Silicone-coated non-woven polyester dressing enhances reepithelialisation in a sheep model of dermal wounds

Negative-pressure wound therapy (NPWT) also known as V.A.C. (Vacuum-assisted closure), is widely used to manage various type of wounds and accelerate healing. NPWT has so far been delivered mainly via open-cell polyurethane (PU) foam or medical gauze. In this study an experimental setup of sheep wound model was used to evaluate, under NPWT conditions, the performance of a silicone-coated non-woven polyester (N-WPE) compared with PU foam and cotton hydrophilic gauze, used as reference materials. Animals were anesthetized with spontaneous breathing to create three 3 × 3 cm skin defects bilaterally; each animal received three different samples on each side (n = 6 in each experimental group) and was subjected to negative and continuous 125 mmHg pressure up to 16 days. Wound conditions after 1, 8 and 16 days of treatment with the wound dressings were evaluated based on gross and histological appearances. Skin defects treated with the silicone-coated N-WPE showed a significant decrease in wound size, an increase of re-epithelialization, collagen deposition and wound neovascularisation, and a minimal stickiness to the wound tissue, in comparison with gauze and PU foam. Taken all together these findings indicate that the silicone-coated N-WPE dressing enhances wound healing since stimulates higher granulation tissue formation and causes minor tissue trauma during dressing changes.

Negative pressure wound therapy for skin grafts and surgical wounds healing by primary intention

BACKGROUND

Indications for the use of negative pressure wound therapy (NPWT) are broadening with a range of systems on the market, including those designed for use on clean, closed incisions and skin grafts. Reviews have concluded that the evidence for the effectiveness of NPWT remains uncertain. However, this is a rapidly evolving therapy. Consequently, a systematic review of the evidence for the effects of NPWT on postoperative wounds expected to heal by primary intention is required.

OBJECTIVES

To assess the effects of NPWT on surgical wounds (primary closure or skin grafting) that are expected to heal by primary intention.

SEARCH METHODS

We searched the following electronic databases to identify reports of relevant randomised clinical trials: the Cochrane Wounds Group Specialised Register (searched 11 November 2011); the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2011, Issue 4); Database of Abstracts of Reviews of Effects (The Cochrane Library 2011, Issue 4); Ovid MEDLINE (2005 to October Week 4 2011); Ovid MEDLINE (In-Process & Other Non-Indexed Citations 8 November 2011); Ovid EMBASE (2009 to 2011 Week 44); and EBSCO CINAHL (1982 to 04 November 2011). We conducted a separate search to identify economic evaluations.

SELECTION CRITERIA

We included trials if they allocated patients at random and compared NPWT with any other type of wound dressing or compared one type of NPWT with a different type of NPWT.

DATA COLLECTION AND ANALYSIS

We assessed trials for their appropriateness for inclusion and for their quality. This was done by three review authors working independently, using pre-determined inclusion and quality criteria.

MAIN RESULTS

We included five eligible trials with a total of 280 participants. Two trials involved skin grafts and three acute wounds. Only one of the five trials reported the proportion of wounds completely healed and in this study all wounds healed. All five studies reported adverse events. In the four trials that compared standard dressings with negative pressure wound therapy (NPWT) the adverse event rate was similar between groups (negative pressure 33/86; standard dressing 37/103); risk ratio (RR) 0.97 (95% confidence intervals (CI) 0.33 to 2.89). There was significant heterogeneity for this result, due to the high incidence of fracture blisters in the NPWT group in one trial. One trial (87 participants) compared a commercial negative pressure device VAC® system with a negative pressure system developed in the hospital (GSUC). The adverse event rate was lower in the GSUC group (VAC® 3/42; GSUC 0/45); the RR was 0.13 (95% CI 0.01 to 2.51). Results indicate uncertainty about the true effect of either method on adverse events. The mean cost to supply equipment for VAC® therapy was USD 96.51/day compared to USD 4.22/day for the GSUC therapy (P = 0.01). Labour costs for dressing changes were similar. Pain intensity score was also reported to be lower in the GSUC group when compared with the VAC® group (p = 0.02)

