Venous ulcers of the lower extremity: Definition, epidemiology, and economic and social burdens

Metabolic Phenotyping in Venous Disease: The Need for Standardization

Venous thromboembolism (VTE), chronic venous disease (CVD), and venous leg ulceration (VLU) are clinical manifestations of a poorly functioning venous system. Though common, much is unknown of the pathophysiology and progression of these conditions. Metabolic phenotyping has been employed to explore mechanistic pathways involved in venous disease. A systematic literature review was performed: full text, primary research articles on the applications of nuclear magnetic resonance spectroscopy (NMR) and mass spectrometry (MS) in human participants and animals were included for qualitative synthesis. Seventeen studies applying metabolic phenotyping to venous disease were identified: six on CVD, two on VLU, and nine on VTE; both animal (n = 6) and human (n = 10) experimental designs were reported, with one study including both. NMR, MS, and MS imaging were employed to characterize serum, plasma, urine, wound fluid, and tissue. Metabolites found to be upregulated in CVD included lipids, branched chain amino acids (BCAA), glutamate, taurine, lactate, and myo-inositol identified in vein tissue. Upregulated metabolites in VLU included lactate, BCAA, lysine, 3-hydroxybutyrate, and glutamate identified in wound fluid and ulcer biopsies. VTE cases were associated with reduced carnitine levels, upregulated aromatic amino acids, 3-hydroxybutyrate, BCAA, and lipids in plasma, serum, thrombus, and vein wall; kynurenine and tricarboxylic acid pathway dysfunction were reported. Future research should focus on targeted studies with internal and external validation.

Regeneration and Repair of Skin Wounds: Various Strategies for Treatment

Skin as a mechanical barrier between the inner and outer environment of our body protects us against infection and electrolyte loss. This organ consists of 3 layers: the epidermis, dermis, and hypodermis. Any disruption in the integrity of skin leads to the formation of wounds, which are divided into 2 main categories: acute wounds and chronic wounds. Generally, acute wounds heal relatively faster. In contrast to acute wounds, closure of chronic wounds is delayed by 3 months after the initial insult. Treatment of chronic wounds has been one of the most challenging issues in the field of regenerative medicine, promoting scientists to develop various therapeutic strategies for a fast, qualified, and most cost-effective treatment modality. Here, we reviewed more recent approaches, including the development of stem cell therapy, tissue-engineered skin substitutes, and skin equivalents, for the healing of complex wounds.

Biobehavioral Mechanisms Associated With Nonhealing Wounds and Psychoneurologic Symptoms (Pain, Cognitive Dysfunction, Fatigue, Depression, and Anxiety) in Older Individuals With Chronic Venous Leg Ulcers

The prevalence and incidence of chronic venous leg ulcers (CVLUs) are increasing worldwide, as are the associated financial costs. Although it has long been known that their underlying etiology is venous insufficiency, the molecular aspects of healing versus nonhealing, as well as the psychoneurologic symptoms (PNS; pain, cognitive dysfunction, fatigue, depression, and anxiety) associated with CVLUs remain understudied. In this biobehaviorally focused review, we aim to elucidate the complex mechanisms that link the biological and molecular aspects of CLVUs with their PNS. Innovations in "omics" research have increased our understanding of important wound microenvironmental factors (e.g., inflammation, microbial pathogenic biofilm, epigenetic processes) that may adversely alter the wound bed's molecular milieu so that microbes evade immune detection. Although these molecular factors are not singularly responsible for wound healing, they are major components of wound development, nonhealing, and PNS that, until now, have not been amenable to systematic study, especially over time. Further, this review explores our current understanding of the molecular mechanisms by which the immune activation that contributes to the development and persistence of CVLUs also leads to the development, persistence, and severity of wound-related PNS. We also make recommendations for future research that will expand the field of biobehavioral wound science. Biobehavioral research that focuses on the interrelated mechanisms of PNS will lead to symptom-management interventions that improve quality of life for the population burdened by CVLUs.

