Blister formation with negative pressure dressings after total knee arthroplasty

Closed-incision negative pressure therapy to reduce groin wound infections in vascular surgery: a randomised controlled trial

Groin wound infections pose a major problem in vascular surgery. Closed-incision negative pressure therapy (ciNPT) was especially designed for the management of incisions at risk of surgical site infections. The aim of this study was to investigate whether ciNPT is able to reduce the incidence of wound infections after vascular surgery. Data on 132 consecutive patients, scheduled for vascular surgery with a longitudinal femoral cutdown, were collected prospectively. All patients were randomised either to the ciNPT group (n = 64) or the control group (n = 68) with conventional dressing. In the ciNPT group, the foam dressing was applied intraoperatively and removed after 5 days. The control group received an absorbent dressing. All wounds were evaluated after 5 and 42 days. Infections were graded according the Szilagyi classification (I-III°). There were no significant differences between both groups considering patient characteristics. Indications for surgery were peripheral arterial disease in 95% (125/132) and aneurysm in 5% (7/132). The overall infection rates were 14% (9/64) in the ciNPT group and 28% (19/68) in the control group (P = 0·055). Early infections were observed in 6% (4/64) of the ciNPT group and 15% (10/68) of the control group (P = 0·125). ciNPT did not reduce infection rates associated with different risk factors for infection. While the experiences with the ciNPT device were encouraging, the study fails to provide evidence of the efficacy of the device to reduce groin wound infections after vascular surgery. It illustrates far more that larger multicentre studies are required and appear promising to provide further evidence for the use of ciNPT.

Local Modalities for Preventing Surgical Site Infections: An Evidence-based Review

Surgical site infections remain a dreaded complication of orthopaedic surgery, affecting both patient economics and quality of life. It is important to note that infections are multifactorial, involving both surgical and patient factors. To decrease the occurrence of infections, surgeons frequently use local modalities, such as methicillin-resistant Staphylococcus aureus screening; preoperative bathing; intraoperative povidone-iodine lavage; and application of vancomycin powder, silver-impregnated dressings, and incisional negative-pressure wound therapy. These modalities can be applied individually or in concert to reduce the incidence of surgical site infections. Despite their frequent use, however, these interventions have limited support in the literature.

Closed Incision Negative Pressure Therapy Effects on Postoperative Infection and Surgical Site Complication After Total Hip and Knee Arthroplasty

BACKGROUND

The aim of this study is to determine whether negative pressure wound therapy, used prophylactically in clean surgical incisions, reduces surgical site infection, hematoma, and seroma after total joint replacement.

METHODS

A single center, open-label study with a prospective cohort of patients undergoing primary total knee arthroplasty or total hip arthroplasty treated with closed incision negative pressure therapy (ciNPT) of clean surgical wounds was conducted. One hundred ninety-six incisions treated with ciNPT in 192 patients were compared with a historical control group of 400 patients treated with traditional gauze dressing. The rates of clinically significant hematoma, seroma, dehiscence, surgical site infection, and complication were compared using univariate analyses and multiple logistic regression.

RESULTS

The rate of deep infection was unchanged in the ciNPT group compared with control (1.0% vs 1.25%); however, the overall rate of infection (including superficial wound infection) decreased significantly (3.5% vs 1.0%, P = .04). Overall complication rate was lower in the ciNPT group than controls (1.5% vs 5.5%, P = .02). Upon logistic regression, only treatment group was associated with complication; patients treated with ciNPT were about 4 times less likely to experience a surgical site complication compared with control (P = .0277, odds ratio 4.251, 95% confidence interval 1.172-15.414).

CONCLUSION

ciNPT for total knee arthroplasty and total hip arthroplasty in a comprehensive patient population reduced overall incidence of complication, but did not significantly impact the rate of deep infection. Further research to determine clinical and economic advantages of routine use of ciNPT in total joint arthroplasty is warranted.

