The influence of different sizes and types of wound fillers on wound contraction and tissue pressure during negative pressure wound therapy

Tissue Pressure Changes and Implications on Dressing Selection when utilising Negative Pressure Wound Therapy on an Ex Vivo Porcine Model

Negative Pressure Wound Therapy (NPWT) is broadly used in surgical wound management and more recently burn care; however, the tissue pressure changes and best dressing application technique remains unknown. This study was done to help understand the tissue pressure changes beneath negative pressure when varying the delivered pressures, dressing thickness and distribution of dressings. This study was done in 2021 at a quaternary paediatric burns hospital. Utilising a cadaveric porcine model, an intracranial pressure monitor and transducer were used to assess pressure. The transducer was placed on the epidermis or inserted under ultrasound guidance via cannulation to the dermis, subcutaneous or muscular layer. Mepitel™, ACTICOAT™, varying layers of Kerlix™ (10, 20 or 30 layers) and NPWT were then applied either circumferentially or non-circumferentially. Each set of results is indicative of the intracranial pressure probe reading when NPWT was delivered at -40, -60, -80, -100 and -120 mmHg. The median and interquartile pressure recordings were epidermis: -42 (-42.5 - -41), -60.5 (-62.5 - -60), -80.5 (-82 - -80), - 99 (-99 - -98)mmHg (p < 0.001); dermis: 1 (0 - 2), 2 (1 - 3.5), 3 (2 - 5.5), 4 (3 - 7), 5.5 (4 - 7.5)mmHg (p < 0.001) (the increase in pressure was less when circumferential dressings (p < 0.001) or more layers of Kerlix were applied (p < 0.001)); subcutis: 1.5 (-4.5-1), -2.5 (-7.5 - 1.5), -3.5 (-11 - 1.5), -5 (-14 - 1.5) and -6 (-16 - 2)mmHg (p = 006) (the decrease in pressure was less with increased layers of Kerlix (0.047) and muscular: 0 (-0.5 - 0), 0 (-1 - 0.5), 0 (-1 - 1), 0 0 (-1 - 1), 00 (-1.5 - 1)mmHg (p = 0.55). These data suggest negative pressure paradoxically exerts a positive pressure on the dermis. Circumferential and multi-layer dressings reduce this positive pressure. This knowledge has impacted our burn negative pressure wound therapy dressing selection. The limitation of this study is the cadaveric model, a live model is suggested for future studies.

Effect of negative pressure therapy on the treatment response to scar thickness and viscoelasticity

Patients with scars face a grave threat to their mental and physical health. Negative pressure has been used for scar therapy in medical care and provides a microenvironment conducive to scar healing while stimulating cell regeneration. Negative pressure may disrupt scar tissue regeneration when the pressure is too high or too low, so finding a suitable negative pressure is important. We hypothesized that different negative pressure magnitudes would affect scar tissue properties differently. This research aimed to provide practical recommendations for scar therapy. This study used three negative pressures (-105 mmHg, -125 mmHg, and -145 mmHg) to compare scar material properties. We measured scar tissue thickness and viscoelasticity with a motor-driven ultrasound indentation system. According to the results of this study, scar thickness is most effectively reduced at a negative pressure of -105 mmHg. In comparison, scar viscoelasticity continuously increases at a negative pressure of -125 mmHg. Negative pressure therapy can be recommended to scar care clinics based on the results of this study.

Seconds Timescale Synthesis of Highly Stretchable Antibacterial Hydrogel for Skin Wound Closure and Epidermal Strain Sensor

Effective wound healing is critical for patient care, and the development of novel wound dressing materials that promote healing, prevent infection, and are user-friendly is of great importance, particularly in the context of point-of-care testing (POCT). This study reports the synthesis of a hydrogel material that can be produced in less than 10 s and possesses antibacterial activity against both gram-negative and gram-positive microorganisms, as well as the ability to inhibit the growth of eukaryotic cells, such as yeast. The hydrogel is formed wholly based on covalent-like hydrogen bonding interactions and exhibits excellent mechanical properties, with the ability to stretch up to more than 600% of its initial length. Furthermore, the hydrogel demonstrates ultra-fast self-healing properties, with fractures capable of being repaired within 10 s. This hydrogel can promote skin wound healing, with the added advantage of functioning as a strain sensor that generates an electrical signal in response to physical deformation. The strain sensor composed of a rubber shell realizes fast and responsive strain sensing. The findings suggest that this hydrogel has promising applications in the field of POCT for wound care, providing a new avenue for improved patient outcomes.

