Vacuum-assisted closure instill as a method of sterilizing massive venous stasis wounds prior to split thickness skin graft placement

Assessment between antiseptic and normal saline for negative pressure wound therapy with instillation and dwell time in diabetic foot infections

Negative pressure wound therapy with instillation and dwell time (NPWTi-d) is increasingly used for a diverse range of wounds. Meanwhile, the topical wound irrigation solution consisting of polyhexamethylene biguanide and betaine (PHMB-B) has shown efficacy in managing wound infections. However, the effectiveness of this solution as a topical instillation solution for NPWTi-d in patients with diabetic foot infections (DFIs) has not been thoroughly studied. The objective of this retrospective study was to evaluate the impact of using PHMB-B as the instillation solution during NPWTi-d on reducing bioburden and improving clinical outcomes in patients with DFIs. Between January 2017 and December 2022, a series of patients with DFIs received treatment with NPWTi-d, using either PHMB-B or normal saline as the instillation solution. Data collected retrospectively included demographic information, baseline wound characteristics, and treatment outcomes. The study included 61 patients in the PHMB-B group and 73 patients in the normal saline group, all diagnosed with DFIs. In comparison to patients treated with normal saline, patients with PHMB-B exhibited no significant differences in terms of wound bed preparation time (P = 0.5034), length of hospital stay (P = 0.6783), NPWTi-d application times (P = 0.1458), duration of systematic antimicrobial administration (P = 0.3567), or overall cost of hospitalization (P = 0.6713). The findings of the study suggest that the use of either PHMB-B or normal saline as an instillation solution in NPWTi-d for DFIs shows promise and effectiveness, yet no clinical distinction was observed between the two solutions.

The impact of negative-pressure wound therapy with instillation on wounds requiring operative debridement: Pilot randomised, controlled trial

Presence of bacteria in wounds can delay healing. Addition of a regularly instilled topical solution over the wound during negative‐pressure wound therapy (NPWT) may reduce bioburden levels compared with standard NPWT alone. We performed a prospective, randomised, multi‐centre, post‐market trial to compare effects of NPWT with instillation and dwell of polyhexamethylene biguanide solution vs NPWT without instillation therapy in wounds requiring operative debridement. Results showed a significantly greater mean decrease in total bacterial counts from time of initial surgical debridement to first dressing change in NPWT plus instillation (n = 69) subjects compared with standard NPWT (n = 63) subjects (−0.18 vs 0.6 log₁₀ CFU/g, respectively). There was no significant difference between the groups in the primary endpoint of required inpatient operating room debridements after initial debridement. Time to readiness for wound closure/coverage, proportion of wounds closed, and incidence of wound complications were similar. NPWT subjects had 3.1 times the risk of re‐hospitalisation compared with NPWT plus instillation subjects. This study provides a basis for exploring research options to understand the impact of NPWT with instillation on wound healing.

Benefits of negative pressure wound therapy with instillation in the treatment of hard-to-heal wounds: a case series

Objective:

Impaired wound healing can lead to hard-to-heal wounds, which impact on patients, clinicians and healthcare systems. Negative pressure wound therapy with instillation and dwell time (NPWTi-d) was developed to manage wounds through early-stage cleansing. This study describes the use of NPWTi-d to help manage hard-to-heal wounds in patients with risk factors for impaired wound healing.

Method:

In this case series, patients were treated between October 2015 and March 2018 at a community hospital in western France. Normal saline solution was instilled into wounds with a dwell time of 10 minutes, followed by the application of negative pressure at −75 mmHg to −125 mmHg for 2–3 hours. If needed, patients were given appropriate oral or intravenous antibiotic treatment in conjunction with NPWTi-d and subsequent wound therapies.

Results:

A total of 15 patients participated in the study. Mean age was 81±13 years, and 12 (80%) patients were malnourished with blood albumin levels of 30.1±5.7g/l, and 12 (80%) patients were given antibiotic therapy. The mean duration of NPWTi-d was 19.4±20.8 days, with a mean number of dressing changes of 6.6±6.8; the duration of NPWTi-d and the number of dressing changes for pressure ulcers was three times that of the other wound types. The mean cost of NPWTi-d in this study was €1643.40±€1709.13. Overall, NPWTi-d provided early-stage wound cleansing and helped achieve adequate granulation tissue formation and progression to the next phase of wound healing.

Conclusion:

In these cases, NPWTi-d was a beneficial and effective method of treating hard-to-heal wounds that were resistant to traditional treatments, yielding favourable clinical outcomes.

Three Cases Describing Outcomes of Negative-Pressure Wound Therapy With Instillation for Complex Wound Healing

BACKGROUND

We describe 3 cases where negative-pressure wound therapy with instillation and dwell time (NPWTi-d) was used as an adjunctive therapy for 3 chronic wounds.

CASES

Three patients (2 males and 1 female), ranging in age from 28 to 53 years, presented with complex, infected wounds: (1) a diabetic foot ulcer with underlying infection, (2) a dehisced abdominal wound with enterocutaneous fistula, and (3) a large wound of the upper torso and axillary region resulting from soft tissue necrosis. Negative-pressure wound therapy with instillation and dwell time was initiated by instilling normal saline or an antiseptic solution; the solution was left in place for 3 to 10 minutes. Continuous negative pressure was then applied at -125 or -150 mm Hg; cycles were repeated every 1 or 3 hours. Treatment was applied for 5 to 44 days, and dressings were changed every 2 to 3 days. Granulation tissue developed in all 3 wounds; all closed after subsequent skin grafting.

CONCLUSIONS

Outcomes of these cases suggest that NPWTi-d may be used as an adjunctive treatment modality for a variety of chronic wounds.

