Infection in Venous Leg Ulcers: Considerations for Optimal Management in the Elderly. Drugs Aging. 2016;33:87-96. [PMID: 26833351 DOI: 10.1007/s40266-016-0343-8]

Associations Among Wound-Related Factors Including Biofilm, Wound-Related Symptoms and Systemic Inflammation in Older Adults with Chronic Venous Leg Ulcers

Objective: The purposes of this observational prospective study were to (1) characterize the wound-related factors (wound area, the presence of biofilm, and total bacteria), wound-related symptoms (fatigue, pain, exudate, itching, and edema or swelling), and systemic inflammation (level of serum C-reactive protein [CRP]), and (2) explore associations between wound-related factors, wound-related symptoms, and systemic inflammation in older individuals with chronic venous leg ulcers (CVLUs) over 8 weeks of wound treatment. Approach: A total of 117 participants who received standardized care (weekly sharp debridement) for chronic venous ulcer were enrolled. We collected clinical data every 2 weeks during the 8 weeks of the study period or until the wound was healed (if healed before 8 weeks). Associations among variables were estimated using a Bayesian approach applied to general linear mixed models. Results: Based on Bayes factor (BF) value, there was extremely strong evidence for the association of biofilm with mean total bacteria (BF >1,000). There was moderate evidence of a direct association between biofilm presence and levels of CRP (BF 4.3) and moderate evidence of direct associations between biofilm and wound-related symptoms, pain and exudate (BF 5.12, 8.49, respectively). Innovation: Wound-related symptoms and the level of systemic CRP were associated with biofilm among patients who were receiving weekly sharp debridement. Symptom severity associated with CVLUs requires assessment and management of wound-related factors and levels of inflammation in addition to symptom assessment. Conclusion: This study is the first to examine associations among biofilm, as wound-related factors, systemic inflammation, wound-related symptoms, and wound healing in clinical settings. Symptom severity, level of systemic CRP, and wound-related factors should be considered as well as assessment of biofilm in CVLU in older individuals with CVLU.

A prospective study on the efficacy of sequential treatment of technology Lipido-Colloid Impregnated with Silver and Technology Lipido-Colloid Nano-Oligosaccharide Factor in the management of venous leg ulcers

Background and Aims

Venous leg ulcers (VLUs) are associated with significant morbidity and poor quality of life (QOL). Compression therapy and wound dressing are the mainstay treatment options. Technology Lipido-Colloid Impregnated with Silver (TLC-Ag) reduces bacterial load and Technology Lipido-Colloid Nano-Oligosaccharide Factor (TLC-NOSF) reduces elevated matrix metalloproteinases and improve wound healing. However, evidence is scarce on the role of sequential therapy. This study aims to evaluate if sequential treatment with TLC-Ag and TLC-NOSF improves VLU wound healing and QOL.

Methods

This is a prospective cohort study from May 2020 to October 2021 on patients with VLUs who received sequential therapy, consisting of 2 weeks of TLC-Ag followed by two-layer compression bandage (2LB) with TLC-NOSF until complete wound healing. Participants were followed-up with weekly dressing changes. Our primary outcomes were wound area reduction (WAR) and Pressure Ulcer Scale of Healing (PUSH) score. Our secondary outcomes were QOL measures.

Results

There were 28 patients with 57.1% males (n = 16) with a mean age of 65.3 years. Mean duration of VLU was 13.9 ± 11.7 weeks before the initiation of sequential therapy. Mean baseline wound area was 8.44 cm2. Median time to wound healing was 10 weeks. 57.1% of patients achieved complete wound closure at 3 months. There was significant WAR after 1 month (mean area 8.44-5.81 cm2, 31.2% decrease) and after 3 months (mean area 8.44-2.53 cm2, 70.0% decrease). Mean monthly WAR was 28.9%. PUSH score also decreased at 1 month (16.5% decrease, p < 0.001) and 3 months (63.3% decrease, p < 0.001) marks following the sequential therapy. EuroQol Visual Analog Scale (EQ-VAS) improved following sequential therapy (baseline: 69.0 ± 15.0, week 13: 80.2 ± 13.2, p < 0.001).

Conclusion

Sequential therapy with TLC-Ag followed by TLC-NOSF and 2LB is feasible, with good wound healing and improvement in QOL of patients with VLUs.

Do Commonly Used Antimicrobial Topicals Facilitate Venous Leg Ulcer Healing?

OBJECTIVE

To survey which topical antimicrobials are most helpful in treating venous leg ulcers (VLUs).

DATA SOURCES

In this narrative review, the authors searched the databases of Google Scholar, Cochrane Library, and Wiley Online Library.

STUDY SELECTION

Studies were eligible for inclusion if they studied the effects of antimicrobial agents on chronic VLU healing and were published after 1985. Exceptions to this were in vitro studies of manuka honey and Dakin solution (Century Pharmaceuticals). Search terms included "venous leg ulcer", "nonhealing ulcer", "antimicrobial resistance", and "biofilms".

DATA EXTRACTION

Data extracted included design, setting, descriptions of intervention and control groups, outcomes, data collection tools, and potential harms.

DATA SYNTHESIS

A total of 19 articles encompassing 26 studies/trials met the inclusion criteria. Of the 26 studies, 17 were randomized controlled trials; the remaining 9 were a mix of lower-quality case series and comparative, nonrandomized, or retrospective studies.

CONCLUSION

Studies suggest that VLUs can be treated with multiple different topical antimicrobials. Depending on the extent of chronicity and bacterial colonization, some antimicrobials may be better suited than others.

Topical Hyperbaric Oxygen Therapy Versus Local Ozone Therapy in Healing of Venous Leg Ulcers

BACKGROUND

the treatment of venous leg ulcers still poses a difficult interdisciplinary medical problem. The aim of this study was to compare the therapeutic efficacy of local hyperbaric oxygen therapy with local ozone therapy in the treatment of venous leg ulcers.