NEGATIVE-PRESSURE WOUND THERAPY IN THE TREATMENT OF COMPLEX INJURIES AFTER TOTAL KNEE ARTHROPLASTY

OBJECTIVE

To present an experience with negative-pressure wound therapy (NPWT) in the treatment of surgical wounds in patients treated for infections after total knee arthroplasty (TKA) with or without dehiscence and prophylaxis in wounds considered at risk of healing problems.

METHODS

We prospectively evaluated patients with TKA infection with or without surgical wound dehiscence and patients with risk factors for infection or surgical wound complications treated with Pico^(r) device for NPWT in addition to standard treatment of infection or dehiscence in our institution. We considered as an initial favorable outcome the resolution of the infectious process and the closure of the surgical wound dehiscences in the treated cases and the good progression of the wound without complicating events in the prophylactic cases.

RESULTS

We evaluated 10 patients who used Pico^(r) in our service. All patients had a favorable outcome according to established criteria. No complications were identified regarding the use of the NPWT device. The mean follow-up of the patients after the use of the device was 10.5 months.

CONCLUSION

The NPWT can be safely used in wound infections and complications following TKA with promising results. Long-term randomized prospective studies should be conducted to prove its effectiveness. Level of Evidence IV, Case Series.

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

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

New WHO recommendations on intraoperative and postoperative measures for surgical site infection prevention: an evidence-based global perspective

Surgical site infections (SSIs) are the most common health-care-associated infections in developing countries, but they also represent a substantial epidemiological burden in high-income countries. The prevention of these infections is complex and requires the integration of a range of preventive measures before, during, and after surgery. No international guidelines are available and inconsistencies in the interpretation of evidence and recommendations in national guidelines have been identified. Considering the prevention of SSIs as a priority for patient safety, WHO has developed evidence-based and expert consensus-based recommendations on the basis of an extensive list of preventive measures. We present in this Review 16 recommendations specific to the intraoperative and postoperative periods. The WHO recommendations were developed with a global perspective and they take into account the balance between benefits and harms, the evidence quality level, cost and resource use implications, and patient values and preferences.

Closed Incision Negative Pressure Wound Therapy vs Conventional Dry Dressings After Primary Knee Arthroplasty: A Randomized Controlled Study

BACKGROUND

The purpose of this study was to assess the effect of negative pressure wound therapy (NPWT) on quality of life (QoL), wound complications, and cost after primary knee arthroplasty.

METHODS

A prospective analysis of 33 patients undergoing primary knee arthroplasty performed by 3 surgeons in one institution. The first 12 patients (3 bilateral and 9 unilateral) had conventional dry dressings (CDD) applied and cost of dressings was assessed. The other 21 patients all underwent bilateral knee arthroplasty and had either side randomized to receiving NPWT or CDD. Cost of dressings, wound complications, and QoL were compared.

RESULTS

One patient had a reaction to the NPWT requiring readmission. Another had persistent wound drainage that required NPWT application. There were no wound issues in the remaining 31 patients. The average cost in the first 12 patients was Australian dollar $48.70 with an average of 1.5 changes on ward. In the 21 patients receiving both dressings, the average cost for CDD was less (Australian dollar $43.51 vs $396.02, P ≤ .011, effect size [ES] = 1.06). When comparing QoL factors, wound leakage (0.14 vs 0.39 P = .019, ES = 1.02), and wound protection (0.16 vs 0.33, P = .001, ES = 0.021) were better in the NPWT group. There was no other significant difference in QoL factors. The average number of changes on the ward was less for the NPWT group (1.19 vs 1.38, P = .317, ES = 1.02).

CONCLUSION

We found no benefit in wound healing or cost with NPWT post knee arthroplasty. There was some benefit in NPWT QoL factors less wound leakage and better protection.

Soft-tissue Defects After Total Knee Arthroplasty: Management and Reconstruction

Wound healing complications associated with total knee arthroplasty present a considerable challenge to the orthopaedic surgeon. To ensure preservation of a functional joint, the management of periprosthetic soft-tissue defects around the knee requires rapid assessment, early and aggressive débridement, and durable, contoured coverage. Several reconstructive options are available to tailor soft-tissue coverage to the location, size, and depth of the wound. Special consideration should be given to the timing of the intervention, management of infection, and prosthesis salvage. The merits of each reconstructive option, including perforator, fasciocutaneous, muscular, and free microvascular flaps, should be weighed to select the most appropriate option. The proposed approach can guide surgeons in treating patients with these complex soft-tissue defects.

