The clinical effectiveness of negative pressure wound therapy: a systematic review

Effectiveness of negative pressure wound therapy on chronic wound healing: A systematic review and meta-analysis

BACKGROUND

Negative Pressure Wound Therapy (NPWT) is considered an effective treatment in facilitating the healing of chronic wounds. However, its effect remains inconsistent, which allows for further investigation.

OBJECTIVE

This study aimed to assess the effectiveness of the NPWT program in improving the management of chronic wound healing.

DESIGN

Systematic review and meta-analysis was used.

DATA SOURCES

The search strategy ranged from 2016 to 2021 in PubMed, CINAHL, ProQuest, and ScienceDirect.

REVIEW METHODS

Risk of bias was done based on the Risk of Bias 2.0 guideline using RevMan 5.4.1, and meta-analysis was done using Jeffreys's Amazing Statistics Program (JASP) software version 0.16.3. Critical appraisal of the included articles was done according to Joanna Briggs Institute's (JBI) appraisal checklist.

RESULTS

A total of 15 articles were included, with 3,599 patients with chronic wounds. There was no publication bias in this study seen from the results of the Egger's test value of 0.447 (p >0.05), symmetrical funnel plot, and fail-safe N of 137. However, heterogeneity among studies was present, with I2 value of 66.7%, Q = 41.663 (p <0.001); thus, Random Effect (RE) model was used. The RE model showed a significant positive effect of the NPWT on chronic wound healing, with z = 3.014, p = 0.003, 95% CI 0.085 to 0.400. The observed effects include decreased rate of surgical site infection, controlled inflammation, edema, and exudate, as well as increased tissue with varying forest plot size, as demonstrated by the small effect size (ES = 0.24, 95% CI -0.26 to 0.79, p <0.05).

CONCLUSION

The analysis results show that the standard low pressure of 80-125 mmHg could improve microcirculation and accelerate the healing process of chronic wounds. Therefore, applying the NPWT program could be an alternative to nursing interventions. However, it should be carried out by competent wound nurses who carry out procedure steps, implement general patient care, and give tips on overcoming device problems and evaluation.

PROSPERO REGISTRATION NUMBER

CRD42022348457.

Closed Incision Negative Pressure Therapy: Indications and Adherence to Protocol

BACKGROUND

Complications associated with wound management not only increase the morbidity and mortality of surgical interventions but they also increase the cost and decrease the quality of care. Closed incision negative pressure therapy (CINPT) has been proposed as a superior method of wound care compared to the more traditional wound management methods. Since the Food and Drug Administration indications for using CINPT are broad and generally nonspecific, it is unclear whether patients are appropriately screened for and receive this treatment modality.

MATERIAL AND METHODS

To identify common clinical indications for CINPT, we conducted a literature review to define a consensus for CINPT candidates and used the American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP) database to indicate if certain patient demographics impact decision-making.

RESULTS

Based on the literature review, encompassing 57 articles, and the National Surgical Quality Improvement Program (NSQIP) database, over 11,000 patients received CINPT. Both the NSQIP data and the literature review commonly reported BMI >30 (47.1% and 39.6%), smoking (22.7% and 29.2%), and diabetes mellitus (22.7% and 47.9) as the most common clinical indications for using CINPT.

DISCUSSION

The most common indications for using CINPT according to the literature review and the NSQIP database are BMI > 30, smoking status, and diabetes mellitus. Besides identifying patients who potentially benefit the most from CINPT, the results of this study suggest clinical adherence to the practice guidelines reported in the literature regarding wound management using this treatment modality.

Split Thickness Skin Graft of the Foot and Ankle Bolstered With Negative Pressure Wound Therapy in a Diabetic Population: The Results of a Retrospective Review and Review of the Literature

Split thickness skin graft (STSG) is a versatile procedure performed for the treatment of wounds resulting from varying pathology. This remains very useful because of its ability for quick healing and low complication rate. The surface of the foot and ankle is an area frequently affected by severe skin and soft tissue structure infections (SSTIs) whose treatment results in wounds. These infections and resultant surgical wounds are commonly seen patients with diabetes. The objective of the present study was to retrospectively evaluate initial healing and immediate post-operative outcomes following STSG application in a diabetic population when negative pressure wound therapy (NPWT) was used as a bolster. Ten patients were identified, including 11 surgical wounds, who underwent STSG bolstered with NPWT from January 2016 to October 2018. Mean follow-up was 13 months (range 1-33 months) with an average time to heal of 17 days (range 14-30 days) for 11 surgical wounds averaging 57 cm2 (range 6.3 - 91 cm2). Consistent improved outcomes have been demonstrated when compared to alternative bolstering techniques available in the literature making a STSG bolstered with NPWT a powerful tool in the reconstruction of diabetic foot wounds resulting from the treatment of infection.Levels of Evidence: Level IV.

Treatment of hard-to-heal leg ulcers with hyaluronic acid, sodium alginate and negative pressure wound therapy

OBJECTIVE

Hard-to-heal lower extremity ulcer is a common healthcare problem and can lead to a poor quality of life (QoL). Despite the advances in wound care, conventional therapies, such as necrotic tissue debridement, cleansing, treatment of infection and local treatment with dressing application are still considered the standard of care in patients with hard-to-heal leg ulcers. However, managing hard-to-heal ulcers that do not respond well to these methods has led to new treatment strategies. In this study, the effects of hyaluronic acid (HA) and sodium alginate (SA), combined with negative pressure wound therapy (NPWT), in patients with hard-to-heal leg ulcers are evaluated.

METHOD

Patients with hard-to-heal lower extremity ulcers were treated with HA-SA combined with NPWT (HA-SA-NWPT, n=11), or conventional therapy (n=14), between June 2014 and September 2015. Demographics, comorbidities, time to complete healing and change in wound area were recorded and compared.

RESULTS

A total of 25 patients took part. Complete healing was achieved in 63.6% (n=7) of the patients in the HA-SA with NPWT group, compared with 14.3% (n=2) of the patients in the conventional therapy group (p=0.017). The mean decrease in wound size was significantly higher in the HA-SA-NPWT group than in the conventional therapy group (73.8% versus 34.8%, respectively, p=0.029). Despite a shorter healing period in the HA-SA-NPWT group than in the conventional group, no statistically significant difference was found between groups for time to complete healing (37 days versus 55 days, respectively).