AUTHORS' CONCLUSIONS

Evidence for the effectiveness of NPWT on complete healing of wounds expected to heal by primary intention remains unclear. Rates of graft loss may be lower when NPWT is used; but evidence to date suggests that hospital-based products are as effective in this area as commercial applications. There are clear cost benefits when non-commercial systems are used to create the negative pressure required for wound therapy, with no reduction in clinical outcome. Pain levels are also rated lower when hospital systems are compared with their commercial counterparts. The high incidence of blisters occurring when NPWT is used following orthopaedic surgery suggests that the therapy should be limited until safety in this population is established. Given the cost and widespread use of NPWT, there is an urgent need for suitably powered, high-quality trials to evaluate the effects of the newer NPWT products that are designed for use on clean, closed surgical incisions. Such trials should focus initially on wounds that may be difficult to heal, such as sternal wounds or surgeries for obese patients.

Pressure transduction and fluid evacuation during conventional negative pressure wound therapy of the open abdomen and NPWT using a protective disc over the intestines

BACKGROUND

Negative pressure wound therapy (NPWT) has gained acceptance among surgeons, for the treatment of open abdomen, since very high closure rates have been reported with this method, compared to other kinds of wound management for the open abdomen. However, the method has occasionally been associated with increased development of fistulae. We have previously shown that NPWT induces ischemia in the underlying small intestines close to the vacuum source, and that a protective disc placed between the intestines and the vacuum source prevents the induction of ischemia. In this study we compare pressure transduction and fluid evacuation of the open abdomen with conventional NPWT and NPWT with a protective disc.

METHODS

Six pigs underwent midline incision and the application of conventional NPWT and NPWT with a protective disc between the intestines and the vacuum source. The pressure transduction was measured centrally beneath the dressing, and at the anterior abdominal wall, before and after the application of topical negative pressures of -50, -70 and -120 mmHg. The drainage of fluid from the abdomen was measured, with and without the protective disc.

RESULTS

Abdominal drainage was significantly better (p < 0. 001) using NPWT with the protective disc at -120 mmHg (439 ± 25 ml vs. 239 ± 31 ml), at -70 mmHg (341 ± 27 ml vs. 166 ± 9 ml) and at -50 mmHg (350 ± 50 ml vs. 151 ± 21 ml) than with conventional NPWT. The pressure transduction was more even at all pressure levels using NPWT with the protective disc than with conventional NPWT.

CONCLUSIONS

The drainage of the open abdomen was significantly more effective when using NWPT with the protective disc than with conventional NWPT. This is believed to be due to the more even and effective pressure transduction in the open abdomen using a protective disc in combination with NPWT.

Negative pressure therapy: theory and practice

Negative pressure (wound) therapy, synonymous with topical negative pressure or vacuum therapy mainly cited as branded VAC® (vacuum-assisted closure) therapy, is a mode of therapy used to encourage wound healing. It is used both as primary treatment of chronic and complex wounds and as an adjunct for temporary closure and wound bed preparation preceding surgical procedures such as skin grafts and flap surgery. The device has come into wide and successful use, although the physiological basis of its effect is not yet fully understood, and with a delay, increasingly evidence-based data become available. A meta-analysis was made of peer-reviewed publications (PubMed-Medline) chosen on the basis of inclusion of the terms randomized clinical trial, vacuum-assisted closure, and topical negative pressure. Scientific data were evaluated from experimental animal studies, randomized clinical trials, observations of clinical applications, and case reports on all known effects of VAC therapy. Systematic analysis of the data shows efficacy concerning induction of wound healing mechanisms, especially in the early stage. Increased perfusion can be considered proven. Data analysis shows positive efficacy for treatment of infection. Although this therapy appears effective and its superiority to conventional techniques has been demonstrated, there are still some critical votes concerning efficacy. Because its mechanisms of action remain unclear, and because there is still some gap between evidence-based data and the excellent clinical results, further prospective, randomized, blinded studies are needed. Even so, we conclude that vacuum therapy, used when indicated and especially by experienced surgeons, is an excellent tool to support wound healing.