MATERIALS

this study included 114 patients; 60 males (52.63%) and 54 females (47.36%) of ages ranging between 39 and 88 years (mean age: 68.9 ± 9.8 years) with venous leg ulcers, who underwent topical hyperbaric oxygen therapy (group I) and local ozone therapy (group II). In each of the study groups, the patients underwent 30 therapeutic procedures lasting 30 min each. The progress in wound healing was evaluated by computerized planimetry, and the intensity of pain was assessed with the use of the Visual Analogue Scale (VAS).

RESULTS

in both groups of treated patients, a statistically significant (p = 0.000001) reduction in the area of treated ulcers was achieved. In group I, the wound area decreased by an average of 69.67 ± 22.52%, from 7.55 ± 2.99 cm² to 2.78 ± 2.43 cm², and in group II, by an average of 41.33 ± 21.31%, from 7.36 ± 2.82 cm² to 4.62 ± 2.76 cm². In both groups of patients, a statistically significant (p = 0.000001) reduction in the intensity of pain ailments was observed: in group I, by an average of 0.55 ± 0.54 points, and in group II, by an average of 2.33 ± 0.82 points on the VAS scale.

CONCLUSIONS

local hyperbaric oxygen therapy and local ozone therapy cause a statistically significant reduction in the surface area of venous leg ulcers as well as in the intensity of pain. Better results were observed after the application of local hyperbaric oxygen therapy procedures.

Cost-effectiveness of Compression Therapy With Early Endovenous Ablation in Venous Ulceration for a Medicare Population

Importance

Venous leg ulcers (VLU) are the most common cause of lower extremity ulceration that commonly occur among older individuals and are characterized by a slow healing trajectory and frequent recurrence; in the United States, VLUs affect more than 600 000 people per year with an estimated cost of $3.5 billion. Clinical trial data show that early intervention with endovenous ablation substantially improves the healing rate and reduces recurrence among patients with VLUs, but there is a need to assess the cost-effectiveness of early endovenous ablation in the US context.

Objectives

To evaluate the cost-effectiveness of early endovenous ablation of superficial venous reflux in patients with VLU from the US Medicare perspective.

Design, Setting, and Participants

This economic evaluation used a Markov model to simulate the disease progression of VLU for patients receiving compression therapy with early vs deferred ablation over 3 years. The simulated cohort included patients with VLU aged 65 years and older who had clinical characteristics similar to those in the randomized Early Venous Reflux Ablation trial in the United Kingdom. Data were analyzed from September 2021 to June 2022.

Main Outcomes and Measures

Direct medical costs, quality-adjusted life years (QALYs), and the incremental monetary benefits at a willingness-to-pay threshold of $100 000/QALY. Univariate and probabilistic sensitivity analyses were performed to test uncertainty of model results.

Results

This model used a simulated cohort of patients with VLU aged 65 years and older enrolled in Medicare. Early ablation dominated, with a lower per-patient cost of $12 527 and an increase of 2.011 QALYs, whereas compression therapy with deferred ablation yielded a per-patient cost of $15 208 and 1.985 QALYs gained. At a $100 000/QALY cost-effectiveness threshold, the incremental net monetary benefit was $5226 per patient in favor of early ablation. Probability of healing, followed by the probability of recurrence, was the parameter with greatest impact on model uncertainty. The probabilistic sensitivity analysis showed that early ablation was cost-effective in 59.2% of simulations at the $100 000/QALY threshold.

Conclusions and Relevance

In this economic evaluation of compression therapy with early endovenous ablation, early intervention was dominant, as it was cost saving and generated greater QALYs over 3 years from the US Medicare perspective. Payers should prioritize coverage for early ablation to prevent VLU complications rather than treat a costly outcome that also reduces patient well-being.

A desiccation compound as a biofilm- and necrosis-removing agent: a case series

Objective:

A new compound, Debrichem (DEBx Medical BV, the Netherlands), a topical desiccation agent (TDA), is an active gel that contains an acidic species with a potent hygroscopic action. When in contact with microorganisms and necrosis, rapid desiccation and carbonisation of the proteins in these microorganisms, as well as of the extracellular matrix of biofilms and necrosis, occurs. The resulting ‘precipitate’ rapidly dislodges from the wound bed, resulting in a clean wound which granulates, which is a prerequisite for healing by secondary intention.

Method:

In a retrospective study, a series of mostly large and hard-to-heal lesions of different aetiologies were treated with a one-time application of the TDA, followed by weekly dressing changes.

Results:

Of the total of 54 lesions included in this case series, 22 were diagnosed as venous leg ulcers (VLUs), 20 as diabetic foot ulcers (DFUs), nine as post-traumatic, hard-to-heal lesions, two as vascular ulcers and one as an ischaemic ulcer. All of the VLUs, 75% of the DFUs and all of the other lesions reached complete granulation.

Conclusion:

The use of a TDA may contribute to the consistent, fast and easy removal of both biofilms and necrosis, and hence to wound healing.

Homocysteine and Inflammatory Cytokines in the Clinical Assessment of Infection in Venous Leg Ulcers

Inflammation and biofilm-associated infection are common in chronic venous leg ulcers (VU), causing deep pain and delayed healing. Albeit important, clinical markers and laboratory parameters for identifying and monitoring persistent VU infections are limited. This study analyzed 101 patients with infected (IVU) and noninfected VUs (NVU). Clinical data were collected in both groups. The serum homocysteine (Hcys) and inflammatory cytokines from the wound fluid were measured. In addition, microbial identification, antibiotic susceptibility, and biofilm production were examined. IVU were 56 (55.4%) while NVU were 45 (44.5%). IVUs showed a significant increase in the wound's size and depth compared to NVUs. In addition, significantly higher levels of interleukin (IL)-6, IL-10, IL17A, and tumor necrosis factor-alpha (TNF-α) were found in patients with IVUs compared to those with NVUs. Notably, hyperhomocysteinemia (HHcy) was significantly more common in patients with IVUs than NVUs. A total of 89 different pathogens were identified from 56 IVUs. Gram-negative bacteria were 51.7%, while the Gram-positives were 48.3%. At the species level, Staphylococcus aureus was the most common isolate (43.8%), followed by Pseudomonas aeruginosa (18.0%). Multidrug-resistant organisms (MDROs) accounted for 25.8% of the total isolates. Strong biofilm producers (SBPs) (70.8%) were significantly more abundant than weak biofilm producers (WBP) (29.2%) in IVUs. SBPs were present in 97.7% of the IVUs as single or multispecies infections. Specifically, SBPs were 94.9% for S. aureus, 87.5% for P. aeruginosa, and 28.6% for Escherichia coli. In IVU, the tissue microenvironment and biofilm production can support chronic microbial persistence and a most severe clinical outcome even in the presence of an intense immune response, as shown by the high levels of inflammatory molecules. The measurement of local cytokines in combination with systemic homocysteine may offer a novel set of biomarkers for the clinical assessment of IVUs caused by biofilm-producing bacteria.