A systematic review and meta-analysis including GRADE qualification of the risk of surgical site infections after prophylactic negative pressure wound therapy compared with conventional dressings in clean and contaminated surgery

OBJECTIVE

Systematically review and Grading of Recommendations Assessment, Development, and Evaluation (GRADE) studies on prophylactic negative pressure wound therapy (pNPWT) to prevent surgical site infections (SSIs).

INTRODUCTION

pNPWT has been suggested as a new method to prevent wound complications, specifically SSIs, by its application on closed incisional wounds.

METHODS

This review was conducted as part of the development of the Global Guidelines for prevention of SSIs commissioned by World Health Organization in Geneva. PubMed, Embase, CENTRAL, CINAHL, and the World Health Organization database between January 1, 1990 and October 7, 2015 were searched. Inclusion criteria were randomized controlled trials and observational studies comparing pNPWT with conventional wound dressings and reporting on the incidence of SSI. Meta-analyses were performed with a random effect model. GRADE Pro software was used to qualify the evidence.

RESULTS

Nineteen articles describing 21 studies (6 randomized controlled trials and 15 observational) were included in the review. Summary estimate showed a significant benefit of pNPWT over conventional wound dressings in reducing SSIs in both randomized controlled trials and observational studies, odds ratio of 0.56 (95% confidence interval, 0.32-0.96; P = 0.04) and odds ratio of 0.30 (95% confidence interval, 0.22-0.42; P < 0.00001), respectively. This translates into lowering the SSI rate from 140 to 83 (49-135) per 1000 patients and from 106 to 34 (25-47) per 1000 patients, respectively. In stratified analyses, these results were consistent in both clean and clean-contaminated procedures and in different types of surgery, however results were no longer significant for orthopaedic/trauma surgery. The level of evidence as qualified with GRADE was however low.

CONCLUSIONS

Low-quality evidence indicates that prophylactic NPWT significantly reduces the risk of SSIs.

The impact of surgical site occurrences and the role of closed incision negative pressure therapy

Surgical site occurrences are observed in up to 60% of inpatient surgical procedures in industrialised countries. The most relevant postoperative complication is surgical site infection (SSI) because of its impact on patient outcomes and enormous treatment costs. Literature reviews ('SSI', 'deep sternal wound infections' (DSWI), 'closed incision negative pressure wound therapy' (ciNPT) were performed by electronically searching MEDLINE (PubMed) and subsequently using a 'snowball' method of continued searches of the references in the identified publications. Search criteria included publications in all languages, various study types and publication in a peer-reviewed journal. The SSI literature search identified 1325, the DSWI search 590 and the ciNPT search 103 publications that fulfilled the search criteria. Patient-related SSI risk factors (diabetes mellitus, obesity, smoking, hypertension, female gender) and operation-related SSI risk factors (re-exploration, emergency operations, prolonged ventilation, prolonged operation duration) exist. We found that patient- and operation-related SSI risk factors were often different for each speciality and/or operative procedure. Based on the evidence, we found that high-risk incisions (sternotomy and incisions in extremities after high-energy open trauma) are principally recommended for ciNPT use. In 'lower'-risk incisions, the addition of patient-related or operation-related risk factors justifies the application of ciNPT.

Incisional negative pressure wound therapy dressings (iNPWTd) in routine primary hip and knee arthroplasties: A randomised controlled trial

Objectives

Wound complications are reported in up to 10% hip and knee arthroplasties and there is a proven association between wound complications and deep prosthetic infections. In this randomised controlled trial (RCT) we explore the potential benefits of a portable, single use, incisional negative pressure wound therapy dressing (iNPWTd) on wound exudate, length of stay (LOS), wound complications, dressing changes and cost-effectiveness following total hip and knee arthroplasties.

