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

Negative Pressure Wound Therapy With Instillation and Dwell Time: Mechanisms of Action Literature Review

Background

Negative pressure wound therapy (NPWT) is commonly used in wound management of both acute and chronic wounds. As wound care has advanced, traditional NPWT has evolved to include instillation and dwell time (NPWTi-d). To better understand the potential clinical benefits of NPWTi-d, an assessment of the available literature focusing on NPWTi-d mechanisms of action in wound management was conducted. Methods. A literature search was performed for abstracts and articles published between 2010 and 2023. Published studies in English that discussed NPWTi-d mechanisms of action and included a study population larger than 10 patients were examined.

Results

A total of 1878 articles were identified through the literature search. After removal of duplicates and article reviews, 29 studies discussing the mechanisms of action for NPWTi-d were found. Study types included case series (n = 20), comparative study (n = 6), randomized controlled trial (n = 2), and retrospective study (n = 1). These studies included approximately 1108 patients who received NPWTi-d as part of a wound care treatment plan. NPWTi-d use was associated with improved wound and clinical outcomes through wound cleansing, removal of exudate and infectious materials, and promotion of granulation tissue development.

Conclusions

The mechanisms of action for NPWTi-d helps provide wound management through wound cleansing, removal of exudate and infectious materials, and promoting the development of granulation tissue. Additional studies are warranted to fully assess the potential clinical and health economic benefits of NPWTi-d use.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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

Effects of negative pressure wound therapy with instillation and dwell time (NPWTi-d) versus NPWT or standard of care in orthoplastic surgery: A systematic review and meta-analysis

Negative pressure wound therapy (NPWT) is a wound-dressing system that applies sub-atmospheric pressure on the surface of a wound to promote healing. An evolution of this technology, NPWT with solution instillation and dwell time (NPWTi-d), is increasingly being used to maximise wound closure and reduce failure rates. However, there is still a lack of evidence concerning its use in orthoplastic surgery. Therefore, the aim of this study is to compare NPWTi-d with NPWT and standard of care for wound management in orthoplastic surgery. A comprehensive literature search using PubMed, Web of Science, and Cochrane databases up to 15 March 2022 was performed, including studies describing the outcomes of NPWTi-d for traumatic/orthopaedic injuries. A meta-analysis on the number of surgical debridements, as well as the rate of complete wound closure and complications was carried out, although for other outcomes, a descriptive statistic was applied. Risk of bias and quality of evidence were assessed using the Downs& Black's Checklist for Measuring Quality. Thirteen studies with a total number of 871 patients were included, in which NPWTi-d demonstrated significantly higher primary wound closure and lower complication rates (P < .05). No difference in the number of surgical procedures required for final wound healing was observed. Moreover, five out of six studies showed better results for NPWTi-d when the change of the bioburden and bacterial count of the wound were analysed. A singular study investigating the length of the hospital stay of patients treated with NPWTi-d showed a reduction in the latter. The present meta-analysis proves that NPWTi-d is superior to NPTW or conventional dressings in orthoplastic wound care management, in terms of complete wound closure rate and the reduced number of complications. Still, the limited quality of the studies analysed shows that future randomised studies are needed to confirm the benefits and to identify the most appropriate recommendations for using NPWTi-d in orthoplastic surgery, as well as to investigate the cost-effectiveness of this wound-dressing system.

Clinical outcomes of negative pressure wound therapy with instillation vs standard negative pressure wound therapy for wounds: A meta‐analysis of randomised controlled trials