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 diagnosis of infection in chronic leg ulcers: A narrative review on clinical practice

This literature review aimed to provide a narrative review of evidence on validity of clinical and microbial indicators of infection and to gain insights into the diagnosis of infection in chronic leg ulcers (CLUs). A search was conducted in Cinahl, Medline, the Cochrane Library databases, Embase, Web of Science, ScienceDirect, Pubmed, PsycINFO, ProQuest dissertations, and Google Scholar from January 1990 to July 2017. The inclusion criteria were original studies, systematic reviews, and consensus documents focused on "infection" in CLUs, English language, clinical and community settings, and human. The reviewed studies were inconsistent in criteria for infection between investigated wound types and lack of specificity regarding wound types. There were few studies investigating the criteria for diagnosis of infection in leg ulcers. The identification of leg ulcer infection still remains problematic and relies on out-of-date and not uniform evidence. Literature in this area was mostly limited to level III and IV evidence based on The Australian National Health and Medical Research Council Levels of Evidence, or expert opinion. This literature review showed seven clinical signs and symptoms that could be diagnostic for infection in CLUs, including: new, increased, or altered ulcer pain; malodour; increased ulcer area; wound breakdown, delayed or non-healing; and erythema and increased local temperature, whilst the microbial indicators used to diagnose infected leg ulcers were varied and regarded as less important.

Comparing Negative Pressure Wound Therapy with Instillation and Conventional Dressings for Sternal Wound Reconstructions

Background:

Muscle flap reconstruction has become a mainstay of therapy following treatment of sternal wound complications; however, success depends on removing wound exudate and infectious material from the wound before reconstruction and closure. Importantly, time to closure is a key factor affecting morbidity/mortality and cost-to-treat for this wound type.

Methods:

A retrospective analysis of 30 patients who were treated for sternal wound complications between June 2015 and October 2017 was performed. After surgical debridement, group 1 patients (n = 15) received negative pressure wound therapy (NPWT) with instillation and dwell time (NPWTi-d), instilling 1/8-strength Dakin’s solution with a 20-minute dwell time followed by 2 hours of NPWT (-125 mm Hg); group 2 patients (n = 15) were treated with wet-to-moist dressings soaked in 1/8-strength Dakin’s solution. After muscle flap reconstruction and closure with sutures, group 1 patients received closed incision negative pressure therapy, and group 2 patients received Benzoin and wound closure strips. Data collected included time to closure, therapy duration, number of debridements/dressing changes, drain duration, and complications.

Results:

There was a significantly shorter time to closure (P < 0.0001) for group 1 when compared with group 2. In addition, there were fewer therapy days (P = 0.0041), fewer debridements/dressing changes (P = 0.0011), and shorter drain duration (P = 0.0001) for group 1 when compared with group 2.

Conclusions:

We describe a novel regimen consisting of adjunctive NPWTi-d, along with debridement and systemic antibiotics, followed by closed incision negative pressure therapy after muscle flap reconstruction and closure, to help manage preexisting sternal wounds that had failed to close following a previous cardiac procedure.

Negative Pressure Wound Therapy with Instillation and Dwell Time in the Surgical Management of Severe Hidradenitis Suppurativa

Background: Hidradenitis suppurativa (HS) is a physically debilitating disease that greatly impairs the quality of life of affected individuals. Advanced disease is often difficult to treat with topical and systemic therapies. Surgical resection of diseased skin has become paramount in HS management but proposes challenges of wound care and closure.

Methods: Four patients with a total of 12 complex wounds were treated over a three year period. All of the patients were males between the ages of 28 and 61 years. The lesions were located on the buttocks (n=5), chest (n=1), perianal (n=2), perineal (n=2), and axillary regions (n=2). A protocol of wide local excision, followed by negative pressure wound therapy with instillation and dwell time (NPWTi-d) to decrease bioburden and promote angiogenesis of the exposed base, and subsequent skin grafting was used. Patients remained hospitalized between procedures.

Results: The original wound area ranged from 210-540 cm². Skin grafts of comparable sizes were taken from donor sites. The average duration of NPWTi-d placement was 3.5 days and the average time from excision to wound coverage was 4.3 days. The percent of graft uptake ranged from 70%-90%. All patients were resolved of their local disease with no complications.

Conclusions: Surgical management of HS can be complicated by difficult closures. This case series demonstrates that wide local excision followed by NPWTi-d and skin grafting is able to achieve local resolution of disease in HS patients who have failed multiple minimally invasive therapies.

Negative pressure wound treatment with computer-controlled irrigation/instillation decreases bacterial load in contaminated wounds and facilitates wound closure

Microbial wound contamination is known to be a hindrance to wound healing. Negative pressure wound therapy (NPWT) with or without irrigation is known to optimise conditions in problem wounds. The aim of this study was to investigate the influence of computer-controlled wound irrigation with NPWT on the bacterial load in contaminated wounds. A total of 267 patients were treated with NPWT with automated instillation because of problematic wounds using an antiseptic instillation solution. In 111 patients, a minimum of 4 operative procedures were necessary, and swabs were taken at least at the first and at the fourth operation in a standardised procedure. The number of different bacteria and the amount of bacteria were analysed during the course. In a subgroup of 51 patients, swabs were taken at all 4 operative procedures and analysed separately. In an overall analysis, the number of different bacteria and the amount of bacteria significantly decreased independent of wound localisation and diagnosis. NPWT with automated instillation demonstrates a positive influence in the reduction of bacterial load in problem wounds. Thus, it may help to optimise wound conditions before definite wound closure.