Review of adjustable velcro wrap devices for venous ulceration

Compression therapy is the mainstay of treatment for patients with venous leg ulcers. Current gold standard is 4 layer bandaging, which has a significant impact on patients comfort, ability to wear their own shoes, and quality of life, as well as taking significant time to apply, and losing compression over time. This systematic review aims to evaluate the use of Velcro wrap devices for the treatment of venous ulceration. Preferred reporting items for systematic reviews and meta-analyses (PRISMA) guidelines were used to identify articles reporting the use of Velcro wrap devices in patients with venous ulceration. Sixteen articles were identified (14 case series, 1 randomised trial, and 1 audit) reporting on 192 patients. There were reports of improved time to healing, reduced cost by >50%, reduced number and duration of nursing appointments, and improved quality of life in patients in Velcro wrap devices. Although the evidence remains poor, Velcro devices have potential to improve outcomes for patients with venous ulceration and further good quality studies should be undertaken to evaluate these further.

Use of Native Type I Collagen Matrix Plus Polyhexamethylene Biguanide for Chronic Wound Treatment

Background:

Chronic wounds represent a significant financial burden to the healthcare system and a quality-of-life burden to patients. Many chronic wounds have elevated bioburden in the form of biofilm, which has been associated with delayed wound healing. This study examined the use of a native type I collagen matrix with the antimicrobial polyhexamethylene biguanide (PCMP) in the management of bioburden and treatment of chronic, nonhealing wounds over 12 weeks.

Methods:

A prospective case series of PCMP enrolled adults ≥18 years old with a nonhealing wound. At week 0, the wound was prepared by sharp or mechanical debridement. Patients received standard wound care plus PCMP applications at week 0 and then weekly up to week 12 at the investigator’s discretion. Dressings were applied over PCMP to fix it in place. At each visit, wounds were assessed for the extent of healing and signs of wound infection.

Results:

Of the 41 wounds studied, 44% were pressure ulcers, 22% were surgical wounds, 12% were venous ulcers, 10% were diabetic ulcers, and 12% were another type. The median (interquartile range) baseline wound area was 7.2 (14.9) cm², and the mean wound duration was 103 weeks. Of the 41 wounds, 73% demonstrated a reduction in wound area at 12 weeks, and 37% achieved complete wound closure, with a mean time of 6.7 weeks to complete closure.

Conclusion:

PCMP treatment appeared to positively impact the course of wound healing in a variety of complex, chronic wounds that were unresponsive to prior treatment.

Epidemiology of venous leg ulcers in primary health care: Incidence and prevalence in a health centre-A time series study (2010-2014)

The aims of the study were to describe and analyse the temporal trend of the prevalence and incidence of venous leg ulcers (VLU) over the years 2010 to 2014, to determine healing times and temporal trends in the study period, and to evaluate related aspects such as the use of the Ankle-Brachial Pressure Index (ABPI) in a primary care health centre. This was a retrospective study based on a time series (years 2010-2014) of the prevalence and incidence of VLUs in people aged over 40 years in a primary care centre in Barcelona City. We reviewed 3920 electronic health records selecting patients, per year (2010-2014), with VLUs based on the ICD-10 diagnoses. For prevalence, we took into account any patient with an active VLU in the year of study. For incidence, we took into account patients with a new VLU in the year of study. A descriptive analysis was carried out based on each of the collected variables. The variables were examined according to the years of study (time series) by one-factor analysis of variance (anova) or Kruskal-Wallis non-parametric test, as appropriate. A survival analysis by Kaplan-Meier curves and log-rank test was also performed. A total of 139 patients met the VLU criteria. Among them, only 79.2% were classified as having a VLU and had a correct ICD diagnosis. The prevalence and incidence increased over the years, doubling in patients aged over 65 years. Incidence increased from 0.5 new cases per 1000 people/year in 2010 to 1 new case for every 1000 people/year in 2014. Moreover, the prevalence ranged between 0.8 and 2.2 patients with VLU for every 1000 people/year. During the study period, a total of 84.2% of the VLUs healed (117/139 VLU). Regarding average annual time to healing, the trend indicates that lesions took less time to heal (Kruskal-Wallis test, P = 0.004), ranging between 453,9 weeks in 2005 to 19 weeks in 2014. The use of ABPI also evolved and was found to be increasingly performed prior to the appearance of the lesion. The epidemiological profile of people affected by VLUs continues to be, mainly, that of women of an advanced age, over 70 years. The frequency of VLU occurrence rose continually over the years, but healing took less time, and use of ABPI improved. Assigning a reference nurse in the wounds unit and the organisational structure around this problem may have an influence on improving care and the approach to these types of lesions.