Negative pressure wound therapy (NPWT) with or without instillation has been extensively applied for patients with multiple wound types. Whether NPWT with instillation is superior to NPWT alone is not known. This study aims to compare the efficacy between negative pressure wound therapy with instillation (NPWTi) and standard negative pressure wound therapy for wounds. The authors searched for randomised controlled trials (RCTs) in PubMed, EMBASE, and the Cochrane Central Register of Controlled Trials investigating clinical outcomes of negative pressure wound therapy with instillation vs standard negative pressure wound therapy for wounds. The registration number (protocol) on PROSPERO is CRD42022287178. Eight RCTs involved 564 patients met the inclusion criteria and were included finally. NPWTi showed a significant fewer surgeries and dressing changes (RR and 95% CI, -9.31 [-17.54, -1.08], P < 0.05), and smaller wound area after treatment (RR and 95% CI, -9.31 [-17.54, -1.08], P < 0.05) compared with NPWT. No significant difference was observed on healing rate, time to heal, length of stay, dehiscence, reinfection, reoperation and readmission between NPWTi and NPWT. The addition of instillation to NPWT could improve clinical outcomes regarding the number of surgeries and dressing changes, and wound area after treatment in patients with multiple wound types. However, because of the heterogeneity these conclusions still need to be further validated by more well-designed RCTs with large sample sizes.

Negative Pressure Wound Therapy With Instillation: An Adjunctive Therapy for Infection Management in Orthopaedic Trauma

Negative Pressure Wound Therapy with Instillation is a device that provides the benefits of standard negative pressure wound therapy and instillation of a topical wound solution. This combination can benefit acute and chronic wounds by continuously cleansing the wound and providing soft tissue stability between staged operations or in preparation for a single procedure. Although skeletal stability is important in orthopaedic trauma, the overlying soft tissue envelop may also be compromised, which can lead to contamination and infection. This review will discuss the growing body of evidence for the use of negative pressure wound therapy with instillation with a focus on infection and recommendations for its proper use.

The Effect of Negative-Pressure Wound Therapy with Instillation Compared to Current Standard Care on Wound Closure Time of Infected Wounds: A Systematic Review and Meta-Analysis

BACKGROUND

Infected wounds extend healing time and are associated with higher treatment costs than noninfected wounds. Several observational studies indicate that negative-pressure wound therapy with instillation can effectively reduce bacterial bioburden and improve wound healing. Only a few randomized trials with small sample sizes have been published, and a meta-analysis directly comparing negative-pressure wound therapy with instillation to current standard care is lacking. It is therefore uncertain whether negative-pressure wound therapy with instillation actually improves wound healing. The authors performed a systematic review and hypothesized that negative-pressure wound therapy with instillation reduces wound closure time.

METHODS

The PubMed, Embase, and CENTRAL databases were searched up to December of 2020 for English studies that compare negative-pressure wound therapy with instillation-to either negative-pressure wound therapy without instillation or to other types of wound care-for the treatment of acute or chronically infected wounds. Time to wound closure was analyzed using a random effects meta-analysis in predefined subgroups according to study design and comparative wound care.

RESULTS

The authors identified 14 studies describing 1053 patients. Meta-analysis of three randomized trials shows no significant difference in time to wound closure between negative-pressure wound therapy with instillation and that without (mean difference, 0.48 day; 95 percent CI, -0.70 to 1.65; I ² = 0 percent). Data from eleven observational studies indicate that negative-pressure wound therapy with instillation reduces wound closure time (from 1.6 to 16.8 days; no pooled data). Because of imprecision and risk of bias, the available evidence provides only low-level certainty.

CONCLUSIONS

There is currently insufficient evidence to support or discard the use of negative-pressure wound therapy with instillation for infected wounds. More randomized trials are needed to determine whether a beneficial effect can be substantiated.

Negative pressure wound therapy for surgical wounds healing by primary closure

BACKGROUND

Indications for the use of negative pressure wound therapy (NPWT) are broad and include prophylaxis for surgical site infections (SSIs). Existing evidence for the effectiveness of NPWT on postoperative wounds healing by primary closure remains uncertain.

OBJECTIVES

To assess the effects of NPWT for preventing SSI in wounds healing through primary closure, and to assess the cost-effectiveness of NPWT in wounds healing through primary closure.

SEARCH METHODS

In January 2021, we searched the Cochrane Wounds Specialised Register; the Cochrane Central Register of Controlled Trials (CENTRAL); Ovid MEDLINE (including In-Process & Other Non-Indexed Citations); Ovid Embase and EBSCO CINAHL Plus. We also searched clinical trials registries and references of included studies, systematic reviews and health technology reports. There were no restrictions on language, publication date or study setting.