Methods

A total of 220 patients undergoing elective primary total hip and knee arthroplasties were recruited into in a non-blinded RCT. For the final analysis there were 102 patients in the study group and 107 in the control group.

Results

An improvement was seen in the study (iNPWTd) group compared to control in all areas. Peak post-surgical wound exudate was significantly reduced (p = 0.007). Overall LOS reduction (0.9 days, 95% confidence interval (CI) -0.2 to 2.5) was not significant (p = 0.07) but there was a significant reduction in patients with extreme values of LOS in the iNPWTd group (Moses test, p = 0.003). There was a significantly reduced number of dressing changes (mean difference 1.7, 95% CI 0.8 to 2.5, p = 0.002), and a trend to a significant four-fold reduction in reported post-operative surgical wound complications (8.4% control; 2.0% iNPWTd, p = 0.06).

Conclusions

Based on the results of this RCT incisional negative pressure wound therapy dressings have a beneficial role in patients undergoing primary hip and knee arthroplasty to achieve predictable length of stay, especially to eliminate excessive hospital stay, and minimise wound complications.

Cite this article: S. L. Karlakki, A. K. Hamad, C. Whittall, N. M. Graham, R. D. Banerjee, J. H. Kuiper. Incisional negative pressure wound therapy dressings (iNPWTd) in routine primary hip and knee arthroplasties: A randomised controlled trial. Bone Joint Res 2016;5:328–337. DOI: 10.1302/2046-3758.58.BJR-2016-0022.R1

Meta-analysis of negative-pressure wound therapy for closed surgical incisions

Background

Postoperative wound complications are common following surgical procedures. Negative‐pressure wound therapy (NPWT) is well recognized for the management of open wounds and has been applied recently to closed surgical incisions. The evidence base to support this intervention is limited. The aim of this study was to assess whether NPWT reduces postoperative wound complications when applied to closed surgical incisions.

Methods

This was a systematic review and meta‐analysis of randomized clinical trials of NPWT compared with standard postoperative dressings on closed surgical incisions.

Results

Ten studies met the inclusion criteria, reporting on 1311 incisions in 1089 patients. NPWT was associated with a significant reduction in wound infection (relative risk (RR) 0·54, 95 per cent c.i. 0·33 to 0·89) and seroma formation (RR 0·48, 0·27 to 0·84) compared with standard care. The reduction in wound dehiscence was not significant. The numbers needed to treat were three (seroma), 17 (dehiscence) and 25 (infection). Methodological heterogeneity across studies led to downgrading of the quality of evidence to moderate for infection and seroma, and low for dehiscence.

Conclusion

Compared with standard postoperative dressings, NPWT significantly reduced the rate of wound infection and seroma when applied to closed surgical wounds. Heterogeneity between the included studies means that no general recommendations can be made yet.

Good for closed wounds too

Video Abstract

Closed incision negative pressure therapy: international multidisciplinary consensus recommendations

Surgical site occurrences (SSOs) affect up to or over 25% of patients undergoing operative procedures, with the subset of surgical site infections (SSIs) being the most common. Commercially available closed incision negative pressure therapy (ciNPT) may offer surgeons an additional option to manage clean, closed surgical incisions. We conducted an extensive literature search for studies describing ciNPT use and assembled a diverse panel of experts to create consensus recommendations for when using ciNPT may be appropriate. A literature search of MEDLINE, EMBASE and the Cochrane Central Register of Controlled Trials using key words ‘prevention’, ‘negative pressure wound therapy (NPWT)’, ‘active incisional management’, ‘incisional vacuum therapy’, ‘incisional NPWT’, ‘incisional wound VAC’, ‘closed incisional NPWT’, ‘wound infection’, and ‘SSIs’ identified peer‐reviewed studies published from 2000 to 2015. During a multidisciplinary consensus meeting, the 12 experts reviewed the literature, presented their own ciNPT experiences, identified risk factors for SSOs and developed comprehensive consensus recommendations. A total of 100 publications satisfied the search requirements for ciNPT use. A majority presented data supporting ciNPT use. Numerous publications reported SSI risk factors, with the most common including obesity (body mass index ≥30 kg/m²); diabetes mellitus; tobacco use; or prolonged surgical time. We recommend that the surgeon assess the individual patient's risk factors and surgical risks. Surgeons should consider using ciNPT for patients at high risk for developing SSOs or who are undergoing a high‐risk procedure or a procedure that would have highly morbid consequences if an SSI occurred.