On the significance of negative-pressure wound therapy with instillation in dermatology

Methods used in the treatment of acute and chronic wounds undergo constant evolution, reevaluation, and innovation. While negative-pressure wound therapy (NPWT) is an established treatment modality, the combination of NPWT and instillation of normal saline as well as solutions with active antiseptic components for topical treatment of the wound bed represents a novel approach. The well-known effects of NPWT may thus be combined with those of local antisepsis. They include a decrease in wound area, induction of granulation tissue, and reduction in bacterial colonization. To date, studies have focused on NPWT with instillation for orthopedic/surgical indications, whereas clinical data in dermatosurgery is limited to case reports or small case series. There are as yet no randomized prospective studies investigating NPWT with instillation in the treatment of skin disorders. The goal of this review is to present the method of NPWT with instillation, to highlight its mode of action as well as possible complications and contraindications, and to review the recent literature. In summary, there is increasing evidence that both simple and complicated wounds may be effectively treated with NPWT with instillation, resulting in markedly accelerated tissue granulation and thus earlier defect closure.

Experiência inicial com terapia por pressão negativa por instilação em feridas complexas

RESUMO Objetivo: relatar a experiência inicial com a terapia por pressão negativa por instilação em feridas complexas infectadas ou contaminadas. Métodos: a terapia por pressão negativa por instilação utilizada foi o V.A.C. Ulta com instilação Veraflo (Kinetic Concepts, Inc). O modo de operação foi contínuo com pressão sub-atmosférica ajustada em 125 mmHg por duas horas e instilação entre as pausas. O tempo de instilação foi de 20 minutos (tempo de contato do agente tópico com a ferida) e a substância instilada foi solução salina padrão a 0,9%. Após obtenção de preparo adequado da ferida, ela foi coberta com enxerto ou retalho. Resultados: foram operados dez pacientes com feridas complexas contaminadas ou infectadas. O número médio de trocas da TPNi foi 1,4, o número médio total de cirurgias foi de 2,4, o intervalo até a cobertura da ferida foi de 6,3 dias e o intervalo até a alta foi de 11,4 dias. Conclusão: a comparação da terapia por pressão negativa por instilação com dois estudos prévios (controle histórico) evidenciou um tempo de internação menor, favorecendo a TPNi. Este estudo teve um caráter inicial, fazendo-se necessário conduzir um trabalho randomizado e controlado para confirmar a eficácia desta terapia e verificar a sua custo-efetividade.

Evidence based review of negative pressure wound therapy

Vacuum-assisted closure, sometimes referred to as microdeformational wound therapy or most commonly negative pressure wound therapy (NPWT), has significantly improved wound care over the past two decades. NPWT is known to affect wound healing through four primary mechanisms (macrodeformation, microdeformation, fluid removal, and alteration of the wound environment) and various secondary mechanisms (including neurogenesis, angiogenesis, modulation of inflammation, and alterations in bioburden) which are described in this review. In addition, the technique has many established uses, for example in wound healing of diabetic and pressure ulcers, as well as burn and blast wounds. This therapy also has many uses whose efficacy has yet to be confirmed, for example the use in digestive surgery. Modifications of the traditional NPWT have also been established and are described in detail. This therapy has various considerations and contraindications which are summarized in this review. Finally, future perspectives, such as the optimal cycling of the treatment and the most appropriate interface material, are touched upon in the final segment. Overall, despite the fact that questions remain to be answered about NPWT, this technology is a major breakthrough in wound healing with significant potential use both in the hospital but also in the community.

Prolonged Negative Pressure Wound Therapy Followed by Split-Thickness Skin Graft Placement for Wide Dehiscence of Clamshell Incision After Bilateral Lung Transplantation: A Case Report

Clamshell incision is a standard approach for bilateral lung transplantation, providing a good operative field; however, once wide dehiscence occurs, its management is sometimes difficult because of intense immunosuppression and malnutrition of the recipient. A 22-year-old man with idiopathic pulmonary arterial hypertension underwent cadaveric bilateral lung transplantation through a clamshell incision using standard cardiopulmonary bypass. He developed wound dehiscence on postoperative day (POD) 20 that resulted in exposure of the bilateral fifth ribs and open pneumothorax. Considering the extreme malnutrition and emaciation of the recipient, we avoided initial closure of the dehiscence. After the debridement of necrotic tissue, negative pressure wound therapy was initiated on POD 25 and was continued for approximately 6 months with trafermin spray application. Eventually, the wound, including the fifth ribs, was completely covered with granulation tissue except for the wire tying the sternum. On POD 217, the patient underwent removal of the sternal wire followed by split-thickness skin grafting. His wound was successfully closed and he was discharged without activity limitation on POD 265.

Treating Fasciotomy Wounds with Negative Pressure Wound Therapy with Instillation and Dwell Time (NPWTi-d)

Acute compartment syndrome (ACS) is a serious complication of lower-extremity trauma caused by accidents or post-procedure complications. ACS is characterized by increased pressure within the compartment, resulting in reduced blood flow, tissue hypoxia, and tissue necrosis. Fasciotomies to relieve pressure and debridement of necrotic tissue comprise primary treatment. My purpose is to present initial experience using negative pressure wound therapy with instillation and dwell time (NPWTi-d)* to treat fasciotomy wounds in two patients. NPWTi-d provides automated, volumetric control of instilled topical wound solutions with a dwell time in combination with negative pressure wound therapy (NPWT).

Patient 1, a 33-year-old male injured in a motorcycle accident, developed ACS within 24 hours of hospitalization. Prior treatments included wet-to-dry dressings and NPWT^†. In the latter course of treatment, NPWTi-d was applied; 40 ml of normal saline (NS) were instilled with a ten-minute dwell time, followed by four hours of NPWT at ‑125 mmHg. After five days of NPWTi‑d, granulation tissue covered the bone. Four days later, the patient was discharged home. The wound continued to improve and, at the last recorded visit, was completely closed.