SELECTION CRITERIA

We included trials if they allocated participants to treatment randomly and compared NPWT with any other type of wound dressing, or compared one type of NPWT with another.

DATA COLLECTION AND ANALYSIS

At least two review authors independently assessed trials using predetermined inclusion criteria. We carried out data extraction, assessment using the Cochrane risk of bias tool, and quality assessment according to Grading of Recommendations, Assessment, Development and Evaluations methodology. Our primary outcomes were SSI, mortality, and wound dehiscence.

MAIN RESULTS

In this fourth update, we added 18 new randomised controlled trials (RCTs) and one new economic study, resulting in a total of 62 RCTs (13,340 included participants) and six economic studies. Studies evaluated NPWT in a wide range of surgeries, including orthopaedic, obstetric, vascular and general procedures. All studies compared NPWT with standard dressings. Most studies had unclear or high risk of bias for at least one key domain. Primary outcomes Eleven studies (6384 participants) which reported mortality were pooled. There is low-certainty evidence showing there may be a reduced risk of death after surgery for people treated with NPWT (0.84%) compared with standard dressings (1.17%) but there is uncertainty around this as confidence intervals include risk of benefits and harm; risk ratio (RR) 0.78 (95% CI 0.47 to 1.30; I² = 0%). Fifty-four studies reported SSI; 44 studies (11,403 participants) were pooled. There is moderate-certainty evidence that NPWT probably results in fewer SSIs (8.7% of participants) than treatment with standard dressings (11.75%) after surgery; RR 0.73 (95% CI 0.63 to 0.85; I² = 29%). Thirty studies reported wound dehiscence; 23 studies (8724 participants) were pooled. There is moderate-certainty evidence that there is probably little or no difference in dehiscence between people treated with NPWT (6.62%) and those treated with standard dressing (6.97%), although there is imprecision around the estimate that includes risk of benefit and harms; RR 0.97 (95% CI 0.82 to 1.16; I² = 4%). Evidence was downgraded for imprecision, risk of bias, or a combination of these. Secondary outcomes There is low-certainty evidence for the outcomes of reoperation and seroma; in each case, confidence intervals included both benefit and harm. There may be a reduced risk of reoperation favouring the standard dressing arm, but this was imprecise: RR 1.13 (95% CI 0.91 to 1.41; I² = 2%; 18 trials; 6272 participants). There may be a reduced risk of seroma for people treated with NPWT but this is imprecise: the RR was 0.82 (95% CI 0.65 to 1.05; I² = 0%; 15 trials; 5436 participants). For skin blisters, there is low-certainty evidence that people treated with NPWT may be more likely to develop skin blisters compared with those treated with standard dressing (RR 3.55; 95% CI 1.43 to 8.77; I² = 74%; 11 trials; 5015 participants). The effect of NPWT on haematoma is uncertain (RR 0.79; 95 % CI 0.48 to 1.30; I² = 0%; 17 trials; 5909 participants; very low-certainty evidence). There is low-certainty evidence of little to no difference in reported pain between groups. Pain was measured in different ways and most studies could not be pooled; this GRADE assessment is based on all fourteen trials reporting pain; the pooled RR for the proportion of participants who experienced pain was 1.52 (95% CI 0.20, 11.31; I² = 34%; two studies; 632 participants). Cost-effectiveness Six economic studies, based wholly or partially on trials in our review, assessed the cost-effectiveness of NPWT compared with standard care. They considered NPWT in five indications: caesarean sections in obese women; surgery for lower limb fracture; knee/hip arthroplasty; coronary artery bypass grafts; and vascular surgery with inguinal incisions. They calculated quality-adjusted life-years or an equivalent, and produced estimates of the treatments' relative cost-effectiveness. The reporting quality was good but the evidence certainty varied from moderate to very low. There is moderate-certainty evidence that NPWT in surgery for lower limb fracture was not cost-effective at any threshold of willingness-to-pay and that NPWT is probably cost-effective in obese women undergoing caesarean section. Other studies found low or very low-certainty evidence indicating that NPWT may be cost-effective for the indications assessed.