Polyurethane foam dressing with non-adherent membrane improves negative pressure wound therapy in pigs

OBJECTIVE

Negative pressure wound therapy (NPWT) is considered to be an effective technique to promote the healing of various wounds. The aim of this study was to evaluate different wound dressings combined with NPWT in treating wounds in Wuzhishan pigs.

METHOD

Excisions were made in the backs of the pigs and were covered with polyvinyl alcohol (PVA) dressing, polyurethane (PU) dressing or PU dressing with non-adherent membrane (PU-non-ad). NPWT was applied to the wound site. In the control group, basic occlusive dressing (gauze) without NPWT was applied. On days 0, 3, 7, 14, 21 and 28 post-surgery, the wound size was measured during dressing change, and wound healing rate (WHR) was calculated. In addition, blood perfusion within 2cm of the surrounding wound was measured by laser doppler flowmetry. Dressing specimen was collected and microbiology was analysed. Granulation tissues from the central part of the wounds were analysed for histology, vascular endothelial growth factor (VEGF) and cluster of differentiation 31 (CD31) mRNA expression.

RESULTS

The PU-non-ad-NPWT significantly (p<0.01) accelerated wound healing in the pigs. Further pathological analysis revealed that the non-adherent membrane effectively protected granulation tissue formation in PU-NPWT treated wounds. The blood perfusion analysis suggested that the non-adherent membrane improved the blood supply to the wound area. Microbiological analysis showed that non-adherent membrane decreased the bacterial load in the PU-NPWT dressing. VEGF and CD31 mRNA expression was upregulated in the wound tissue from the PU-non-ad-NPWT treated groups.

CONCLUSION

In this study, the PU dressing with non-adherent membrane was an ideal dressing in NPWT-assisted wound healing.

Mesh Infection After Hernia Repair and Negative Pressure Wound Therapy. A Systematic Review

BACKGROUND

Surgical mesh infection (SMI) after abdominal wall hernia repair (AWHR) is a challenging and highly debated clinical problem with no current consensus. The purpose of this review was to analyze the literature about the use of negative pressure wound therapy (NPWT) in the management of the conservative treatment of SMI and report results about infected mesh salvage.

METHODS

A systematic review of EMBASE and PUBMED was performed describing the use of NPWT in patients with SMI following AWHR. Reviewed articles evaluating data about the association between clinical, demographic, analytic and surgical characteristics about SMI after AWHR were analyzed. The high heterogeneity of these studies did not allow a meta-analysis of outcomes.

RESULTS

The search strategy yielded 33 studies from PubMed, and 16 studies from EMBASE. NPWT was performed in 230 patients across 9 studies being achieved the mesh salvage in 196 (85.2%). Of these 230 cases, 46% were polypropylene (PPL), 9.9% polyester (PE), 16.8% polytetrafluoroethylene (PTFE), 4% biologic and 10.2% composite mesh (PPL and PTFE). Infected mesh location was onlay (43%), retromuscular (22%), preperitoneal (19%), intraperitoneal (10%) and between the oblique muscles (5%). The better option on salvageability with the use of NPWT was the combination of macroporous PPL mesh in an extraperitoneal position (19.2% onlay, 23.3% preperitoneal, 48.8% retromuscular).

CONCLUSION

NPWT is a sufficient approach to treat SMI following AWHR. In most cases, infected prostheses can be salvaged with this management. Further studies with a larger sample size are needed to confirm our analysis results.

