The challenge of using randomized trials in wound healing

Efficacy of MMP-inhibiting wound dressings in the treatment of chronic wounds: a systematic review

OBJECTIVE

Matrix metalloproteinases (MMPs) substantially contribute to the development of chronicity in wounds. Thus, MMP-inhibiting dressings may support healing. A systematic review was performed to determine the existing evidence base for the treatment of hard-to-heal wounds with these dressings.

METHODS

A systematic literature search in databases and clinical trial registers was conducted to identify randomised controlled trials (RCTs) investigating the efficacy of MMP-inhibiting dressings. Studies were analysed regarding their quality and clinical evidence.

RESULTS

Of 721 hits, 16 relevant studies were assessed. There were 13 studies performed with collagen and three with technology lipido-colloid nano oligosaccharide factor (TLC-NOSF) dressings. Indications included diabetic foot ulcers, venous leg ulcers, pressure ulcers or wounds of mixed origin. Patient-relevant endpoints comprised wound size reduction, complete wound closure, healing time and rate. Considerable differences in the quality and subsequent clinical evidence exist between the studies identified. Substantial evidence for significant improvement in healing was identified only for some dressings.

CONCLUSION

Evidence for the superiority of some MMP-inhibiting wound dressings exists regarding wound closure, wound size reduction, healing time and healing rate. More research is required to substantiate the existing evidence for different types of hard-to-heal wounds and to generate evidence for some of the different types of MMP-inhibiting wound dressings.

Oleogel-S10 Phase 3 study "EASE" for epidermolysis bullosa: study design and rationale

Background

Epidermolysis bullosa (EB) is a group of rare, genetic diseases that affect the integrity of epithelial tissues, most notably the skin. Patients experience recurrent skin wounding, with severity depending on type, sub-type, and mutation. Oleogel-S10, a formulation of birch bark extract, has demonstrated efficacy in a Phase 2 trial assessing re-epithelialization of wounds in EB. EASE (NCT03068780, EudraCT 2016–002066-32) is a randomized, Phase 3, placebo-controlled study designed to determine the efficacy of Oleogel-S10 versus placebo in patients with EB.

Methods

EASE is a Phase 3, two-phase study comprising a 90-day, double-blind, randomized, placebo-controlled phase, followed by 24 months of open-label, single-arm follow-up. Patients with junctional EB, dystrophic EB, or Kindler syndrome and target wounds (10 - 50cm²) present for > 21 days and < 9 months, are randomized in a 1:1 ratio to receive wound dressings according to local standard of care with or without Oleogel-S10. Placebo is based on the Oleogel-S10 vehicle, which is sunflower oil formulated to have a consistency indistinguishable from that of the active product. The primary endpoint of the trial, directed by the US health authority according to the required study endpoints for chronic cutaneous ulcer and burn wounds, is to compare the efficacy of Oleogel-S10 versus placebo according to the proportion of patients with complete closure of the target wound within 45 ± 7 days of treatment. Additional EB-focused endpoints include wound burden, patient-reported outcomes, and safety.

Results

Results of the primary endpoint are anticipated to be available by H2 2019.

Trial registration

ClinicalTrials.gov, NCT03068780. EudraCT, 2016–002066-32. Registered on 3 March 2017.

Electronic supplementary material

The online version of this article (10.1186/s13063-019-3362-z) contains supplementary material, which is available to authorized users.

Negative pressure wound therapy: A systematic review of randomized controlled trials from 2000 to 2017

BACKGROUND

Negative pressure wound therapy (NPWT) proposes to provide better wound healing than standard wound management. Evidence quality of randomized controlled trials (RCTs) varies.

METHODS

We included participants with any kind of wounds and commercial as well as the homemade NPWT system. Comparators were any other wound dressing including variant NPWTs. We included RCTs randomizing patients or wounds in parallel or crossover designs. We searched PubMed and Cochrane Library on January 03, 2018. We assessed the risk of bias according to Cochrane and appropriateness of clinical endpoints according to the Food and Drug Administration (FDA).

RESULTS

We included 93 RCTs originating in 30 countries, 70 studies on open wounds and 23 studies on closed wounds. With respect to random sequence generation, we judged an unclear or high risk of bias in 50% (47 of 93) studies. With respect to allocation concealment, we judged an unclear or high risk of bias in 90% (84 of 93). We identified 41% (38 of 93) studies that based their conclusion on not appropriate endpoints.

