A Novel Randomized Trial Protocol for Evaluating Wound Healing Interventions

Background: Randomized controlled trials using complete healing as an endpoint suffer from poor statistical power, owing to the heterogeneity of wounds and their healing trajectories. The Food and Drug Administration (FDA) has recently consulted with expert groups to consider percentage area reduction (PAR) of the wound over a 4-week period as a valid intermediate endpoint, creating the opportunity for more powerful study designs. Methods: A within-subject controlled study design comparing the PAR of venous leg ulcers (VLU) in patients over 4 weeks receiving different interventions. Twenty-nine patients received multilayer compression over 4 weeks, followed by neuromuscular electrostimulation (NMES) of the leg muscle pump in addition to compression for a further 4 weeks. Paired comparison was then made of PAR between the two phases. A second cohort of 22 patients received only multilayer compression throughout both 4-week phases. Results: Patients randomized to NMES saw a significant increase in healing rate compared with compression alone, whereas patients receiving compression only saw no significant change in healing rate throughout the course of the study. Conclusions: Intermittent NMES of the common peroneal nerve significantly accelerates the healing of VLU. It is well tolerated by patients and deserves serious consideration as an adjuvant to compression therapy. PAR is a useful metric for comparing the performance of wound healing interventions, and the self-controlled trial design allows sensitive discrimination with a relatively small number of subjects over a reasonably short trial period. The study is reported according to the CONSORT reporting guidelines. Clinical Trial Registration: NCT03396731 (ClinicalTrials.gov).

The impact of a new intervention for venous leg ulcers: A within-patient controlled trial

A major obstacle to the development of new treatments for venous leg ulcers is the difficulty in generating evidence for their effectiveness. Randomised controlled trials using complete healing as the endpoint are seldom powered to be successful, owing to the heterogeneity of cohorts. A novel approach to the evaluation of treatments is presented, using a self-controlled trial model and two metrics of short-term healing rate as alternate endpoints: rate of wound margin advance, and percentage area reduction over 4 weeks. Two different treatment regimens are compared: multi-layer compression alone, versus multi-layer compression combined with activation of the venous leg pump by neuromuscular stimulation. With 60 patients, adding neuromuscular stimulation to multilayer compression resulted in a significant two-fold increase in the rate of wound healing over a 4-week period, both in terms of wound margin advance and in terms of percentage area reduction. The use of these short-term intermediate endpoint metrics together with a self-controlled study design offers potential for distinguishing between the relative efficacies of interventions more rapidly, with greater sensitivity, and with fewer subjects than a conventional RCT cohort model.

A95 OUTCOMES OF ERCP UNDER CONSCIOUS SEDATION COMPARED TO GENERAL ANESTHESIA: A PRE-POST RETROSPECTIVE COHORT REVIEW

Background

Endoscopic retrograde cholangiopancreatography (ERCP) is a diagnostic and therapeutic procedure used to address pathologies of the pancreatic and biliary systems. ERCP performed under conscious sedation (CS) is the current standard of care but is limited by patient movement and agitation, especially in the context of lengthy or technically complex cases. Recent literature suggests that general anesthesia (GA) may optimize patient comfort and safety while reducing complications such as pancreatitis, perforation, and mortality. In October 2017, Kelowna General Hospital (KGH) transitioned the standard anesthesia modality for ERCP from CS to GA.

Aims

To investigate differences in complications and patient outcomes for ERCP performed under CS (n=1334) before the practice change compared to GA (n=899) after the practice change.

Methods

Our study is a pre-post retrospective chart review of 2,233 patients who underwent ERCP between 2015 and 2020 at KGH. Demographic, clinical, procedural and outcome data were extracted from patient charts, and the data in CS and GA groups were compared using univariate statistical analysis.

Results

Preliminary results show rates of post-ERCP pancreatitis (6% vs. 4%; p=0.018) and rates of procedure failure (8% vs. 3%; p<0.001) were statistically significant and higher under CS before the practice change compared to under GA afterwards, respectively. The 30-day mortality rates, ICU transfer rates, return rates post-discharge, and rates of cholangitis were similar.

Our study showed improvements in several patient safety outcomes, including lower procedure failure rates and lower post-ERCP pancreatitis rates with ERCP performed under GA compared to CS.

Conclusions

Performing ERCP under GA rather than under CS is a valuable practice change that should be considered by ERCP-related programs across all health authorities due to its potential to optimize both patient comfort and safety significantly. The reduction in complication rates may have implications for net cost savings in the long term.

Funding Agencies

Kelowna General Hospital Foundation, Interior Health

Wound healing: potential therapeutic options

This review highlights the range of therapeutic options available to clinicians treating difficult-to-heal wounds. While certain treatments are established in daily clinical practice, most therapeutic interventions lack robust and rigorous data regarding their efficacy, which would help to determine when, and for whom, they should be used. The purpose of this review is to give a broad overview of the available interventions, with a brief summary of the evidence base for each intervention.

Measuring progress to healing: A challenge and an opportunity

Complete healing is problematic as an endpoint for evaluating interventions for wound healing. The great heterogeneity of wounds makes it difficult to match groups, and this is only possible with multivariate stratification and/or very large numbers of subjects. The substantial time taken for wounds to heal necessitates a very lengthy study. Consequently, high quality randomised controlled trials demonstrating an effect of an intervention to a satisfactory level of statistical significance and with a satisfactory level of generalisability are extremely rare. This study determines that the healing of venous leg ulcers receiving multi‐component compression bandaging follows a linear trajectory over a 4‐week period, as measured by gross area healed, percentage area healed, and advance of the wound margin. The linear trajectories of these surrogates make it possible to identify an acceleration in healing resulting from an intervention, and allows self‐controlled or crossover designs with attendant advantages of statistical power and speed. Of the metrics investigated, wound margin advance was the most linear, and was also independent of initial ulcer size.

