBJECTIVES

To determine whether topical agents and wound dressings affect healing in arterial ulcers. To compare healing rates, patient-centred outcomes and costs between wound dressings and topical agents.

SEARCH METHODS

For this update the Cochrane Peripheral Vascular Diseases Group Trials Search Co-ordinator searched the Specialised Register (last searched November 2014) and The Cochrane Central Register of Controlled Trials (CENTRAL) (the Cochrane Library) (2014, Issue 10).

SELECTION CRITERIA

Randomised controlled trials (RCTs), or controlled clinical trials (CCTs) evaluating dressings and topical agents in the treatment of arterial leg ulcers were eligible for inclusion. The participants had to have ulcers that were described as arterial, and the time to healing, proportion completely healed, or rate of reduction in ulcer area had to be reported. All wound dressings and topical agents were eligible for inclusion in this review.

DATA COLLECTION AND ANALYSIS

The two review authors independently extracted information on the participants' characteristics, the interventions, and outcomes using a standardised data extraction form. Disagreements between the review authors were resolved through discussion.

MAIN RESULTS

One trial met the inclusion criteria, which was a small trial that compared 2% ketanserin ointment in polyethylene glycol (PEG) with vehicle alone (PEG) control, changed twice a day in 40 participants with arterial leg ulcers. The overall quality of the evidence was low with a single small included study which showed inadequate reporting of the results and had too short a follow-up time (eight weeks) to be able to capture sufficient healing events to allow comparisons to be made. In addition, the study was of low methodological quality. The majority of the 'risk of bias' domains received an 'unclear' risk rating as very little information was provided in the text on the methods of the study. The trial demonstrated increased wound healing in the ketanserin group, compared with the control group, but the trial was too small and had too short a follow-up period (eight weeks) to be able to determine whether there was any difference in healing rates. It should also be noted that ketanserin is not licensed in all countries for use in humans.

AUTHORS' CONCLUSIONS

There is insufficient evidence to determine whether the choice of topical agent or dressing affects the healing of arterial leg ulcers.

Electrostimulation: Current Status, Strength of Evidence Guidelines, and Meta-Analysis

Significance: Delayed healing of skin wounds is a serious problem for the patients, clinicians, and society. The application of interventions with proven effectiveness to increase wound healing is relevant. Recent Advances: This article summarizes the results of effect studies with the application of electrostimulation (ES) as additional treatment to standard wound care (SWC). Therefore, five published narrative reviews are discussed. In addition, 15 studies with a clear randomized controlled trial design are analyzed systematically and the results are presented in four forest plots. The healing rate is expressed in the outcome measure percentage area reduction in 4 weeks of treatment (PAR4). This leads to a continuous measure with mean differences between the percentage healing in the experimental group (SWC plus ES) and in the control group (SWC alone or SWC plus placebo ES). Adding ES to SWC in all wound types increases PAR4 by an extra 26.7% (95% confidence interval [CI] 15.6, 37.8); adding unidirectional ES to SWC increases PAR4 by 30.8% (95% CI 20.9, 40.6) and adding unidirectional ES to the treatment of pressure ulcers increases PAR4 by 42.7% (95% CI 32.0, 53.3). Critical Issues: There is a discrepancy between the proven effectiveness of ES as additional treatment to SWC and the application of ES in real practice. Possible drawbacks are the lack of clinical expertise concerning the proper application of ES and the extra time effort and necessary equipment that are needed. Future Directions: Clinicians concerned about the optimal treatment of patients with delayed wound healing should improve their practical competency to be able to apply ES.

Hyaluronic acid derivatives and their healing effect on burns, epithelial surgical wounds, and chronic wounds: a systematic review and meta-analysis of randomized controlled trials

Hyaluronic acid (HA) is a polysaccharide common to most species and is found in many sites in the human body, including the skin and soft tissue. A systematic review of the literature and meta-analysis was performed to identify randomized controlled trials, evaluating the use of HA derivatives in healing burns, epithelial surgical, and chronic wounds. Nine studies were identified, which met the search criteria and clinical endpoints of complete healing and percent wound size reduction when using HA vs. either an active or passive comparator. It was found in the vast majority of randomized controlled trials (eight of nine) that HA derivatives significantly improved the healing of wounds vs. traditional therapies or placebo (either via complete healing or a significant reduction in wound size) occurring from burns, venous insufficiency, diabetes, neuropathic insufficiency, and surgical removal of the epithelial layer (for tattoo removal). In the other remaining trial, one formulation of HA was compared with another, with the higher concentration showing improved application characteristics. Further, it was found in a meta-analysis in subsets of patients with diabetic foot ulcers (neuropathic) that HA derivatives healed these types of wounds significantly faster than standard of care. These studies in aggregate show that HA derivatives accelerate the healing process in burns, epithelial surgical wounds, and chronic wounds.