Negative-Pressure Wound Therapy: What We Know and What We Need to Know

Negative-pressure wound therapy (NPWT) promotes wound healing by applying negative pressure to the wound surface. A quarter of a century after its introduction, NPWT has been used in various clinical conditions, although molecular biological evidence is insufficient due to delay in basic research. Here, we have summarized the history of NPWT, its mechanism of action, what is currently known about it, and what is expected to be known in the future. Particularly, attention has shifted from the four main mechanisms of NPWT to the accompanying secondary effects, such as effects on various cells, bacteria, and surgical wounds. This chapter will help the reader to understand the current status and shortcomings of NPWT-related research, which could aid in the development of basic research and, eventually, clinical use with stronger scientific evidence.

Negative pressure therapy in abdominal wall surgery

Negative pressure wound therapy (NPWT) is widely known in surgical practice. The initial indications for NPWT were chronic wounds, especially diabetic foot, vascular and decubitus ulcers, and infected traumatic wounds. Nowadays, the use has been widely increased. Although in the field of abdominal wall surgery, it has mainly been used in the treatment of surgical wound complications after hernia repair, other indications have been added after years of experience in the management of NPWT. Therefore, the aim of this article is to analyze and review the main indications of NPWT in abdominal wall surgery, as well as the advantages obtained with its application.

A Randomized Controlled Trial to Assess the Cost-effectiveness of a Novel, Simple Modification to the Negative Pressure Wound Therapy System

Background:

Negative pressure wound therapy (NPWT) has shown remarkable adaptation in wound management worldwide. Numerous studies have provided evidence that demonstrates both the medical and financial advantages of NPWT. In this study, the VAC Therapy System, one of the leading commercially used NPWT systems, has been utilized to treat patients with either acute or chronic wounds requiring surgical intervention, with the aim of demonstrating the efficacy of using a modified version of the VAC system while reducing the total associated cost.

Method:

The patients were divided into two randomly selected groups using randomization generator software. A modification was made by replacing the disposable canister provided by Kinetic Concepts Inc., with an alternative reusable canister (Baxter, Inc.); one group was assigned to use the conventional VAC Therapy System, and the other was assigned to use the modified version. Our study aimed to investigate whether this modification would lower the cost of the VAC Therapy System while still achieving the desired outcome.

Results:

The VAC Therapy System contributed to improving the wound bed score in both groups, which supports previous findings on the effectiveness of NPWT while reflecting that the modification did not negatively impact the functionality and the integrity of the VAC Therapy System. Furthermore, the average daily consumables cost was markedly reduced in the modified group compared with the standard group, which reduced the overall cost of treatment.

Conclusion:

It is possible to use the VAC Therapy System to its full advantage, while minimizing the financial burden of using it.

Topical negative-pressure wound therapy: emerging devices and techniques

Introduction: The treatment of chronic wounds constitutes a massive financial burden to society and our health-care system. Therefore, efficient wound care is of great importance to all kinds of medical fields. The implementation and modification of negative-pressure wound therapy can be seen as a major improvement in wound healing. Many different NPWT applications evolved trying to address various wound etiologies.Areas covered: This review aims to give an overview of various NPWT applications, show its effects on wound healing, and discuss future modifications.Expert opinion: NPWT as a delivery device for cold plasma, growth factors, or targeted stem cells to the wound bed and the ability to monitor the inflammatory activity, bacterial load and wound healing factors can be seen as possible future steps to individualized wound care. In addition, it requires high-quality experimental studies to develop the ideal foam in terms of microstructure, pore size, and material properties.