Patient 2, a 44-year-old male, developed right lower extremity ACS due to complications post cardiac surgery. NPWT was initiated in the hospital and continued post-discharge to a nursing home. The patient was readmitted to the hospital with a right leg wound infection that was surgically debrided. NPWTi-d was then applied; 60 ml of NS were instilled with a ten-minute dwell time, followed by 3.5 hours of NPWT at -125 mmHg. After ten days of NPWTi-d, granulation tissue covered the bone. In Patient 2, NPWTi-d improved the likelihood of healing in a malnourished patient who had been critically ill by promoting granulation tissue over exposed bone. The use of NPWTi-d with NS contributed to positive outcomes for both patients.

*V.A.C. VeraFlo™ Therapy, ^†V.A.C.® Therapy (KCI, an Acelity company, San Antonio, TX)

Zum Stellenwert der Unterdruck-Instillationstherapie in der Dermatologie

Die Methoden zur Behandlung akuter und chronischer Wunden unterliegen einer steten Weiterentwicklung, Reevaluierung und Anwendung innovativer Therapieformen. Die Vakuumtherapie zur Wundbehandlung gehört zu den etablierten Behandlungsmodalitäten. Ein innovatives Verfahren kombiniert die Vakuumtherapie mit der automatisierten, kontrollierten Zufuhr und Drainage wirkstoffhaltiger Lösungen zur topischen Wundbehandlung im Wundbett und auch wirkstofffrei durch Instillation physiologischer Kochsalzlösung (Unterdruck-Instillationstherapie). Hierdurch können die Effekte der konventionellen Vakuumtherapie mit denen der lokalen Antisepsis kombiniert werden. Hierdurch kommt es zu einer Reduktion der Wundfläche, einer Induktion von Granulationsgewebe sowie einer Reduktion der Keimbesiedelung der Wunden. Bisher publizierte Studien konzentrieren sich auf die Anwendung dieses Therapieverfahrens zur Behandlung orthopädisch-chirurgischer Krankheiten. Die Datenlage bezüglich der Vakuum-Instillationstherapie in der Dermatochirurgie beschränkt sich derzeit auf Fallberichte und Einzelfallerfahrungen. Randomisierte, prospektive Studien zum Vergleich der Vakuum-Instillationstherapie zur Behandlung dermatologischer Krankheitsbilder existieren bislang nicht. Ziele des vorliegenden Artikels sind die Vorstellung der Vakuumtherapie mit Instillation einschließlich ihres Wirkprinzips, deren mögliche Komplikationen, die Diskussion erdenklicher Kontraindikationen sowie eine Übersicht über die aktuell verfügbare Datenlage. Zusammenfassend scheint sich die Evidenz zu verdichten, dass mittels Unterdruck-Instillationstherapie sowohl einfache als auch komplizierte Wunden effizient behandelt werden können, was sich in einer deutlichen Beschleunigung der Wundgranulation mit konsekutiv früher möglichem Defektverschluss äußert.

VAC-instillation therapy in abdominal mesh exposure: a novel indication

BACKGROUND

Defects of the abdominal wall pose a problem for general surgeons that negatively affects patient prognosis. In cases of abdominal wall wound dehiscence and exposed abdominal mesh, conservative treatment has not been proven effective to date. We aimed to study patient outcomes in cases of abdominal wall wound dehiscence with mesh exposure treated with vacuum-assisted closure system with intermittent instillation (VAC-instillation) as a temporary cover to achieve wound closure.

METHODS

A retrospective cohort study was performed to evaluate and compare the outcomes of 45 patients with postoperative abdominal wall wound dehiscence and exposed mesh: 34 were treated with conventional dressings and 11 with the VAC-instillation device. Clinical records were reviewed, and patient demographics, indication for abdominal surgery, and existing risk factors were noted. Patient outcome was evaluated in terms of number of reoperations, length of hospital stay, and total time of treatment.

RESULTS

Demographic features did not differ significantly between the two groups. Patients treated with conventional dressings required a significantly higher number of surgeries to achieve wound closure. We did not find statistical differences between the two groups regarding length of hospital stay, but the VAC-instillation group showed a significantly shorter total time of treatment. The incidence of complications was lower in the VAC-instillation group, though hernia recurrence rate was slightly higher in these patients.

CONCLUSIONS

VAC-instillation is a valid option for the conservative treatment of critical patients with abdominal wall wound dehiscence and exposed infected mesh that allows recovery with fewer surgeries and complications and avoids the need of mesh removal.

Well-promising outcomes with vacuum-assisted closure in an infected wound following laparotomy: A case report

Introducation

Negative pressure wound therapy (NPWT) represents an alternative method to optimize conditions for wound healing. Delayed wound closure is a significant health problem, which is directly associated with pain and suffering from patient's aspect, as well with social and financial burden.

Presentation of case

We report a case of vacuum-assisted wound therapy with hypertonic solution distillation and continuous negative pressure application, in an infected wound after laparotomy for incisional hernia reconstruction with mesh placement. Negative pressure was initiated at the wound margins after failure of conventional treatment with great outcomes, achieving a total closure of the incision within two weeks.

Discussion

Each wound has particular characteristics which must be managed. Vacuum assisted closure (VAC) with continuous negative pressure and simultaneous wound instillation and cleanse can provide optimum results, reducing the cavity volume, by newly produced granulated tissue.

Conclusion

The simultaneous use of instillation and constant pressure seemed to be superior in comparison with NPWT alone. Compared to conventional methods, the use of VAC ends to better outcomes, in cases of infected wounds following laparotomy.

•

A VAC device with automated solution distribution (with saline solution plus hypertonic saline), continuous pressure of −125 mmHg with equal distribution was applied.

•

Within 4 days bacterial culture was negative.

•

On the 7th day the wound was half in diameter and depth.

•

After 15 days in total, therapy was discontinued achieving closure.

