Topical negative pressure (TNP): the evolution of a novel wound therapy

Long-term follow-up and exploration of the mechanism of stromal vascular fraction gel in chronic wounds

BACKGROUND

Chronic refractory wounds easily relapse and seriously affect the patients' quality of life. Previous studies have shown that stromal vascular fraction gel (SVF-gel) significantly promotes the early healing of chronic wounds; however, the mechanisms of SVF-gel function per se remain unclear, and a long-term follow-up is lacking. This study aims to explore the mechanisms of SVF-gel promoting the healing of chronic wounds and follow up the long-term efficacy of SVF-gel.

METHODS

Autologous SVF-gel transplantation was performed in 20 patients with chronic wounds (from March 2016 to September 2019), and the size of the wound before and after SVF-gel transplantation was observed. The conditioned medium (CM) was harvested from SVF-gel under serum-free, serum-deprivation and 10% fetal bovine serum (FBS) microenvironment in vitro, respectively. The concentration of the growth factors in the two kinds of gel-CM was tested, and their effects on the proliferation and migration of human dermal fibroblasts (HDFs) were detected.

RESULTS

All patients had 100% wound closure eventually, and the average time to complete closure was 28.3 ± 9.7 days. The time of follow-up ranged from 2 to 6 years, and there was no wound recurrence. Interestingly, the concentrations of epidermal growth factor and transforming growth factor β1 of the CM were higher in serum-free and serum-deprivation condition than in 10% FBS microenvironment (p < 0.05). Correspondingly, the proliferation and migration ability of HDFs treated with gel-CM from serum-free condition were stronger than those treated with gel-CM from serum-deprivation (2% FBS) or 10% FBS microenvironment (p < 0.05).

CONCLUSION

These results indicate that it is safe, effective, and lasting in effect to treat chronic wounds with SVF-gel and mechanisms of action that include secreting various cytokines and promoting cell proliferation and migration ability.

TRIAL REGISTRATION

Chinese Clinical Trail Registry, ChiCTR2000034624. Registered 12 July 2020-Retrospectively registered, http://www.chictr.org.cn/showproj.aspx?proj=56058.

Surgical outcome after using negative pressure therapy in infected leg wounds in coronary bypass grafting surgery

Background

Infection of leg wounds is a common complication following great saphenous vein harvesting (GSV) for coronary bypass grafting (CABG). This complication can result in increased risk of patient morbidity and mortality by causing septicemia, and gangrene, subjecting the patients to amputation. This study aimed to assess the efficacy of negative pressure wound therapy (NPWT) compared to conventional wound care in infected leg wounds following GSV harvesting for myocardial revascularization.

Results

The NPWT group had a significantly lower rate of deep vein thrombosis (p = 0.013), osteomyelitis (p < 0.001), bed sores (p < 0.001), shorter duration of tissue edema (p < 0.001), and lesser discharge (p < 0.001). Also, the length of hospital stay was significantly shorter in the NPWT group (p < 0.001). Multivariable analysis revealed that traditional wound care (without NPWT, p < 0.001) and wound stage IV (p = 0.001) significantly and independently prolonged the length of hospital stay.

Conclusions

The use of NPWT in advanced complicated infected leg wounds could improve patients’ outcomes and satisfaction by decreasing the rate of complications and the length of hospital stay.

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.

A Comparative Study Between Vacuum Dressing and Normal Saline Dressing for Chronic Non-Healing Ulcers

Introduction

Isn’t it a boon that all living organisms possess the ability to heal their injuries? The wound healing is faster when the normal physiology of the wound healing is maintained. Our understanding of wound healing has undergone dramatic changes in the recent past. Almost all materials and methods available on earth have been used and tested to facilitate the process of wound healing. The mental agony and the disability suffered by patients with chronic ulcers have led to the reappraisal of the basic components of the wound healing process and how they are influenced by biological, mechanical, and physical forces.

The Department of General Surgery in our Government Chengalpattu Medical College and Hospital, Chengalpattu, Tamil Nadu, India, admits and treats a large volume of patients with wounds and ulcers. Here many materials are being used regularly for dressing to make wound healing faster. Vacuum dressings were also done on many patients, and promising results were observed. This kindled our interest in conducting this prospective study and comparing wound healing with vacuum dressing versus normal saline dressing.