Abstract PS17-48: Potential role of activated leukocyte cell adhesion molecule (ALCAM) in hepatocyte growth factor (HGF) signalling in vascular endothelial cells and implications in breast cancer

Background. Activated Leukocyte Cell Adhesion Molecule, ALCAM (also known as CD166) is a member of the immunoglobulin superfamily and a cell surface adhesion molecule involved in heterophilic and homophilic interactions during cell-cell adhesion in epithelial cells, cancer cells and endothelial cells. ALCAM appears to be linked to tumour progression in a number of cancers including breast cancer, though there are conflicting reports as to its precise prognostic implications and significance. We have previously reported that ALCAM has a tumour suppressive role in breast cancer and is inversely correlated with clinical outcome (1) and interestingly bone metastasis of breast cancer (2). We have also reported that ALCAM has a diverse role in other cell types including keratinocytes and endothelial cells. In the present study, we investigated the association between ALCAM and hepatocyte growth factor (HGF)/cMET, a signalling pathway established as a key promoter of cancer progression, influencing both the aggressive nature of cancer cells and acting as an angiogenic and lymphangiogenic factor, in breast cancer and endothelial cells.

Methods. The expression pattern and correlation of ALCAM, HGF and cMET in human breast cancer were deduced from a clinical breast cancer cohort. ALCAM manipulated HECV cell lines, previously established in our laboratories, were used in conjunction with recombinant human HGF and cMET inhibitors to assess cellular functions and the implications of this relationship at a cellular level.

Results. We compared the expression of ALCAM with that of HGF and cMET within the breast cancer cohort and found that ALCAM/CD166 showed a highly significant negative correlation with the HGF receptor cMET (r=-0.17, p<0.0001) and a weak negative correlation with HGF, although this was not significant. ALCAM was not found to correlate with its heterophilic partner CD6. In previously generated HECV models, ALCAM manipulation showed a marked influence on cellular function and responsiveness to HGF treatment.

Discussion. ALCAM’s role in breast cancer progression and related mechanisms is complex. Our current data suggests this may involve an interaction with the cMET/HGF signalling pathway and may also impact the endothelial component within the tumour microenvironment to influence disease progression.

Reference1 King JA, Ofori-Acquah SF, Stevens T, et al. Activated leukocyte cell adhesion molecule in breast cancer: prognostic indicator. Breast Cancer Res. 2004;6:R478-87.

Reference2 Davies SR, Dent C, Watkins G et al. Expression of the cell to cell adhesion molecule, ALCAM, in breast cancer patients and the potential link with skeletal metastasis. Oncol Rep. 2008;19:555-61.

Citation Format: Andrew James Sanders, David Guo Jiang, Jianyuan Zeng, Robert Edward Mansel, Eleri Davies, Amber Xinyu Li, Keith Gordon Harding, Wen Guo Jiang. Potential role of activated leukocyte cell adhesion molecule (ALCAM) in hepatocyte growth factor (HGF) signalling in vascular endothelial cells and implications in breast cancer [abstract]. In: Proceedings of the 2020 San Antonio Breast Cancer Virtual Symposium; 2020 Dec 8-11; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2021;81(4 Suppl):Abstract nr PS17-48.

Development and validation of a gene expression test to identify hard-to-heal chronic venous leg ulcers

Background

Chronic venous leg ulcers pose a significant burden to healthcare systems, and predicting wound healing is challenging. The aim of this study was to develop a genetic test to evaluate the propensity of a chronic ulcer to heal.

Methods

Sequential refinement and testing of a gene expression signature was conducted using three distinct cohorts of human wound tissue. The expression of candidate genes was screened using a cohort of acute and chronic wound tissue and normal skin with quantitative transcript analysis. Genes showing significant expression differences were combined and examined, using receiver operating characteristic (ROC) curve analysis, in a controlled prospective study of patients with venous leg ulcers. A refined gene signature was evaluated using a prospective, blinded study of consecutive patients with venous ulcers.

Results

The initial gene signature, comprising 25 genes, could identify the outcome (healing versus non-healing) of chronic venous leg ulcers (area under the curve (AUC) 0·84, 95 per cent c.i. 0·73 to 0·94). Subsequent refinement resulted in a final 14-gene signature (WD14), which performed equally well (AUC 0·88, 0·80 to 0·97). When examined in a prospective blinded study, the WD14 signature could also identify wounds likely to demonstrate signs of healing (AUC 0·73, 0·62 to 0·84).

Conclusion

A gene signature can identify people with chronic venous leg ulcers that are unlikely to heal.

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.

The clinical significance and impact of interleukin 15 on keratinocyte cell growth and migration

Chronic wounds represent a significant burden to health services and are associated with patient morbidity. Novel methods to diagnose and/or treat problematic wounds are needed. Interleukin (IL)-15 is a cytokine involved in a number of biological processes and disease states such as inflammation, healing and cancer progression. The current study explores the expression profile of IL-15 and IL-15 receptor α (IL-15Rα) in chronic wounds and its impact on keratinocytes. IL-15 and IL-15Rα expression were examined in healing and non-healing chronic wounds using qPCR and immunohistochemical analysis. The impact of recombinant IL-15 (rhIL-15) on human adult low calcium temperature (HaCaT) keratinocyte growth and migratory potential was further examined. IL-15 transcript expression was slightly, though non-significantly elevated in healing chronic wounds compared with non-healing chronic wounds. IL-15 protein staining was minimal in both subtypes of chronic wounds. By contrast, IL-15Rα transcript and protein expression were both observed to be enhanced in non-healing chronic wounds compared with healing chronic wounds. The treatment of HaCaT cells with rhIL-15 generally enhanced cell growth and promoted migration. Analysis with small molecule inhibitors suggested that the pro-migratory effect of rhIL-15 may be associated with ERK, AKT, PLCγ and FAK signalling. IL-15 may promote healing traits in keratinocytes and the differential expression of IL-15Rα is observed in chronic wounds. Together, this may imply a complex role for this interleukin in wound healing.