EWMA Document: Negative Pressure Wound Therapy

1. Introduction Since its introduction in clinical practice in the early 1990's negative pressure wounds therapy (NPWT) has become widely used in the management of complex wounds in both inpatient and outpatient care.¹ NPWT has been described as a effective treatment for wounds of many different aetiologies^2,3 and suggested as a gold standard for treatment of wounds such as open abdominal wounds,^4-6 dehisced sternal wounds following cardiac surgery^7,8 and as a valuable agent in complex non-healing wounds.^9,10 Increasingly, NPWT is being applied in the primary and home-care setting, where it is described as having the potential to improve the efficacy of wound management and help reduce the reliance on hospital-based care.¹¹ While the potential of NPWT is promising and the clinical use of the treatment is widespread, highlevel evidence of its effectiveness and economic benefits remain sparse.^12-14 The ongoing controversy regarding high-level evidence in wound care in general is well known. There is a consensus that clinical practice should be evidence-based, which can be difficult to achieve due to confusion about the value of the various approaches to wound management; however, we have to rely on the best available evidence. The need to review wound strategies and treatments in order to reduce the burden of care in an efficient way is urgent. If patients at risk of delayed wound healing are identified earlier and aggressive interventions are taken before the wound deteriorates and complications occur, both patient morbidity and health-care costs can be significantly reduced. There is further a fundamental confusion over the best way to evaluate the effectiveness of interventions in this complex patient population. This is illustrated by reviews of the value of various treatment strategies for non-healing wounds, which have highlighted methodological inconsistencies in primary research. This situation is confounded by differences in the advice given by regulatory and reimbursement bodies in various countries regarding both study design and the ways in which results are interpreted. In response to this confusion, the European Wound Management Association (EWMA) has been publishing a number of interdisciplinary documents^15-19 with the intention of highlighting: The nature and extent of the problem for wound management: from the clinical perspective as well as that of care givers and the patients Evidence-based practice as an integration of clinical expertise with the best available clinical evidence from systematic research The nature and extent of the problem for wound management: from the policy maker and healthcare system perspectives The controversy regarding the value of various approaches to wound management and care is illustrated by the case of NPWT, synonymous with topical negative pressure or vacuum therapy and cited as branded VAC (vacuum-assisted closure) therapy. This is a mode of therapy used to encourage wound healing. It is used as a primary treatment of chronic wounds, in complex acute wounds and as an adjunct for temporary closure and wound bed preparation preceding surgical procedures such as skin grafts and flap surgery. Aim An increasing number of papers on the effect of NPWT are being published. However, due to the low evidence level the treatment remains controversial from the policy maker and health-care system's points of view-particularly with regard to evidence-based medicine. In response EWMA has established an interdisciplinary working group to describe the present knowledge with regard to NPWT and provide overview of its implications for organisation of care, documentation, communication, patient safety, and health economic aspects. These goals will be achieved by the following: Present the rational and scientific support for each delivered statement Uncover controversies and issues related to the use of NPWT in wound management Implications of implementing NPWT as a treatment strategy in the health-care system Provide information and offer perspectives of NPWT from the viewpoints of health-care staff, policy makers, politicians, industry, patients and hospital administrators who are indirectly or directly involved in wound management.

The Role of Negative-Pressure Wound Therapy in Lower-Limb Reconstruction

Negative-pressure wound therapy (NPWT) has gained increasing popularity among clinicians since its introduction in 1997 as a potential aid to wound healing. Multiple benefits of NPWT have since been proven in studies, including increase in granulation tissue formation, decrease in bacterial load, and the improved survival of flaps. With our increasing use and greater understanding of the tissue and cellular changes that occur in a wound treated with NPWT, our lower-limb reconstructive practice has also evolved. Although controversial, the definite timing for lower-limb reconstruction has stretched from 72 hours to longer than 2 weeks as NPWT contains the wound within a sterile, closed system. It has also shown to decrease the rate of infection in open tibia fractures. Previously, a large number of critical defects of the lower limb would require free tissue transfer for definitive reconstruction. NPWT has reduced this rate by more than 50% and has allowed for less complicated resurfacing procedures to be performed instead.

Negative pressure wound therapy use in diabetic foot syndrome-from mechanisms of action to clinical practice

BACKGROUND

Diabetes and its complications constitute a rising medical challenge. Special attention should be given to diabetic foot syndrome (DFS) due to its high rate of associated amputation and mortality. Negative pressure wound therapy (NPWT) is a frequently used supportive modality in a diabetic foot with ulcerations (DFUs).

DESIGN

Here, we reviewed the current knowledge concerning the tissue and molecular mechanisms of NPWT action with an emphasis on diabetes research followed by a summary of clinical DFU studies and practice guidelines.