Materials and methods

A total of 74 patients were included in the study, out of which 37 patients were randomly included in the experimental group and vacuum dressing was done, while the other 37 included in the control group were treated with dressing done with normal saline moistened gauze and bandage roll. Rates at which the wound healed were compared.

Results

We were able to observe a statistically significant difference in the rate of appearance of granulation tissue between the two and increased clearance of bacteria and toxins. The study group promised better progress as compared to the control group in various aspects.

Conclusion

Vacuum dressing brings an obvious improvement in the healing of non-healing ulcers and decreases the overall duration of stay in the hospital.

Treatment options for soft tissue defects in severe foot trauma in children

OBJECTIVE

Severe foot trauma in children is a therapeutic challenge, with presence of devitalised and soiled distal tissues. Several reconstruction and covering procedures can be applied, including artificial dermis (AD), negative pressure wound therapy (NPWT), fasciocutaneous flaps and free flaps. Here, we have developed and evaluated an algorithm for treating severe foot injuries with skin defects in children.

METHOD

Paediatric cases of severe foot injury treated over a 16-year period were retrospectively reviewed. Characteristics of the injuries, surgical procedures, complications and the modified Kitaoka score (clinical and functional rating score of the ankle and foot) were recorded.

RESULTS

A total of 18 children were included. The mean age at the time of injury was four years and 10 months (range: 1-11 years). The mean follow-up period was 6.2 years. Of the children, 13 presented with an amputation (12 partial foot amputations and one whole ankle and foot). The skin defect was combined with tendon exposure in nine cases, and/or bone and cartilage in seven cases, and heel damage in two cases. A flap was implemented in eight cases, of which one failed. NPWT was used in 13 patients (for an average of 21 days) and was combined with AD in six patients. The mean modified Kitaoka score was 68 (range: 55-80). Additional surgery during the follow-up period was required in seven patients (dorsal skin retraction, a thick flap, osteoma, trophic ulcer or ankle deviation).

CONCLUSION

Our algorithm suggests different therapeutic strategies for skin coverage and healing, depending on the size of the lesion and the exposed structures, and seems to offer good results. These procedures should be combined with NPWT to optimise these results (improved healing, reduced infections, decreased skin defects and enhanced granulation tissue) and so should be used more frequently.

Oncoplastic breast surgery: the role of negative pressure wound therapy

Wound-related problems following breast surgery are common. Delayed wound healing can lead to poor cosmesis and, among breast cancer patients, can result in delays in receiving adjuvant treatment. The aim of our review was to look at the literature in relation to the role of negative pressure wound therapy in oncoplastic breast surgery, as at the time of writing, there is no consensus on the use of prophylactic negative pressure dressings in closed wounds following breast surgery.

Chronic wounds and novel therapeutic approaches

In the past decade, the frequency of chronic wounds in older population has increased, and their impact on quality of life is substantial. Chronic wounds are a public health problem associated with very high economic and psychosocial costs. These wounds result from various pathologies and comorbidities, such arterial and venous insufficiency, diabetes mellitus and continuous skin pressure. Recently, the role of infection and biofilms in the healing of chronic wounds has been the subject of considerable research. This paper presents an overview of various methods and products used to manage chronic wounds and discusses recent advances in wound care. To decide on the best treatment for any wound, it is crucial to holistically assess the patient and the wound. Additionally, multiple strategies could be used to prevent or treat chronic wounds.

A Wound Treatment Strategy for "Super Long-Term Difficult-to-Heal Wounds": A Single-Center Retrospective Study