Risk factors associated with the venous leg ulcer that fails to heal after 1 year of treatment

BACKGROUND

Despite regular treatment of venous leg ulcers (VLUs), some fail to heal. Although several risk factors have previously been identified to be associated with the failure of VLUs to heal, the majority of studies are limited to <24-week follow-up.

METHODS

A retrospective cohort study was performed at an academic vascular and wound center. A total of 65 patients with VLUs who were observed for a year or more were identified. These patients underwent a variety of treatments following the Society for Vascular Surgery and American Venous Forum VLU guidelines. Risk factors, which were based on previously defined elements for failure of VLUs to heal after a period of treatment, were examined. Both univariate (unadjusted) and multivariate (adjusted) logistic regression analyses were used to assess the magnitude of effect that a given risk factor had on healing.

RESULTS

Of 65 patients treated for a minimum of 52 weeks, 19 (29%) remained unhealed. By univariate analysis, deep venous disease (P = .01; odds ratio [OR], 5.82; 95% confidence interval [CI], 1.49-22.72), history of deep venous thrombosis (P < .001; OR, 14.06; 95% CI, 3.77-52.39), and depression (P = .04; OR, 3.89; 95% CI, 1.10-13.80) were all shown to be significant risk factors for nonhealing. The patient's race (ie, being nonwhite; P = .02; OR, 103.45; 95% CI, 1.94-5.53 × 10³), deep venous disease (P = .05; OR, 37.0; 95% CI, 1.05-1.31 × 10³), and history of deep venous thrombosis (P = .01; OR, 122.4; 95% CI, 3.09-4.84 × 10³), however, were all shown to be significant for nonhealing under multivariate analysis. In addition, identification of an incompetent perforator (P = .02; OR, 0.006; 95% CI, 9.27 × 10^-5-0.44) was conversely shown to be a good prognostic factor for healing.

CONCLUSIONS

This study confirmed that risk factors known to be associated with the failure of a VLU to heal-deep venous disease and post-thrombotic etiology-were significant at 52 weeks, whereas depression and race (nonwhite) are novel risk factors. An analysis of markers of access to care showed no difference between white and nonwhite, suggesting other factors as a cause. The predominance of deep venous disease in the unhealed vs healed cohort (84% vs 48%) highlights the need for a viable treatment option for deep venous disease due to reflux. Overall, this study emphasizes the need to consider all risk factors when evaluating a patient for VLU to coordinate an effective treatment plan and to identify gaps in our treatment.

Health-related quality of life in patients with venous leg ulcer treated in primary care in Brazil and Portugal

BACKGROUND

Venous ulcers constitute an important public health problem as they can cause disability with consequences for multiple dimensions of quality of life.

OBJECTIVE

To describe the quality of life in patients with venous leg ulcer treated in primary care in two cities from Brazil and Portugal.

METHODS

This was a cross-sectional comparative study with a non-probabilistic sample of 171 patients with venous leg ulcers who were treated in primary care in two cities from Brazil and Portugal, namely, Natal and Évora. A form covering sociodemographic and health data and the Medical Outcomes Study 36-Item Short-Form Health Survey were used, and descriptive and inferential analyses were performed.

RESULTS

Significant differences in age and income were observed between the two samples. Patients with venous leg ulcer from Brazil had lower income and were younger than those from Portugal. Quality of life scores were significantly higher in Portugal for the physical aspects, pain, and social functioning, among domains, and for the physical health dimension and total score of QOL.