Value of wound biopsy in chronic venous ulceration

Objectives: Malignant transformation in chronic venous ulcers (CVU) is a limb threatening complication, which has an insidious onset. Clinical experience in our practice suggests a lack of suspicious macroscopic features making diagnosis difficult. The aim of this study is to evaluate the role of routine wound biopsy in the outpatient clinic for CVU without suspicious appearances but with no signs of healing despite appropriate treatment.

Methods: A three-year (2000-2003) retrospective review of records for all patients who underwent biopsy of a CVU in the outpatient clinic in a specialist wound healing clinic set in a university hospital.

Results: In our series ( n =76), three indications for biopsy were identified: CVU that had developed features suspicious of carcinoma ( n =17), CVU that had no suspicious features but were non-healing ( n =24) and CVU that had developed features of inflammatory ulceration ( n =35). A positive finding of carcinoma (squamous or basal cell carcinoma) or intraepidermal carcinoma (Bowen's disease) was made in four (24%), nine (37.5%) and 0 cases respectively.

Conclusions: Malignancy may arise in CVU without showing suspicious features and wound biopsy should be advocated for any ulcer that fails to respond to appropriate treatment.

Chronic wound and postamputation claudication pain in a diabetic patient

Underlying ischaemic disease should be excluded in patients with delayed wound healing. Contrast angiography is a useful imaging method for assessing the specific cause of wound chronicity and may also be helpful in assessing the aetiology of unexplained pain symptoms. Angioplasty provides a practical alternative to more invasive techniques in addressing peripheral ischaemia. Our patient suffered claudication-type pain in his thigh and a non-healing stump wound following below-knee amputation. Magnetic resonance angiography confirmed the presence of arterial stenoses and an angioplasty was successfully performed to improve patency of the profunda femoris vessel. Following the operation, the claudication pain symptoms were significantly reduced and the stump wound went on to heal.

Topical steroids for chronic wounds displaying abnormal inflammation

INTRODUCTION

Chronic, non-healing wounds are often characterised by an excessive, and detrimental, inflammatory response. We review our experience of using a combined topical steroid, antibiotic and antifungal preparation in the treatment of chronic wounds displaying abnormal and excessive inflammation.

METHODS

A retrospective review was undertaken of all patients being treated with a topical preparation containing a steroid (clobetasone butyrate 0.05%), antibiotic and antifungal at a tertiary wound healing centre over a ten-year period. Patients were selected as the primary treating physician felt the wounds were displaying excessive inflammation. Healing rates were calculated for before and during this treatment period for each patient. Changes in symptom burden (pain, odour and exudate levels) following topical application were also calculated.

RESULTS

Overall, 34 ulcers were identified from 25 individual patients (mean age: 65 years, range: 37-97 years) and 331 clinic visits were analysed, spanning a total time of 14,670 days (7,721 days 'before treatment' time, 6,949 days 'during treatment' time). Following treatment, 24 ulcers demonstrated faster rates of healing, 3 ulcers showed no significant change in healing rates and 7 were healing more slowly (p=0.0006). Treatment generally reduced the burden of pain and exudate, without affecting odour.

CONCLUSIONS

In normal wound healing, inflammation represents a transient but essential phase of tissue repair. In selected cases, direct application of a steroid containing agent has been shown to improve healing rates, presumably by curtailing this phase. Further evaluation is required to establish the role of preparations containing topical steroids without antimicrobials in the management of chronic wounds.

P4-09-24: Correlation of Aurora Family Member Expression with Clinical Breast Cancer Prognosis

Introduction:

Aurora-A, Aurora-B and Aurora-C are a family of protein kinases which have been identified as key regulators of the mitotic cell division process. Members of this group have been linked with pro-tumorigenic effects and have been reported as being up-regulated in certain cancers. Our current study examines the expression profile of the Aurora-A, Aurora-B and Aurora-C members in a breast cancer cohort in relation to a number of predictive factors.

Materials and Methods:

The expression of Aurora-A, Aurora-B and Aurora-C was examined in a breast cancer cohort using quantitative real time PCR (normal samples n = 34, tumour samples n = 109) and immunhistochemistry (IHC). Expression of the aurora members was related to clinical parameters such as staging and Nottingham prognostic index (NPI).

Results:

Examination of Aurora-A levels in the breast cancer cohort revealed an association of Aurora-A expression with NPI grouping. High levels of Aurora-A levels were seen in NPI-1 and NPI-2 stages (NPI-1 median = 66.0, NPI-2 median = 64.3), with expression reducing significantly at the higher NPI-3 group (NPI-3 median = 20.3; p = 0.029 vs NPI-2 and p = 0.009 vs NPI-1 respectively). Additionally, Aurora-A levels were found to be significantly lower in grade 3 cancers compared to grade 1 (median grade 1 = 86.5 vs median grade 3 levels = 52.6, p = 0.04). In contrast to this, examination of Aurora-C levels in the cohort identified a relatively low level of Aurora-C in NPI-1 and NPI-2 group (median values NPI-1 = 88, NPI-2 = 34.4) compared to a substantial increase in Aurora-C expression in NPI-3 (median value = 1602, p = 0.05 vs NPI-1 and p = 0.06 vs NPI-2). Aurora-B expression levels did not exhibit any significant differences within the breast cancer cohort.