Challenges and innovations in treating chronic and acute wound infections: from basic science to clinical practice

Acute and chronic wound infection has become a major worldwide healthcare burden leading to significantly high morbidity and mortality. The underlying mechanism of infections has been widely investigated by scientist, while standard wound management is routinely been used in general practice. However, strategies for the diagnosis and treatment of wound infections remain a great challenge due to the occurrence of biofilm colonization, delayed healing and drug resistance. In the present review, we summarize the common microorganisms found in acute and chronic wound infections and discuss the challenges from the aspects of clinical diagnosis, non-surgical methods and surgical methods. Moreover, we highlight emerging innovations in the development of antimicrobial peptides, phages, controlled drug delivery, wound dressing materials and herbal medicine, and find that sensitive diagnostics, combined treatment and skin microbiome regulation could be future directions in the treatment of wound infection.

Therapeutic strategies for chronic wound infection

Chronic wounds have always been a tough fight in clinical practice, which can not only make patients suffer from pain physically and mentally but also impose a heavy burden on the society. More than one factor is relevant to each step of the development of chronic wounds. Along with the in-depth research, we have realized that figuring out the pathophysiological mechanism of chronic wounds is the foundation of treatment, while wound infection is the key point concerned. The cause of infection should be identified and prevented promptly once diagnosed. This paper mainly describes the mechanism, diagnosis and therapeutic strategies of chronic wound infection, and will put an emphasis on the principle of debridement.

Decreased mobility, lack of social support, haemosiderosis and use of antidepressant medications may predict recurrent venous leg ulcers within 12 months of healing: A prospective longitudinal study

AIM

To identify clinical, medical and psychosocial predictors of venous leg ulcer recurrence within 12 months of healing.

METHODS

A multi-site study was conducted in Australia in community and hospital outpatient settings. Adults with venous leg ulcers were recruited within 4 weeks of healing and data were collected on preventative treatments and health, medical, clinical and psychosocial factors. Follow-up data on recurrences were collected every 3 months until ulcer recurrence, or until 12 months after healing pending which occurred first. Factors associated with time to recurrence were analysed using a Cox proportional hazards regression model.

DESIGN

Secondary data analysis of a multi-site, prospective longitudinal study to validate a risk assessment tool for recurrence.

RESULTS

A sample of 143 participants was recruited (51% male, M^age = 73 years, SD 13.6). Almost half (49.6%) had an ulcer recurrence within 12 months, with a mean time to ulcer recurrence of 37 weeks (SE 1.63, 95% CI 33.7-40.1). Factors measured at the time of healing that were significant independent predictors of recurrence were: prescribed antidepressant medications (p = .035), presence of haemosiderosis (p = .006), decreased mobility (longer sitting times) (p = .007) and lower social support scale scores (p = .002). Participants who wore compression systems providing 20 mmHg or higher for at least 5 days/week were less likely to recur, although not reaching statistical significance (p = .06).

CONCLUSION

Results provide evidence that antidepressant medications, haemosiderosis, decreased mobility and lack of social support are risk factors associated with ulcer recurrence; therefore, these variables are modifiable and could guide early intervention.

Wound infection: A review of qualitative and quantitative assessment modalities

Surgical site infections (SSI) and chronic wounds represent a burden to patients and the health care system. One in 24 surgical patients will develop an SSI, making SSI the most common nosocomial infection in the USA. Early detection and monitoring of wound infection are critical for timely healing and return to normal function. However, the mainstay of wound infection diagnostic entails subjective clinical examination and semi-quantitative, invasive microbiological tests. In this review, we present current wound infection assessment modalities in the clinical and translational fields. There is a need for a point-of-care assessment tool that provides fast, accurate, and quantitative information on wound status, with minimal to no contact with the patient. In the next ten years, the evolution of wound diagnostic tools reported here may allow medical providers to optimize patient care while minimizing patient discomfort.

Complete healing and short-term treatment by Argania honey dressing in a venous leg ulcer: case report

Background:

Recent advances in care aware that inadequate management of the healing process in wounds and the development of bacterial infections leads to increase morbidity. Health professionals have progressively recognized the value of choosing suitable dressings to manage wounds particularly in developing countries. Honey has been used for thousands of years as a wound dressing and considered as biologic treatment due to its multiple bioactivities related to healing process.

Objective:

The aim of this case report is to demonstrate that Argania Honey dressing improve the healing process in a venous leg ulcer.

Method:

Pure raw Argania honey (Argania spinosa, endemic tree in southwestern of Morocco) with no additives, pasteurization, or manipulation was used and provided from local beekeepers. A mechanical debridement process was achieved previously to the application of honey dressings to a venous leg ulcer of a 67-year-old woman affected by type II diabetes for 11 years.

Results :

The Argania honey dressing accompanied by mechanical debridement process demonstrated a rapid recovery and complete healing of the wound for 12 weeks approximately (79 days).

Conclusion:

This Moroccan honey (Argania) experienced for the first time in venous leg ulcer management may represent a good alternative to treat other types of wounds. Further investigations by using Argania honey dressing are required to explain its effect and the mechanisms involved in the improvement of healing process.