Reviewing the benefits and harm of NPWT in the management of closed surgical incisions

The use of negative pressure wound therapy (NPWT) for the treatment of open traumatic, non-traumatic, chronic wounds and coverage over skin grafts has increased in popularity over the past decade. Although the exact mechanism of the action of NPWT on wound healing is still an active area of research, evidence propose it is achieved by removing oedema, increasing blood circulation, reducing bacterial bio-burden, providing a moist wound-healing environment, and increasing granulation tissue formation. In recent years, there has been an emerging body of literature describing a novel application of NPWT on closed surgical wounds, especially on closed orthopaedic incisional (COI) wounds. It has been suggested that applying NPWT to a COI may decrease the incidence of surgical wound-healing complications, such as hematoma, seroma, infection, or dehiscence, and hasten the healing of the incision. This review will evaluate the potential effect on the reduction of postoperative closed wound complications and examine the benefits and harm of NPWT in the management of COI.

Role of negative pressure wound therapy in total hip and knee arthroplasty

Negative-pressure wound therapy (NPWT) has been a successful modality of wound management which is in widespread use in several surgical fields. The main mechanisms of action thought to play a role in enhancing wound healing and preventing surgical site infection are macrodeformation and microdeformation of the wound bed, fluid removal, and stabilization of the wound environment. Due to the devastating consequences of infection in the setting of joint arthroplasty, there has been some interest in the use of NPWT following total hip arthroplasty and total knee arthroplasty. However, there is still a scarcity of data reporting on the use of NPWT within this field and most studies are limited by small sample sizes, high variability of clinical settings and end-points. There is little evidence to support the use of NPWT as an adjunctive treatment for surgical wound drainage, and for this reason surgical intervention should not be delayed when indicated. The prophylactic use of NPWT after arthroplasty in patients that are at high risk for postoperative wound drainage appears to have the strongest clinical evidence. Several clinical trials including single-use NPWT devices for this purpose are currently in progress and this may soon be incorporated in clinical guidelines as a mean to prevent periprosthetic joint infections.

Use of Negative Pressure Wound Therapy on Closed Surgical Incision After Total Ankle Arthroplasty

BACKGROUND

Wound healing problems of the anterior ankle incision are among the most common complications after total ankle arthroplasty, possibly resulting in exposure of the prostheses and infection. The aim of this study was to investigate the role of negative pressure wound therapy (NPWT) in decreasing the rate of wound healing problems after total ankle arthroplasty.

METHODS

This is a retrospective cohort study including consecutive patients who underwent total ankle arthroplasty by a single surgeon at a single institution between 2009 and 2013. The incisional negative pressure dressing was applied to all patients who underwent total ankle arthroplasty between 2012 and 2013 with a continuous application of -80 mm Hg negative pressure for 6 days postoperatively. The control group consisted of patients who underwent total ankle arthroplasty between 2009 and 2012 with a conventional nonadherent gauze dressing. Seventy-four patients were involved in this study: 37 in the control group and 37 in the incisional NPWT group.

RESULTS

All patients tolerated the incisional NPWT to completion without any dressing failures or skin problems. Both groups showed similar distributions in demographics and perioperative risk factors for wound healing. There were 9 (24%) wound healing problems in the control group and 1 (3%) in the incisional NPWT group. Incisional NPWT was found to reduce wound healing problems with an odds ratio of 0.10 (95% CI, 0.01-0.50; P = .004).