Conclusions:

Differential expression of Aurora-A, Aurora-B and Aurora-C were observed within the breast cancer cohort. Higher Aurora-A expression was associated with low NPI groups and grades and potentially with better patient prognosis whereas lower levels were seen in the poorer prognostic NPI-3 group and higher grades. An opposite trend was seen in Aurora-C where lower levels were associated with the NPI-1 and NPI-2 groups and significantly higher levels were seen in the NPI-3 group. Aurora-B levels appeared to have no predictive function. This data suggests that together Aurora-A and Aurora-C levels, within a patient may be useful for predicting patient outcome.

Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr P4-09-24.

Abstract P1-04-02: The Role of BIK (BCL-2 Interaction Killer) Pro-Apoptotic Gene in Breast Cancer

Background: The human BIK (BCL-2 interaction killer) gene is a pro-apoptotic member in the Bcl-2 gene family. The BIK gene encodes a Mr 18,000 protein product, which contains a BH3 domain critical for its pro-apoptotic activities. Bik forms heterodimers with various anti-apoptotic proteins, including Bcl-2 and Bcl-XL, the association of which hinders the function of the anti-apoptotic proteins. Fluorescent in-situ hybridization has established the chromosomal localization of the BIK gene to 22q13.3. Recent evidence also reveals that oestrogen starvation-induced apoptosis of breast cancer cells requires BIK.

Methods: Breast cancer tissues (n = 122) and Normal background tissues (n = 33) were collected post surgery. Q-PCR was performed on these tissues to quantify BIK transcript levels in both tissue samples. For in vitro tests, MDA-MB-231 wild type (WT) cell was transfected with anti-BIK ribozyme transgenes, constructed based on the secondary structure of BIK and specifically targeted human BIK, in order to generate a BIK-knockdown subline. The successful knock down of the gene transcript was then verified with RT-PCR and Quantitative real time PCR (Q-PCR) alongside control MDA-MB-231 WT and MDA-MB-231 pEF cells. Cell functions; cell growth using a colorimetric growth assay and cellular motility using conventional scratch wounding assay were tested. Results: Median BIK levels on the normal background and breast cancer tissues were 0.827 and 1.23 respectively being non-significant on Mann-Whitney U test(p=0.27). Patients with higher histological grade (Grade3) (n=55, median 1.53) and TNM4 (n= 4, median= 9.75) demonstrated relatively higher levels of BIK. Tumours from patients with a poor prognosis (Nottingham prognostic index (NPI)&gt;5.4) (n=15, median=2.54) had higher level of BIK transcripts in comparison with patients with good prognosis (NPI&lt;3.4) (n = 65, Median = 1.010), P&lt;0.05. Overall mean survival for patients with low levels of BIK was 139.1 months and 119.2 months for those with high levels. The disease free survival was 133.5 and 113.2 months for patients with low and high levels of BIK, respectively. In vitro, breast cancer cells MDA MB-231 expressed BIK transcript as shown by both RT-PCR and Q-PCR. The anti-BIK transgene successfully knocked down of BIK transcript in the cells. Using a scratch wounding assay and growth assays, it was shown that there was an increase in the rate of migration and growth in the BIK knockdown cells compared to control cell lines.

Conclusion: BIK is a recognized apoptosis promoting gene in breast cancer. Our cohort of breast cancer patients showed a correlation of increased levels of BIK with advancing disease, which also correlates to the estimated overall and disease free survival times. Together with the results from in vitro tests, it is postulated that BIK played a complex role in breast cancer and that the type of interactions with other apoptosis interaction regulators of BIK may be key in deciding the aggressiveness of breast cancer cells.

Citation Information: Cancer Res 2010;70(24 Suppl):Abstract nr P1-04-02.

Investigation of standing balance in patients with diabetic neuropathy at different stages of foot complications

BACKGROUND

Diabetic peripheral neuropathy is known to cause postural instability. This study investigated standing balance in patients with diabetic neuropathy with secondary foot complications: foot ulceration, partial foot amputation and trans-tibial amputation, which are expected to pose further challenge to balance control.

METHODS

In this cross-sectional study, 23 patients with diabetic neuropathy alone (controls) were compared with 23 patients with diabetic foot ulceration, 16 patients with partial foot amputation and 22 patients with trans-tibial amputation. Posturography was used to determine the centre of pressure excursion during quiet standing. Differences between the 4 groups were tested using ANOVA and post-hoc comparisons.

FINDINGS

The 4 groups varied in neuropathy score (P=0.001) and demonstrated significant decline in balance from neuropathy alone to foot ulceration, to partial foot amputation and trans-tibial amputation based on total excursion of centre of pressure (P<0.001) and centre of pressure excursion in antero-posterior direction (P<0.001). The excursion of centre of pressure in medio-lateral direction varied between 4 groups (P<0.05) however, there was no significant trend. The distance between ankles increased significantly from neuropathy to trans-tibial amputee group (P=0.001). Post-hoc comparison with controls revealed that each of three study groups demonstrated decreased balance (diabetic neuropathy vs. foot ulceration, P=0.001, diabetic neuropathy vs. partial foot amputation, P=0.002 and diabetic neuropathy vs. trans-tibial amputation, P=0.009).