Chronic wounds are a challenge for clinicians. Treating chronic wounds in elderly patients is difficult due to comorbidities and poor immunity, tissue renewal, and regeneration. This study shared the therapeutic experiences of 40 patients with super long-term difficult-to-heal wounds and to describe the effects of negative pressure wound therapy (NPWT)-assisted debridement and autologous scalp grafting. Elderly patients with chronic wounds for more than 60 years who underwent NPWT-assisted debridement and autologous scalp grafting between 2015 and 2017 were retrospectively analyzed. Forty patients were identified and analyzed. Among all patients, the average wound area was 56 (interquartile range 30-90) cm². The wound infection rate was 82.1%, and that before the first autologous scalp grafting was 51.3%. The average total number of surgeries was 3, and the number of times the NPWT device was replaced was once. A total of 97.4% of patients had one autologous scalp grafting performed. The transplanted scalp survived completely in 97.4% of patients. One hundred percent of patients had no postoperative complications and healed. The average wound healing time was 34.5 ± 10.1 days. This study showed that NPWT-assisted debridement and autologous scalp grafting have the advantages of high survival rate of the skin and decreased wound recurrence and may be a suitable treatment for super long-term difficult-to-heal wounds in elderly patients.

The Effect of Cold Water on Pain Evaluation During Negative Pressure Wound Therapy Dressing Changes: A Prospective, Randomized Controlled Study

Negative pressure wound therapy (NPWT) is a technique using vacuum dressing to promote wound healing in complicated wound. However, for many patients, the application and removal of the NPWT is source of procedural pain. The authors hypothesized that administering cold sterile water into the NPWT sponge would decrease pain during dressing changes. A prospective randomized controlled study was conducted on 27 patients who were undergoing 81 NPWT wound dressing changes (n = 81) at a single institution between October 2016 and September 2017. Each patient had 3 NPWT dressing changes. Cold sterile water (5.74 °C), room temperature sterile water (26.89 °C), and nothing were randomized and administered in the NPWT tubing into the sponge 10 minutes before changing the dressing in each and every procedure. Pain scores were assessed using a 0 to 10 numeric pain scale. Patients administered with cold water reported less pain than those administered with room temperature sterile water during the dressing change (4 vs 5.67; P < .003), and much less pain than those with nothing instilled before dressing change (4 vs 6.59; P < .001). There is no statistically significant difference in pain score between using the room temperature sterile water group and the control group that instilled nothing (5.67 vs 6.59; P = .065). This study has shown that cold water administered through the suction tubing before the dressing change had a better reduction in pain score than using room temperature sterile water and the control group.

Negative Pressure Wound Therapy (NPWT): Our Experience in Pakistan With Locally Made Dressing

Introduction

Worldwide numbers of patients suffering from complex wounds appear to increase annually. These patients present with acute, sub-acute and chronic wounds which can be difficult to manage. Management of these patients typically requires a multi-disciplinary approach by a plastic surgeon, orthopaedic surgeon and infectious disease control team. Despite the advent of numerous new techniques and technologies, negative pressure wound therapy (NPWT) remains a cornerstone to the management of complex wounds. We present our experience with NPWT in this study.

Methods

This is a retrospective study of 380 patients who were treated with NPWT in the last 10 years at a single center. We receive hundreds of infected wounds of limbs each year which are either post-traumatic or post-debridement. Frequency of dressing change, C-reactive protein levels, bacterial cultures, complication rate and cost of apparatus in each case were noted. All patients received systemic antibiotics during the treatment.

Results

We reviewed hospital data of 520 patients in which debridement was performed. Of the 520 patients derided, 380 patients were treated with NPWT, and included in study. Number of NPWT sessions was decided on the basis of wound status (adequate healthy granulation tissue, clinically improved circulation). A single session of NPWT dressing was applied in 84% (n = 320) patients, 8% (n = 31) patients needed two sessions of NPWT dressing, 6% (n = 24) patients had three sessions of NPWT dressing and only 1% (n = 5) patients did not respond to NPWT dressing. 78% (n = 297) patients had reduced levels of C-reactive protein levels and wound cultures were negative in 54% (n = 208) patients after application of NPWT dressing. Minor complications occurred in 0.7% (n = 3) patients due to occult osteomyelitis. In 0.5% (n = 2) patients, NPWT dressing was discontinued due to persistent leakage near a natural orifice. Sinus formation was seen in 6% (n = 23) patients who were treated with curettage and conventional dressings. The mean pain score on the verbal analogue scale was 3 out of 10. The mean cost of an NPWT dressing apparatus was 90 dollars.

Conclusion

We conclude from this study that NPWT dressing can be easily applied to any region of the body and it can be customized to the needs of patients from different socio-economic status.