CONCLUSIONS

Our study demonstrated that there was a decreased incidence of wound healing problems following total ankle arthroplasty with incisional NPWT dressings. This is the first study evaluating the efficacy of incisional NPWT as an adjunct treatment for wound healing after total ankle arthroplasty.

LEVEL OF EVIDENCE

Level III, retrospective comparative study.

Use of Negative-Pressure Wound Dressings to Prevent Surgical Site Complications After Primary Hip Arthroplasty

Purpose. Negative-pressure wound therapy (NPWT) is increasingly used for primary surgical incisions despite the paucity of evidence. Study objectives were to assess the use of NPWT on surgical sites to prevent infections and other wound complications after elective primary hip arthroplasty and to consider feasibility of a larger trial. Methods. A nonmasked, randomized controlled pilot trial. Patients were recruited preoperatively from the preadmission clinic of an Australian hospital during 2013-2014. Computer-generated randomization was performed with allocation concealed until completion of surgery. The intervention group received NPWT (PICO) while the control group received the standard care hydrocolloid, reinforced with 2 absorbent dressings. Patients were followed for 6 weeks for postoperative complications (infection, length of stay, readmission) and skin complications (bruising, seroma, hematoma, dehiscence). Feasibility end points included numbers recruited, randomized, and followed up; fidelity; and costs. Results. Of 77 people approached, 76 were recruited, and 70 were randomized. Of 35 in the negative-pressure group, 2 received the standard dressing. Attrition at 6 weeks exceeded 10% in both groups. Dressing costs were lower in the control group ($3.01/d vs $38.40/d); SSI incidence was 2/35 in the NPWT and 3/35 in the control group (intention to treat: risk ratio [RR] = 0.67; 95% confidence interval [CI] = 0.12-3.7; P = .65). NPWT patients experienced more postoperative wound complications (RR = 1.6; 95% CI = 1.0-2.5; P = .04). Conclusion. A reduction of 3% in SSI incidence suggests that a definitive trial requires approximately 900 patients per group. Yet there is uncertainty around the benefit of NPWT after elective hip arthroplasty.

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 now available 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, it is a rapidly evolving therapy. Consequently, an updated 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, skin grafting or flap closure) 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 28 January 2014); the Cochrane Central Register of Controlled Trials (CENTRAL; 2013, issue 12); Database of Abstracts of Reviews of Effects (2013, issue 12); Ovid MEDLINE (2011 to January 2014); Ovid MEDLINE (In-Process & Other Non-Indexed Citations 24 January 2014); Ovid EMBASE (2011 to January 2014 Week 44); and EBSCO CINAHL (2011 to January 2014). We conducted a separate search to identify economic evaluations.

SELECTION CRITERIA

We included trials if they allocated patients to treatment randomly 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

In this first update, we included an additional four trials, taking the total number of trials included to nine (785 participants). Three trials involved skin grafts, four included orthopaedic patients and two included general surgery and trauma surgery patients; all the included trials had unclear or high risk of bias for one or more of the quality indicators we assessed. Seven trials compared NPWT with a standard dressing (two of these were 'home-made' NPWT devices), one trial compared one 'home-made' NPWT with a commercially available device. In trials where the individual was the unit of randomisation, there were no differences in the incidence of surgical site infections (SSI); wound dehiscence, re-operation (in incisional wounds); seroma/haematoma; or failed skin grafts. Lower re-operation rates were observed among skin graft patients in the 'home-made' NPWT group (7/65; 10.8%) compared to the standard dressing group (17/66; 25.8%) (risk ratio (RR) 0.42; 95% CI 0.19 to 0.92). The mean cost to supply equipment for VAC® therapy was USD 96.51/day compared to USD 4.22/day for one of the 'home-made' devices (P value 0.01); labour costs for dressing changes were similar for both treatments. Pain intensity score was also reported to be lower in the 'home-made' group when compared with the VAC® group (P value 0.02). One of the trials in orthopaedic patients was stopped early because of a high incidence of fracture blisters in the NPWT group (15/24; 62.5%) compared with the standard dressing group (3/36; 8.3%) (RR 7.50; 95% CI 2.43 to 23.14).