CONCLUSION

These results demonstrate that the combination of HA-SA-NPWT is a promising treatment for decreasing the healing time and increasing the success rate by their synergistic effect on wound healing in hard-to-heal lower extremity ulcers. However, further studies with a larger number of patients are needed to confirm the results.

PWD: Treatment Platform for Both Prolonged Field Care and Definitive Treatment of Burn-Injured Warfighters

INTRODUCTION

Burns are a very frequent injury type in the battlefield, comprising 5-20% of combat casualties in the recent conflicts. Almost 80% of the burns occur to the face, in part because the face is often not protected. Immediate treatment is critical in the first hours after severe burn injury in order to prevent infection and wound progression. Immediate treatment in the battlefield can be a serious challenge especially if the injury occurs in a remote area with limited transport options. Therefore, novel treatment modalities for prolonged field care when transport to the definitive care is delayed are needed. The purpose of this study was to utilize the platform wound device (PWD) with negative pressure capabilities for the immediate and definitive treatment of porcine full-thickness head burns.

MATERIALS AND METHODS

Full-thickness burn wounds were created on foreheads of seven Yorkshire pigs. Burns were created on day 0, immediately enclosed with the PWD and treated topically with minocycline and lidocaine. On day 3, the burns were surgically debrided. Subsequently, new PWDs were placed on the wounds and continuous negative pressure wound therapy was initiated with either -50 mmHg or -80 mmHg. On day 7, the animals were euthanized and wounds were harvested for analyses. Control wounds were treated with silver sulfadiazine cream.

RESULTS

The PWD treatment with negative pressure significantly reduced erythema and edema in the injured tissue and promoted granulation tissue and neocollagen formation by day 7 in comparison to control wounds. In addition, the PWD with both topical minocycline and negative pressure (-80 mmHg or -50 mmHg) reduced bacterial counts in the wounds similar to the current standard of care.

CONCLUSION

This study demonstrates that the PWD is an effective platform for delivery of antibiotics and negative pressure wound therapy for the treatment of full-thickness burns. Therefore, the PWD may be utilized for both prolonged field care and definitive treatment of burn- and blast-injured warfighters.

Use of home negative pressure wound therapy in peripheral artery disease and diabetic limb salvage

Use of negative pressure wound therapy (NPWT) in peripheral artery disease (PAD) and diabetic limb salvage (DLS) improves wound healing by providing moist wound conditions, reducing exudate, controlling wound-bed infection, and stimulating granulation. NPWT duration may take several weeks, and home-based NPWT allows patient to recover in the community while minimising risks of prolonged hospitalisation. The aim of this study is to review the use and outcomes of home NPWT in PAD and DLS. The methodology is the retrospective review of patients who were discharged with home NPWT after in-patient PAD revascularisation and DLS debridement or minor amputations. The results included a total of 118 patients who received home NPWT between January 2017 and December 2017. The mean age was 62.8 years with 66% male and 34% female patients. The study population comprised 25% smokers, 98% patients with diabetics, 35% with ischemic heart disease, and 21% with end-stage renal failure (ESRF). Of which, 56% of patients required revascularisation while 31% of patients underwent foot debridement, 48% underwent toe amputations, and 20% underwent forefoot amputations. All patients received in-patient NPWT for a week before being discharged on home NPWT for 4 weeks. Then, 62% received targeted antibiotics regime while 36% received empirical antibiotics on discharge; 60% of patients achieved wound healing on home NPWT, with 9% requiring split-thickness skin graft; 4% required further surgical debridement, 16% required further minor amputation while 20% required major amputation. 9% required further home NPWT extension, with a mean length of 7.1 ± 4.7 weeks' extension. Overall survival of 1 year was 89%. Risk factors that predict the failure of home NPWT includes subjects with a background of ESRF and wet gangrene on presentation. Home NPWT is a useful adjunct in the management of PAD and DLS foot wounds.

The effectiveness of negative pressure wound therapy as a novel management of diabetic foot ulcers: an overview of systematic reviews

Background

Diabetic foot ulcer (DFU) is one the serious disabling conditions in patients with diabetes. Several approaches are available to manage DFU including Negative Pressure Wound Therapy (NPWT). The objective of this overview is systematically reviewing the related reviews about the effectiveness, safety, and cost benefits of NPWT interventions.

Methods

In October 2018, electronic databases including Medline, Embase, Scopous, Web of Science, the Cochrane Library and Google scholar were searched for systematic reviews about the NPWT's effectiveness and safety in DFUs. The Assessment of Multiple Systematic Reviews 2 (AMSTAR2) checklist was used for the appraisal of the systematic reviews. According to this checklist the studies were categorized as high, moderate, low and critically low quality.

Results

The electronic searches yielded 6889 studies. After excluding duplicates and those not fellfield the inclusion criteria, 23 systematic reviews were considered. The sample size of the reviews ranged between 20 and 2800 patients published since 2004 to 2018. Twenty systematic reviews (86.95%) included only randomized clinical trials (RCT). Regarding the AMSTAR-2 checklist, 7 studies were assigned to high quality, 8 were categorized as low quality and 8 studies belonged to the critically low quality groups. Accordingly, three, two and one out of seven high quality studies approved the effectiveness, safety and cost benefit of the NPWT therapy, respectively. However, some of them declared that there is some flaws in RCTs designing.

Conclusion

This overview illustrated that either systematic reviews or the included RCTs had wide variety of quality and heterogeneity in order to provide high level of evidence. Hence, well-designed RCTs as well as meta-analysis are required to shade the light on different aspects of NPWT.

Bioinorganics and Wound Healing

Wound dressings and the healing enhancement (increasing healing speed and quality) are two components of wound care that lead to a proper healing. Wound care today consists mostly of providing an optimal environment by removing waste and necrotic tissues from a wound, preventing infections, and keeping the wounds adequately moist. This is however often not enough to re-establish the healing process in chronic wounds; with the local disruption of vascularization, the local environment is lacking oxygen, nutrients, and has a modified ionic and molecular concentration which limits the healing process. This disruption may affect cellular ionic pumps, energy production, chemotaxis, etc., and will affect the healing process. Biomaterials for wound healing range from simple absorbents to sophisticated bioactive delivery vehicles. Often placing a material in or on a wound can change multiple parameters such as pH, ionic concentration, and osmolarity, and it can be challenging to pinpoint key mechanism of action. This article reviews the literature of several inorganic ions and molecules and their potential effects on the different wound healing phases and their use in new wound dressings.