CONCLUSIONS

High risk of bias concerning random sequence generation and allocation concealment limited the credibility of the majority of 93 included RCTs on NPWT. A low risk of bias can and should be achieved with both items, and we recommend to align future RCTs to Cochrane. Many primary clinical endpoints were deemed not valid for making inferences on the efficacy of NPWT. We recommend using patient-centered endpoints as requested by the FDA and suggested in the present systematic review.

Economic and organizational sustainability of a negative-pressure portable device for the prevention of surgical-site complications

Purpose

Surgical-site complications (SSCs) affect patients’ clinical pathway, prolonging their hospitalization and incrementing their management costs. The present study aimed to assess the economic and organizational implications of a portable device for negative-pressure wound therapy (NPWT) implementation, compared with the administration of pharmacological therapies alone for preventing surgical complications in patients undergoing general, cardiac, obstetrical–gynecological, or orthopedic surgical procedures.

Patients and methods

A total of 8,566 hospital procedures, related to the year 2015 from one hospital, were evaluated considering infection risk index, occurrence rates of SSCs, drug therapies, and surgical, diagnostic, and specialist procedures and hematological exams. Activity-based costing and budget impact analyses were implemented for the economic assessment.

Results

Patients developing an SSC absorbed i) 64.27% more economic resources considering the length of stay (€ 8,269±2,096 versus € 5,034±2,901, p<0.05) and ii) 42.43% more economic resources related to hematological and diagnostic procedures (€ 639±117 versus € 449±72, p<0.05). If the innovative device had been used over the 12-month time period, it would have decreased the risk of developing SSCs; the hospital would have realized an average reduction in health care expenditure equal to −0.69% (−€ 483,787.92) and an organizational saving in terms of length of stay equal to −1.10% (−898 days), thus allowing 95 additional procedures.

Conclusion

The implementation of a portable device for NPWT would represent an effective and sustainable strategy for reducing the management costs of patients. Economic and organizational savings could be reinvested, thus i) treating a wider population and ii) reducing waiting lists, with a higher effectiveness in terms of a decrease in complications.

Molecular and cellular impact of Psoriasin (S100A7) on the healing of human wounds

Psoriasin, which is also known as S100A7, is a member of the S100 protein family, a group of calcium-responsive signalling proteins. Psoriasin expression remains high in patients with psoriasis, whereas it is downregulated in patients with invasive breast carcinoma. This observation suggests that this protein may be a notable marker of keratinocyte function and differentiation during wound healing. The aim of the present study was to determine the cellular impact of Psoriasin in keratinocytes, which are the primary cell type associated with wound healing. Psoriasin expression in wound tissues was examined using reverse transcription-quantitative polymerase chain reaction and immunochemical staining. Knockdown of Psoriasin in HaCaT cells was performed using anti-Psoriasin ribozyme transgenes and the effect on growth, adhesion and migration of keratinocytes was subsequently determined using in vitro cellular functional assays. Psoriasin expression is upregulated in wounds, particularly at the wound edges. The present study demonstrated that Psoriasin is expressed in keratinocytes and is a fundamental regulator of keratinocyte migration. Significant increases in the rate of keratinocyte adhesion, migration and growth were observed in Psoriasin-deficient cells (P<0.01 vs. control). Application of small inhibitors identified the potential association of neural Wiskott-Aldrich syndrome protein, focal adhesion primase and rho-associated protein kinase signalling pathways with Psoriasin-regulated cell adhesion and motility. In conclusion, Psoriasin serves an important role in the wound healing process, suggesting that it may be utilized as a potential wound healing biomarker.

A national survey by the SDMA: use of evidence in nursing practice

OBJECTIVE

Recently, two surveys were conducted by the Surgical Dressing Manufacturers Association (SDMA) to investigate the evidence required to support wound care products. These showed very clearly that industry provides significant amounts of evidence in a way that appears to meet the expectations of relevant health professionals and their practice for treating patients with wounds. The responses of health professionals refuted the opinion that evidence may be lacking for wound care products. Hopefully, the results of these surveys also add weight to the argument that the Cochrane Review approach is not always the most appropriate for wound care-where the comorbidities of patients are variable and often plural.