AUTHORS' CONCLUSIONS

Evidence for the effects of negative pressure wound therapy (NPWT) for reducing SSI and wound dehiscence remains unclear, as does the effect of NPWT on time to complete healing. Rates of graft loss may be lower when NPWT is used, but hospital-designed and built 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 evidence of a negative effect on clinical outcome. In one study, pain levels were also rated lower when a 'home-made' system was compared with a commercial counterpart. 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 incisions on obese patients.

Negative Pressure Wound Therapy on Surgical Site Infections in Women Undergoing Elective Caesarean Sections: A Pilot RCT

Obese women undergoing caesarean section (CS) are at increased risk of surgical site infection (SSI). Negative Pressure Wound Therapy (NPWT) is growing in use as a prophylactic approach to prevent wound complications such as SSI, yet there is little evidence of its benefits. This pilot randomized controlled trial (RCT) assessed the effect of NPWT on SSI and other wound complications in obese women undergoing elective caesarean sections (CS) and also the feasibility of conducting a definitive trial. Ninety-two obese women undergoing elective CS were randomized in theatre via a central web based system using a parallel 1:1 process to two groups i.e., 46 women received the intervention (NPWT PICO™ dressing) and 46 women received standard care (Comfeel Plus(®) dressing). All women received the intended dressing following wound closure. The relative risk of SSI in the intervention group was 0.81 (95% CI 0.38-1.68); for the number of complications excluding SSI it was 0.98 (95% CI 0.34-2.79). A sample size of 784 (392 per group) would be required to find a statistically significant difference in SSI between the two groups with 90% power. These results demonstrate that a larger definitive trial is feasible and that careful planning and site selection is critical to the success of the overall study.

Negative pressure wound therapy - a review of its uses in orthopaedic trauma

The use of Negative Pressure Wound Therapy (NPWT) for complex and large wounds has increased in popularity over the past decade. Modern NPWT systems consisting of an open pore foam sponge, adhesive dressing and a vacuum pump producing negative pressure have been used as an adjunct to surgical debridement to treat tissue defects around open fractures and chronic, contaminated wounds. Other uses include supporting skin grafts and protecting wounds at risk of breaking down. This review outlines the current and emerging indications for negative pressure wound therapy in Orthopaedic trauma and the existing preclinical and clinical evidence base for its use.

Negative-pressure wound therapy over surgically closed wounds in open fractures

PURPOSE

To evaluate the outcome of open fracture surgery with negative-pressure wound therapy (NPWT) applied directly over surgical wounds.

METHODS

Medical records of 10 men and 4 women aged 6 to 70 (mean, 43.7) years who underwent internal fixation, external fixation, or splint application for open fractures of the lower leg (n=7), foot and ankle (n=5), or knee (n=2), and NPWT were reviewed. The NPWT was applied directly over the surgical wound without a non-adherent contact layer. The foam was changed every 3 days. The standard negative pressure was 125 mm Hg. The NPWT was stopped when the wound discharge became <50 ml per day. The duration of NPWT and the level of negative pressure were recorded, as were wound condition, reasons for NPWT, and outcome.

RESULTS

The mean duration of NPWT was 9.1 (range, 3-24) days. Four patients developed maceration of the skin under the foam, whereas 2 patients developed skin blisters under the drape. No necrosis of flap skin or infection occurred, and all the fractures eventually united.

CONCLUSIONS

Maceration of the skin was seen in some cases but did not affect the overall outcome. NPWT directly over the skin surface had no deleterious effect on wound and fracture healing.

Negative pressure wound therapy for managementof the surgical incision in orthopaedic surgery: A review of evidence and mechanisms for an emerging indication

Objectives

The period of post-operative treatment before surgical wounds are completely closed remains a key window, during which one can apply new technologies that can minimise complications. One such technology is the use of negative pressure wound therapy to manage and accelerate healing of the closed incisional wound (incisional NPWT).

Methods

We undertook a literature review of this emerging indication to identify evidence within orthopaedic surgery and other surgical disciplines. Literature that supports our current understanding of the mechanisms of action was also reviewed in detail.