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 June 2019, 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 type of NPWT.

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.

MAIN RESULTS

In this third update, we added 15 new randomised controlled trials (RCTs) and three new economic studies, resulting in a total of 44 RCTs (7447 included participants) and five economic studies. Studies evaluated NPWT in the context of a wide range of surgeries including orthopaedic, obstetric, vascular and general procedures. Economic studies assessed NPWT in orthopaedic, obstetric and general surgical settings. All studies compared NPWT with standard dressings. Most studies had unclear or high risk of bias for at least one key domain. Primary outcomes Four studies (2107 participants) reported mortality. There is low-certainty evidence (downgraded twice for imprecision) showing no clear difference in the risk of death after surgery for people treated with NPWT (2.3%) compared with standard dressings (2.7%) (risk ratio (RR) 0.86; 95% confidence interval (CI) 0.50 to 1.47; I² = 0%). Thirty-nine studies reported SSI; 31 of these (6204 participants), were included in meta-analysis. There is moderate-certainty evidence (downgraded once for risk of bias) that NPWT probably results in fewer SSI (8.8% of participants) than treatment with standard dressings (13.0% of participants) after surgery; RR 0.66 (95% CI 0.55 to 0.80 ; I² = 23%). Eighteen studies reported dehiscence; 14 of these (3809 participants) were included in meta-analysis. There is low-certainty evidence (downgraded once for risk of bias and once for imprecision) showing no clear difference in the risk of dehiscence after surgery for NPWT (5.3% of participants) compared with standard dressings (6.2% of participants) (RR 0.88, 95% CI 0.69 to 1.13; I² = 0%). Secondary outcomes There is low-certainty evidence showing no clear difference between NPWT and standard treatment for the outcomes of reoperation and incidence of seroma. For reoperation, the RR was 1.04 (95% CI 0.78 to 1.41; I² = 13%; 12 trials; 3523 participants); for seroma, the RR was 0.72 (95% CI 0.50 to 1.05; I² = 0%; seven trials; 729 participants). The effect of NPWT on occurrence of haematoma or skin blisters is uncertain (very low-certainty evidence); for haematoma, the RR was 0.67 (95% CI 0.28 to 1.59; I² = 0%; nine trials; 1202 participants) and for blisters the RR was 2.64 (95% CI 0.65 to 10.68; I² = 69%; seven trials; 796 participants). The overall effect of NPWT on pain is uncertain (very low-certainty evidence from seven trials (2218 participants) which reported disparate measures of pain); but moderate-certainty evidence suggests there is probably little difference between the groups in pain after three or six months following surgery for lower limb fracture (one trial, 1549 participants). There is also moderate-certainty evidence for women undergoing caesarean sections (one trial, 876 participants) and people having surgery for lower limb fractures (one trial, 1549 participants) that there is probably little difference in quality of life scores at 30 days or 3 or 6 months, respectively. Cost-effectiveness Five economic studies, based wholly or partially on trials included in our review, assessed the cost-effectiveness of NPWT compared with standard care. They considered NPWT in four indications: caesarean sections in obese women; surgery for lower limb fracture; knee/hip arthroplasty and coronary artery bypass graft surgery. They calculated quality-adjusted life-years for treatment groups and produced estimates of the treatments' relative cost-effectiveness. The reporting quality was good but the grade of the evidence 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 experiencing primary wound closure of their surgical wound and treated prophylactically with NPWT following surgery probably experience fewer SSI than people treated with standard dressings (moderate-certainty evidence). There is no clear difference in number of deaths or wound dehiscence between people treated with NPWT and standard dressings (low-certainty evidence). There are also no clear differences in secondary outcomes where all evidence was low or very low-certainty. In caesarean section in obese women and surgery for lower limb fracture, there is probably little difference in quality of life scores (moderate-certainty evidence). Most evidence on pain is very low-certainty, but there is probably no difference in pain between NPWT and standard dressings after surgery for lower limb fracture (moderate-certainty evidence). 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.