Dealing with heterogeneous populations in randomized wound trials: challenges and potential solutions

Chronic wounds have a great variety of etiologies and manifestations that influence wound healing. Such heterogeneity potentially threatens the validity and clinical usefulness of trials if not considered appropriately. In 82 randomized wound trials retrieved from 10 Cochrane reviews, we assessed if and how authors considered wound and other prognostically important characteristics in the conduct and analysis of wound trials. We assessed whether these characteristics were discussed, reflected in the eligibility criteria, used for prestratification or for adjustments to ensure comparability of treatment groups, and whether subgroup analyses were conducted to identify heterogeneity of treatment effects. Nine percent of all trials explicitly discussed characteristics that influence wound healing in the introduction and 43% in the Discussion section. Ninety percent of trials had at least one prognostically important characteristic as eligibility criterion. Only 11% of trials used prestratification, and 6% adjusted the results for imbalances between treatment groups. Twenty-seven percent performed subgroup analyses with prognostically important characteristics defining subgroups. Chronic wound trials use simple randomization, but rarely adapt the study design and analysis to take the heterogeneity of patients into consideration. Collaborative multicenter trials would overcome many of the limitations and provide statistical power to detect important treatment effects both overall and in subgroups.

Evidence-based treatment of chronic leg ulcers

BACKGROUND

Chronic leg ulcers are defined as those that show no tendency to heal after 3 months of appropriate treatment or are still not fully healed at 12 months. In this article, we present an approach to the challenging problem of chronic leg ulcers that is based on the principles of evidence-based medicine, i.e., the explicit use of the best available scientific evidence as a guide to treatment.

METHODS

Selective review of the relevant literature, including current guidelines and meta-analyses, concerning diagnostic and therapeutic strategies for chronic leg ulcers.

RESULTS

The main types of causally directed treatment are: vein surgery to eliminate pathological reflux, interventions to improve the circulation in arterial occlusive disease, and treatment of underlying diseases, such as diabetes mellitus.

CONCLUSION

Physicians providing modern evidence-based management of chronic leg ulcers should make use of their own clinical experience in combination with the best current scientific evidence. It seems clear that the many available treatment options should be evaluated critically in an interdisciplinary setting. In particular, causally directed treatment must be provided in addition to symptomatic, stage-based local wound treatment.

Effects of isoniazid and niacin on experimental wound-healing

BACKGROUND

There is a need for effective treatments of ischemic wounds. Our aim was to test the hypothesis that systemic administration of isoniazid or niacin can enhance wound healing in ischemic as well as nonischemic tissues.

METHODS

One 8-mm, full-thickness wound was made in a standardized, ischemic skin flap and 1 in adjacent nonischemic skin on the back of male Sprague-Dawley rats. Starting just after wounding, twice-daily intraperitoneal isoniazid (10 mg/kg b.i.d.), xanthinol nicotinate (30 mg/kg), or saline (control) were given for 14 days. Wound-healing was monitored by planimetry and oxygen tension in periphery of the wound using a microcatheter probe. Cellular proliferation in granulation tissue was assessed by immunohistochemical detection of proliferating cell nuclear antigen. The angiogenic activity of isoniazid and niacin was assessed using in vitro and ex vivo models.

RESULTS

Although wound ischemia was evident by decreased oxygen tension (26 +/- 10 mmHg; n = 9) compared with the adjacent nonischemic wounds (51 +/- 8 mmHg; n = 8), neither compound significantly influenced intracutaneous oxygen tension. Isoniazid (P < .0001), but not niacin, promoted ischemic wound-healing even though both compounds increased proliferation measured on day 14 (P < .01). In normal wounds, the cumulative change in relative wound area over 14 days was increased by niacin (P = .002), but not by isoniazid, although both niacin (P = .011) and isoniazid (P = .036) increased cellular proliferation. Neither isoniazid nor niacin showed activity in either an endothelial tube formation assay or organotypic angiogenic assay under normoxic conditions.

CONCLUSION

Isoniazid was capable of stimulating wound-healing in ischemic tissue to the level of nonischemic wounds and might offer a novel treatment option for wounds associated with arterial insufficiency. Although active in normal wounds, niacin did not promote ischemic wound-healing.

The use of hyperbaric oxygen therapy to treat chronic wounds: A review

Chronic wounds, defined as those wounds which fail to proceed through an orderly process to produce anatomic and functional integrity, are a significant socioeconomic problem. A wound may fail to heal for a variety of reasons including the use of corticosteroids, formation of squamous cell carcinoma, persistent infection, unrelieved pressure, and underlying hypoxia within the wound bed. Hypoxia appears to inhibit the wound healing process by blocking fibroblast proliferation, collagen production, and capillary angiogenesis and to increase the risk of infection. Hyperbaric oxygen therapy (HBOT) has been shown to aid the healing of ulcerated wounds and demonstrated to reduce the risk of amputation in diabetic patients. However, the causal reasons for the response of the underlying biological processes of wound repair to HBOT, such as the up-regulation of angiogenesis and collagen synthesis are unclear and, consequently, current protocols remain empirical. Here we review chronic wound healing and the use of hyperbaric oxygen as an adjunctive treatment for nonhealing wounds. Databases including PubMed, ScienceDirect, Blackwell Synergy, and The Cochrane Library were searched for relevant phrases including HBOT, HBO/HBOT, wound healing, and chronic/nonhealing wounds/ulcers.