Fundamentals of randomized clinical trials in wound care: reporting standards

In wound care research, available high-level evidence according to the evidence pyramid is rare, and is threatened by a poor study design and reporting. Without comprehensive and transparent reporting, readers will not be able to assess the strengths and limitations of the research performed. Randomized clinical trials (RCTs) are universally acknowledged as the study design of choice for comparing treatment effects. To give high-level evidence the appreciation it deserves in wound care, we propose a step-by-step reporting standard for comprehensive and transparent reporting of RCTs in wound care. Critical reporting issues (e.g., wound care terminology, blinding, predefined outcome measures, and a priori sample size calculation) and wound-specific barriers (e.g., large diversity of etiologies and comorbidities of patients with wounds) that may prevent uniform implementation of reporting standards in wound care research are addressed in this article. The proposed reporting standards can be used as guidance for authors who write their RCT, as well as for peer reviewers of journals. Endorsement and application of these reporting standards may help achieve a higher standard of evidence and allow meta-analysis of reported wound care data. The ultimate goal is to help wound care professionals make better decisions for their patients in clinical practice.

The use of biatain Ag in hard-to-heal venous leg ulcers: meta-analysis of randomised controlled trials

Background

Venous leg ulcers are common, troublesome, and their failure to heal is often related to a heavy bio-burden. Ionized silver has both anti-inflammatory and antimicrobial properties. The ulcer healing properties of the silver releasing foam dressing Biatain Ag has been examined in 4 randomized controlled trials (RCTs).

Aim

To evaluate ulcer healing through a meta-analytic approach after treatment with either Biatain Ag or a non-active dressing.

Patients and Methods

685 subjects with pure or mixed hard-to-heal venous leg ulcers were included in the meta-analysis.

Results

Biatain Ag showed a significant treatment effect (p<0.0001), responder rate (p<0.001), and healing rate (p = 0.002).

Conclusion

The meta-analysis of the 4 RCTs provided statistical significant evidence to support the use of Biatain Ag dressing in treatment of hard-to-heal venous leg ulcers.

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

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

Identifying and exploring physical and psychological morbidity and patient and family caregiver resilience following acute wound development and/or wound blistering post orthopaedic surgery: a systematic review

The aim of this article was to identify the literature that examined and explored physical and psychological morbidity and patient and family caregiver resilience following acute wound development and/or wound blistering post orthopaedic surgery. A systematic review of the literature using the databases MEDLINE, CINAHL and EMBASE was undertaken. The papers were examined using title and abstract for relevance to the primary and secondary outcomes. The primary outcome of interest was family caregiver resilience following acute wound development and/or wound blistering post orthopaedic surgery. The search yielded 275 records after removing any duplicates; eight studies were considered eligible and were reviewed as full text. Following full review, none of the studies was included in this article. To conclude, there were no papers that investigated or examined the concept of resilience in relation to the management of acute post-surgical orthopaedic wounds. Four of the papers identified, following the review process, did discuss quality of life outcomes and how these may be improved following wound development; most papers focused on the management of chronic wounds. It is apparent from the review that there is no evidence currently available that explores patient and family caregiver resilience following acute wound development and/or wound blistering post orthopaedic surgery.

Does evidence permeate all surgical areas equally? Publication trends in wound care compared to breast cancer care: a longitudinal trend analysis

BACKGROUND

Evidence-based decision making has permeated the daily practice of healthcare professionals. However, in wound care this seems more difficult than in other medical areas, such as breast cancer, which has a similar incidence, variety of etiologies, financial burden, and diversity of treatment options. This incongruence could be due to a lack in quantity and quality of available evidence. We therefore compared worldwide publication trends to answer whether research in wound care lags behind that in breast cancer.

METHODS

In order to assess the trends in quantity and methodological quality of publications as to wound care and breast cancer treatments, we examined relevant publications over the last five decades. Publications in MEDLINE were classified into seven study design categories: (1) guidelines, (2) systematic reviews (SR), (3) randomized (RCT), and controlled clinical trials (CCT), (4) cohort studies, (5) case-control studies, (6) case series and case reports, and (7) other publications.

RESULTS

We found a 30-fold rise in publications on wound care, versus a 70-fold increase in those on breast cancer. High-quality study designs like SR, RCT, or CCT were less frequent in wound care (difference 1.9, 95 % CI 1.8-2.0 %) as were guidelines; 76 on wound care versus 231 for breast cancer.

CONCLUSIONS

Publications on wound care fall behind in quantity and quality as compared to breast cancer. Nevertheless, SR, RCT, and CCT in wound care are becoming more numerous. These high-quality study designs could motivate clinicians to make evidence-based decisions and researchers to perform proper research in wound care.