INTERPRETATION

Balance deterioration among patient groups from diabetic neuropathy alone to trans-tibial amputation appears to result from bio-mechanical impairment caused by progression of foot complications in addition to postural instability caused by diabetic neuropathy.

The influence of exercise on foot perfusion in diabetes

AIMS

Diabetic foot disease is associated with both macro- and microvascular disease. Exercise has both positive and negative effects on the perfusion of lower limbs with peripheral arterial occlusive disease (PAOD). We aimed to measure changes in foot perfusion following a brief period of lower-limb exercise in individuals with and without Type 2 diabetes and non-critical PAOD.

METHODS

Subjects were allocated to groups according to the presence or absence of diabetes, PAOD on colour duplex imaging and clinically detectable peripheral neuropaIthy. Transcutaneous oxygen tension (TcPO(2)), transcutaneous carbon dioxide tension (TcPCO(2)), ankle-brachial pressure indices, toe pressures and toe-brachial pressure indices (TBI) were measured.

RESULTS

One hundred and sixteen limbs were studied in 61 subjects. Post-exercise, toe pressure and TBI increased in the non-diabetic group with arterial disease, but not in the groups with diabetes. Foot TcPO(2) values increased in groups with diabetes and TcPCO(2) decreased in all groups with arterial disease. Increased chest TcPO(2) and decreased TcPCO(2) were demonstrated in the groups with diabetes.

CONCLUSIONS

Elevations in foot TcPO(2) and reductions in TcPCO(2) indicate improved cutaneous perfusion response to local heating post-exercise. Elevated toe pressures in the non-diabetes group suggest that improved perfusion may be associated with enhanced lower limb macrovascular haemodynamics. However, improvements in TcPO(2) and TcPCO(2) at foot and chest sites in diabetes imply a global change in cutaneous perfusion. The results suggest that brief exercise results in an improvement in cutaneous perfusion in non-critical PAOD, particularly in individuals with diabetes.

Environmental analysis of plastic production processes: Comparing petroleum-based polypropylene and polyethylene with biologically-based poly-β-hydroxybutyric acid using life cycle analysis

Polymers based on olefins have wide commercial applicability. However, they are made from non-renewable resources and are characterised by difficulty in disposal where recycle and re-use is not feasible. Poly-beta-hydroxybutyric acid (PHB) provides one example of a polymer made from renewable resources. Before motivating its widespread use, the advantages of a renewable polymer must be weighed against the environmental aspects of its production. Previous studies relating the environmental impacts of petroleum-based and bio-plastics have centred on the impact categories of global warming and fossil fuel depletion. Cradle-to-grave studies report equivalent or reduced global warming impacts, in comparison to equivalent polyolefin processes. This stems from a perceived CO(2) neutral status of the renewable resource. Indeed, no previous work has reported the results of a life cycle assessment (LCA) giving the environmental impacts in all major categories. This study investigates a cradle-to-gate LCA of PHB production taking into account net CO(2) generation and all major impact categories. It compares the findings with similar studies of polypropylene (PP) and polyethylene (PE). It is found that, in all of the life cycle categories, PHB is superior to PP. Energy requirements are slightly lower than previously observed and significantly lower than those for polyolefin production. PE impacts are lower than PHB values in acidification and eutrophication.

A pilot study on the effect of topical negative pressure on quality of life

OBJECTIVE

To discover the impact of topical negative pressure (TNP) on quality of life.

METHOD

An exploratory prospective cohort study was conducted on 26 patients undergoing TNP. The Cardiff Wound Impact Schedule (CWIS), a wound-specific tool, was used to investigate quality-of-life scores before therapy and four weeks after therapy or at wound closure. Wound dimensions were measured at both assessments, and the values for the CWIS domains (physical symptoms, social functioning, well-being and overall quality of life) were investigated using parametric and non-parametric tests.

RESULTS

The mean duration of TNP therapy was 3.3 +/- 1.7 weeks. Topical negative pressure therapy helped to achieve complete wound closure in 14 patients (54%), and there was a mean reduction in wound surface area from 52.2 cm2 (range 4-150) to 26.8 cm2 (0-120). While there was no significant change in quality of life in patients whose wounds healed (1 +/- 11.9), the physical-functioning domain improved in obese patients (20 +/- 21, p < 0.05) and worsened in ambulatory patients (-3 +/- 13, p < 0.05). The portableTNP system had no significant impact on quality of life (-3 +/- 16), while the global quality-of-life score worsened with surgical intervention (-0.5 +/- 2, p < 0.05).

CONCLUSION

Although TNP aids wound closure in patients with complex wounds, in selected cases their quality of life can worsen. This is the first exploratory cohort study of its kind, and has identified an urgent need to validate the use of patient-based outcome measures in TNP therapy. Such data can be useful in allocating resources and justifying funding in wound care.

Use of a hydrocapillary dressing in the management of highly exuding ulcers: a comparative study

OBJECTIVE

To evaluate the safety and performance of Alione Hydrocapillary dressing (Coloplast A/S) in the management of highly exuding chronic venous leg ulcers and compare it with two hydropolymer dressings,Tielle and Tielle Plus (Johnson & Johnson).

METHOD

A comparative clinical trial was conducted on 97 patients with an ankle brachial pressure index > or = 0.8 and a highly exuding leg ulcer. Ulcer duration was at least four weeks. Treatment continued until healing or for a maximum of 12 months.

RESULTS

There was no statistically significant difference in healing time or wound area reduction between the two treatment protocols. The test dressing (Alione Hydrocapillary) had better absorption capacity and was more comfortable for the patients than the comparator dressings (Tielle/Tielle Plus) and adhered less to the wound bed.Also, more patients preferred the test dressing to their previous treatment. Although severe leakage and maceration were observed more frequently in the comparator group compared with the test group, this was not statistically significant.