Estrategias de protección antimicrobiana en el cuidado de heridas: evidencia para el uso de apósitos recubiertos con DACC

BACKGROUND

Antimicrobial resistance (AMR) is one of the most serious health threats globally. The development of new antimicrobials is not keeping pace with the evolution of resistant microorganisms, and novel ways of tackling this problem are required. One of such initiatives has been the development of antimicrobial stewardship programmes (AMS). The use of wound dressings that employ a physical sequestration and retention approach to reduce bacterial burden offers a novel approach to support AMS. Bacterial-binding by dressings and their physical removal can minimise their damage and prevent the release of harmful endotoxins.

OBJECTIVE

To highlight AMS to promote the correct use of antimicrobials and to investigate how dialkylcarbamyl chloride (DACC)-coated dressings can support AMS.

METHOD

MEDLINE, Cochrane Database of Systematic Reviews, and Google Scholar were searched to identify articles relating to AMS, and the use of wound dressings in the prevention and treatment of wound infections. The evidence supporting alternative wound dressings that can reduce bioburden and prevent wound infection in a way that does not kill or damage the microorganisms were reviewed.

RESULTS

The evidence demonstrated that using bacterial-binding wound dressings that act in a physical manner (eg, DACC-coated dressings) to preventing infection in both acute and hard-to-heal wounds does not exacerbate AMR and supports AMS.

CONCLUSION

Some wound dressings work via a mechanism that promotes the binding and physical sequestration and removal of intact microorganisms from the wound bed (eg, a wound dressing that uses DACC technology to prevent/reduce infection). They provide a valuable tool that aligns with the requirements of AMS by effectively reducing wound bioburden without inducing/selecting for resistant bacteria.

Nanocarrier-Mediated Topical Insulin Delivery for Wound Healing

Wound care has been clinically demanding due to inefficacious treatment that represents an economic burden for healthcare systems. In Europe, approximately 7 million people are diagnosed with untreated wounds, leading to a cost between 6.000€ and 10.000€ per patient/year. In the United States of America, 1.5 million people over 65 years old suffer from chronic wounds. A promising therapeutic strategy is the use of exogenous growth factors because they are decreased at the wound site, limiting the recovery of the skin. Insulin is one of the cheapest growth factors in the market able to accelerate the re-epithelialization and stimulate angiogenesis and cell migration. However, the effectiveness of topical insulin in wound healing is hampered by the proteases in the wound bed. The encapsulation into nanoparticles improves its stability in the wound, providing adhesion to the mucosal surface and allowing its sustained release. The aim of this review is to perform a standing point about a promising strategy to treat different types of wounds by the topical delivery of insulin-loaded nanocarriers.

Safety of Silk-elastin Sponges in Patients with Chronic Skin Ulcers: A Phase I/II, Single-center, Open-label, Single-arm Clinical Trial

Background:

Although traditional wound dressings such as collagen scaffolds promote granulation tissue formation, the efficacy of these dressings in chronic wounds is limited because of high susceptibility to bacterial growth. Biomaterials that can be applied to chronic wounds should have an anti-bacterial function. We previously reported that administering a silk-elastin solution that forms moisturizing hydrogels to wound surfaces of diabetic mice reduced bacterial growth and promoted granulation tissue formation compared with control or carboxymethyl cellulose hydrogels. We hypothesized that silk-elastin promotes wound healing in human chronic wounds by suppressing bacterial growth.

Methods:

An open-label, clinical case series was conducted with a prospective, single-arm design at Kyoto University Hospital in Kyoto, Japan. In this study, 6 patients with chronic skin ulcers of any origin (2 < ulcer area (cm²) < 25) on their lower extremities were included; patients with critical ischemia were excluded. Silk-elastin sponges were applied and covered with a polyurethane film without changing the dressing for 14 days. Inflammation triggered treatment discontinuation due to fear of infection. The primary study endpoint was adverse events, including inflammation and infection.

Results:

Poor hydrogel formation, possibly due to continuous exudation, was observed. No serious adverse events were noted. Two patients discontinued treatment on day 6 and day 7, respectively, due to inflammation, but they were not infected. The other 4 patients completed the 14-day silk-elastin sponge treatment without infection.

Conclusion:

Silk-elastin sponge is safe for chronic skin ulcers, and its ability to promote wound healing should be determined by confirmatory clinical trials.

Virulence and Drug-Resistance of Staphylococcus aureus Strains Isolated from Venous Ulcers in Polish Patients

Infected chronic venous ulcers (VUs) represent a major health problem. We analysed the aerobic microbiome in the VUs, the virulence, and drug-resistance of Staphylococcus aureus (SA) strains. Swabs from 143 outpatients and inpatients Polish subjects were collected. SA strains were tested for drug sensitivity using a phenotyping method and for methicillin-resistant SA (MRSA) and macrolide-lincosamide-streptogramin B (MLSB) resistance using PCR. We analysed virulence genes, the genetic similarity of strains, and performed Staphylococcal cassette chromosome mec typing and Staphylococcal protein A typing. SA was isolated as a single one in 34.9% of cases, 31.5% paired with another pathogen, and 33.6% S. aureus combined with at least two other strains. The majority of SA isolates (68.5%) possessed the virulence lukE gene. Drug resistance was significantly common in hospitalised than in ambulatory patients (OR 3.8; 95%CI 1.8–7.91). MLSB (altogether in 19.6% isolates) were observed mostly in non-hospitalised patients (OR 9.1; 95%CI 1.17–71.02), while MRSA was detected in 11.9% of strains equally. Hospitalisation and patient’s age group (aged > 78.0 or < 54.5 years) were significant predictors of the multi-drug resistant SA (MDR-SA). Over 30% of the infected VUs were associated with multi-species biofilms and presence of potentially highly pathogenic microorganisms. Elderly hospitalised patients with chronic venous ulcers are prone to be infected with a MDR-SA.