Treatment of open upper limb injuries with infection prevention and negative pressure wound therapy: a systematic review

OBJECTIVE

Open upper limb injuries requiring soft reconstruction can pose a dilemma for trauma surgeons when considering the treatment options. The British Orthopaedic Association and British Association of Plastic, Reconstructive and Aesthetic Surgeons Standard for Trauma (BOAST) have addressed the management of severe open lower limb fractures with the creation of the BOAST 4 guidelines. However, no such gold standard exists for the treatment of open injuries of the upper limb. Furthermore, treatment of these injuries is often more difficult and requires complicated strategies. Since the advent of negative pressure wound therapy (NPWT), there has been an improvement in wound care, though a focused review of its use in wound closure and infection prevention in the upper limb has not been published. We examine wound care management for open upper limb injuries with regard to the dressings applied, NPWT, wound closure and infection prevention.

METHOD

A systematic search of Medline, Cochrane and Google Scholar was performed using the key words. The key word searches were performed by two independent reviewers and 8,792 papers were found. Manuscripts between 1990 and 2010 were included, with the addition of key manuscripts before this date. Each manuscript was assessed by the two authors independently for methodology and validity Results: Approximately 120 manuscripts fulfilled selection criteria examining the influence of NPWT on open upper and lower limb injuries, and those examining infection risk in the same injuries. Of these 120 manuscripts, 28 were suitable for inclusion in the review. The systematic review is presented, allied to the BOAST 4 principles, examining the use of NPWT and the tools available for infection prevention for wounds of the upper and lower limb. The use of NPWT in conjunction with antibiotic-bead therapy improved the way in which open fractures of both the upper and lower limb are treated.

CONCLUSION

Production of guidelines is warranted for the treatment of upper limb injuries. The treatment options available for wound closure and infection prevention that are used in the treatment of open injuries of the lower limb could be adopted to open injuries of the upper limb.

Bacterial-binding dressings in the management of wound healing and infection prevention: a narrative review

The aim of this review was to present the clinical data on the use of the family of bacterial-binding dressings (Sorbact; dialkylcarbamoyl chloride-coated) in the treatment of a variety of acute and chronic wounds. The findings are discussed in terms of the effectiveness of the bacterial-binding dressings on bacterial bioburden reduction, infection prevention, initiation/progression of wound healing and cost-effectiveness. The evidence in support of the bacterial-binding dressings is strongest in the area of infection prevention in surgical wounds, with several controlled trials showing the prophylactic benefit of the dressing in these wounds. Wound bioburden management in chronic wounds is supported by a number of clinical studies. In total, 29 published clinical studies (with a total of 4044 patients) were included in this review.

Crafting Polymeric and Peptidic Hydrogels for Improved Wound Healing

Wound healing is a multifaceted biological process involving the replacement of damaged tissues and cellular structures, restoring the skin barrier's function, and maintaining internal homeostasis. Over the past two decades, numerous approaches are undertaken to improve the quality and healing rate of complex acute and chronic wounds, including synthetic and natural polymeric scaffolds, skin grafts, and supramolecular hydrogels. In this context, this review assesses the advantages and drawbacks of various types of supramolecular hydrogels including both polymeric and peptide-based hydrogels for wound healing applications. The molecular design features of natural and synthetic polymers are examined, as well as therapeutic-based and drug-free peptide hydrogels, and the strategies for each system are analyzed to integrate key elements such as biocompatibility, bioactivity, stimuli-responsiveness, site specificity, biodegradability, and clearance.

Endoluminal Vacuum Therapy (E-Vac): A Treatment Option in Oesophagogastric Surgery

Background

Leaks from the upper gastrointestinal tract often pose a management challenge, particularly when surgical treatment has failed or is impossible. Vacuum therapy has revolutionised the treatment of wounds, and its role in enabling and accelerating healing is now explored in oesophagogastric surgery.

Methods

A piece of open cell foam is sutured around the distal end of a nasogastric tube using a silk suture. Under general anaesthetic, the foam covered tip is placed endoscopically through the perforation and into any extra-luminal cavity. Continuous negative pressure (125 mmHg) is then applied. Re-evaluation with change of the negative pressure system is performed every 48–72 h depending on the clinical condition. Patients are fed enterally and treated with broad-spectrum antibiotics and anti-fungal medication until healing, assessed endoscopically and/or radiologically, is complete.

Results

Since April 2011, twenty one patients have been treated. The cause of the leak was postoperative/iatrogenic complications (14 patients) and ischaemic/spontaneous perforation (seven patients). Twenty patients (95%) completed treatment successfully with healing of the defect and/or resolution of the cavity and were subsequently discharged from our care. One patient died from sepsis related to an oesophageal leak after withdrawing consent for further intervention following a single endoluminal vacuum (E-Vac) treatment. In addition, two patients who were successfully treated with E-Vac for their leak subsequently died within 90 days of E-Vac treatment from complications that were not associated with the E-Vac procedure. In two patients, E-Vac treatment was complicated by bleeding. The median number of E-Vac changes was 7 (range 3–12), and the median length of hospital stay was 35 days (range 23–152).

Conclusions

E-Vac therapy is a safe and effective treatment for upper gastrointestinal leaks and should be considered alongside more established therapies. Further research is now needed to understand the mechanism of action and to improve the ease with which E-Vac therapy can be delivered.