CONCLUSION

The quality of life was better in Portugal than in Brazil and the differences between the countries need further investigation.

Randomized, controlled clinical pilot study of venous leg ulcers treated with using two types of shockwave therapy

Background. Venous leg ulcers are difficult to heal wounds. The basis of their physiotherapeutic treatment is compression therapy. However, for many years, the search for additional or other methods to supplement the treatment of venous ulcers, which would shorten the duration of treatment, is underway. One of such methods is the shockwave therapy. Methods. The purpose of our study was to compare radial shockwave therapy (R-ESWT) with focused shockwave therapy (F-ESWT) in venous leg ulcers treatment. Patients were randomly assigned to tree groups. In the first group the radial shockwave therapy (0.17mJ/mm², 100 impulses/cm², 5 Hz), in the second group the focused shockwave therapy (0.173mJ/mm², 100 impulses/cm², 5 Hz) was used and in third group standard care was used. Patients in shockwave therapy groups were given 6 treatments at five-day intervals. Total area, circumference, Gilman index, maximum length and maximum width of ulcers were measured. The patients from the third group wet gauze dressing with saline and gently compressing elastic bandages were used (standard wound care SWC). Results. Analysis of the results shows that a complete cure of ulcers was achieved in 35% of patients who were treated with radial shockwave, 26% of patients with focused shockwave used. There is statistically significant difference between the standard care and radial shockwave therapy as well as between the standard care and focused shockwave therapy. There is no statistically significant difference between the use of radial and focused shockwave in the treatment of venous leg ulcers (p> 0.05). Conclusion. There is no statistically significant difference between the use of radial and focused shockwave in the treatment of venous leg ulcers. Treatment of venous leg ulcers with shockwaves is more effective than the standard wound care.

Implementing clinical process management of vascular wounds in a tertiary facility: impact evaluation of a performance improvement project

Background

Chronic vascular wounds have a significant economic and social impact on our society calling for allocation of a great deal of attention and resources. Efforts should be oriented toward the achievement of the most effective and efficient clinical management. The Angiology Unit at the University Hospital of Padova, Italy, developed a performance improvement project to enhance the quality of practice for vascular ulcers.

Methods

The project consisted in a multistep process comprising a critical revision of the previous clinical process management, staff education, tightening connections between operators and services, and creation of a position for a wound care nurse. The previous standard of practice was modified according to the results of revision and the current evidence-based practice.

Results

The new standard of practice reached its full application in September 2015. The number of patients treated and the number of visits in 2015 remained almost unvaried from 2014. However, the total annual expenditure for treating vascular ulcers was reduced by ~60% from the previous year.

Conclusion

Standardization of guidelines and practice is effective in creating an efficient clinical management and in reducing the economic burden of vascular ulcers.

Incidence of venous leg ulcer healing and recurrence after treatment with endovenous laser ablation

BACKGROUND

The Effect of Surgery and Compression on Healing and Recurrence (ESCHAR) trial previously reported that patients with venous leg ulcers treated with saphenous stripping experienced a significantly reduced incidence of ulcer recurrence compared with patients treated with compression therapy. Most patients with leg ulcers and saphenous insufficiency are currently treated with endovenous thermal ablation (EVTA), but little information is available on the long-term results after EVTA in Clinical, Etiology, Anatomy, and Pathophysiology (CEAP) clinical class 5 (C5) and class 6 (C6) patients.

METHODS

We retrospectively reviewed all CEAP C5 or C6 patients treated with EVTA to define the incidence of ulcer healing and recurrence. Patients with active ulcers were managed weekly in a comprehensive wound center until healed. After healing, patients were treated with compression stockings and returned at 6-month intervals for follow-up. Time to healing and time to ulcer recurrence were determined by Kaplan-Meier survival analysis. Risk factors were assessed to determine their association with ulcer recurrence.