AUTHORS' CONCLUSIONS

People with primary closure of their surgical wound and treated prophylactically with NPWT following surgery probably experience fewer SSIs  than people treated with standard dressings but there is probably no difference in wound dehiscence (moderate-certainty evidence). There may be a reduced risk of death after surgery for people treated with NPWT compared with standard dressings but there is uncertainty around this as confidence intervals include risk of benefit and harm (low-certainty evidence). People treated with NPWT may experience more instances of skin blistering compared with standard dressing treatment (low-certainty evidence). There are no clear differences in other secondary outcomes where most evidence is low or very low-certainty. Assessments of cost-effectiveness of NPWT produced differing results in different indications. There is a large number of ongoing studies, the results of which may change the findings of this review. Decisions about use of NPWT should take into account surgical indication and setting and consider evidence for all outcomes.

Novel Diagnostic Technologies and Therapeutic Approaches Targeting Chronic Wound Biofilms and Microbiota

Purpose of Review

To provide an up-to-date overview of recent developments in diagnostic methods and therapeutic approaches for chronic wound biofilms and pathogenic microbiota.

Recent Findings

Biofilm infections are one of the major contributors to impaired wound healing in chronic wounds, including diabetic foot ulcers, venous leg ulcers, pressure ulcers, and nonhealing surgical wounds. As an organized microenvironment commonly including multiple microbial species, biofilms develop and persist through methods that allow evasion from host immune response and antimicrobial treatments. Suppression and reduction of biofilm infection have been demonstrated to improve wound healing outcomes. However, chronic wound biofilms are a challenge to treat due to limited methods for accurate, accessible clinical identification and the biofilm's protective properties against therapeutic agents. Here we review recent approaches towards visual markers for less invasive, enhanced biofilm detection in the clinical setting. We outline progress in wound care treatments including investigation of their antibiofilm effects, such as with hydrosurgical and ultrasound debridement, negative pressure wound therapy with instillation, antimicrobial peptides, nanoparticles and nanocarriers, electroceutical dressings, and phage therapy.

Summary

Current evidence for biofilm-targeted treatments has been primarily conducted in preclinical studies, with limited clinical investigation for many therapies. Improved identification, monitoring, and treatment of biofilms require expansion of point-of-care visualization methods and increased evaluation of antibiofilm therapies in robust clinical trials.

A simple, safe and easily accessible polyvinyl alcohol hydrogel for wound cleaning

Acute wounds are often contaminated by some kind of filth, and fluids are usually used to wash away the dirt, but the force of the fluid may cause secondary injury at the wound site or even increase the risk of infection. Hydrogels have several advantages over liquid scouring since they are less intense, more portable, and easier to control. In this study, poly(vinyl alcohol) was used to prepared a series of hydrogels, which were tested in terms of their properties and abilities to clean simulated dirty wounds. Simulated dirt and bacterial (Serratia marcescens) adhesion experiments demonstrated that they could effectively adhere to a certain amount of dirt or bacteria to achieve the purpose of wound cleaning. In addition to the bacterial adhesion, the antibacterial experiments also proved that the hydrogels have a certain inhibitory effect on the proliferation of E.coli and S.aureus. The hydrogels could change shape freely and exhibited excellent biocompatibility, ductility, and self-healing capabilities, which increase their service life and make them more suitable for treating wounds or acting as protection buffers. Based on all these characteristics, the developed hydrogel may be a potentially valuable material for wound cleaning.