Quality of life and scar evolution after negative pressure or conventional therapy for wound dehiscence following post-bariatric abdominoplasty

No studies have examined scars and quality of life after different treatments of wound dehiscence in patients undergoing post-bariatric abdominoplasty. Scars and quality of life of patients with postoperative wound dehiscence managed with negative pressure wound therapy (group A) and conventional wound therapy (group B) were reviewed 6 months after wound healing. Of 38 patients undergoing treatment for wound dehiscence after 203 abdominoplasty, 35 (group A = 14 versus group B = 21) entered the study. Wound healing in group A was significantly faster than group B (P = 0·001). Patients (P = 0·0001) and observers (P = 0·0001) reported better overall opinions on a scar assessment scale for group A. Better overall quality of life and general health satisfaction were observed in group A (P < 0·05). A significant correlation was observed between the World Health Organization Quality of Life scores and Patient and Observer Scar Assessment Scale scores (r=-0·68, P < 0·0001) in all 35 patients. Negative pressure wound therapy is feasible and effective in patients with wound dehiscence following post-bariatric abdominoplasty. An adequate post-treatment outcome is achieved compared with conventional wound therapy in light of a strong association found between worse patient scar self-assessment and poor overall quality of life, regardless of the received treatment.

Prevention of postsurgical wound dehiscence after abdominal surgery with NPWT: a multicentre randomised controlled trial protocol

OBJECTIVE

The effectiveness of negative pressure wound therapy (NPWT) in the prevention of postoperative surgical wound dehiscence (SWD) is the subject of much debate and remains to be determined. This study will identify individuals at risk of postoperative SWD and trial the use of NPWT as a prophylactic measure against the occurrence of SWD, compared with a non-NPWT standard surgical dressing (SSD).

METHOD

A prospective multicentre randomised controlled trial comparing NPWT dressing against standard surgical dressings (SSD) will be conducted. An intention-to-treat (ITT) approach will be used for the trial.

AIMS

The primary outcome is the prevention of postoperative SWD up to and including day 30 postoperative. Secondary outcomes are: prevention of surgical site infection (SSI) and economic analysis of treatment groups.

CONCLUSION

This study will determine the effectiveness of NPWT in the prevention of postoperative abdominal SWD in a predefined level of risk population. This level 1 study will provide further data for abdominal SWD risk classification, which is anticipated to inform preventive postoperative management. The study design uses a prospective real-world scenario in order to identify clinically significant differences between the intervention and control groups.

TRIAL REGISTRATION

This trial was prospectively registered on 10 December 2012 with Australian and New Zealand Clinical Trials Network (ANZCTR): 12612001275853.

Uso de curativo a vácuo como terapia adjuvante na cicatrização de sítio cirúrgico infectado

Resumo Infecções de sítios cirúrgicos com envolvimento de próteses sintéticas constituem grande desafio para tratamento. Apresentamos o caso de uma paciente com múltiplas comorbidades, histórico de enxerto aortobifemoral há 6 anos e reabordagem das anastomoses femorais por reestenoses há 5 anos. Apresentou dor inguinal esquerda e abaulamento súbitos com diagnóstico de pseudoaneurisma femoral roto e instabilidade hemodinâmica. Foi submetida a correção emergencial com interposição de prótese de dácron recoberta por prata e correção de grande hérnia incisional abdominal com tela sintética ao mesmo tempo. No pós-operatório, manteve-se por longo período sob terapia intensiva com dificuldade de extubação. Nesse ínterim, apresentou deiscência das suturas e fístula purulenta inguinal esquerda em contato com a prótese vascular. Optou-se pelo tratamento conservador, com desbridamento das feridas e aplicação de curativo a vácuo. A paciente evoluiu com melhora e cicatrização das feridas. Essa pode se constituir em ferramenta importante em casos similares.

Improving wound healing and preventing surgical site complications of closed surgical incisions: a possible role of Incisional Negative Pressure Wound Therapy. A systematic review of the literature

Advances in preoperative care, surgical techniques and technologies have enabled surgeons to achieve primary closure in a high percentage of surgical procedures. However, often, underlying patient comorbidities in addition to surgical-related factors make the management of surgical wounds primary closure challenging because of the higher risk of developing complications. To date, extensive evidence exists, which demonstrate the benefits of negative pressure dressing in the treatment of open wounds; recently, Incisional Negative Pressure Wound Therapy (INPWT) technology as delivered by Prevena™ (KCI USA, Inc., San Antonio, TX) and Pico (Smith & Nephew Inc, Andover, MA) systems has been the focus of a new investigation on possible prophylactic measures to prevent complications via application immediately after surgery in high-risk, clean, closed surgical incisions. A systematic review was performed to evaluate INPWT's effect on surgical sites healing by primary intention. The primary outcomes of interest are an understanding of INPWT functioning and mechanisms of action, extrapolated from animal and biomedical engineering studies and incidence of complications (infection, dehiscence, seroma, hematoma, skin and fat necrosis, skin and fascial dehiscence or blistering) and other variables influenced by applying INPWT (re-operation and re-hospitalization rates, time to dry wound, cost saving) extrapolated from human studies. A search was conducted for published articles in various databases including PubMed, Google Scholar and Scopus Database from 2006 to March 2014. Supplemental searches were performed using reference lists and conference proceedings. Studies selection was based on predetermined inclusion and exclusion criteria and data extraction regarding study quality, model investigated, epidemiological and clinical characteristics and type of surgery, and the outcomes were applied to all the articles included. 1 biomedical engineering study, 2 animal studies, 15 human studies for a total of 6 randomized controlled trials, 5 prospective cohort studies, 7 retrospective analyses, were included. Human studies investigated the outcomes of 1042 incisions on 1003 patients. The literature shows a decrease in the incidence of infection, sero-haematoma formation and on the re-operation rates when using INPWT. Lower level of evidence was found on dehiscence, decreased in some studies, and was inconsistent to make a conclusion. Because of limited studies, it is difficult to make any assertions on the other variables, suggesting a requirement for further studies for proper recommendations on INPWT.

The Diabetic Foot: A Historical Overview and Gaps in Current Treatment

Significance: The number of patients with diabetes is rapidly increasing around the world. A large percentage of this population can be expected to develop diabetic ulcers. The economic, social, and public health burden of these ulcers is enormous. It is a common problem that is tackled every day by many healthcare workers throughout the world. Recent Advances: Many pioneers contributed to the good standard of care we have today when treating diabetes and its complications. Current treatment of diabetic foot ulcers involves a multidisciplinary team approach, controls the underlying disease, and treats the wounds using debridement, different wound dressings, and redistributes pressure off the wound. Critical Issues: Since the discovery of the association between diabetes and gangrene of the foot 160 years ago, there have been developments and milestones that are the base of our treatment today. However, with all the modern wound treatment available today, there is a group of patients with hard-to-heal ulcers who do not seem to respond to the regular treatment. Future Directions: It is clear that more research has to be done to improve techniques that will enhance wound healing in chronic wounds. Innovative techniques will be discussed and outlined in this article.