Management of Wounds with Exposed Bones or Tendons in Children by Vacuum-Assisted Closure Therapy: A Prospective Study

Background  The management of complex soft tissue defects with exposed bones/tendons is always a challenging task for the surgeon and the problem becomes more pronounced when it comes to the management of these wounds in children. Though flap procedures are considered the standard for managing the complex soft tissue defects with exposed bones/tendons yet small blood vessels for anastomosis, long operative period, increased chances of perioperative thrombosis, and difficult perioperative management in children add to the difficulty in performing flap procedures in children. The vacuum-assisted closure (VAC) therapy has emerged as a novel modality for the management of the difficult wounds with added advantages, especially in children.

Objective  To evaluate the efficacy of VAC in the management of wounds with exposed bones/tendons in children.

Patients and Method  Forty-six children of complex wounds with exposed bones/tendons were included in the study from July 2016 to June 2018.

Results  Out of 46 patients, 31 were male; the patients had a mean age of 8.4 years. Road traffic accident was the most common mode of injury (54%), with most of the wounds located over extremities. The mean duration of VAC therapy was 12 days. More than 90% coverage of the exposed structure was seen in 89% of patients. The wounds were definitively managed by split-thickness skin graft in 89% of patients and flap cover in 6.5% of patients. The mean cost of the VAC therapy at our government run hospital was 187 Indian rupees per day. No significant major complications were seen during the treatment.

Conclusion  VAC therapy is an efficient, safe, and cost-effective modality of treatment for the management of complex wounds in the pediatric population.

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 June 2019, 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 type of NPWT.

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.

MAIN RESULTS

In this third update, we added 15 new randomised controlled trials (RCTs) and three new economic studies, resulting in a total of 44 RCTs (7447 included participants) and five economic studies. Studies evaluated NPWT in the context of a wide range of surgeries including orthopaedic, obstetric, vascular and general procedures. Economic studies assessed NPWT in orthopaedic, obstetric and general surgical settings. All studies compared NPWT with standard dressings. Most studies had unclear or high risk of bias for at least one key domain. Primary outcomes Four studies (2107 participants) reported mortality. There is low-certainty evidence (downgraded twice for imprecision) showing no clear difference in the risk of death after surgery for people treated with NPWT (2.3%) compared with standard dressings (2.7%) (risk ratio (RR) 0.86; 95% confidence interval (CI) 0.50 to 1.47; I² = 0%). Thirty-nine studies reported SSI; 31 of these (6204 participants), were included in meta-analysis. There is moderate-certainty evidence (downgraded once for risk of bias) that NPWT probably results in fewer SSI (8.8% of participants) than treatment with standard dressings (13.0% of participants) after surgery; RR 0.66 (95% CI 0.55 to 0.80 ; I² = 23%). Eighteen studies reported dehiscence; 14 of these (3809 participants) were included in meta-analysis. There is low-certainty evidence (downgraded once for risk of bias and once for imprecision) showing no clear difference in the risk of dehiscence after surgery for NPWT (5.3% of participants) compared with standard dressings (6.2% of participants) (RR 0.88, 95% CI 0.69 to 1.13; I² = 0%). Secondary outcomes There is low-certainty evidence showing no clear difference between NPWT and standard treatment for the outcomes of reoperation and incidence of seroma. For reoperation, the RR was 1.04 (95% CI 0.78 to 1.41; I² = 13%; 12 trials; 3523 participants); for seroma, the RR was 0.72 (95% CI 0.50 to 1.05; I² = 0%; seven trials; 729 participants). The effect of NPWT on occurrence of haematoma or skin blisters is uncertain (very low-certainty evidence); for haematoma, the RR was 0.67 (95% CI 0.28 to 1.59; I² = 0%; nine trials; 1202 participants) and for blisters the RR was 2.64 (95% CI 0.65 to 10.68; I² = 69%; seven trials; 796 participants). The overall effect of NPWT on pain is uncertain (very low-certainty evidence from seven trials (2218 participants) which reported disparate measures of pain); but moderate-certainty evidence suggests there is probably little difference between the groups in pain after three or six months following surgery for lower limb fracture (one trial, 1549 participants). There is also moderate-certainty evidence for women undergoing caesarean sections (one trial, 876 participants) and people having surgery for lower limb fractures (one trial, 1549 participants) that there is probably little difference in quality of life scores at 30 days or 3 or 6 months, respectively. Cost-effectiveness Five economic studies, based wholly or partially on trials included in our review, assessed the cost-effectiveness of NPWT compared with standard care. They considered NPWT in four indications: caesarean sections in obese women; surgery for lower limb fracture; knee/hip arthroplasty and coronary artery bypass graft surgery. They calculated quality-adjusted life-years for treatment groups and produced estimates of the treatments' relative cost-effectiveness. The reporting quality was good but the grade of the evidence 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 experiencing primary wound closure of their surgical wound and treated prophylactically with NPWT following surgery probably experience fewer SSI than people treated with standard dressings (moderate-certainty evidence). There is no clear difference in number of deaths or wound dehiscence between people treated with NPWT and standard dressings (low-certainty evidence). There are also no clear differences in secondary outcomes where all evidence was low or very low-certainty. In caesarean section in obese women and surgery for lower limb fracture, there is probably little difference in quality of life scores (moderate-certainty evidence). Most evidence on pain is very low-certainty, but there is probably no difference in pain between NPWT and standard dressings after surgery for lower limb fracture (moderate-certainty evidence). 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.