A critical review of modern and emerging absorbent dressings used to treat exuding wounds

Wound management has progressed significantly over the last five decades. This emanates from a greater understanding of wound healing, technological progression and improved clinical and scientific research. There are currently a plethora of absorbent dressings on the wound care market which claim to have the ability to manage exudates whilst encouraging healing. However, it is becoming clear, from analysing randomised controlled trials, that some of these absorbent dressings are not meeting their expectations when applied in a clinical setting. Many clinicians now feel that there should be more focus, not only on a dressing's ability to manage exudate efficiently, but on a dressing's ability to proactively encourage healing and thus exudate reduction will ensue. This paper proposes to critically review modern and emerging absorbent wound care dressings used to manage exuding wounds and discuses some advances in this area.

Evidence-based decisions for local and systemic wound care

Background

Decisions on local and systemic wound treatment vary among surgeons and are frequently based on expert opinion. The aim of this meta-review was to compile best available evidence from systematic reviews in order to formulate conclusions to support evidence-based decisions in clinical practice.

Methods

All Cochrane systematic reviews (CSRs), published by the Cochrane Wounds and Peripheral Vascular Diseases Groups, and that investigated therapeutic and preventive interventions, were searched in the Cochrane Database up to June 2011. Two investigators independently categorized each intervention into five levels of evidence of effect, based on size and homogeneity, and the effect size of the outcomes.

Results

After screening 149 CSRs, 44 relevant reviews were included. These contained 109 evidence-based conclusions: 30 on venous ulcers, 30 on acute wounds, 15 on pressure ulcers, 14 on diabetic ulcers, 12 on arterial ulcers and eight on miscellaneous chronic wounds. Strong conclusions could be drawn regarding the effectiveness of: therapeutic ultrasonography, mattresses, cleansing methods, closure of surgical wounds, honey, antibiotic prophylaxis, compression, lidocaine–prilocaine cream, skin grafting, antiseptics, pentoxifylline, debridement, hyperbaric oxygen therapy, granulocyte colony-stimulating factors, prostanoids and spinal cord stimulation.

Conclusion

For some wound care interventions, robust evidence exists upon which clinical decisions should be based.

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.

Present and new techniques and devices in the treatment of DFU: a critical review of evidence

Management of foot ulcer in individuals with diabetes remains a major therapeutic challenge throughout the world. We performed a critical review of evidence of present and new techniques and devices in the treatment of diabetic foot ulcer. The golden standard for optimal evidence in the Cochrane system is level I - randomized controlled trials, and meta-analyses of several randomized controlled trials. Available evidence on different types of wound debridement; use of antimicrobials; use of dressings in wounds; topical negative pressure, hyperbaric oxygen treatment; electrical, electromagnetic, laser, shockwave, and ultrasound therapies; growth and cell biology factors; cell products and tissue engineering; bioengineered skin and skin grafts; and adjuvant therapies were evaluated. The results of this review show that there is limited evidence on the highest level to justify a change in routine clinical practice. There is a paucity of high-quality evidence, because the studies are often based on inadequate sample size, short follow-up, nonrandom allocation to treatment arms, nonblinded assessment of outcomes, poor description of control, and concurrent intervention. The heterogeneity of the population (of both people and ulcers), with multiple factors contributing to both ulcer onset and failure to heal, makes the trial design difficult in this field. Another fundamental reason for the lack of evidence is the general use of the outcome measure 'complete healing'. In conclusion, when the results of this updated review are taken together with those of the earlier reports, they provide limited evidence to justify a change in routine clinical practice. For this reason, there is an urgent need to increase the quality of clinical studies. A re-evaluation of which type of research is acceptable for producing evidence in the wound area may be important in the future.

A prospective, multi-centre, randomised, open label, parallel, comparative study to evaluate effects of AQUACEL® Ag and Urgotul® Silver dressing on healing of chronic venous leg ulcers

This study compared wound healing efficacy of two silver dressings, AQUACEL(®) Ag and Urgotul(®) Silver, against venous ulcers at risk of infection, over 8 weeks of treatment. The primary objective was to show non inferiority of AQUACEL(®) Ag to Urgotul(®) Silver. Patients (281) were randomised into two groups. The AQUACEL(®) Ag group had 145 patients treated with AQUACEL(®) Ag for 4 weeks followed by AQUACEL for another 4 weeks. TheUrgotul(®) Silver group had 136 patients treated with Urgotul(®) Silver for 4 weeks followed by Urgotul(®) for another 4 weeks. In both groups, ulcer size and depth, safety events and ulcer healing were compared. After 8 weeks of treatment, the AQUACEL(®) Ag group had a relative wound size reduction (49·65% ± 52·53%) compared with the Urgotul(®) Silver group (42·81% ± 60·0%). The non inferiority of the AQUACEL(®) Ag group to the Urgotul(®) Silver group was established based on the difference between them (6·84% ± 56·3%, 95% confidence interval -6·56 to 20·2) and the pre-defined non inferiority margin (-15%). Composite wound healing analysis showed that the AQUACEL(®) Ag group had statistically higher percentage of subjects with better wound progression (66·9% versus 51·9%, P = 0·0108). In general, both dressings were effective at promoting healing of venous ulcers.