Antimicrobial stewardship strategies in wound care: evidence to support the use of dialkylcarbamoyl chloride (DACC)- coated wound dressings

BACKGROUND

Traditionally, infections are treated with antimicrobials (for example, antibiotics, antiseptics, etc), but antimicrobial resistance (AMR) has become one of the most serious health threats of the 21st century (before the emergence of COVID-19). Wounds can be a source of infection by allowing unconstrained entry of microorganisms into the body, including antimicrobial-resistant bacteria. The development of new antimicrobials (particularly antibiotics) is not keeping pace with the evolution of resistant microorganisms and novel ways of addressing this problem are urgently required. One such initiative has been the development of antimicrobial stewardship (AMS) programmes, which educate healthcare workers, and control the prescribing and targeting of antimicrobials to reduce the likelihood of AMR. Of great importance has been the European Wound Management Association (EWMA) in supporting AMS by providing practical recommendations for optimising antimicrobial therapy for the treatment of wound infection. The use of wound dressings that use a physical sequestration and retention approach rather than antimicrobial agents to reduce bacterial burden offers a novel approach that supports AMS. Bacterial-binding by dressings and their physical removal, rather than active killing, minimises their damage and hence prevents the release of damaging endotoxins.

AIM

Our objective is to highlight AMS for the promotion of the judicious use of antimicrobials and to investigate how dialkylcarbamoyl chloride (DACC)-coated dressings can support AMS goals.

METHOD

MEDLINE, Cochrane Database of Systematic Reviews, and Google Scholar were searched to identify published articles describing data relating to AMS, and the use of a variety of wound dressings in the prevention and/or treatment of wound infections. The evidence supporting alternative wound dressings that can reduce bioburden and prevent and/or treat wound infection in a manner that does not kill or damage the microorganisms (for example, by actively binding and removing intact microorganisms from wounds) were then narratively reviewed.

RESULTS

The evidence reviewed here demonstrates that using bacterial-binding wound dressings that act in a physical manner (for example, DACC-coated dressings) as an alternative approach to preventing and/or treating infection in both acute and hard-to-heal wounds does not exacerbate AMR and supports AMS.

CONCLUSION

Some wound dressings work via a mechanism that promotes the binding and physical uptake, sequestration and removal of intact microorganisms from the wound bed (for example, a wound dressing that uses DACC technology to successfully prevent/reduce infection). They provide a valuable tool that aligns with the requirements of AMS (for example, reducing the use of antimicrobials in wound treatment regimens) by effectively reducing wound bioburden without inducing/selecting for resistant bacteria.

Strategies and challenges in the treatment of chronic venous leg ulcers

Evaluating patients with chronic venous leg ulcers (CVLUs) is essential to find the underlying etiology. The basic tenets in managing CVLUs are to remove the etiological causes, to address systemic and metabolic conditions, to examine the ulcers and artery pulses, and to control wound infection with debridement and eliminating excessive pressure on the wound. The first-line treatments of CVLUs remain wound care, debridement, bed rest with leg elevation, and compression. Evidence to support the efficacy of silver-based dressings in healing CVLUs is unavailable. Hydrogen peroxide is harmful to the growth of granulation tissue in the wound. Surgery options include a high ligation with or without stripping or ablation of the GSVs depending on venous reflux or insufficiency. Yet, not all CVLUs are candidates for surgical treatment because of comorbidities. When standard care of wound for 4 wk failed to heal CVLUs effectively, use of advanced wound care should be considered based on the available evidence. Negative pressure wound therapy facilitates granulation tissue development, thereby helping closure of CVLUs. Autologous split-thickness skin grafting is still the gold standard approach to close huge CVLUs. Hair punch graft appears to have a better result than traditional hairless punch graft for CVLUs. Application of adipose tissue or placenta-derived mesenchymal stem cells is a promising therapy for wound healing. Autologous platelet-rich plasma provides an alternative strategy for surgery for safe and natural healing of the ulcer. The confirmative efficacy of current advanced ulcer therapies needs more robust evidence.

Strategies and challenges in the treatment of chronic venous leg ulcers

Evaluating patients with chronic venous leg ulcers (CVLUs) is essential to find the underlying etiology. The basic tenets in managing CVLUs are to remove the etiological causes, to address systemic and metabolic conditions, to examine the ulcers and artery pulses, and to control wound infection with debridement and eliminating excessive pressure on the wound. The first-line treatments of CVLUs remain wound care, debridement, bed rest with leg elevation, and compression. Evidence to support the efficacy of silver-based dressings in healing CVLUs is unavailable. Hydrogen peroxide is harmful to the growth of granulation tissue in the wound. Surgery options include a high ligation with or without stripping or ablation of the GSVs depending on venous reflux or insufficiency. Yet, not all CVLUs are candidates for surgical treatment because of comorbidities. When standard care of wound for 4 wk failed to heal CVLUs effectively, use of advanced wound care should be considered based on the available evidence. Negative pressure wound therapy facilitates granulation tissue development, thereby helping closure of CVLUs. Autologous split-thickness skin grafting is still the gold standard approach to close huge CVLUs. Hair punch graft appears to have a better result than traditional hairless punch graft for CVLUs. Application of adipose tissue or placenta-derived mesenchymal stem cells is a promising therapy for wound healing. Autologous platelet-rich plasma provides an alternative strategy for surgery for safe and natural healing of the ulcer. The confirmative efficacy of current advanced ulcer therapies needs more robust evidence.

Venous leg ulcer healing time is increased with each subsequent bacterial strain identified in the ulcer. A retrospective study

OBJECTIVE

The aim of the study was to analyze bacterial flora in venous leg ulcers, empiric and targeted antibiotic therapy, and factors influencing healing time.

MATERIALS AND METHODS

Data from 30 patients with venous leg ulcers were retrospectively analyzed. Collected data included: sociodemographic data, wounds information, number of comorbidities, results of the microbiological examination, and empiric and targeted antibiotic therapy. To compare the empiric and targeted treatment in terms of their compatibility, the group of patients was divided into the four subgroups: NEA (no empiric antibiotics), NA (no antibiotics), ETA+ (compatibility of empiric and targeted antibiotic), ETA- (no compatibility of empiric and targeted antibiotic).