EWMA Document: Negative Pressure Wound Therapy

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

The efficacy of negative pressure wound therapy for diabetic foot ulcers: A systematised review

AIM

This review investigated the current state of knowledge on negative pressure wound therapy (NPWT) used to treat diabetic foot ulceration (DFU), its clinical effectiveness and any current issues in the research. NICE have recommended research into the clinical effectiveness of different dressing types for DFUs since 2015.

METHODS

A systematic search of the British Nursing Index, CINAHL, Cochrane Central and PubMed was undertaken. Only primary studies were included and studies investigating a combination of NPWT and other therapies were excluded. All the included studies were published in English between 2008 and 2018 and were peer reviewed.

RESULTS

The search yielded seven studies for inclusion in the qualitative analysis. The studies included a variety of methodologies specifically; 3 randomized controlled trials, 2 case series', 1 non-controlled trial and 1 randomized case-control study. Three main themes were identified and formed the focus of the qualitative synthesis.

DISCUSSION

All the included studies reported that NPWT led to better clinical outcomes when compared to standard treatment. However, the studies had numerous methodological flaws such as the absence of validated tools for the measurement of outcomes such as wound area and depth; a lack of statistical power calculations to determine adequate sample sizes or the significance of outcome measures. Additionally, there was little consistency in the pressures used for the NPWT devices. Finally, many of the controlled trials did not conform to the standard of reporting trials stipulated by the CONSORT statement.

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). While existing evidence for the effectiveness of NPWT remains uncertain, new trials necessitated an updated review of the evidence for the effects of NPWT on postoperative wounds healing by primary closure.

OBJECTIVES

To assess the effects of negative pressure wound therapy for preventing surgical site infection in wounds healing through primary closure.

SEARCH METHODS

We searched the Cochrane Wounds Specialised Register, CENTRAL, Ovid MEDLINE (including In-Process & Other Non-Indexed Citations), Ovid Embase, and EBSCO CINAHL Plus in February 2018. We also searched clinical trials registries for ongoing and unpublished studies, and checked reference lists of relevant included studies as well as reviews, meta-analyses, and health technology reports to identify additional studies. There were no restrictions on language, publication date, or 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 type of NPWT.

DATA COLLECTION AND ANALYSIS

Four review authors independently assessed trials using predetermined inclusion criteria. We carried out data extraction, 'Risk of bias' assessment using the Cochrane 'Risk of bias' tool, and quality assessment according to GRADE methodology.