RESULTS

Negative pressure wound therapy action results in two types of tissue deformations-macrodeformation, such as wound contraction, and microdeformation occurring at microscopic level. Both of them stimulate a wound healing cascade including tissue granulation promotion, vessel proliferation, neoangiogenesis, epithelialization and excess extracellular fluid removal. On the molecular level, NPWT results in an alteration towards more pro-angiogenic and anti-inflammatory conditions. It increases expression of several key growth factors, including vascular endothelial growth factor and fibroblast growth factor 2, while expression of inflammatory cytokinesis reduced. The NPWT application also alters the presence and function of matrix metalloproteinases. Clinical studies in DFU patients showed a superiority of NPWT over standard therapy in terms of efficacy outcomes, primarily wound healing and amputation rate, without a rise in adverse events. International guidelines point to NPWT as an important adjuvant therapy in DFU whose use is expected to increase.

CONCLUSIONS

This current knowledge improves our understanding of NPWT action and its tailoring for application in diabetic patients. It may inform the development of new treatments for DFU.

MnSOD is implicated in accelerated wound healing upon Negative Pressure Wound Therapy (NPWT): A case in point for MnSOD mimetics as adjuvants for wound management

Negative Pressure Wound Therapy (NPWT), a widely used modality in the management of surgical and trauma wounds, offers clear benefits over conventional wound healing strategies. Despite the wide-ranging effects ascribed to NPWT, the precise molecular mechanisms underlying the accelerated healing supported by NPWT remains poorly understood. Notably, cellular redox status-a product of the balance between cellular reactive oxygen species (ROS) production and anti-oxidant defense systems-plays an important role in wound healing and dysregulation of redox homeostasis has a profound effect on wound healing. Here we investigated potential links between the use of NPWT and the regulation of antioxidant mechanisms. Using patient samples and a rodent model of acute injury, we observed a significant accumulation of MnSOD protein as well as higher enzymatic activity in tissues upon NPWT. As a proof of concept and to outline the important role of SOD activity in wound healing, we replaced NPWT by the topical application of a MnSOD mimetic, Mn(III) meso-tetrakis(N-ethylpyridinium-2-yl)porphyrin (MnTE-2-PyP5+, MnE, BMX-010, AEOl10113) in the rodent model. We observed that MnE is a potent wound healing enhancer as it appears to facilitate the formation of new tissue within the wound bed and consequently advances wound closure by two days, compared to the non-treated animals. Taken together, these results show for the first time a link between NPWT and regulation of antioxidant mechanism through the maintenance of MnSOD activity. Additionally this discovery outlined the potential role of MnSOD mimetics as topical agents enhancing wound healing.

Mechanical effects of negative pressure wound therapy on abdominal wounds - effects of different pressures and wound fillers

The mechanical deformation of the wound edge resulting from negative pressure wound therapy (NPWT) at the standard setting of around -120 mmHg has positive effects in promoting wound healing. However, it may cause pain to the patient during treatment. It is therefore important to study the mechanical effects of the wound edges using lower pressure and different wound fillers. Abdominal wounds were created on eight pigs. The wounds were sealed for NPWT using foam or gauze. Negative pressures between -20 and -160 mmHg were applied, and the decrease in wound diameter and the force with which the edges of the wound were drawn together (wound edge force) were measured. Increasing levels of negative pressure resulted in a gradual decrease in wound diameter and increase in wound edge force and reached a maximum at -120 mmHg, which is the pressure commonly used in clinical practice. Both the decrease in wound diameter and the increase in wound edge force was greater with foam than with gauze. A pressure of -80 mmHg has only 15% less effect than -120 mmHg, while a lower pressure (-40 mmHg) diminished the effects on diameter and force markedly. The NPWT-induced decrease in wound diameter and increase in wound edge force are greater at higher levels of negative pressure and when using foam than when using gauze as a wound filler. It may be possible to tailor the type of wound filler and level of negative pressure to obtain the best balance between wound healing and patient comfort.