A D-optimal design to model the performances of dressings and devices for negative pressure wound therapy

A D-optimal design was used to identify and model variables that affect the transit time of wound exudate through an illustrative dressing used for negative pressure wound therapy. Many authors have addressed the clinical benefits of negative pressure wound therapy, but limited information is available on how to assess performances of dressings. In this paper, the transit time of wound exudate through a dressing was chosen as a model parameter to show how experimental design (DOE) can be used for this purpose. Results demonstrated that rate of exudate production, temperature and dressing thickness were the variables with the largest impact on transit time. The DOE approach could be used to model other dressing properties, like for example capability of absorbing excess exudate or breathability.

Seeking effective interventions to treat complex wounds: an overview of systematic reviews

BACKGROUND

Numerous, often multi-faceted regimens are available for treating complex wounds, yet the evidence of these interventions is recondite across the literature. We aimed to identify effective interventions to treat complex wounds through an overview of systematic reviews.

METHODS

MEDLINE (OVID interface, 1946 until October 26, 2012), EMBASE (OVID interface, 1947 until October 26, 2012), and the Cochrane Database of Systematic Reviews (Issue 10 of 12, 2012) were searched on October 26, 2012. Systematic reviews that examined adults receiving care for their complex wounds were included. Two reviewers independently screened the literature, abstracted data, and assessed study quality using the Assessment of Multiple Systematic Reviews (AMSTAR) tool.

RESULTS

Overall, 99 systematic reviews were included after screening 6,200 titles and abstracts and 422 full-texts; 54 were systematic reviews with a meta-analysis (including data on over 54,000 patients) and 45 were systematic reviews without a meta-analysis. Overall, 44% of included reviews were rated as being of high quality (AMSTAR score ≥ 8). Based on data from systematic reviews including a meta-analysis with an AMSTAR score ≥ 8, promising interventions for complex wounds were identified. These included bandages or stockings (multi-layer, high compression) and wound cleansing for venous leg ulcers; four-layer bandages for mixed arterial/venous leg ulcers; biologics, ultrasound, and hydrogel dressings for diabetic leg/foot ulcers; hydrocolloid dressings, electrotherapy, air-fluidized beds, and alternate foam mattresses for pressure ulcers; and silver dressings and ultrasound for unspecified mixed complex wounds. For surgical wound infections, topical negative pressure and vacuum-assisted closure were promising interventions, but this was based on evidence from moderate to low quality systematic reviews.

CONCLUSIONS

Numerous interventions can be utilized for patients with varying types of complex wounds, yet few treatments were consistently effective across all outcomes throughout the literature. Clinicians and patients can use our results to tailor effective treatment according to type of complex wound. Network meta-analysis will be of benefit to decision-makers, as it will permit multiple treatment comparisons and ranking of the effectiveness of all interventions. Please see related article: http://dx.doi.org/10.1186/s12916-015-0326-3.

Adipose stromal cells repair pressure ulcers in both young and elderly mice: potential role of adipogenesis in skin repair

More than 2.5 million patients in the U.S. require treatment for pressure ulcers annually, and the elderly are at particularly high risk for pressure ulcer development. Current therapy for pressure ulcers consists of conservative medical management for shallow lesions and aggressive debridement and surgery for deeper lesions. The current study uses a murine model to address the hypothesis that adipose-derived stromal/stem cell (ASC) treatment would accelerate and enhance pressure ulcer repair. The dorsal skin of both young (2 months old [mo]) and old (20 mo) C57BL/6J female mice was sandwiched between external magnets for 12 hours over 2 consecutive days to initiate a pressure ulcer. One day following the induction, mice were injected with ASCs isolated from congenic mice transgenic for the green fluorescent protein under a ubiquitous promoter. Relative to phosphate-buffered saline-treated controls, ASC-treated mice displayed a cell concentration-dependent acceleration of wound closure, improved epidermal/dermal architecture, increased adipogenesis, and reduced inflammatory cell infiltration. The ASC-induced improvements occurred in both young and elderly recipients, although the expression profile of angiogenic, immunomodulatory, and reparative mRNAs differed as a function of age. The results are consistent with clinical reports that fat grafting improved skin architecture in thermal injuries; the authors of this published study have invoked ASC-based mechanisms to account for their clinical outcomes. Thus, the current proof-of-principle study sets the stage for clinical translation of autologous and/or allogeneic ASC treatment of pressure ulcers.

SIGNIFICANCE

Adipose-derived stromal/stem cells (ASCs) promote the healing of pressure ulcer wounds in both young and old mice. ASCs enhance wound healing rates through adipogenic differentiation and regeneration of the underlying architecture of the skin.

A Multicenter Randomized Controlled Trial Comparing Treatment of Venous Leg Ulcers Using Mechanically Versus Electrically Powered Negative Pressure Wound Therapy

Objective: This study compares two different negative pressure wound therapy (NPWT) modalities in the treatment of venous leg ulcers (VLUs), the ultraportable mechanically powered (MP) Smart Negative Pressure (SNaP^®) Wound Care System to the electrically powered (EP) Vacuum-Assisted Closure (V.A.C.^®) System. Approach: Patients with VLUs from 13 centers participated in this prospective randomized controlled trial. Each subject was randomly assigned to treatment with either MP NPWT or EP NPWT and evaluated for 16 weeks or complete wound closure. Results: Forty patients (n=19 MP NPWT and n=21 EP NPWT) completed the study. Primary endpoint analysis of wound size reduction found wounds in the MP NPWT group had significantly greater wound size reduction than those in the EP NPWT group at 4, 8, 12, and 16 weeks (p-value=0.0039, 0.0086, 0.0002, and 0.0005, respectively). Kaplan-Meier analyses showed greater acceleration in complete wound closure in the MP NPWT group. At 30 days, 50% wound closure was achieved in 52.6% (10/19) of patients treated with MP NPWT and 23.8% (5/21) of patients treated with EP NPWT. At 90 days, complete wound closure was achieved in 57.9% (11/19) of patients treated with MP NPWT and 38.15% (8/21) of patients treated with EP NPWT. Innovation: These data support the use of MP-NPWT for the treatment of VLUs. Conclusions: In this group of venous ulcers, wounds treated with MP NPWT demonstrated greater improvement and a higher likelihood of complete wound closure than those treated with EP NPWT.