RESULTS

The average ulcer healing time was 163.4 ± 97.1 (range 51.0 to 426.0) days and increased by 28 days with each additional bacterial strain in the ulcer (p = 0.041). Healing time did not differ between the four groups. Staphylococcus aureus and Pseudomonas aeruginosa were the most frequent bacteria. Amoxicillinium/acidum clavulanicum was the most common empirical antibiotic and amoxicillinium/acidum clavulanicum, and levofloxacinum was the most common targeted antibiotic.

CONCLUSIONS

Venous leg ulcer healing time was prolonged with each subsequent bacterial strain in the ulcer, and it was independent from systemic antibiotic therapy.

Effectiveness of a hydrophobic dressing for microorganisms' colonization of vascular ulcers: Protocol for a randomized controlled trial (CUCO-UV Study)

AIM

To determine the effectiveness of a hydrophobic dressing (Cutimed Sorbact® ) against a silver dressing (Aquacel® Ag Extra) in the level of colonization of chronic venous leg ulcers. The secondary endpoints are health-related quality of life, level of pain, and time to complete healing.

DESIGN

Open randomized controlled trial, with blinded endpoint.

METHODS

Patients with chronic venous leg ulcers with signs of critical colonization will be randomized in a concealed sequence using computer software to receive one of the alternative dressings. A total of 204 participants recruited in Primary Health Care and nursing homes will be necessary to assure statistical power. Measures will include sociodemographic variables, wound-related variables (area, exudate, and time to healing), level of pain, adverse effects, and health-related quality of life. Smear samples will be collected from the ulcers and will be subject to DNA-typing technique through polymerase chain reaction to obtain the level of colony-forming units. Measures will be collected at baseline, 4, 8, and 12 weeks.

DISCUSSION

Elevated levels of microorganisms prevent wound healing and favour its chronification. The main target when colonization is present is to reduce the bacterial load to levels that promote immune system mobilization. Hydrophobic dressings prevent the formation of biofilm in the wound by means of physical effect, so that the possibility of antimicrobial resistance is significantly reduced.

IMPACT

Current evidence about the effectiveness of dressings to minimize venous leg ulcers colonization is very limited. Previous studies have important methodological flaws. This study will permit to obtain the effectiveness of hydrophobic dressings against silver dressings with a robust design based on conditions of routine clinical practice in Primary Health Care and nursing homes.

In-vivo evaluation of the effect of cyanoacrylate on prosthetic vascular graft infection – does cyanoacrylate increase the severity of infection?

Summary. Background: Prosthetic vascular graft infection (PVGI) is a complication with high mortality. Cyanoacrylate (CA) is an adhesive which has been used in a number of surgical procedures. In this in-vivo study, we aimed to evaluate the relationship between PVGI and CA. Materials and methods: Thirty-two rats were equally divided into four groups. Pouch was formed on back of rats until deep fascia. In group 1, vascular graft with polyethyleneterephthalate (PET) was placed into pouch. In group 2, MRSA strain with a density of 1 ml 0.5 MacFarland was injected into pouch. In group 3, 1 cm 2 vascular graft with PET piece was placed into pouch and MRSA strain with a density of 1 ml 0.5 MacFarland was injected. In group 4, 1 cm 2 vascular graft with PET piece impregnated with N-butyl cyanoacrylate-based adhesive was placed and MRSA strain with a density of 1 ml 0.5 MacFarland was injected. All rats were scarified in 96th hour, culture samples were taken where intervention was performed and were evaluated microbiologically. Bacteria reproducing in each group were numerically evaluated based on colony-forming unit (CFU/ml) and compared by taking their average. Results: MRSA reproduction of 0 CFU/ml in group 1, of 1410 CFU/ml in group 2, of 180 200 CFU/ml in group 3 and of 625 300 CFU/ml in group 4 was present. A statistically significant difference was present between group 1 and group 4 (p < 0.01), between group 2 and group 4 (p < 0.01), between group 3 and group 4 (p < 0.05). In terms of reproduction, no statistically significant difference was found in group 1, group 2, group 3 in themselves. Conclusions: We observed that the rate of infection increased in the cyanoacyrylate group where cyanoacrylate was used. We think that surgeon should be more careful in using CA in vascular surgery.

The effect of natural matrix biopolymer membrane on hard-to-heal venous leg ulcers: a pilot randomised clinical trial

OBJECTIVE

The aim of this study was to evaluate the therapeutic effects of natural matrix biopolymer membrane (NMBM) in the treatment of venous leg ulcers (VLUs).

METHOD

Patients exhibiting one or more VLU were assigned to a test group receiving NMBM or to a control group receiving conventional treatment. Patients exhibiting venous insufficiency-related ulcers within 0.1-170cm² were included. Efficacy was assessed based on ulcer size and visual analogue scale (VAS) pain scores at baseline and at weeks one, two and four. Ulcer size and pain were compared between groups using a two-way ANOVA.

RESULTS

In this study, 25 patients with 32 VLUs (NMBM group: 14 patients with 17 ulcers; control group: 11 patients with 15 ulcers) were included in the final analysis. At four weeks after baseline measurements, the mean percentage change in VLU area of patients in the NMBM group was 61.6% (95% CI: 40.3-82.9) compared with 84.1% (95% CI: 56.5-111.7) for control group patients. Additionally, the mean percentage change in VLU volume of NMBM group patients was 51.2% (95% CI: 31.8-70.6) compared with 84.0% (95% CI: 57.0-121.0) for control group patients. The NMBM group patients exhibited a mean decrease of 0.38 (95% CI: -0.85-1.61) in VAS pain score over four weeks, compared with a mean decrease of 0.13 (95% CI: -1.32-1.58) for control group patients. No significant differences in VLU area (p=0.210), volume (p=0.122) or VAS pain score (p=0.460) were shown between groups.