The importance of hydration in wound healing: reinvigorating the clinical perspective

Balancing skin hydration levels is important as any disruption in skin integrity will result in disturbance of the dermal water balance. The discovery that a moist environment actively supports the healing response when compared with a dry environment highlights the importance of water and good hydration levels for optimal healing. The benefits of 'wet' or 'hyper-hydrated' wound healing appear similar to those offered by moist over a dry environment. This suggests that the presence of free water may not be detrimental to healing, but any adverse effects of wound fluid on tissues is more likely related to the biological components contained within chronic wound exudate, for example elevated protease levels. Appropriate dressings applied to wounds must not only be able to absorb the exudate, but also retain this excess fluid together with its protease solutes, while concurrently preventing desiccation. This is particularly important in the case of chronic wounds where peri-wound skin barrier properties are compromised and there is increased permeation across the injured skin. This review discusses the importance of appropriate levels of hydration in skin, with a particular focus on the need for optimal hydration levels for effective healing. Declaration of interest: This paper was supported by Paul Hartmann Ltd. The authors have provided consultative services to Paul Hartmann Ltd.

Simplified negative pressure wound therapy with instillation: advances and recommendations

Positive results have been demonstrated with the adjunctive use of negative pressure wound therapy (NPWT) and instillation (NPWTi) for stalled and/or complex wounds. With these combined therapies, instillation assists in wound bed preparation and cleansing by loosening soluble material in the wound bed, which can be subsequently removed during the NPWT phase. Previously reported instilled solutions have included saline, topical cleansers, and antiseptics. Recently, a new NPWTi system (V.A.C. VeraFlo™ Therapy, KCI USA, Inc., San Antonio, TX) has been introduced that includes automated, volumetrically controlled delivery of solutions and new foam dressings specifically designed for use with NPWTi. We present the latest NPWTi technologies, provide nursing recommendations for patient management, and conclude with a case study.

Comparison of Outcomes for Normal Saline and an Antiseptic Solution for Negative-Pressure Wound Therapy with Instillation

BACKGROUND

Negative-pressure wound therapy with instillation is an adjunctive treatment that uses periodic instillation of a solution and negative pressure for a wide diversity of wounds. A variety of solutions have been reported, with topical antiseptics as the most frequently chosen option. The objective of this study was to compare the outcomes of normal saline versus an antiseptic solution for negative-pressure wound therapy with instillation for the adjunctive treatment of infected wounds.

METHODS

This was a prospective, randomized, effectiveness study comparing 0.9% normal saline versus 0.1% polyhexanide plus 0.1% betaine for the adjunctive treatment of infected wounds that required hospital admission and operative débridement. One hundred twenty-three patients were eligible, with 100 patients randomized for the intention-to-treat analysis and 83 patients for the per-protocol analysis. The surrogate outcomes measured were number of operative visits, length of hospital stay, time to final surgical procedure, proportion of closed or covered wounds, and proportion of wounds that remained closed or covered at the 30-day follow-up.

RESULTS

There were no statistically significant differences in the demographic profiles in the two cohorts except for a larger proportion of male patients (p = 0.004). There was no statistically significant difference in the surrogate outcomes with the exception of the time to final surgical procedure favoring normal saline (p = 0.038).

CONCLUSION

The authors' results suggest that 0.9% normal saline may be as effective as an antiseptic (0.1% polyhexanide plus 0.1% betaine) for negative-pressure wound therapy with instillation for the adjunctive inpatient management of infected wounds.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Therapeutic, II.

What's new in wound treatment: a critical appraisal

With the growing demand for the specialized care of wounds, there is an ever expanding abundance of wound care modalities available. It is difficult to identify which products or devices enhance wound healing, and thus, a critical and continual look at new advances is necessary. The goal of any wound regimen should be to optimize wound healing by combining basic wound care modalities including debridement, off-loading, and infection control with the addition of advanced therapies when necessary. This review takes a closer look at current uses of negative pressure wound therapy, bioengineered alternative tissues, and amniotic membrane products. While robust literature may be lacking, current wound care advances are showing great promise in wound healing.

Use of negative pressure wound therapy with instillation in the management of cervical necrotizing fasciitis

BACKGROUND

Cervical necrotizing fasciitis is an aggressive infection that can be rapidly fatal if aggressive therapies are not initiated early. Negative pressure wound therapy has been established as an effective tool in promoting wound healing, but its use in the acutely infected wound has been avoided because it limits frequent irrigations and standard dressing changes.

METHODS

We discuss a novel application of negative pressure wound therapy with instillation in an immunocompromised patient with extensive cervical necrotizing fasciitis.

RESULTS

The negative pressure wound therapy with instillation provided pain relief by minimizing the frequency of dressing changes, increased the speed of healing, helped to control infection, and facilitated the development of a healthy wound bed sufficient for reconstruction with a split thickness skin graft.

CONCLUSION

The role of negative pressure wound therapy with instillation continues to expand and can be used in the management of both acute and chronic wounds in the head and neck.

Clinical recommendations and practical guide for negative pressure wound therapy with instillation

Effective wound management involves a comprehensive assessment of the patient and the wound to determine an optimal wound treatment plan. It is critical to identify and address factors that may impair wound healing, prior to selecting the most appropriate therapy for each patient. Negative pressure wound therapy (NPWT) is a well-established advanced therapy that has been successful in adjunctive management of acute and chronic wounds. In recent years, the introduction of topical wound solution delivery in combination with NPWT has provided further benefits to wound healing. A commercially available system now offers automated, volumetric control of instilled topical wound solutions with a dwell time in combination with NPWT (NPWTi-d; V.A.C. VeraFlo Therapy, KCI, an Acelity company, San Antonio, TX). This NPWTi-d system differs from other instillation systems in that a timed, predetermined volume of topical wound solution is intermittently delivered (versus continuously fed) and allowed to dwell in the wound bed (without NPWT), for a user-selected period of time before NPWT is resumed. This added accuracy and process simplification of solution delivery in tandem with NPWT have prompted use of NPWTi-d as first-line therapy in a wider subset of complex wounds. However, considerably more research is required to validate efficacy of NPWTi-d in various wound types. The purpose of this review is to provide a relevant overview of wound healing, describe current literature supporting the adjunctive use of NPWTi-d, propose a clinical approach for appropriate application of NPWTi-d and conclude with case studies demonstrating successful use of NPWTi-d. Based on this review, we conclude that either a large case series examining effects of NPWTi-d on different wound types or possibly a large prospective registry evaluating NPWTi-d with real-world topical wound solutions versus immediate debridement and closure would be valuable to the medical community in evaluating the efficacy of this promising therapy.