CONCLUSION

Both treatment protocols were safe and effective in treating highly exuding chronic venous leg ulcers. The test dressing performed as well as or better than the comparator dressings for all study parameters and more patients preferred the test dressing to their previous dressing compared with the comparator dressings.

Sustained silver-releasing dressing in the treatment of diabetic foot ulcers

This study investigated the clinical performance and safety of a sustained silver-releasing foam dressing, Contreet Foam, in the treatment of diabetic foot ulcers. Twenty-seven patients with diabetic foot ulcers of grade I or II (Wagner's classification) were followed for six weeks: one week run-in using Biatain dressings, four weeks' treatment with Contreet dressings. Four ulcers healed during the four-week treatment with Contreet 56% in average. Contreet Foam showed good exudate management properties and was considered easy to use. Only two infections occurred showed that all six of the non-study ulcers developed an infection during the study. All ulcers (study ulcers as well as non-study ulcers) were treated according to good practice of diabetic wound care. There were no directions for the treatment of secondary wounds. No device-related adverse events were observed. This study demonstrated that Contreet Foam is safe and easy to use and effectively supports healing and good wound progress of diabetic foot ulcers.

Diagnosing foot infection in diabetes

Infection represents the presence of an inflammatory response and tissue injury due to the interaction of the host with multiplying bacteria. The disease spectrum is a consequence of the variability in these interactions. Diabetes, because of its effects on the vascular, neurological, and immune systems, can compromise the local and systemic response to infection, potentially masking the typical clinical features and hindering diagnosis. The early recognition of infection, particularly osteomyelitis, is paramount in the management of diabetic foot disease. Careful clinical appraisal remains the cornerstone of the assessment. Hematologic, biochemical, and radiological investigations are important aids in assessing the severity of infection. Microbiological assessment, particularly in more severe infection, requires good-quality samples, combined with rapid transport in an appropriate medium and effective communication with the laboratory. A focused, systematic approach to the accurate diagnosis and treatment of infection, combined with careful monitoring, ensures the maintenance of optimal management.

Wound dressings in diabetic foot disease

Wound dressings represent a part of the management of diabetic foot ulceration. Ideally, dressings should alleviate symptoms, provide wound protection, and encourage healing. No single dressing fulfills all the requirements of a diabetic patient with an infected foot ulcer. Dressings research in this area is generally poor. However, each category of dressings has particular characteristics that aid selection. Nonadhesive dressings are simple, inexpensive, and well tolerated. Foam and alginate dressings are highly absorbent and effective for heavily exuding wounds. Hydrogels facilitate autolysis and may be beneficial in managing ulcers containing necrotic tissue. Dressings containing inidine and silver may aid in managing wound infection. Occlusive dressings should be avoided for infected wounds. All dressings require frequent change for wound inspection. Heavily exudating ulcers require frequent change to reduce maceration of surrounding skin. Dressing choice should be guided by the characteristics of the ulcer, the requirements of the patient, and costs.

Wound-related osteomyelitis: a case of containment not cure

Community nurses need to be aware that some patients with osteomyelitis are treated with antibiotics alone. Such patients often have co-morbidities and quality of life issues that directly impact on the decision to treat osteomyelitis surgically. However, adopting a conservative approach to osteomyelitis management is associated with an increased risk of osteomyelitis recurrence. The rationale for managing chronic wound-related osteomyelitis with antibiotics is discussed. Community nurses caring for patients that have received antibiotics alone to treat osteomyelitis need to be aware of the potential for osteomyelitis recurrence and how to make the diagnosis.

Safety and performance of a new non-adhesive foam dressing for the treatment of diabetic foot ulcers

OBJECTIVE

This study aimed to document the safety and performance of a new non-adhesive foam dressing (Biatain Non-adhesive Dressing, Coloplast A/S) in the treatment of established foot ulcers in patients with diabetes.

METHOD

This was an open non-comparative prospective study. Participants had an ankle brachial pressure index score of over 0.4 (neuro-ischaemic) and an ulcer bigger than 1 cm2 and less than 8 cm2 in any direction. The treatment period was six weeks.

RESULTS

Thirty-five out of 37 patients completed the study. The mean wound area reduced from 5.4 cm2 to 2.5 cm2. Relative wound area reduced from 100% at baseline to 40% at week 6. 'Wearing comfort' improved throughout the study (p = 0.039). Maceration remained stable or improved. None of the four reported adverse events were device related.

CONCLUSION

This study demonstrates that treatment of diabetic foot ulcers with Biatain Non-adhesive Dressing results in considerable wound area reduction and prevents any deterioration in maceration. The dressing is safe and effective in the management of these ulcers.

Measurement of the skin microcirculation through intact bandages using laser Doppler flowmetry

The microcirculation under compression bandages has been assessed by numerous methods; however, the measurement techniques can disrupt the bandage-skin interface, affecting the measurement. In this study, a non-invasive method for measuring cutaneous blood flow using laser Doppler flowmetry (LDF) is presented. Ten volunteers had their microcirculation assessed by a laser Doppler probe being placed on their upper forearm with and without a light-transmissive gel and with a compression bandage plus light-transmissive gel. A circulatory challenge to the bandaged forearm in two of the volunteers was also undertaken. The median (95% confidence interval) perfusion (p.u.) for the skin surface was 24 (15-33) perfusion units (p.u.), and the skin plus light-transmissive gel demonstrated a higher perfusion: 66 (50-82) p.u., (p < 0.012). The addition of the compression bandage, with additional gel allowed to permeate through to the underlying skin, decreased the perfusion to 27 (20-34) p.u. (p < 0.007). In both volunteers, the microcirculatory flow responded to the vascular challenge, resulting in flow changes related to the cuff pressure (45-27 and 14-8 p.u.). This method demonstrated that it may be possible to assess the microcirculation through intact bandages, without the need to place any sensors at the skin-bandage interface.