Use of vacuum-assisted closure device in a disastrous form of abdominal sepsis and stoma site infection: systematic review and report of a case

Use of Vacuum-Assisted Closure (VAC) for treatment of open abdomen has been established predominantly in cases of severe abdominal trauma, resulting with high percentage of primary fascial closure. The role of VAC technique in cases of severe diffuse peritonitis is not definitely incorrigible. However, in cases of severe complicated abdominal sepsis VAC come up as a last resort.

Maintenance of negative-pressure wound therapy while undergoing hyperbaric oxygen therapy

BACKGROUND

Both negative wound pressure therapy (NPWT) and hyperbaric oxygen therapy (HBOT) are useful modalities in the treatment of problem wounds. However, none of the commercially available portable negative-pressure devices have been certified safe for use in a recompression chamber. Thus, the NPWT device is removed while the patient undergoes HBOT. The purpose of this study is to demonstrate that wound negative pressure can be effectively and safely maintained during HBOT.

PATIENTS AND METHODS

In a small, prospective, randomised crossover trial, we used commonly available clinical materials to connect the NPWT suction tubing to the negative suction generating device in the hyperbaric chamber. Six patients each underwent one HBOT session with continuous NPWT and one HBOT session without concurrent NPWT. We assessed the patient's pain score, the amount of exudate aspirated by the NPWT during HBOT, and the appearance of the wound dressing after each session was assessed in a blinded manner.

RESULTS

There were no differences in pain scores between the two HBOT sessions. The amount of exudate aspirated during HBOT with NPWT ranged from 5 to 12 ml. Five of the six patients had a better appearance scoring of their dressing when NPWT was maintained during HBOT (P = 0.006).

CONCLUSION

We successfully demonstrated a simple design that allows the maintenance of NPWT during HBOT without causing additional pain, and with continued extraction of exudate. The maintenance of NPWT during HBOT also allowed the dressing to be maintained undisturbed.

Comparison of vacuum-assisted closure device and conservative treatment for fasciotomy wound healing in ischaemia-reperfusion syndrome: preliminary results

Ischaemia-reperfusion syndrome (IRS) is a condition that may require early fasciotomy. In the past, fasciotomies ultimately required prolonged hospitalisation. Vacuum-assisted closure (VAC) therapy system is an innovative method which promotes wound healing by reducing wound oedema, increasing microcirculation, and stimulation of granulation tissue. The aim of this retrospective study was to compare the VAC treatment with the conservative treatment of the fasciotomy wound until definitive surgical closure. The researchers retrospectively identified 15 patients, 3 females and 12 males, with a mean age of 69 years, who underwent a fasciotomy between January 2003 and December 2009 at the University Hospital of Geneva. All of the fasciotomies performed on the patients were on account of IRS. Seven patients were subjected to wound treatment using the VAC-system device and eight patients underwent treatment through the usual conservative method. The data were analysed by comparing the operative wound size, length of time for wound closure and duration of hospital stay in both groups. The number of days after fasciotomy until surgical wound closure in the VAC-system group (n = 7) ranged from 8 to 13 days with a mean of 11 days. The wound size at the day of closure was decreased in length by a mean of 58% (range 29-67%) and in diameter by a mean of 56% (range 33-75%). The duration of hospital stay for this group ranged from 12 to 18 days with a mean of 14 days. No signs of infections were observed and no re-operation was required after first closure. In the conservative group (n = 8), the time to wound closure ranged between 12 and 20 days with a mean of 15 days. The wound size was decreased in length by a mean of 40% (range 32-53%) and in diameter by a mean 46% (range 30-70%). The mean duration of hospital stay was 18·5 days. Three of the patients in the conservative treatment group manifested wound infection during the course of the treatment. VAC device could be a new standard for treatment of fasciotomy wound. VAC therapy is a recent innovation and becoming more and more a necessary complementary therapy to hasten wound healing. In our preliminary study, the VAC-system device showed significantly reduction of the wound size, decreased tissue oedema, duration of hospital days and improvement of granulation tissue.