Treatment of a paediatric patient with a distal lower extremity traumatic wound using a dermal regeneration template and NPWT

Degloving injuries are common in trauma and represent a spectrum of complex wounds, the management of which may be highly challenging especially in the paediatric population. In severe injuries leading to wounds reaching tendon and bone, vascularity is compromised precluding traditional wound management, and sometimes necessitating amputation. This report highlights the use of a dermal regeneration template combined with vacuum-assisted closure (VAC) in the treatment of complex traumatic degloving wounds. Here, we present a case of a five-year-old boy who sustained a high-energy shear injury to his lower extremity that resulted in an extensive degloving wound involving the distal third of his leg and the dorsum of his foot. After debridement, the patient underwent VAC combined with a dermal skin substitute placement, followed by split-thickness skin grafting. The extremity healed with no complications and without the need for amputation or flap reconstruction, achieving satisfactory recovery of range of motion and favourable cosmetic results.

Negative pressure wound therapy in head and neck surgery

IMPORTANCE Negative pressure wound therapy has been shown to accelerate healing. There is a paucity of literature reporting its use as a tool to promote wound healing in head and neck reconstruction. OBJECTIVE To review 1 institution's experience with negative pressure dressings to further describe the indications, safety, and efficacy of this technique in the head and neck. DESIGN, SETTING, AND PARTICIPANTS Retrospective case series at a tertiary care academic hospital. One hundred fifteen patients had negative pressure dressings applied between April 2005 and December 2011. Data were gathered, including indications, details of negative pressure dressing use, adverse events, wound healing results, potential risk factors for compromised wound healing (defined as previous radiation therapy, hypothyroidism, or diabetes mellitus), and wound characteristics (complex wounds included those with salivary contamination, bone exposure, great vessel exposure, in the field of previous microvascular free tissue transfer, or in the case of peristomal application in laryngectomy). EXPOSURE Negative pressure wound therapy utilized after head and neck reconstruction. MAIN OUTCOMES AND MEASURES Indications for therapy, length and number of dressing applications, identification of wound healing risk factors, classification of wound complexity, wound healing results, and adverse events related to the use of the device. RESULTS Negative pressure wound therapy was used primarily for wounds of the neck (94 of 115 patients [81.7%]) in addition to other head and neck locations (14 of 115 patients [12.2%]), and free tissue transfer donor sites (7 of 115 patients [6.1%]). The mean (SD) wound size was 5.6 (5.0) cm. The mean number of negative pressure dressing applications was 1.7 (1.2), with an application length of 3.7 (1.4) days. Potential risk factors for compromised wound healing were present in 82 of 115 patients (71.3%). Ninety-one of 115 patients (79.1%) had complex wounds. Negative pressure dressings were used in wounds with salivary contamination (n = 64), bone exposure (n = 40), great vessel exposure (n = 25), previous free tissue transfer (n = 55), and peristomal application after laryngectomy (n = 32). Adverse events occurred in 4 of 115 patients (3.5%). CONCLUSIONS AND RELEVANCE Negative pressure wound therapy in head and neck surgery is safe and has potential to be a useful tool for complex wounds in patients with a compromised ability to heal. LEVEL OF EVIDENCE 4.

The role of Renasys-GO™ in the treatment of diabetic lower limb ulcers: a case series

Introduction

This case series aims to study the effectiveness of Renasys-GO™ negative pressure wound therapy system in the healing of diabetic lower limb ulcers.

Materials and methods

An electronic vacuum pump (Renasys-GO™, Smith & Nephew GmbH) was used to apply negative pressure wound therapy on wounds, with pressure settings determined according to clinical indication. Changes in wound dimension, infection status and duration of treatment were recorded over the course of Renasys-GO™ therapy in 10 patients with diabetic lower limb ulcers.

Results

Healing was achieved in all wounds, three by secondary closure and seven by split-thickness skin grafting. Eight wounds showed a reduction in wound size. The average duration of treatment with Renasys-GO™ therapy was 15.9 days, and all wounds showed sufficient granulation and were cleared of bacterial infection at the end of therapy.

Conclusions

Renasys-GO™ therapy may be beneficial in the treatment of diabetic lower limb ulcers and wounds. In this study, which included wounds presenting as post-surgery ray amputation, metatarsal excision wounds, post-debridement abscesses and ulcers, the Renasys-GO™ therapy prepared all wounds for closure via split-thickness skin grafting or secondary healing by promoting granulation tissue and reducing bacterial infection in approximately 2 weeks.

The enhanced healing of a high-risk, clean, sutured surgical incision by prophylactic negative pressure wound therapy as delivered by Prevena™ Customizable™: cosmetic and therapeutic results

According to the literature, incisional closure complications may range from postoperative surgical site infections, representing 17-22% of health care-associated infections, surgical wound dehiscence and formation of haematomas or seromas, and can lead to delayed or impaired incision healing. These kinds of situations are more common when wounds are closed under tension or in specific patient morbidities. Obesity, in particular, is associated with an impaired blood flow to tissues, predisposing the patient to increased risk of wound complications by various mechanisms. Incisional complications can become relevant economic burdens for health care systems because of an increase in the average length of hospital stay and readmissions, and additional medical and surgical procedures. Thus, a preventive therapy may have a critical role in the management of healing. Negative pressure wound therapy (NPWT) technology as delivered by Prevena™ Customizable™ (Kinetic Concepts Inc., San Antonio, TX) has recently been the focus of a new investigation, as a prophylactic measure to prevent complications via immediate postoperative application in high-risk, clean, closed surgical incisions. The authors present a 62-year-old class II obese female, who underwent bilateral inguinal dermolipectomy. Prophylactic NPWT as delivered by Prevena™ was performed successfully over surgical incisions. Cosmetic and therapeutic results are shown.