RESULTS

EVTA of the great saphenous vein (n = 146), small saphenous vein (n = 20), or both (n = 7) was performed on 173 limbs with active (n = 72) or healed (n = 101) ulcers. Deep venous insufficiency was present in 54 cases (31.2%). Concomitant phlebectomy was performed in 59 limbs (34%). Median follow-up time was 25.2 months after EVTA. Venous ulcers healed after EVTA in 57% of cases at 3 months, 74% at 6 months, and 78% at 12 months. Ulcers recurred in 9% of patients at 1 year after EVTA, 20% at 2 years, and 29% at 3 years of follow-up. Ulcers recurred significantly more often in patients with deep venous insufficiency and in patients who did not undergo phlebectomy of associated varicose veins at the time of EVTA.

CONCLUSIONS

Ulcers recurred in a minority of CEAP clinical C5 and C6 patients after EVTA of the saphenous veins. Ulcer recurrence was less frequent in patients without concomitant deep venous reflux and in those treated with phlebectomy of varicose veins at the time of EVTA. We suggest consideration of phlebectomy at the time of EVTA for patients with C5 and C6 venous insufficiency, particularly in those with isolated superficial venous insufficiency.

The use of medicinal plants in venous ulcers: a systematic review with meta-analysis

The aim of this study was to systematically review the use of medicinal plants for the treatment of varicose ulcers. The databases used in the search were: Medline/Pubmed, Scopus, Cinhal, Lilacs and Web of Science. The selection process was divided into two phases: the reading of titles and abstracts and the full reading of selected articles. The item description was compared with the checklist of the Consolidated Standards of Reporting Trials. The initial search produced 3505 articles and seven were selected for inclusion in the systematic review. Of the included studies, 7 (100%) evaluated the reduction of the ulcer area, 4 (57·14%) evaluated reepithelisation, 2 (28·57%) evaluated bacterial flora and 1 (14·28%) evaluated the oxygen pressure and percutaneous carbon dioxide. The level of evidence rating indicated that five studies (71·42%) were rated at level 2 and two (28·57%) were rated at level 3. The quality assessment was performed using the Jadad scale, which is prevalent in the literature. The quality score of the Jadad questionnaire ranges from 0 to 5; here, the studies analysed had an average of 2·5. A meta-analysis was performed on two studies that analysed the effects of Mimosa tenuiflora hydrogel in the treatment of venous ulcer and included 42 patients with a mean age of 60·5 years and a mean duration of treatment of 10·5 weeks. Heterogeneity was assessed using I² ; we obtained a high value of 84%. We concluded that, despite the efficacy of the incorporation of Ageratina pichinchensis into the gel, the hydrogel that incorporated M. tenuiflora appeared to be a promising candidate for the management of venous ulcers.

Treatment of Chronic Lower Extremity Ulcers with A New Er:Yag Laser Technology

Chronic lower extremity ulcers (CLEUs) have a high prevalence and are difficult to treat due to their various aetiologies. The aim of this study is to evaluate the results achieved in treating CLEUs using an Erbium: YAG (Er:YAG) laser with RecoSMA technology. This laser emits thousands of microbeams of energy causing superficial epidermal ablation and a separation of dermal fibres due to a mechanical-acoustic and resonance effect. The evaluation of the results achieved was carried out by questionnaires completed by 18 patients enrolled in the study. Histological studies and photographs taken before each session (16 sessions in total) were analysed to visually monitor the clinical progress. The analyses were carried out with the help of computer software. The results after 16 treatment sessions showed the complete healing of ulcers or a decrease in their initial area of at least 55% in over 65% of the patients treated. The Student's t-test and Fisher's exact test were used for statistical analysis. The Er:YAG laser and RecoSMA technology ablates few epidermal cell layers, producing a mechanical-acoustic effect with resonance action leading to tissue regeneration mechanisms. This technology offers an effective and safe alternative for treating CLEUs.