[Treatment of purulent wounds using vacuum-therapy]

The results of treatment of complex wounds in 115 patients, in 56 of whom vacuum-therapy was conducted, were analyzed. The duration of a bandage holding constitutes 1 - 3 days at average. The peculiarities of clinical course, the dynamics of the wounds microbic spillage, cellular content in the wounding prints, phagocytic activity and phagocytic number, the phagocytosis completeness index were estimated and calculated. Application of vacuum-therapy have promoted the earlier cleansing and epithelization of the wounds as well as the tissues reparation occurrence and the laboratory indices normalization.

Custom subatmospheric dressing for fingertip injuries

Fingertip injuries are difficult to treat. Although the best way is to cover the wound with flap or graft without finger shortening, coverage of the wound with flap or graft cannot be suitable in each case. For some cases, secondary wound healing can be an alternative treatment. In the secondary healing process, to promote the granulation tissue and to reduce wound-healing time, subatmospheric dressing (vacuum dressing) can be a useful method. In this study, a new custom-made subatmospheric dressing method designed for fingertip injuries has been described.

Macroscopic changes during negative pressure wound therapy of the open abdomen using conventional negative pressure wound therapy and NPWT with a protective disc over the intestines

BACKGROUND

Higher closure rates of the open abdomen have been reported with negative pressure wound therapy (NPWT) than with other wound management techniques. However, the method has occasionally been associated with increased development of fistulae. We have previously shown that NPWT induces ischemia in the underlying small intestines close to the vacuum source, and that a protective disc placed between the intestines and the vacuum source prevents the induction of ischemia. In the present study we compare macroscopic changes after 12, 24, and 48 hours, using conventional NPWT and NPWT with a protective disc between the intestines and the vacuum source.

METHODS

Twelve pigs underwent midline incision. Six animals underwent conventional NPWT, while the other six pigs underwent NPWT with a protective disc inserted between the intestines and the vacuum source. Macroscopic changes were photographed and quantified after 12, 24, and 48 hours of NPWT.

RESULTS

The surface of the small intestines was red and mottled as a result of petechial bleeding in the intestinal wall in all cases. After 12, 24 and 48 hours of NPWT, the area of petechial bleeding was significantly larger when using conventional NPWT than when using NPWT with the protective disc (9.7 ± 1.0 cm(2) vs. 1.8 ± 0.2 cm(2), p < 0.001, 12 hours), (14.5 ± 0.9 cm(2) vs. 2.0 ± 0.2 cm(2), 24 hours) (17.0 ± 0.7 cm(2) vs. 2.5 ± 0.2 cm(2) with the disc, p < 0.001, 48 hours)

CONCLUSIONS

The areas of petechial bleeding in the small intestinal wall were significantly larger following conventional NPWT after 12, 24 and 48 hours, than using NPWT with a protective disc between the intestines and the vacuum source. The protective disc protects the intestines, reducing the amount of petechial bleeding.

Navigating new technologies in negative pressure wound therapy

Plastic surgeons and their support staff are tasked with proficient management of a wide variety of complex wounds. Since its introduction, negative pressure wound therapy (NPWT) has increasingly been used within the plastic surgery specialty to improve and simplify wound management. Increased usage of the therapy has prompted the development of a myriad of new NPWT systems. While an expanded product selection allows greater choice to maximize patient outcomes, sound decision-making also requires a clear understanding of the characteristics of various NPWT systems and applications. Wound-specific NPWT systems of varying size are available for low- to moderate-severity wounds, clean closed incisions, and acute abdominal wounds. Wound size and severity, amount of exudate, and patient mobility issues have become important considerations when choosing an NPWT device. The purpose of this article is to familiarize the reader with the latest sophistications in NPWT systems to guide decision making and usage.