The fluid dynamics of simultaneous irrigation with negative pressure wound therapy

Saline irrigation has been shown to be both experimentally and clinically efficacious in decreasing bacterial contamination as well as decreasing infection rates. The dynamics of irrigation delivery fall into two primary categories: simultaneous and intermittent irrigation. An important component to irrigation therapy is distribution of irrigation solution to hard-to-reach areas of a wound bed, including undermining and fissure-like structures. Here we test the effectiveness of simultaneous irrigation to fill the irregular structures of a wound bed. In order to visualise the dynamic movement of irrigation solution, three-dimensional wound models were constructed using clear synthetic ballistic gel. Wounds with the aforementioned characteristics were carved into the ballistic gel with varying area, depth and volume. All three wounds were dressed as per manufacturer's instructions. Data demonstrate that simultaneous irrigation is effective in reaching all parts of a wound bed in wound models that have both undermining and tunnelling, and irrigation effectively saturates bridged wounds. Finally, this study shows that there is constant turnover of irrigation solution in the wound that is driven more by administration volume and less by flow rate. These data show that simultaneous irrigation is an effective technique for delivering irrigation solution to both simple and complex wounds.

Use of negative pressure wound therapy with automated, volumetric instillation for the treatment of extremity and trunk wounds: clinical outcomes and potential cost-effectiveness

OBJECTIVE

A growing body of literature supports use of negative pressure wound therapy (NPWT) with instillation and dwell time (NPWTi-d) with positive clinical outcomes and potential cost savings. A retrospective analysis was performed to compare clinical outcomes of wounds treated with NPWTi-d versus NPWT and to estimate cost-differences between treatments based on clinical outcomes.

METHODS

Data were extracted from records of patients with extremity or trunk wounds treated with NPWT (n = 34) or NPWTi-d using saline or polyhexanide (n = 48). On the basis of outcomes data, a hypothetical economic model using cost assumptions was created to calculate cost savings for NPWTi-d (related to) number of debridements and length of therapy. Operating room debridement cost was $3393 according to Granick et al. Daily therapy cost for each modality was $194.80 (NPWTi-d) and $106.08 (NPWT) based on internal company information.

RESULTS

RESULTS showed significant differences (P < 0.0001) between NPWTi-d and NPWT patients, respectively, for the following: mean operating room debridements (2.0 vs 4.4), mean hospital stay (8.1 vs 27.4 days), mean length of therapy (4.1 vs 20.9 days), and mean time to wound closure (4.1 vs 20.9 days). Hypothetical economic model showed potential average reduction of $8143 for operating room debridements between NPWTi-d ($6786) and NPWT ($14,929) patients. There was a $1418 difference in average therapy costs between groups ($799/NPWTi-d vs $2217/NPWT).

CONCLUSIONS

In this study, NPWTi-d appeared to assist in wound cleansing and exudate removal, which may have allowed for earlier wound closure compared to NPWT. Hypothetical economic model findings illustrate potential cost-effectiveness of NPWTi-d compared to NPWT.

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.

Negative Pressure Wound Therapy With Instillation (NPWTi) Better Reduces Post-debridement Bioburden in Chronically Infected Lower Extremity Wounds Than NPWT Alone

OBJECTIVE

An overabundance of bacteria in the chronic wound plays a significant role in the decreased ability for primary closure. One means of decreasing the bioburden in a wound is to operatively debride the wound for wound bed optimization prior to application of other therapy, such as Negative Pressure Wound Therapy (NPWT). We undertook a prospective pilot study to assess the efficacy of wound bed preparation for a standard algorithm (sharp surgical debridement followed by NPWT) versus one employing sharp surgical debridement followed by Negative Pressure Wound Therapy with Instillation (NPWTi).

METHODS

Thirteen patients, corresponding to 16 chronic lower leg and foot wounds were taken to the operating room for debridement. The patients were sequentially enrolled in 2 treatment groups: the first receiving treatment with operative debridement followed by 1 week of NPWT with the instillation of quarter strength bleach solution; the other receiving a standard algorithm consisting of operative debridement and 1 week of NPWT. Quantitative cultures were taken pre-operatively after sterile preparation and draping of the wound site (POD # 0, pre-op), post-operatively once debridement was completed (POD # 0, post-op), and on post-operative day 7 after operative debridement (POD # 7, post-op).

RESULTS

After operative debridement (post-operative day 0) there was a mean of 3 (±1) types of bacteria per wound. The mean CFU/gram tissue culture was statistically greater - 3.7 × 10(6) (±4 × 10(6)) in the NPWTi group, while in the standard group (NPWT) the mean was 1.8 × 10(6) (±2.36 × 10(6)) CFU/gram tissue culture (p = 0.016); at the end of therapy there was no statistical difference between the two groups (p = 0.44). Wounds treated with NPWTi had a mean of 2.6 × 10(5) (±3 × 10(5)) CFU/gram of tissue culture while wounds treated with NPWT had a mean of 2.79 × 10(6) (±3.18 × 10(6)) CFU/gram of tissue culture (p = 0.43). The mean absolute reduction in bacteria for the NPWTi group was 10.6 × 10(6) bacteria per gram of tissue while there was a mean absolute increase in bacteria for the NPWT group of 28.7 × 10(6) bacteria per gram of tissue, therefore there was a statistically significant reduction in the absolute bioburden in those wounds treated with NPWTi (p = 0.016).