Regulation of angiogenesis and endothelial cell motility by matrix-bound fibroblasts

This study sought to examine the effect of matrix-bound fibroblasts on angiogenesis and endothelial cell motility. Promotion of angiogenesis by matrix-bound fibroblasts was assessed using rat aortic ring and endothelial tube formation assays. Enhancement of human endothelial cell motility by matrix-bound fibroblasts was assessed using cytodex-2 bead and colloidal gold phagokinetic motility assays. Antibody to hepatocyte growth factor/scatter factor (HGF/SF) but not vascular endothelial growth factor (VEGf) decreased fibroblast-enhanced motility of endothelial cells. The promotion of tube formation by matrix-bound fibroblasts was neutralised with antibodies to HGF/SF and VEGf, both known promoters of angiogenesis. HGF/SF presence was detected by ELISA; whilst the presence of VEGf was detected by Western blotting. These data show that matrix-embedded fibroblasts regulate the motility of vascular endothelial cells and enhance angiogenesis, an effect partly attributed to production of angiogenesis-promoting cytokines HGF/SF and/or VEGf.

Molecular analysis of the microflora in chronic venous leg ulceration

There is growing evidence to suggest that the resident microflora of chronic venous leg ulcers impairs cellular wound-healing responses, thereby playing an important role in maintaining the non-healing phenotype of many of these wounds. The significance of individual species of bacteria will remain unclear until it is possible to characterize fully the microflora of such lesions. The limitations and biases of culture-based microbiology are being realized and the subsequent application of molecular methods is revealing greater diversity within mixed bacterial populations than that demonstrated by culture alone. To date, this approach has been limited to a small number of systems, including the oral microflora. Here, for the first time, the comprehensive characterization of the microflora present in the tissue of a chronic venous leg ulcer is described by the comparison of 16S rDNA sequences amplified directly from the wound tissue with sequences obtained from bacteria that were isolated by culture. The molecular approach demonstrated significantly greater bacterial diversity than that revealed by culture. Furthermore, sequences were retrieved that may possibly represent novel species of bacteria. It is only by the comprehensive analysis of the wound microflora by both molecular and cultural methods that it will be possible to further our understanding of the role of bacteria in this important condition.

Anaerobic cocci populating the deep tissues of chronic wounds impair cellular wound healing responses in vitro

BACKGROUND

Anaerobic cocci are estimated to be present in the deep tissues of over 50% of chronic skin wounds. While the part they play in the chronicity of these wounds is uninvestigated, anaerobic cocci have previously been shown to be involved in other chronic inflammatory human conditions.

METHODS

In this study the anaerobic microflora of the deep tissues of 18 patients with refractory chronic venous leg ulcers (mean age 80.3 years; mean duration > 24 months) was characterized using strict anaerobic culture conditions. The effect of the anaerobic organisms isolated from these tissues on extracellular matrix (ECM) proteolysis and cellular wound healing responses was studied using in vitro models.

RESULTS

Anaerobic organisms were present in the deep tissues of 14 of 18 wounds and were principally Peptostreptococcus spp. The effects of three Peptostreptococcus spp. isolated from these wounds (P. magnus, P. vaginalis and P. asaccharolyticus) on cellular wound healing responses were compared with those of two pathogenic organisms also isolated from these wounds (Pseudomonas aeruginosa and Citrobacter diversus). While the direct ECM proteolytic activity exhibited by the Peptostreptococcus spp. was limited, they did significantly inhibit both fibroblast and keratinocyte proliferation, but only at high concentrations. However, at lower concentrations peptostreptococcal supernatants profoundly inhibited keratinocyte wound repopulation and endothelial tubule formation. The magnitude of these effects varied between strains and they were distinct from those demonstrated by Pseudomonas aeruginosa and Citrobacter diversus.

CONCLUSIONS

These studies confirm the importance of anaerobic organisms in chronic wounds and demonstrate an indirect, strain-specific mechanism by which these microorganisms may play a part in mediating the chronicity of these wounds.

The sensitivity to honey of Gram-positive cocci of clinical significance isolated from wounds

AIMS

To determine the sensitivity to honey of Gram-positive cocci of clinical significance in wounds and demonstrate that inhibition is not exclusively due to osmotic effects.

METHODS AND RESULTS

Eighteen strains of methicillin-resistant Staphylococcus aureus and seven strains of vancomycin-sensitive enterococci were isolated from infected wounds and 20 strains of vancomycin-resistant enterococci were isolated from hospital environmental surfaces. Using an agar incorporation technique to determine the minimum inhibitory concentration (MIC), their sensitivity to two natural honeys of median levels of antibacterial activity was established and compared with an artificial honey solution. For all of the strains tested, the MIC values against manuka and pasture honey were below 10% (v/v), but concentrations of artificial honey at least three times higher were required to achieve equivalent inhibition in vitro. Comparison of the MIC values of antibiotic-sensitive strains with their respective antibiotic-resistant strains demonstrated no marked differences in their susceptibilities to honey.

CONCLUSIONS

The inhibition of bacteria by honey is not exclusively due to osmolarity. For the Gram-positive cocci tested, antibiotic-sensitive and -resistant strains showed similar sensitivity to honey.