Comparative effectiveness of the SNaP™ Wound Care System

Diabetic lower extremity wounds cause substantial burden to healthcare systems, costing tens of thousands of dollars per episode. Negative pressure wound therapy (NPWT) devices have been shown to be cost-effective at treating these wounds, but the traditional devices use bulky electrical pumps that require a durable medical equipment rental-based procurement process. The Spiracur SNaP™ Wound Care System is an ultraportable NPWT system that does not use an electric pump and is fully disposable. It has superior healing compared to standard of care with modern dressings and comparable healing to traditional NPWT devices while giving patients greater mobility and giving clinicians a simpler procurement process. We used a mathematical model to analyse the costs of the SNaP™ system and compare them to standard of care and electrically powered NPWT devices. When compared to standard of care, the SNaP™ system saves over $9000 per wound treated and more than doubles the number of patients healed. The SNaP system has similar healing time to powered NPWT devices, but saves $2300 in Medicare payments or $2800 for private payers per wound treated. Our analysis shows that the SNaP™ system could save substantial treatment costs in addition to allowing patients greater freedom and mobility.

Medical devices; general and plastic surgery devices; classification of non-powered suction apparatus device intended for negative pressure wound therapy. Final rule

The Food and Drug Administration (FDA) is classifying the non-powered suction apparatus device intended for negative pressure wound therapy (NPWT) into class II (special controls). The special control that will apply to the device is the guidance document entitled "Class II Special Controls Guidance Document: Non-Powered Suction Apparatus Device Intended for Negative Pressure Wound Therapy." The agency is classifying the device into class II (special controls) in order to provide a reasonable assurance of safety and effectiveness of the device. Elsewhere in this issue of the Federal Register, FDA is publishing a notice of availability for the guidance document entitled "Class II Special Controls Guidance Document: Non-Powered Suction Apparatus Device Intended for Negative Pressure Wound Therapy."

Possible devices to temporary cover the open abdomen: pros and cons

In the last 25 years increased popularity of damage control surgery and recognition of abdominal compartment syndrome has lead to a raised incidence of open abdomens. Even though these procedures are often life-saving, morbidity and mortality associated with an open abdomen remains high. Third spacing after aggressive fluid resuscitation, fascial retraction, ventilatory problems and fistula formations are problems often associated with an open abdomen. Management of an open abdomen is often complicated and challenging. The viscera need to be protected and the abdomen needs coverage. Several techniques have been described for both temporary and definitive closure. This article will discuss the pros and cons of several available temporary devices to cover the abdomen and literature will be reviewed.

[An approach to vacuum-assisted closure therapy using the S-B Vac]

Vacuum-assisted closure (VAC) therapy is increasingly applied for patients with wound dehiscence or mediastinitis caused by surgical site infection (SSI) after open-heart surgery. We have used wall suction for such cases in the past. But this method was an obstacle for improvement of the quality of life (QOL) of the patient. Since the S-B Vac is portable, this equipment may allow wound healing without decreasing QOL. Here, we report a case in which VAC therapy was performed using the S-B Vac.

The SNaP Wound Care System: a case series using a novel ultraportable negative pressure wound therapy device for the treatment of diabetic lower extremity wounds

Although there is significant evidence supporting the use of negative pressure wound therapy (NPWT) for the treatment of lower extremity diabetic ulcers, currently available electrically powered NPWT systems are not ideally suited for treating smaller diabetic foot ulcers. The Smart Negative Pressure (SNaP) Wound Care System is a novel, ultraportable device that delivers NPWT without the use of an electrically powered pump. It was specifically designed to meet the wound care needs of patients with diabetes. The SNaP System is compact, silent, mobile, easy-to-use, and available off-the-shelf. It is fully disposable and may offer other important benefits over electrically powered systems to both the clinician and patient. We review the evidence for use of NPWT for the treatment of diabetic wounds and discuss the potential benefits of this new NPWT technology for patients with diabetes. We also present a case series of four difficult lower extremity diabetic ulcers that were successfully treated with the SNaP System. This study suggests that the SNaP System may be a useful addition to the armamentarium of the diabetic wound care clinician.