Self-Care-Based Treatment Using Ordinary Elastic Bandages for Venous Leg Ulcers

Objective: We aimed to study venous leg ulcer (VLU) healing and recurrence rates of VLU using a self-care-based treatment strategy. Methods: The study included 36 patients (43 legs) who visited our clinic between April 2009 and June 2015 because of non-healing VLUs and who had been treated by us for more than a year (until June 2016). Patients or their caregivers were first provided instructions for performing the "no-intentional-stretch" bandaging technique using ordinary elastic bandages. Wounds were cleansed with tepid water daily, and bandages were re-applied by patients or their caregivers; this was continued until VLUs were healed. Compression was discontinued after healing, but was restarted if persistent swelling and/or dermatitis was noticed on their legs. Results: The median ulcer size was 6.5 cm² (range, 1-105 cm²). The median number of clinic visits until healing was six (range, 3-35). The 6- and 12-month healing rates were 67% and 86%, respectively. Twenty (44%) legs required compression therapy after VLU healing. The cumulative recurrence-free rate at 60 months was 86%. Conclusion: Reasonable healing and recurrence rates were achieved by applying a self-care-based VLU treatment strategy.

Impact of optimal anticoagulation therapy on chronic venous ulcer healing in thrombophilic patients with post-thrombotic syndrome

OBJECTIVE

Post-thrombotic syndrome (PTS) is the long-term sequelae of deep venous thrombosis (DVT). PTS clinical manifestations include chronic leg pain, oedema, lipodermatosclerosis and ulcers. The objective of this study is to determine in patients with documented history of thrombophilias and DVT whether the number of previous thrombotic events and optimal anticoagulation therapy are associated with the time to venous ulcer healing following the start of compression therapy.

METHOD

Retrospective analysis performed in thrombophilic patients under the age of 50 years old with chronic venous ulcers secondary to DVT at the wound clinic in the National Institute of Medical Sciences and Nutrition 'Salvador Zubirán ' in Mexico City. Variables such as the number or episodes of thrombotic events, type of hypercoagulable disorder, optimal anticoagulation therapy with Warfarin monitored by therapeutic International Normalised Ratio (INR) (2-3) and compliance to compression therapy were examined. Patients that underwent superficial or perforator vein interruption or endovascular recanalisation of deep veins were excluded from the study.

RESULTS

From a database of 29 patients with chronic venous ulcers followed in our clinic from January 1992 to September 2012, only 13 patients (61% female) met the inclusion criteria. Mean age±standard deviation (SD) was 32±12 years old. Of these, seven (54%) patients with suboptimal INR presented with an average of two previous thrombotic events and the remaining six (46%) patients with optimal INR only one event (p=0.28), the mean time to the clinical manifestation of a venous ulcer after the first episode of DVT was 39 months (range: 12-72) for patients with suboptimal INR and 82 months (range: 12-216) for those with optimal anticoagulation therapy (p=0.11). During the mean follow-up period of 52 months, all patients in optimal anticoagulation healed their ulcer; their mean time for wound healing was 44 months (range: 4-102). In the suboptimal INR group, only four healed the ulcers with an mean of 72 months (range: 2-204) (p=0.94).

CONCLUSION

There seems to be an association between an optimal anticoagulation therapy with Warfarin monitored by INR and wound healing rates in thrombophilic patients with chronic venous ulcers. Further research is warranted.

DECLARATION OF INTEREST

The authors have no conflict of interest.

Framing of research question using the PICOT format in randomised controlled trials of venous ulcer disease: a protocol for a systematic survey of the literature

INTRODUCTION

Although venous ulcers have a great social and economic impact, there is a lack of evidence from randomised controlled trials (RCTs) to support appropriate management for this disease. Framing the research question using the Population; Intervention; Comparator; Outcome; Time frame (PICOT) format in RCTs can improve the quality of the research design.

OBJECTIVES

To evaluate how the PICOT format is used to frame a research question in reports of RCTs of venous ulcer disease and to determine the factors associated with better adherence to the PICOT format in framing the research question.