Results

A total of 33 publications were identified, including nine clinical study reports from orthopaedic surgery; four from cardiothoracic surgery and 12 from studies in abdominal, plastic and vascular disciplines. Most papers (26 of 33) had been published within the past three years. Thus far two randomised controlled trials – one in orthopaedic and one in cardiothoracic surgery – show evidence of reduced incidence of wound healing complications after between three and five days of post-operative NPWT of two- and four-fold, respectively. Investigations show that reduction in haematoma and seroma, accelerated wound healing and increased clearance of oedema are significant mechanisms of action.

Conclusions

There is a rapidly emerging literature on the effect of NPWT on the closed incision. Initiated and confirmed first with a randomised controlled trial in orthopaedic trauma surgery, studies in abdominal, plastic and vascular surgery with high rates of complications have been reported recently. The evidence from single-use NPWT devices is accumulating. There are no large randomised studies yet in reconstructive joint replacement.

Cite this article: Bone Joint Res 2013;2:276–84.

Negative pressure wound therapy (NPWT) for spinal wounds: a systematic review

BACKGROUND CONTEXT

The management of postoperative spinal wound complication remains a challenge, with surgical site infection (SSI) incidence rates ranging from 0.4% to 20% after spinal surgery. Negative pressure wound therapy (NPWT) has been highlighted as an intervention that may stimulate healing and prevent SSI. However, the wound healing mechanism by NPWT and its effectiveness in spinal wounds still remain unclear.

PURPOSE

To systematically search, critically appraise, and summarize randomized controlled trials (RCTs) and non-RCTs assessing the effectiveness of NPWT in patients with a spinal wound.

STUDY DESIGN

Systematic review.

METHODS

A systematic review based on search strategies recommended by the Cochrane Back and Wounds Review Groups was undertaken using Cochrane Library, MEDLINE, EMBASE, and CINAHL databases. Any publications between 1950 and 2011 were included. Funding to undertake the review was received from the University of Huddersfield Collaborative Venture Fund ($4,820) and KCI Medical ($4,820).

RESULTS

Ten retrospective studies and four case studies of patients with spinal wound complication were included in this systematic review. No RCTs were found. Only one study described more than 50 patients. Generally, a pressure of -125 mm Hg was used in adults. Duration of NPWT in situ ranged from 3 to 186 days. Wound healing was assessed every 2 to 3 days and generally completed between 7 days and 16 months. Negative pressure wound therapy is contraindicated in the presence of active cerebrospinal fluid leak, metastatic or neoplastic disease in the wound or in patients with an allergy to the NPWT dressing and in those with a bleeding diathesis.

CONCLUSIONS

Published reports are limited to small retrospective and case studies, with no reports of NPWT being used as a prophylactic treatment. Larger prospective RCTs of NPWT are needed to support the current evidence that it is effective in treating spinal wound complications. In addition, future studies should investigate its use as a prophylactic treatment to prevent infection and report data relating to safety and health economics.

Pain and trauma in negative pressure wound therapy: a review

Negative pressure wound therapy (NPWT) is considered an effective wound treatment, but there are a number of issues that need to be addressed for improvements to be made. This review aimed to explore the literature relating to the pain and skin trauma that may be experienced during NPWT. A literature search was carried out using the following databases: Academic Search Complete, CINAHL, PsychINFO, MEDLINE and PsyARTICLES. A total of 30 articles were reviewed. Studies reported varying levels of pain in patients undergoing NPWT, with certain treatment factors affecting the level of pain, such as the NPWT system and the dressing/filler used. Similarly, although there is much less research exploring NPWT-related trauma, findings suggest that dressing and filler type may impact on whether trauma occurs. However, further research needs to consider the different stages of NPWT and how pain and trauma can be minimised during the whole procedure. As both pain and skin trauma impact on the patient's well-being and on wound healing, it is essential that research further explores the factors that may affect the experience of pain and trauma, so as to inform developments in wound care.

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.