Which dressing do donor site wounds need?: study protocol for a randomized controlled trial

Background

Donor site wounds after split-skin grafting are rather 'standard' wounds. At present, lots of dressings and topical agents for donor site wounds are commercially available. This causes large variation in the local care of these wounds, while the optimum 'standard' dressing for local wound care is unclear. This protocol describes a trial in which we investigate the effectiveness of various treatment options for these donor site wounds.

Methods

A 14-center, six-armed randomized clinical trial is being carried out in the Netherlands. An a-priori power analysis and an anticipated dropout rate of 15% indicates that 50 patients per group are necessary, totaling 300 patients, to be able to detect a 25% quicker mean time to complete wound healing. Randomization has been computerized to ensure allocation concealment. Adult patients who need a split-skin grafting operation for any reason, leaving a donor site wound of at least 10 cm² are included and receive one of the following dressings: hydrocolloid, alginate, film, hydrofiber, silicone dressing, or paraffin gauze. No combinations of products from other intervention groups in this trial are allowed. Optimum application and changes of these dressings are pursued according to the protocol as supplied by the dressing manufacturers. Primary outcomes are days to complete wound healing and pain (using a Visual Analogue Scale). Secondary outcomes are adverse effects, scarring, patient satisfaction, and costs. Outcome assessors unaware of the treatment allocation will assess whether or not an outcome has occurred. Results will be analyzed according to the intention to treat principle. The first patient was randomized October 1, 2009.

Discussion

This study will provide comprehensive data on the effectiveness of different treatment options for donor site wounds. The dressing(s) that will prevail in effectiveness, satisfaction and costs will be promoted among clinicians dealing with such patients. Thus, we aim to contribute a well-designed trial, relevant to all clinicians involved in the care for donor site wounds, which will help enhance uniformity and quality of care for these patients.

Trial registration

http://www.trialregister.nl, NTR1849. Date registered: June 9, 2009

Ghee and honey dressing for infected wounds

Ghee and honey has been advocated and used as dressing for infected wounds by Sushruta (600BC) and since 1991 in four Mumbai Hospitals. The gratifying results observed with the dressing have prompted this study which aims to establish its efficacy in five recalcitrant subset of chronic infected wounds over a three year period 2006-2009. A standardized ghee and honey dressing was used to treat: a) Eight cases of fungating malignant lesions. b) Thirteen chronic venous ulcers. c) Twenty nine diabetic foot ulcers. d) Eleven of infected ventral hernia mesh hernioplasty. e) Eleven patient with post-cesarean wound dehiscence. The dressing markedly reduced the foul odour and discharge, significantly improving the quality of life in malignant lesions. The results were equivocal in cases of venous ulcers. The results were uniformly good in the last three groups. In view of our results, as also result of innumerable Randomized Control Trials (RCTs) reported on honey dressing for infected wounds, there is substantial evidence that ghee and honey dressing has at least comparable results to other modes of treatment. The easy availability and low cost of this treatment makes it significant in developing countries. Further trials seem warranted.

Negative-pressure wound therapy: systematic review of randomized controlled trials

BACKGROUND

In negative-pressure wound therapy (NPWT), a wound is covered with an airtight dressing, and negative pressure is applied. This is thought to promote healing. We evaluated NPWT with an updated, systematic review of the literature.

METHODS

We systematically searched the PubMed and Cochrane Library databases for randomized, controlled trials (RCTs) of NPWT for the treatment of acute or chronic wounds. The primary outcome was complete wound closure.

RESULTS

We found reports of 9 RCTs in addition to the 12 covered by earlier IQWiG reviews of this topic. Five of the 9 new trials involved NPWT systems that are not on the market. The frequency of complete wound closure is stated in only 5 of the 9 new reports; a statistically significant effect in favor of NPWT was found in only two trials.The results of 8 of the 9 new trials are hard to interpret, both because of apparent bias and because diverse types of wounds were treated.

CONCLUSION

Although there may be a positive effect of NPWT, we did not find clear evidence that wounds heal any better or worse with NPWT than with conventional treatment. Good RCTs are still needed to evaluate NPWT.