METHODS AND ANALYSES

We will conduct a systematic survey of RCTs on venous ulcers published in the National Institute of Health, PubMed database between January 2009 and May 2016. We will include all RCTs addressing therapeutic intervention for venous ulcer disease involving human subjects, and published in the English language. The selection process will be carried out in duplicate by two independent investigators. First, titles and abstracts will be screened, then full-text articles. We will examine whether the five elements of the PICOT format are used in formulating the research question and give a score between 0 and 5. The primary outcome will be the proportion of studies that have adequately reported all five PICOT elements.

DISSEMINATION

This will be the first survey to assess how the PICOT format is used to frame research questions on the management of venous ulcers in reports of RCTs. On completion, this review will be submitted to a peer-reviewed biomedical journal for publication and the findings will also be presented at scientific conferences.

Compression for Primary Prevention, Treatment, and Prevention of Recurrence of Venous Leg Ulcers: An Evidence-and Consensus-Based Algorithm for Care Across the Continuum

Chronic venous insufficiency is a prevalent disease that frequently leads to development of venous leg ulcers. While a number of evidence-based clinical practice guidelines have been developed that provide guidance for clinicians when caring for patients with chronic venous insufficiency, they lack adequate detail concerning selection and application of compression for prevention and management of venous leg ulcers. In order to address this need, the WOCN Society appointed a task force to develop an algorithm for compression for primary prevention, treatment, and prevention of recurrent venous leg ulcers in persons with chronic venous insufficiency. The task force used findings from a scoping literature review to identify current best evidence needed to support decision points and pathways within the algorithm. In addition, the task force convened a panel of 20 clinicians and researchers with expertise in lower extremity venous disorders in order to establish consensus around pathways and decision points within the algorithm lacking robust evidence. Following initial construction of the algorithm, a second interdisciplinary group of expert clinicians established content validity and provided additional qualitative feedback used to complete final revisions of the algorithm. This article reviews the process used to create this landmark algorithm, including generation of the evidence- and consensus-based statements used in its construction, the various pathways, and rich supplemental materials embedded within the algorithm, and the process used to establish content validity.

Efficacy of gelatin gel sheets in sustaining the release of basic fibroblast growth factor for murine skin defects

BACKGROUND

Gelatin has been used as a material sustaining the release of basic fibroblast growth factor (bFGF), which promotes fibroblast proliferation and capillary formation and accelerates wound healing. In the application of these materials, bFGF is impregnated immediately before application, and it is difficult to conform the shape to the wound. In this study, we prepared a pliable and plastic gelatin gel sheet (GGS) that sustains bFGF and conforms to the shape of the wound as a result of cross-linking just before application. In addition, we examined the sustained release profile of bFGF from GGS and its effect on wound healing in murine skin defects.

MATERIALS AND METHODS

A 13-wt% gelatin solution was mixed with bFGF before cross-linking with 1% glutaraldehyde solution. GGSs impregnated with 7 μg/cm(2) of bFGF were incubated in phosphate-buffered saline and collagenase solution, and GGS degradation and bFGF release were evaluated. In the murine experiments, GGSs treated without bFGF and GGSs impregnated with 1, 3.5, 7, or 14 μg/cm(2) of bFGF were applied to full-thickness skin defects created on the backs of C57BL/6JJcl mice, and the wound closure, epithelial length, extent of granulation tissue and capillary formation were compared.

RESULTS

bFGF was released according to the degradation of GGS in phosphate-buffered saline, and the remaining bFGF was released in collagenase solution. In the animal studies, epithelialization was accelerated in the GGSs treated with 1 and 3.5 μg/cm(2) of bFGF, and granulation tissue formation and angiogenesis were promoted based on the amount of bFGF impregnated into the GGS.

CONCLUSIONS

GGS impregnated with bFGF is capable of sustaining the release of bFGF, with consequent accelerated epithelialization, granulation tissue formation, and angiogenesis in vivo. GGS is a novel and promising wound dressing that sustains bFGF and can be adapted to the shape of various wounds in the treatment of both acute and chronic wounds.