CONCLUSION

It has long been realized that NPWT does not make its greatest impact by bioburden reduction. Other work has demonstrated that debridement alone does not reduce wound bioburden by more than 1 Log. Wounds treated with NPWTi (in this case with quarter strength bleach instillation solution) had a statistically significant reduction in bioburden, while wounds treated with NPWT had an increase in bioburden over the 7 days.

Recommendations on negative pressure wound therapy with instillation and antimicrobial solutions - when, where and how to use: what does the evidence show?

Infections of contaminated or colonised acute or chronic wounds remain a grave risk for patients even today. Despite modern surgical debridement concepts and antibiotics, a great need exists for new therapies in wound management. Since the late 1990s, advantageous effects of negative pressure wound therapy (NPWT) have been combined with local antiseptic wound cleansing in the development of NPWT with instillation (NPWTi). This article summarises the current scientific knowledge on this topic. MEDLINE literature searches were performed on the subject of negative pressure wound and instillation therapy covering publications from the years 1990 to 2013 (36 peer-reviewed citations) and regarding randomised controlled trials (RCTs) covering wound care with bone involvement (27 publications) or soft-tissue wounds without bone participation (11 publications) from 2005 to 2012. The use of NPWTi in the therapy of infected wounds appears to be not yet widespread, and literature is poor and inhomogeneous. However, some reports indicate an outstanding benefit of NPWTi for patients, using antiseptics such as polyhexanide (concentration 0·005-0·04%) and acetic acid (concentration 0·25-1%) in acute and chronic infected wounds and povidone-iodine (10% solution) as prophylaxis in contaminated wounds with potential viral infection. Soaking times are recommended to be 20 minutes each, using cycle frequencies of four to eight cycles per day. Additionally, the prophylactic use of NPWTi with these substances can be recommended in contaminated wounds that cannot be closed primarily with surgical means. Although first recommendations may be given currently, there is a great need for RCTs and multicentre studies to define evidence-based guidelines for an easier approach to reach the decision on how to use NPWTi.

Simultaneous irrigation and negative pressure wound therapy enhances wound healing and reduces wound bioburden in a porcine model

Infected foot wounds are one of the most common reasons for hospitalization and amputation among persons with diabetes. The objective of the study was to investigate a new wound therapy system that employs negative pressure wound therapy (NPWT) with simultaneous irrigation therapy. For this study, we used a porcine model with full-thickness excisional wounds, inoculated with Pseudomonas aeruginosa. Wounds were treated for 21 days of therapy with either NPWT, NPWT with simultaneous irrigation therapy using normal saline or polyhexanide biguanide (PHMB) at low or high flow rates, or control. Data show that NPWT with either irrigation condition improved wound healing rates over control-treated wounds, yet did not differ from NPWT alone. NPWT improved bioburden over control-treated wounds. NPWT with simultaneous irrigation further reduced bioburden over control and NPWT-treated wounds; however, flow rate did not affect these outcomes. Together, these data show that NPWT with simultaneous irrigation therapy with either normal saline or PHMB has a positive effect on bioburden in a porcine model, which may translate clinically to improved wound healing outcomes.

Comparison of the Effects of Different Negative Pressure Wound Therapy Modes-Continuous, Noncontinuous, and With Instillation-on Porcine Excisional Wounds

OBJECTIVE

Negative pressure wound therapy (NPWT) can be delivered in continuous or noncontinuous modes, while NPWT with instillation (NPWTi) couples NPWT with automated delivery and removal of topical wound treatment solutions and suspensions. This porcine study compared granulation response of NPWTi (instillation foam dressing with saline) to NPWT (standard foam dressing) in continuous and noncontinuous modes.

METHODS

Full-thickness dorsal excisional wounds in pigs were treated with continuous NPWT, intermittent NPWT, dynamic (controlled variable) NPWT, and NPWTi with saline (n = 10 per group). Wound dimensions were determined from 3D images collected on days 0, 2, 5, and 7. On day 7, animals were euthanized and specimens were harvested for histopathological review.

RESULTS

Average granulation thickness was not statistically different among continuous (3.29 ± 0.33 mm), intermittent (3.03 ± 0.47 mm), and dynamic (3.40 ± 0.34 mm) NPWT wounds at day 7. Average granulation thickness of NPWTi wounds (4.75 ± 0.54 mm), however, was statistically greater (P < .05) by 44%, 57%, and 40%, respectively, than that of wounds treated with continuous, intermittent, and dynamic NPWT. Analysis of 3D images revealed a greater reduction in wound area and perimeter in NPWTi wounds compared to all NPWT wounds (P < .05). In addition, the average wound fill rate for NPWTi wounds was faster than that for continuous (40%; P < .05), intermittent (25%; P > .05), and dynamic (65%; P < .05) NPWT wounds.

CONCLUSIONS

Although not confirmed in humans, these porcine data suggest that NPWTi with saline may stimulate a faster rate of wound granulation than NPWT in continuous and noncontinuous modes.

In vitro toxicity and activity of Dakin's solution, mafenide acetate, and amphotericin B on filamentous fungi and human cells

OBJECTIVES

Posttraumatic invasive fungal infections threaten critically injured combat-related injuries and require a combination of extensive surgery and systemic antifungal therapy, along with topical antimicrobials used adjunctively to control the infection. We evaluated the in vitro activity of topical agents in varying combinations and concentrations against molds from patients that were responsible for wound invasive fungal infections and the topical agents' toxicity to human cells.