Economic model to estimate cost of negative pressure wound therapy with instillation vs control therapies for hospitalised patients in the United States, Germany, and United Kingdom

An economic model was developed to estimate the cost of negative pressure wound therapy with instillation and dwelling of a topical wound solution vs control therapies. Economic model inputs were means derived from the results of a recently published systematic review and meta‐analysis of 13 comparative studies of negative pressure wound therapy with instillation. Means across studies comprising complex acute and chronic wounds for negative pressure wound therapy‐instillation vs control (negative pressure wound therapy without instillation, gauze dressings, or gentamicin polymethylmethacrylate beads) groups were 1.77 vs 2.69 operating room visits (P = .008) and 9.88 vs 21.80 therapy days (P = .02), respectively. These inputs plus hospital cost data were used to model costs for the United States, Germany, and the United Kingdom. For the United States, Germany, and United Kingdom, respectively, economic model estimates of total potential per patient savings were $33 338, €8467, and £5626 for negative pressure wound therapy‐instillation group vs control, based on assumed number of OR visits during therapy, cost of therapy system, and length of therapy. Model results showed an overall potential cost‐savings with negative pressure wound therapy‐instillation vs control, based on fewer OR visits and shorter therapy duration as reported in the published systematic review and meta‐analysis.

Effects of Negative-Pressure Wound Therapy With Instillation versus Standard of Care in Multiple Wound Types: Systematic Literature Review and Meta-Analysis

BACKGROUND

Large randomized controlled trials that evaluate the effects of negative-pressure wound therapy with instillation of a topical solution and dwell time (NPWTi-d) are lacking. There is a need to synthesize existing data across multiple studies to provide a more precise estimate of the clinical effects of NPWTi-d.

METHODS

A systematic literature review and a meta-analysis of comparative studies were performed to determine the effects of NPWTi-d versus control therapy in the adjunctive management of complex wounds. Weighted standardized mean difference or odds ratios and 95% confidence intervals were calculated to pool study and control group results in each publication for analysis.

RESULTS

Thirteen studies comprising 720 patients were included in the analysis. Significantly fewer surgical debridements were performed in NPWTi-d patients versus control patients (P = 0.01). Wounds in the NPWTi-d group were ready for closure faster than control wounds (P = 0.03). The odds of reducing bacterial count from baseline in the NPWTi-d group was 4.4 times greater than control group wounds (P = 0.003), and percent reduction of bacterial count in NPWTi-d wounds was evident in all studies that captured that endpoint. There was a significantly shorter length of therapy in NPWTi-d patients versus control patients (P = 0.03). Wounds in NPWTi-d group were 2.39 times more likely to close than control group wounds (P = 0.01). Length of hospital stay was not significantly reduced for NPWTi-d patients compared with that for control patients (P = 0.06).

CONCLUSION

Results of this meta-analysis show a positive effect with use of NPWTi-d in various wound types.

NPWTi allows safe delayed free flap repair of Gustilo IIIb injuries: A prospective case series

Introduction

Free flap lower extremity repair is associated with a high complication rate (>31%); higher rates are observed in more severe patients. In cases requiring prior systemic/local stabilization, delayed repair increases complication rate (+10% at 7 days): Negative-pressure Wound Therapy (NPWT) decreases complications but only when applied for less than 7 days. Recent limited evidence suggests that augmentation of NPWT with instillation for wound irrigation (NPWTi) might safely extend such window. This study hypothesizes that, through the combined cleansing effect of NPWT and instillation, NPWTi allows safe (low complication rate) delayed free flap repair in severe patients with Gustilo IIIb injuries (GIIIb).

Methods

A prospective case series was designed (inclusion criteria: GIIIb requiring microsurgical repair, severe patient/injury condition preventing immediate/early repair; exclusion criteria: allergy to NPWTi dressing). Patients received NPWTi (suction: 125 mmHg continuous; irrigation: NaCl 0.9%) until considered clinically ready for repair. Preoperative/postoperative complications (dehiscence, wound infection, bone non-union, osteomyelitis, flap failure) were monitored with clinical signs, imaging, and serum markers (CRP, WBC).

Results

Four patients (male: N = 4, female N = 1; Age: 59 [44-75] years-old) were treated. NPWTi was applied for 15.2 [9-28] days. No complication (0%) was observed preoperatively or postoperatively. Delayed repair occurred by latissimus dorsi musculocutaneous flap (N = 3), and anterolateral thigh flap (N = 2). All patients walked weight-bearing 12 [6-20] weeks after injury.

Conclusions

NPWTi seems to allow safe delayed free flap repair in patients with severe lower extremity injuries unable to undergo immediate/early repair.

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.