SIGNIFICANCE AND IMPACT OF THE STUDY

A possible role for honey in the treatment of wounds colonized by antibiotic-resistant bacteria is indicated.

Science, medicine and the future: healing chronic wounds

Greater interest in wound healing is needed to ensure higher standards of basic care. Precise identification of the systemic, local, and molecular factors underlying the wound healing problem in individual patients should allow better tailored treatment. Allogeneic skin grafting and bioengineered skin equivalents are being used successfully in patients with venous leg ulcers and diabetic patients with foot ulcers.

Use of molecular techniques to study microbial diversity in the skin: chronic wounds reevaluated

The skin is colonized by an array of microorganisms which form its natural microflora. Disruption to the normal barrier function of the skin (due to trauma or disease) may result in invasion of the dermis by opportunistic bacteria. To date, these organisms, which may contribute to the chronicity of skin wounds, have been analyzed solely by culture methods. It is increasingly realized that standard culture methods of analysis do not accurately reflect the full diversity of complex microflora. This review discusses the limitations of traditional culture approaches and reviews recent advances in molecular microbiological techniques which facilitate a more comprehensive characterization of the microflora within clinical samples. The currently available technologies and techniques are described, as is their use in clinical practice and their potential for diagnostic screening. Chronic venous ulceration of the lower limbs is an important skin disorder in which the microflora invading the dermal tissues contribute to the observed delayed healing. Using chronic leg ulcers as a working example, we show how strict culture and molecular microbiological techniques may be employed, for the first time in combination, to definitively characterize the invading microbial community of the dermis.

Inflammatory-cell subpopulations in keloid scars

The aim of this study was to investigate the contribution of lymphocytes and macrophages to keloid scarring by morphologically characterising inflammatory cell subpopulations in keloid scars in comparison with normal skin. We took 3mm punch biopsies from the anterior forearms of eight normal healthy volunteers. Eight keloid scars were excised using an intralesional technique. All tissue was snap frozen in liquid nitrogen and serial sections were stained with a panel of anti-inflammatory cell monoclonal antibodies. The numbers of macrophages and lymphocytes and the proportions of the subpopulations were compared. Higher numbers of both macrophages and lymphocytes were found in keloid dermis (P=0.01 and P=0.02, respectively (Mann-Whitney U -test)). There was no significant increase in the expression of the lymphocyte-activation markers, CD25 and CD27. However, there was a significantly higher CD4(+):CD8(+)(Th:Ts) ratio (P= 0.046) in keloid tissue. This suggests that an imbalance in these inflammatory cell subpopulations may contribute to keloid scarring in man.

Managing gravitational eczema and allergic contact dermatitis

Venous leg ulceration is a common chronic problem in the community, and gravitational eczema is a common complication of it. The presence of gravitational eczema can lead to further ulceration and may also impair wound healing. Treatment often requires more than one topical preparation, to gain control and prevent relapse. Knowledge of the benefits and risks of these therapeutic modalities is essential, in this article we aim to provide a practical approach to the treatment of gravitational eczema. We also discuss allergic contact dermatitis, a common complication of gravitational eczema.

Using wound fluid analyses to identify trace element requirements for efficient healing

A series of wound fluid and blood plasma samples from 20 patients with breast cancer were analysed by Potentiometric Stripping Analysis and computer-aided chemical speciation to quantify the concentrations of the trace elements of copper and zinc in the samples and to investigate the individual species of copper and zinc present. Comparisons were made between total concentrations of copper and zinc in wound fluid, pre-operative blood plasma levels and reference values. A wound fluid model constructed using JESS identified the main copper and zinc species present. It was also used to investigate the effects of a change in pH and changes in the total concentrations of certain components on their predominance. The clinical significance of the research is discussed, together with suggestions for a continuation in the research.

Specific growth factors and the healing of chronic wounds

Part II of this two-part review focuses on the function of specific growth factors in wound healing and considers the results of clinical trials of their use in chronic wounds.

A dynamic regulator: the role of growth factors in tissue repair

Growth factors have the potential to improve wound healing during the three main phases of wound repair. This review, the first in a two-part series, explains how they do this.

Exploring the use of an alginate dressing for diabetic foot ulcers

Few studies have investigated the use of dressings on patients with diabetic foot ulceration. This paper reports the results of a non-comparative, two-centre study investigating the performance characteristics of SeaSorb dressing in patients with this condition. This was an exploratory study to determine the potential use of this dressing, and not a large randomised control trial. All patients had diabetic foot ulceration of 1 cm or more in diameter, classified as Wagner grade I or II, with an ankle brachial pressure index of > 0.4. The investigators carried out objective assessments including photography and ulcer tracing as well as subjective assessments of exudate levels, wound bed condition, peri-ulcer skin condition, ease of application and removal of the dressing, dressing conformability, discomfort during dressing application and removal, and clinical signs of infection. Investigators recruited 41 patients in two sites (31 in site one and 10 in site two). Of these, the findings relating to 39 patients could be evaluated. The patients were treated for a maximum of six weeks or until the ulcer healed. The study found that 28.2% (11/39) of the ulcers healed within the six-week period. Overall, there was a significant reduction in mean ulcer area from 2.8 cm 2 to 1.02 cm 2 from week 0 to week six. The relative ulcer area showed a significant decrease from 100% to 33%. For patients who experienced ulcer pain (11 patients), its intensity decreased over the six weeks. Severe maceration was not reported for any patient throughout the study. Six patients required treatment for infection. A total of 12 adverse events were reported: seven mild to moderate and five severe. None were directly attributed to the study dressing.