Negative pressure wound therapy: experience in 45 dogs

OBJECTIVE

To report experience with negative pressure wound therapy (NPWT) in 45 consecutive dogs admitted with extensive cutaneous wounds and to determine if NPWT is feasible in veterinary hospital practice.

STUDY DESIGN

Prospective descriptive study.

ANIMALS

Dogs (n = 45).

METHODS

Collected data were organized into 6 categories: patient data, wound data, NPWT data, adjunctive treatments, complications, and final outcome.

RESULTS

Wounds (53 in 45 dogs) were largely traumatic in origin, and distributed fairly evenly to the trunk, proximal and distal aspects of the limbs. Most wounds (34 dogs, 76%) had no granulation tissue and were treated a mean of 4.2 days after wounding, whereas 11 dogs had granulating wounds that were initially treated a mean of 87 days after wounding. Median NPWT use was 3 days with a mean hospitalization of 7.8 days. Most wounds (33; 62%) were closed surgically after NPWT and were healed by 14 days. The other 18 wounds healed (mean, 21 days) by second intention after hospital discharge. Overall, 96% of the wounds healed; 2 dogs died before definitive closure could be attempted.

CONCLUSION

NPWT is applicable to a wide variety of canine wounds, is well tolerated, allows for several days between dressing changes, and can used to optimize the wound bed for surgical closure or second intention healing.

Wound care in venous ulcers

Wound dressings: ulcer dressings should create and maintain a moist environment on the ulcer surface. It has been shown that in an ulcer with a hard crust and desiccated bed, the healing process is significantly slowed and sometimes completely blocked so favouring infection, inflammation and pain. In contrast a moist environment promotes autolytic debridement, angiogenesis and the more rapid formation of granulation tissue, favours keratinocytes migration and accelerates healing of wounds. Apart from these common characteristics, wound dressings are completely different in other aspects and must be used according to the ulcer stage. In necrotic ulcers, autolytic debridement by means of hydrogel and hydrocolloids or with enzymatic paste is preferred. In case of largely exuding wounds alginate or hydrofibre are indicated. When bleeding occurs alginate is indicated due to its haemostatic power. Where ulcers are covered by granulation tissue, polyurethane foams are preferred. When infection coexists antiseptics are necessary: dressing containing silver or iodine with large antibacterial spectrum have proved to be very effective. In the epithelization stage polyurethane films or membranes, thin hydrocolloids or collagen based dressings are very useful to favour advancement of the healing wound edge. Despite these considerations, a Cochrane review failed to find advantages for any dressing type compared with low-adherent dressings applied beneath compression. Surgical debridement and grafting of wounds, negative wound pressure treatment: surgical and hydrosurgical debridement are indicated in large, necrotic and infected wounds as these treatments are able to get rid of necrotic, infected tissue very quickly in a single surgical session, thereby significantly accelerating wound bed preparation and healing time. Negative wound pressure treatment creating a negative pressure on ulcer bed is able to favour granulation tissue and shorten healing time. In case of hard-to-heal leg ulcers such as large, deep, infected and long-lasting venous ulcers, sharp debridement and skin grafting may favour and shorten ulcer healing.

Current achievements with topical negative pressure to improve wound healing in dehiscent ischemic stumps of diabetic patients: a case series

Negative pressure wound therapy has been increasingly used either as a primary or as an adjunctive therapeutic measure to treat a variety of recalcitrant wounds during the past years. It is thought to act by creating a local environment that promotes cell proliferation, angiogenesis, and granulation tissue formation, leading to accelerated wound healing to the point of spontaneous closure or reducing the wound size to facilitate significantly further surgical reconstruction. This case series presents our preliminary experience with the use of a Topical Negative Pressure system in the treatment of challenging ischemic wounds of diabetic patients. It aims to underscore its beneficial effects and explore its potential role in the management of ischemic amputated stumps to avoid ipsilateral re-amputation at a higher level.

Effects of negative pressure wound therapy on healing of free full-thickness skin grafts in dogs

OBJECTIVE

To compare healing of free, full-thickness, meshed skin grafts under negative pressure wound therapy (NPWT) with bolster dressings in dogs.

STUDY DESIGN

Randomized, controlled experimental study, paired design.

ANIMALS

Dogs (n = 5) METHODS: Full-thickness skin wounds (4 cm × 1.5 cm) were created bilaterally on the antebrachia of 5 dogs (n = 10). Excised skin was grafted to the contralateral limb. Grafts were randomized to NPWT or bolster dressings (control; CON). NPWT was applied continuously for 7 days. Grafts were evaluated on Days 2, 4, 7, 10, 14, and 17, biopsied on days 0, 4, 7, and 14, and had microbial culture on Day 7. Outcome variables were: time to first appearance of granulation tissue, percent graft necrosis, and percent open mesh. Significance was set at P < .05. Histologic findings, culture results, and graft appearance were reported.

RESULTS

Granulation tissue appeared earlier in the NPWT grafts compared with CON grafts. Percent graft necrosis and remaining open mesh area were both greater in CON grafts compared with NPWT grafts at most time points. Histologic results showed no significant difference in all variables measured, and all cultures were negative.

CONCLUSIONS

Variables of graft acceptance were superior when NPWT was used in the first week post-grafting. Fibroplasia was enhanced, open meshes closed more rapidly and less graft necrosis occurred with NPWT application. More preclinical studies are required to evaluate histologic differences.

Negative-pressure wound therapy: a hemostatic adjunct for control of coagulopathic hemorrhage in large soft tissue wounds

BACKGROUND

Negative-pressure wound therapy has been commonly used for treating chronic wounds and recently applied for treatment of traumatic wounds. We investigated the potential hemostatic benefit of negative-pressure wound therapy for control of refractory hemorrhage in a soft tissue wound model in swine.

METHODS

Coagulopathy was induced in pigs (n = 38, 36 kg) by hemodilution and hypothermia. Next, a large soft tissue wound (diameter, approximately 20 cm) was created by slicing the gluteus maximus muscle. Free bleeding was allowed for 1 minute, and wounds were then randomly dressed with either laparotomy gauze (G) alone or TraumaPad (TP, a kaolin-coated dressing) alone or in combination with negative pressure (NP, approximately -500 mm Hg). All wounds were sealed with adhesive drapes. Fluid resuscitation was administered and targeted to mean arterial pressure of 60 mm Hg. Pigs were observed for 150 minutes or until death after which tissues were sampled for histologic examination.