CONCLUSION

NMBM was found to be as effective and safe as the control group treatments. This pilot study suggests NMBM can be used safely to promote ulcer healing.

Alginate films augmented with chlorhexidine hexametaphosphate particles provide sustained antimicrobial properties for application in wound care

All chronic wounds are colonised by bacteria; for some, colonisation progresses to become infection. Alginate wound dressings are used for highly exuding chronic wounds as they are very absorbent, taking up large quantities of exudate while maintaining a moist wound bed to support healing. Some alginate dressings are doped with antimicrobials, most commonly silver, but evidence regarding the efficacy of these is largely inconclusive. This manuscript describes the development and in vitro assessment of alginate materials doped with chlorhexidine hexametaphosphate (CHX-HMP), a sparingly soluble salt which when exposed to aqueous environments provides sustained release of the common antiseptic chlorhexidine. Comparator materials were a commercial silver alginate dressing material and an alginate doped with chlorhexidine digluconate (CHXdg). CHX-HMP alginates provided a dose-dependent CHX release which was sustained for over 14 days, whereas CHXdg alginates released limited CHX and this ceased within 24 h. CHX-HMP and silver alginates were efficacious against 5 major wound pathogens (MRSA, E. coli, P. aeruginosa, K. pneumoniae, A. baumannii) in a total viable count (TVC) and an agar diffusion zone of inhibition (ZOI) model. At baseline the silver alginate was more effective than the CHX-HMP alginate in the TVC assay but the CHX-HMP alginate was the more effective in the ZOI assay. After 7 days' artificial aging the CHX-HMP alginate was more effective than the silver alginate for four of the five bacteria tested in both assays. These materials may ultimately find application in the development of wound dressings for chronic wounds that provide sustained antimicrobial protection.

Expression of a New Recombinant Collagenase Protein of Lucilia Sericata in SF9 Insect Cell as a Potential Method for Wound Healing

BACKGROUND

Today, the use of maggot therapy has become widespread due to the increase in chronic ulcers in the world. The recombinant production of secreted enzymes from these larvae is a novel non-invasive method for the treatment of chronic ulcers. Lucilia Sericata (L. sericata) collagenase (MMP-1) has been expressed in insect cells. Collagenase is an enzyme that is widely used in clinical therapy and industry. It has been indicated that collagenase is expressed and secreted in salivary glands of L. sericata while using for maggot debridement therapy.

OBJECTIVES

In the present study we decided to produce the recombinant form of collagenase enzyme in Spodoptera frugiperda (SF9) insect cells using the baculovirus expression system (Bac-to-Bac).

MATERIALS AND METHODS

cloned the coding sequences (residues 494-1705) of L. sericata collagenase into the pFastBacHTA as donor plasmid. After transposition in the bacmid of DH10Bac host, the bacmid was transfected into the Sf9 cell line, then the expressed recombinant collagenase (MMP-1) was purified using the Ni-NTA agarose.

RESULTS

The recombinant protein was verified by Western blotting. Furthermore, the biological activity of purified protein was measured in the presence of its specific substrate and its inhibitor, which was 67 IU.mL-1 based on our results, it was revealed that the characterized gene in our previous study codes L. sericata collagenesa enzyme.

CONCLUSION

Considering to the broad applications of collagenase in medical sciences, for the first time, we cloned the L. sericata collagenase (MMP-1) gene into the insect cell line to establish a method for the expression and purification of L. sericata collagenase (MMP-1). The result help for preparing and designing a safe and versatile recombinant drug in future.

Correlation between chronic venous ulcer exudate proteins and clinical profile: A cross-sectional study

Chronic venous ulcers affect the quality of life of patients around the world. The aims of this study were to identify the proteins expressed in chronic venous ulcer exudates, to categorize them according to their roles and to correlate them with the clinical and epidemiological aspects of the disease. The study population consisted of 37 ulcers from 28 patients, and the inflammatory exudates of these thirty-seven ulcers were subjected to tryptic digestion and mass spectrometry analysis. Twenty-three patients were female (62.2%), and five (37.8%) were male. The patients had a mean age of 70 (±10.1) years. Of the patients, 73% adhered to compression and rest, 81.1% reported a history of primary varices, 54.1% reported a history of systemic arterial hypertension, 54.1% reported a history of devitalized tissue in the wound bed and 64.9% reported ulcers with more than ten years of evolution. Seventy-six proteins were identified, and they were grouped according to their primary role in the healing process. Eight correlations between clinical and epidemiological data and protein expression were noteworthy: diabetes mellitus vs. Ig gamma-2 and apolipoprotein-A1 and albumin; congestive heart failure vs. Ig lambda-2; colonization vs. actin; compressive therapy vs. Ig kappa; systemic arterial hypertension vs. alpha-2-macroglobulin and apolipoprotein-A1; area of ulcer vs. apolipoprotein-A1; race vs. heavy chain Ig and Ig γ-1 chain; age and race vs. Ig γ-1 chain. These associations may help to elucidate the prognosis and chronicity of chronic venous ulcers based on secreted proteins.

Human Femoral Vein Diameter and Topography of Valves and Tributaries: A Post Mortem Analysis

The femoral vein (FV) is a clinically important vessel. Failure of its valves can lead to chronic venous insufficiency (CVI) with severe manifestations such as painful ulcers. Although they are crucial for identifying suitable implant sites for therapeutic valves, studies on the topography of FV tributaries and valves are rare. Moreover, the femoral vein diameter (FVD) must be known to assess the morphometric requirements for valve implants. To reassess the anatomical requirements for valve implants, 155 FVs from 82 human corpses were examined. FVDs and tributary and valve topographies were assessed using a laboratory straightedge. The FVD increased from 6 mm in the distal femoropopliteal vein to 11 mm in the iliofemoral vein proximal to the saphenofemoral junction (SFJ). Diameters were significantly bigger in males than females. Height correlated positively with FVD. Distal to the SFJ, within a distance of 38 cm, one to eight valves were present. Up to two valves were present within 10 cm proximal to the SFJ. Individual tributary and valve topography must be considered to ensure appropriate design and successful implantation of a venous valve for CVI therapy in the FV. A suitable implant site would be proximal to the SFJ via an infrainguinal transfemoral access. Clin. Anat. 31:1065-1076, 2018. © 2018 Wiley Periodicals, Inc.