[Mechanism and progressing study in promoting wound healing with negative pressure therapy]

Negative pressure therapy (NPT) has been widely used in clinic and obtained obvious curative effects. However, its mechanism has been relatively less studied. This article updated the enhancing mechanism, physical action and biomechanics effects, etc. and provided thinking for the further development of NPT.

[Treatment of open abdomen in patients with abdominal sepsis using the vacuum pack system]

BACKGROUND

In abdominal sepsis, when the initial surgery fails to control infection, a good choice may be to leave the abdomen open. This is a descriptive study of a series of cases using the vacuum pack system for temporary abdominal closure.

METHODS

We studied 19 patients. Demographic data were obtained, as well as those related to the vacuum pack, and the final fascial closure. We describe the technique of temporary abdominal closure. Values are presented as mean ± standard deviation (SD).

RESULTS

The average length of the hospital stay was 24.7 days. Fourteen (73.7%) patients survived and five patients (26.3%) died. The mean treatment time with the vacuum pack was 12.7 days, with an average of 3.9 changes. Early fascial closing was achieved in seven patients with an average of 14.6 days. In seven patients a planned ventral hernia formed, which was repaired by separation of components on an average of 261 days or by polypropylene mesh on an average of 228 days.

CONCLUSIONS

In our series, early fascial closing was achieved using the vacuum pack at a lower frequency than reported by other authors. Other parameters analyzed were similar to those reported in the literature. The vacuum pack system demonstrated to be effective, although the final selection for temporary abdominal closure will depend on the experience of the institution as well as surgeon preference. The vacuum pack system for temporary abdominal closure of the open abdomen is an effective alternative in patients with abdominal sepsis.

Analysis of the SNaP Wound Care System, a negative pressure wound device for treatment of diabetic lower extremity wounds

Negative pressure wound therapy (NPWT) has become a widely used modality for the treatment of complex wounds. However, patient compliance is frequently difficult due to the need to carry a bulky, noisy electronic device. In this issue of Journal of Diabetes Science and Technology, Lerman and colleagues describe a new system that uses no electricity and is about the size of a deck of cards. It is designed to be stored in the clinic and applied almost as simply as a standard wound dressing. Four cases are reviewed to demonstrate that the device is efficacious and helps to encourage patient compliance. No statistically significant outcomes are presented. By removing compliance barriers, this device may encourage more frequent NPWT applications for small wounds.

Silver: an age-old treatment modality in modern times

The use of silver as an antimicrobial for infection spans hundreds of years. The ancient Greeks and Romans used silver to disinfect their water and food supplies. Silver was also used in ancient times to treat burns and wounds as a wound dressing. Silver solutions were approved by the U.S. Food and Drug Administration in the 1920s. Since that time, silver has established itself as an effective and well-known treatment modality for and in the prevention of high-risk infection in clinical wound care (http://int.hansaplast.com/med-info/wound-care-beautiful-healing/silver-tech.html).

[Vacuum therapy in vascular surgery]

The negative pressure therapy is a system of healing and active non-invasive, which uses a controlled and localized negative pressure to stimulate the healing of acute and chronic wounds, because it promotes the formation of granulation tissue, and allows limited infection proper control of loss of body fluids. Since the beginning of this therapy in December 2007, as treating wounds caused by trauma or dehiscence of different stitches, in our department has monitored 21 patients of which have evolved favourably in a well being 100% tolerated and accepted by them.