RESULTS

Induced coagulopathy as measured by increases in prothrombin time (12%) and activated partial thromboplastin time (22%) and decreases in fibrinogen (48%) were similar in all groups. There were no differences in initial bleeding rates (4.5 mL/kg/min). Dressing the wounds with G or TP produced hemostasis only in one pig (1 of 18 pigs). Addition of NP to these dressings secured hemostasis in 70% (G) and 90% (TP) of animals with average hemostasis time of 34 minutes and 25 minutes, respectively. Blood losses and fluid resuscitation requirements were significantly less, and survival times were significantly longer in NP adjunct groups than in the other groups. Survival rates were 80% (G+NP) and 90% (TP+NP) versus 0% (G) and 10% (TP) in the respective groups. Histologic examination showed similar superficial myofibril damages in all groups.

CONCLUSION

To our knowledge, the present data provide the first evidence that NP serves as an effective hemostatic adjunct and when combined with standard hemostatic dressing it is able to stop lethal coagulopathic bleeding in large soft tissue wounds.

Use of negative pressure wound therapy over clean, closed surgical incisions

The literature has reported that surgical site infections account for 17-22% of health care-associated infections, while surgical wound dehiscence rates range from 0.25% to 3.0% (post laparatomies), 1.6% to 42.3% (post-caesarean incisions) and 0.5% to 2.5% (sternal incisions). These types of incisional complications can become a significant cost burden to the health care system because of lengthy hospital stays and readmissions, additional nursing care and added surgical procedures. Therefore, the type of therapy used for surgical incisions plays a critical role in the healing process. The success of negative pressure wound therapy (NPWT; V.A.C.® Therapy; KCI USA, Inc., San Antonio, TX) for open wounds has been well documented and has led to its use over clean, closed surgical incisions. This review will focus on clinician experience and literature review of incisional NPWT and will include clinical cases describing NPWT's successful use over surgical incisions.

Management of diabetic foot ulcers

Diabetic foot is a serious complication of diabetes which aggravates the patient's condition whilst also having significant socioeconomic impact. The aim of the present review is to summarize the causes and pathogenetic mechanisms leading to diabetic foot, and to focus on the management of this important health issue. Increasing physicians' awareness and hence their ability to identify the "foot at risk," along with proper foot care, may prevent diabetic foot ulceration and thus reduce the risk of amputation.

Does treatment of split-thickness skin grafts with negative-pressure wound therapy improve tissue markers of wound healing in a porcine experimental model?

BACKGROUND

Negative-pressure wound therapy (NPWT) has been used for to treat wounds for more than 15 years and, more recently, has been used to secure split-thickness skin grafts. There are some data to support this use of NPWT, but the actual mechanism by which NPWT speeds healing or improves skin graft take is not entirely known. The purpose of this project was to assess whether NPWT improved angiogenesis, wound healing, or graft survival when compared with traditional bolster dressings securing split-thickness skin grafts in a porcine model.

METHODS

We performed two split-thickness skin grafts on each of eight 30 kg Yorkshire pigs. We took graft biopsies on postoperative days 2, 4, 6, 8, and 10 and submitted the samples for immunohistochemical staining, as well as standard hematoxylin and eosin staining. We measured the degree of vascular ingrowth via immunohistochemical staining for von Willenbrand's factor to better identify blood vessel epithelium. We determined the mean cross-sectional area of blood vessels present for each representative specimen, and then compared the bolster and NPWT samples. We also assessed each graft for incorporation and survival at postoperative day 10.

RESULTS

Our analysis of the data revealed that there was no statistically significant difference in the degree of vascular ingrowth as measured by mean cross-sectional capillary area (p = 0.23). We did not note any difference in graft survival or apparent incorporation on a macroscopic level, although standard hematoxylin and eosin staining indicated that microscopically, there seemed to be better subjective graft incorporation in the NPWT samples and a nonsignificant trend toward improved graft survival in the NPWT group.

CONCLUSION

We were unable to demonstrate a significant difference in vessel ingrowth when comparing NPWT and traditional bolster methods for split-thickness skin graft fixation. More studies are needed to elucidate the manner by which NPWT exerts its effects and the true clinical magnitude of these effects.

Monitoring of systemic inflammatory response in diabetic patients with deep foot infection treated with negative pressure wound therapy

BACKGROUND

The purpose of this study was to establish the safety of negative pressure wound therapy (NPWT) in the treatment of acutely debrided, deep diabetic foot infections (DDFI) and to determine the value of inflammatory markers in monitoring of treatment of these infections with negative pressure wound therapy.

METHODS

A group of ten patients with DDFI treated by radical surgical debridement and simultaneous NPWT was prospectively studied. During the debridement, a deep tissue sample was obtained and sent for microbiological testing. The patients were followed clinically for 10 days and NPWT dressings were changed every 2 to 3 days or sooner when indicated. The peripheral blood samples were obtained before the radical debridement and 3 and 10 days afterwards and concentrations of white blood cell, neutrophils, lymphocytes and C-reactive protein (CRP) were measured. The changes in concentration of inflammatory markers were analyzed with a Friedman test.

RESULTS

In all but one patient the presence of DDFI was confirmed by the culture results. At baseline, the elevated WBC and neutrophil concentrations were observed only in half of the patients while the CRP concentration was elevated in nine patients. During followup, all patients showed a favorable clinical evolution and statistically significant decrease of WBC, neutrophils and CRP (p<0.001). There were not statistically significant changes in lymphocyte count.

CONCLUSION

NPWT can be safely applied in acutely debrided DDFI. CRP seems to be the most adequate parameter for both diagnosis and monitoring of treatment of DDFI.

Combination of negative pressure wound therapy and hyalomatrix application for soft tissue defect of the great toe

Soft tissue defect of the hallux can be particularly difficult to manage because of the absence of local muscle tissue for coverage. The author presents his experience of a combination therapy for severe posttraumatic soft tissue defect of the hallux in a young patient.