METHODS

Mafenide acetate solutions (2.5%, 5%, and 7.5%), amphotericin B solutions (2 µg/mL, 2 mg/mL, and 20 mg/mL), SMAT (5% mafenide acetate in combination with 2 µg/mL, 2 mg/mL, and 20 mg/mL amphotericin B), and Dakin's solutions (buffered sodium hypochlorite) (0.5%, 0.25%, and 0.125% and 10-fold serial dilutions of 0.25%-0.00000025%) were evaluated for antifungal activity against 4 molds using a time-kill assay using standard conidial suspensions of 5 × 10(4) colony-forming units per milliliter. To assess cellular toxicity, confluent monolayers of human keratinocytes, dermal fibroblasts, and osteoblasts were exposed to these topical agents. Based upon efficacy and toxicity ratios, an additional 10 molds were screened with selected concentrations of the topical agents for antifungal activity and toxicity.

RESULTS

All the topical agents seemed to have a dose-dependent killing with only mafenide acetate showing time killing associated with prolonged contact. There was overall evidence of dose-dependent cytotoxicity of the various topical agents against the various cell lines tested, but there did not seem to be increased cell death with continued exposure to the agents over time. Dakin's solution exhibited dose-dependent toxicity and efficacy with 0.00025% appearing to optimize those parameters.

CONCLUSIONS

Mafenide acetate and amphotericin B did not seem to persistently meet the toxicity and efficacy balance as consistently as Dakin's solution.

A novel technique for the treatment of infected metalwork in orthopaedic patients using skin closure over irrigated negative pressure wound therapy dressings

Introduction

There has been recent interest in the use of negative pressure wound therapy (NWPT) as an adjunct to parenteral antibiotics in the treatment of infection in orthopaedic patients with metalwork in situ. To address some of the limitations of standard NPWT in this situation, the senior author has developed a modified method of treatment for infected metalwork (excluding arthroplasty) in orthopaedic patients that includes irrigation and skin closure over the standard NPWT dressing.

Methods

This retrospective study examined the outcome of a case series of 16 trauma and orthopaedic patients with deep infection involving metalwork in whom this modified form of NPWT was used. In conjunction with standard parenteral antibiotic therapy and a multidisciplinary approach, this modified technique included serial debridements in theatre, irrigation and negative pressure dressings over a white polyvinyl alcohol foam (KCI, Kidlington, UK) as well as closure of the skin over the foam.

Results

Among the 16 patients, there was a variety of upper and lower limb as well as spinal trauma and elective cases. In all 16 patients, there was successful resolution of the infection with no early or unplanned removal of any metalwork required.

Conclusions

Patients with infected metalwork are a heterogeneous group, and often suffer high morbidity and mortality. The modified NPWT technique shows potential as an adjunct in the treatment of complex orthopaedic patients with infected metalwork.

Treatment of infected soft tissue blast injury in swine by regulated negative pressure wound therapy

OBJECTIVE

This study was designed to investigate the therapeutic potential of regulated negative pressure wound therapy (RNPT) in treating infected blast injuries in swine.

BACKGROUND

Approximately 30% to 80% of blast injuries develop infection, which increases the morbidity and mortality of these casualties. RNPT has been used in US military operations in Iraq; however, no randomized controlled study has been conducted on the use of RNPT to treat infected war injuries.

METHODS

Infected soft tissue blast injuries were treated with gauze dressings or RNPT with different pressures ranging from -5 to -35 kPa. To evaluate the wound healing process, the wound area, wound depth, the number of proliferative cells, and the vascular endothelial cells in the granulation tissue were measured at different time points. Furthermore, to evaluate the infection and inflammation of the blast injury, the bacterial load, bacterial species, and several inflammatory markers were detected.

RESULTS

Compared with gauze dressing treatments, RNPT reduced bacterial load more efficiently, initiated granulation tissue formation earlier, and increased the inflammation faster. Negative pressures ranging from -10 to -25 kPa applied on the RNPT group showed beneficial effects in treating the infected soft tissue blast injury. RNPT did not significantly change both the aerobic and anaerobic bacterial composition compared with those of the gauze dressing group.

CONCLUSIONS

RNPT clearly shows beneficial effects in treating the infected soft tissue blast injury in comparison with the gauze dressing therapy in swine.

Integrated negative pressure wound therapy system with volumetric automated fluid instillation in wounds at risk for compromised healing

Nearly all wounds are at risk for compromised healing due to excessive exudation, oedema, contaminants and presence of inflammatory mediators. Compromised wounds have the potential to develop complications, such as infection, which may lead to delayed wound healing, prolonged hospitalisation and more frequent readmissions. It is generally believed that the wound advances from contamination to colonisation when the bacteria on the wound's surface begin to replicate and increase their metabolic activity. Heavy bacterial bioburden increases the metabolic requirements, stimulates a proinflammatory environment and encourages the in-migration of monocytes, macrophages and leukocytes - all of which can negatively impact wound healing. Bacteria also secrete harmful cytokines which can lead to vasoconstriction and decreased blood flow. Thus, controlling or preventing infections is essential for normal wound healing process to occur. While the mainstay of treating wound infection has historically included intravenous, oral and/or topical antimicrobials in addition to frequent gauze dressing changes, a shift towards wound management with advanced modalities, such as negative pressure wound therapy (NPWT), has occurred during the past decade. This review will provide expert opinion and scientific support for the use of NPWT with instillation (NPWTi; V.A.C. Instill® Wound Therapy and V.A.C. VeraFlo™ Therapy, KCI USA, Inc., San Antonio, TX) for the treatment of at-risk and complicated wounds.

Wound Healing Society (WHS) venous ulcer treatment guidelines: what's new in five years?

Since the establishment of the guidelines for the treatment of venous ulcers by the Wound Healing Society in 2006, there has been an abundance of new literature, both in accord and discord with the guidelines. The goal of this update is to highlight new findings since the publication of these guidelines to assist practitioner and patient in appropriate health care decisions, as well as to drive future research endeavors.