Effects of topical negative pressure therapy on tissue oxygenation and wound healing in vascular foot wounds

OBJECTIVE

Topical negative pressure (TNP) therapy is widely used in the treatment of acute wounds in vascular patients on the basis of proposed multifactorial benefits. However, numerous recent systematic reviews have concluded that there is inadequate evidence to support its benefits at a scientific level. This study evaluated the changes in wound volume, surface area, depth, collagen deposition, and tissue oxygenation when using TNP therapy compared with traditional dressings in patients with acute high-risk foot wounds.

METHODS

This study was performed with hospitalized vascular patients. Forty-eight patients were selected with an acute lower extremity wound after surgical débridement or minor amputation that had an adequate blood supply without requiring further surgical revascularization and were deemed suitable for TNP therapy. The 22 patients who completed the study were randomly allocated to a treatment group receiving TNP or to a control group receiving regular topical dressings. Wound volume and wound oxygenation were analyzed using a modern stereophotographic wound measurement system and a hyperspectral transcutaneous oxygenation measurement system, respectively. Laboratory analysis was conducted on wound biopsy samples to determine hydroxyproline levels, a surrogate marker to collagen.

RESULTS

Differences in clinical or demographic characteristics or in the location of the foot wounds were not significant between the two groups. All patients, with the exception of two, had diabetes. The two patients who did not have diabetes had end-stage renal failure. There was no significance in the primary outcome of wound volume reduction between TNP and control patients on day 14 (44.2% and 20.9%, respectively; P = .15). Analyses of secondary outcomes showed a significant result of better healing rates in the TNP group by demonstrating a reduction in maximum wound depth at day 14 (36.0% TNP vs 17.6% control; P = .03). No significant findings were found for the other outcomes of changes in hydroxyproline levels (58.0% TNP vs 94.5% control; P = .32) or tissue perfusion by tissue oxyhemoglobin saturation (19.4% TNP vs 12.0% control; P = .07) at day 14. At 1 year of follow-up, there were no significant outcomes in the analysis of wound failure, major amputation, and overall survival rates between the two groups.

CONCLUSIONS

In this pilot study, applying TNP to acute high-risk foot wounds in patients with diabetes or end-stage renal failure improved the wound healing rate in reference to wound depth. This suggests that TNP may play a role in enhancing wound healing. This study sets the foundation for larger studies to evaluate the superiority of TNP over traditional dressings in high-risk foot wounds.

Deconstructing negative pressure wound therapy

Since its introduction 20 years ago for the treatment of chronic wounds, negative pressure wound therapy use has expanded to a variety of other wound types. Various mechanisms of action for its efficacy in wound healing have been postulated, but no unifying theory exists. Proposed mechanisms include induction of perfusion changes, microdeformation, macrodeformation, exudate control and decreasing the bacterial load in the wound. We surmise that these different mechanisms have varying levels of dominance in each wound type. Specifically, negative pressure wound therapy is beneficial to acute open wounds because it induces perfusion changes and formation of granulation tissue. Post-surgical incisional wounds are positively affected by perfusion changes and exudate control. In the context of chronic wounds, negative pressure wound therapy removes harmful and corrosive substances within the wounds to affect healing. When skin grafts and dermal substitutes are used to close a wound, negative pressure wound therapy is effective in promoting granulation tissue formation, controlling exudate and decreasing the bacterial load in the wound. In this review, we elucidate some of the mechanisms behind the positive wound healing effects of negative pressure wound therapy, providing possible explanations for these effects in different wound types.

Effect of negative pressure wound therapy on wound healing

The efficacy of NPWT in promoting wound healing has been largely accepted by clinicians, yet the number of high-level clinical studies demonstrating its effectiveness is small and much more can be learned about the mechanisms of action. In the future, hopefully we will have the data to assist clinicians in selecting optimal parameters for specific wounds including interface material, waveform of suction application, and the amount of suction to be applied. Further investigation into specific interface coatings and instillation therapy are also needed. We believe that advances in mechanobiology, the science of wound healing, the understanding of biofilms, and advances in cell therapy will lead to better care for our patients.