Wounds - from physiology to wound dressing

INTRODUCTION

Optimal wound management remains the subject of active research. Improved knowledge of physiological wound healing, systemic research into wound dressing and the evaluation of chemical disinfection have given rise to new approaches to wound care.

METHODS

Selective literature review.

RESULTS

The primary goals of wound management are rapid wound closure and a functional and aesthetically satisfactory scar. While basic treatment for primary wound healing is often simple, a number of problems can arise in chronic wounds, especially in elderly patients and those with multiple morbidity. It is therefore essential to maintain the basic conditions for physiological wound healing, in particular adequate wound moistness. Each dressing change should entail an evaluation of the wound status, careful cleansing, and treatment tailored to the phase of wound healing. Many therapeutic agents formerly in use are now obsolete. A variety of specific preparations are available for wound covering, including inert, interactive and bioactive substances. There remains a lack of good evidence for these, however.

CONCLUSIONS

New findings in molecular and cell biology have improved our understanding of physiological wound healing, and approach to wound care and dressing.

The influence of polymorbidity, revascularization, and wound therapy on the healing of arterial ulceration

OBJECTIVE

An ulcer categorized as Fontaine's stage IV represents a chronic wound, risk factor of arteriosclerosis, and co-morbidities which disturb wound healing. Our objective was to analyze wound healing and to assess potential factors affecting the healing process.

METHODS

199 patients were included in this 5-year study. The significance levels were determined by chi-squared and log-rank tests. The calculation of patency rate followed the Kaplan-Meier method.

RESULTS

Mean age and co-morbidities did not differ from those in current epidemiological studies. Of the patients with ulcer latency of more than 13 weeks (up to one year), 40% required vascular surgery. Vascular surgery was not possible for 53 patients and they were treated conservatively. The amputation rate in the conservatively treated group was 37%, whereas in the revascularizated group it was only 16%. Ulcers in patients with revascularization healed in 92% of cases after 24 weeks. In contrast, we found a healing rate of only 40% in the conservatively treated group (p<0.001). Revascularization appeared more often in diabetic patients (n=110; p<0.01) and the wound size and number of infections were elevated (p=0.03). Among those treated conservatively, wound healing was decelerated (p=0.01/0.02; chi(2) test).

CONCLUSIONS

The success of revascularization, presence of diabetes mellitus, and wound treatment proved to be prognostic factors for wound healing in arterial ulcers.

Topical silver for treating infected wounds

BACKGROUND

Topical silver treatments and silver dressings are increasingly used for the local treatment of contaminated or infected wounds, however, there is a lack of clarity regarding the evidence for their effectiveness.

OBJECTIVES

To evaluate the effects on wound healing of topical silver and silver dressings in the treatment of contaminated and infected acute or chronic wounds.

SEARCH STRATEGY

We sought relevant trials from the Cochrane Central Register of Controlled Trials (CENTRAL), the Cochrane Wounds Group Specialised Register in March 2006 and in MEDLINE, EMBASE, CINAHL, and digital dissertations databases up to September 2006. In addition, we contacted companies, manufacturers and distributors for information to identify relevant trials.

SELECTION CRITERIA

Randomised controlled trials (RCTs) assessing the effectiveness of topical silver in the treatment of contaminated and infected acute or chronic wounds.

DATA COLLECTION AND ANALYSIS

Eligibility of trials, assessment of trial quality and data extraction were undertaken by two authors independently. Disagreements were referred to a third author.

MAIN RESULTS

Three RCTs were identified, comprising a total of 847 participants. One trial compared silver-containing foam (Contreet) with hydrocellular foam (Allevyn) in patients with leg ulcers. The second trial compared a silver-containing alginate (Silvercel) with an alginate alone (Algosteril). The third trial compared a silver-containing foam dressing (Contreet)) with best local practice in patients with chronic wounds.The data from these trials show that silver-containing foam dressings did not significantly increase complete ulcer healing as compared with standard foam dressings or best local practice after up to four weeks of follow-up, although a greater reduction of ulcer size was observed with the silver-containing foam. The use of antibiotics was assessed in two trials, but no significant differences were found. Data on pain, patient satisfaction, length of hospital stay, and costs were limited and showed no differences. Leakage occurred significantly less frequently in patients with leg ulcers and chronic wounds treated with a silver dressing than with a standard foam dressing or best local practice in one trial.

AUTHORS' CONCLUSIONS

Only three trials with a short follow-up duration were found. There is insufficient evidence to recommend the use of silver-containing dressings or topical agents for treatment of infected or contaminated chronic wounds.