Protease activity as a prognostic factor for wound healing in venous leg ulcers

BACKGROUND

Venous leg ulcers (VLUs) are a common type of complex wound that have a negative impact on people's lives and incur high costs for health services and society. It has been suggested that prolonged high levels of protease activity in the later stages of the healing of chronic wounds may be associated with delayed healing. Protease modulating treatments have been developed which seek to modulate protease activity and thereby promote healing in chronic wounds.

OBJECTIVES

To determine whether protease activity is an independent prognostic factor for the healing of venous leg ulcers.

SEARCH METHODS

In February 2018, we searched the following databases: Cochrane Central Register of Controlled Trials (CENTRAL), Ovid MEDLINE, Ovid Embase and CINAHL.

SELECTION CRITERIA

We included prospective and retrospective longitudinal studies with any follow-up period that recruited people with VLUs and investigated whether protease activity in wound fluid was associated with future healing of VLUs. We included randomised controlled trials (RCTs) analysed as cohort studies, provided interventions were taken into account in the analysis, and case-control studies if there were no available cohort studies. We also included prediction model studies provided they reported separately associations of individual prognostic factors (protease activity) with healing. Studies of any type of protease or combination of proteases were eligible, including proteases from bacteria, and the prognostic factor could be examined as a continuous or categorical variable; any cut-off point was permitted. The primary outcomes were time to healing (survival analysis) and the proportion of people with ulcers completely healed; the secondary outcome was change in ulcer size/rate of wound closure. We extracted unadjusted (simple) and adjusted (multivariable) associations between the prognostic factor and healing.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed studies for inclusion at each stage, and undertook data extraction, assessment of risk of bias and GRADE assessment. We collected association statistics where available. No study reported adjusted analyses: instead we collected unadjusted results or calculated association measures from raw data. We calculated risk ratios when both outcome and prognostic factor were dichotomous variables. When the prognostic factor was reported as continuous data and healing outcomes were dichotomous, we either performed regression analysis or analysed the impact of healing on protease levels, analysing as the standardised mean difference. When both prognostic factor and outcome were continuous data, we reported correlation coefficients or calculated them from individual participant data.We displayed all results on forest plots to give an overall visual representation. We planned to conduct meta-analyses where this was appropriate, otherwise we summarised narratively.

MAIN RESULTS

We included 19 studies comprising 21 cohorts involving 646 participants. Only 11 studies (13 cohorts, 522 participants) had data available for analysis. Of these, five were prospective cohort studies, four were RCTs and two had a type of case-control design. Follow-up time ranged from four to 36 weeks. Studies covered 10 different matrix metalloproteases (MMPs) and two serine proteases (human neutrophil elastase and urokinase-type plasminogen activators). Two studies recorded complete healing as an outcome; other studies recorded partial healing measures. There was clinical and methodological heterogeneity across studies; for example, in the definition of healing, the type of protease and its measurement, the distribution of active and bound protease species, the types of treatment and the reporting of results. Therefore, meta-analysis was not performed. No study had conducted multivariable analyses and all included evidence was of very low certainty because of the lack of adjustment for confounders, the high risk of bias for all studies except one, imprecision around the measures of association and inconsistency in the direction of association. Collectively the research indicated complete uncertainty as to the association between protease activity and VLU healing.

AUTHORS' CONCLUSIONS

This review identified very low validity evidence regarding any association between protease activity and VLU healing and there is complete uncertainty regarding the relationship. The review offers information for both future research and systematic review methodology.

5th Congress of WUWHS Abstract book Florence, Italy September 25–29 2016

The abstract book contains the abstracts of keynote lectures, focus sessions, symposia, workshops, AIUC annual meeting, AISLEC annual meeting, EPUAP annual meeting, ETRS special session, sponsor symposia, oral presentations, poster presentations and the subject index.

Clinical evaluation of a dressing with poly absorbent fibres and a silver matrix for managing chronic wounds at risk of infection: a non comparative trial

OBJECTIVE

To assess the efficacy, safety and acceptability of a new silver poly absorbent dressing (UrgoCleanAg) in the local management of exudative chronic wounds at risk of infection, with inflammatory signs suggesting heavy bacterial load.

METHOD

This prospective, multicentre, non-comparative clinical trial was conducted in French hospital wards (dermatology and vascular medicine) or specialised private-practice physicians. Patients were considered at high-risk of infection when presenting with at least three of five selected inflammatory clinical signs, suggesting a heavy bacterial load (pain between two dressing changes, erythema, oedema, malodorous wound and presence of a heavy exudate). They were treated for a maximum period of four weeks, and followed by the physician on a weekly basis, including a clinical examination, area tracings and photographs. The primary efficacy criterion of the trial was the relative wound surface area reduction at the end of the four weeks of treatment. Acceptability was documented by the nursing staff at each dressing change between the weekly evaluations.

RESULTS

We recruited 37 patients with chronic wounds. Wound surface area, mostly covered by sloughy tissue, was reduced by 32.5% at the end of the treatment (median value), while the clinical score (maximum value of 5, based on inflammatory clinical signs) decreased from 4.0 to 2.0. Effective debridement properties were documented (62.5% relative reduction of sloughy tissue at week 4; 58.8% of debrided wounds at week 4) and improvement of the periwound skin status was noted (healthy for 28.6% of the patients at week 4 versus 2.7% at baseline). In addition, the tested wound dressing presented a good safety profile associated to a high level of acceptability, noted by both patients and nursing staff.

CONCLUSION

These clinical data support that the tested dressing is a credible therapeutic alternative for the management of chronic wounds at risk of infection with inflammatory signs suggesting heavy bacterial load.