Extended negative pressure wound therapy-assisted dermatotraction for the closure of large open fasciotomy wounds in necrotizing fasciitis patients

Background

Necrotizing fasciitis (NF) is a rapid progressive infection of the subcutaneous tissue or fascia and may result in large open wounds. The surgical options to cover these wounds are often limited by the patient condition and result in suboptimal functional and cosmetic wound coverage. Dermatotraction can restore the function and appearance of the fasciotomy wound and is less invasive in patients with comorbidities. However, dermatotraction for scarred, stiff NF fasciotomy wounds is often ineffective, resulting in skin necrosis. The authors use extended negative pressure wound therapy (NPWT) as an assist in dermatotraction to close open NF fasciotomy wounds. The authors present the clinical results, followed by a discussion of the clinical basis of extended NPWT-assisted dermatotraction.

Methods

A retrospective case series of eight patients with NF who underwent open fasciotomy was approved for the study. After serial wound preparation, dermatotraction was applied in a shoelace manner using elastic vessel loops. Next, the extended NPWT was applied over the wound. The sponge was three times wider than the wound width, and the transparent covering drape almost encircled the anatomical wound area. The negative pressure of the NPWT was set at a continuous 100 mmHg by suction barometer. The clinical outcome was assessed based on wound area reduction after treatment and by the achievement of direct wound closure.

Results

After the first set of extended NPWT-assisted dermatotraction procedures, the mean wound area was significantly decreased (658.12 cm² to 29.37 cm²; p = 0.002), as five out of eight patients achieved direct wound closure. One patient with a chest wall defect underwent latissimus dorsi musculocutaneous flap coverage, with primary closure of the donor site. Two Fournier’s gangrene patients underwent multiple sets of treatment and finally achieved secondary wound closure with skin grafts. The patients were followed up for 18.3 months on average and showed satisfactory results without wound recurrence.

Conclusions

Extended NPWT-assisted dermatotraction advances scarred, stiff fasciotomy wound margins synergistically in NF and allows direct closure of the wound without complications. This method can be another good treatment option for the NF patient with large open wounds whose general condition is unsuitable for extensive reconstructive surgery.

Use of a risk assessment method to improve the safety of negative pressure wound therapy

To conduct a risk analysis of the negative pressure wound therapy (NPWT) care process and to improve the safety of NPWT, a working group of nurses, hospital pharmacists, physicians and hospital managers performed a risk analysis for the process of NPWT care. The failure modes, effects and criticality analysis (FMECA) method was used for this analysis. Failure modes and their consequences were defined and classified as a function of their criticality to identify priority actions for improvement. By contrast to classical FMECA, the criticality index (CI) of each consequence was calculated by multiplying occurrence, severity and detection scores. We identified 13 failure modes, leading to 20 different consequences. The CI of consequences was initially 712, falling to 357 after corrective measures were implemented. The major improvements proposed included the establishment of 6-monthly training cycles for nurses, physicians and surgeons and the introduction of computerised prescription for NPWT. The FMECA method also made it possible to prioritise actions as a function of the criticality ranking of consequences and was easily understood and used by the working group. This study is, to our knowledge, the first to use the FMECA method to improve the safety of NPWT.

The effect of regional block over pain levels during vacuum-assisted wound closure

Despite being a wound treatment method with a broad spectrum of indications, vacuum-assisted wound closure (VAWC) can be a painful treatment modality which may even result with patient unwillingness for the continuation of treatment. A prospective study was undertaken to determine the effect of regional pain blocks (RPB) for patients who wanted to abandon treatment due to pain after the first application. Patients were asked to score their pain using a visual analogue scale for two different time frames (i) during dressing changes and (ii) while daytime treatment. This evaluation was carried out for conventional wound dressings, VAWC before RPB and finally for VAWC after RPB. The pain experienced with blocks was significantly lesser than conventional and VAWC dressing changes that were applied without pain blocks. Also, the pain was significantly lesser under pain blocks for daytime treatment. For patients with refractory pain where VAWC would prove to be of most benefit, RPB can be discussed with the patient and used. This study has shown that effective pain control can be obtained through regional blocks for patients with excruciating pain undergoing VAWC treatment.