MAIN RESULTS

In this second update we added 25 intervention trials, resulting in a total of 30 intervention trials (2957 participants), and two economic studies nested in trials. Surgeries included abdominal and colorectal (n = 5); caesarean section (n = 5); knee or hip arthroplasties (n = 5); groin surgery (n = 5); fractures (n = 5); laparotomy (n = 1); vascular surgery (n = 1); sternotomy (n = 1); breast reduction mammoplasty (n = 1); and mixed (n = 1). In three key domains four studies were at low risk of bias; six studies were at high risk of bias; and 20 studies were at unclear risk of bias. We judged the evidence to be of low or very low certainty for all outcomes, downgrading the level of the evidence on the basis of risk of bias and imprecision.Primary outcomesThree studies reported mortality (416 participants; follow-up 30 to 90 days or unspecified). It is uncertain whether NPWT has an impact on risk of death compared with standard dressings (risk ratio (RR) 0.63, 95% confidence interval (CI) 0.25 to 1.56; very low-certainty evidence, downgraded once for serious risk of bias and twice for very serious imprecision).Twenty-five studies reported on SSI. The evidence from 23 studies (2533 participants; 2547 wounds; follow-up 30 days to 12 months or unspecified) showed that NPWT may reduce the rate of SSIs (RR 0.67, 95% CI 0.53 to 0.85; low-certainty evidence, downgraded twice for very serious risk of bias).Fourteen studies reported dehiscence. We combined results from 12 studies (1507 wounds; 1475 participants; follow-up 30 days to an average of 113 days or unspecified) that compared NPWT with standard dressings. It is uncertain whether NPWT reduces the risk of wound dehiscence compared with standard dressings (RR 0.80, 95% CI 0.55 to 1.18; very low-certainty evidence, downgraded twice for very serious risk of bias and once for serious imprecision).Secondary outcomesWe are uncertain whether NPWT increases or decreases reoperation rates when compared with a standard dressing (RR 1.09, 95% CI 0.73 to 1.63; 6 trials; 1021 participants; very low-certainty evidence, downgraded for very serious risk of bias and serious imprecision) or if there is any clinical benefit associated with NPWT for reducing wound-related readmission to hospital within 30 days (RR 0.86, 95% CI 0.47 to 1.57; 7 studies; 1271 participants; very low-certainty evidence, downgraded for very serious risk of bias and serious imprecision). It is also uncertain whether NPWT reduces incidence of seroma compared with standard dressings (RR 0.67, 95% CI 0.45 to 1.00; 6 studies; 568 participants; very low-certainty evidence, downgraded twice for very serious risk of bias and once for serious imprecision). It is uncertain if NPWT reduces or increases the risk of haematoma when compared with a standard dressing (RR 1.05, 95% CI 0.32 to 3.42; 6 trials; 831 participants; very low-certainty evidence, downgraded twice for very serious risk of bias and twice for very serious imprecision. It is uncertain if there is a higher risk of developing blisters when NPWT is compared with a standard dressing (RR 6.64, 95% CI 3.16 to 13.95; 6 studies; 597 participants; very low-certainty evidence, downgraded twice for very serious risk of bias and twice for very serious imprecision).Quality of life was not reported separately by group but was used in two economic evaluations to calculate quality-adjusted life years (QALYs). There was no clear difference in incremental QALYs for NPWT relative to standard dressing when results from the two trials were combined (mean difference 0.00, 95% CI -0.00 to 0.00; moderate-certainty evidence).One trial concluded that NPWT may be more cost-effective than standard care, estimating an incremental cost-effectiveness ratio (ICER) value of GBP 20.65 per QALY gained. A second cost-effectiveness study estimated that when compared with standard dressings NPWT was cost saving and improved QALYs. We rated the overall quality of the reports as very good; we did not grade the evidence beyond this as it was based on modelling assumptions.

AUTHORS' CONCLUSIONS

Despite the addition of 25 trials, results are consistent with our earlier review, with the evidence judged to be of low or very low certainty for all outcomes. Consequently, uncertainty remains about whether NPWT compared with a standard dressing reduces or increases the incidence of important outcomes such as mortality, dehiscence, seroma, or if it increases costs. Given the cost and widespread use of NPWT for SSI prophylaxis, there is an urgent need for larger, well-designed and well-conducted trials to evaluate the effects of newer NPWT products designed for use on clean, closed surgical incisions. Such trials should initially focus on wounds that may be difficult to heal, such as sternal wounds or incisions on obese patients.

The role of negative pressure wound therapy in salvaging a six-year-old child's crushed foot - A case report

Crushed extremity is an infrequent injury in children and represents a major challenge for the orthopaedic surgeon. Sometimes the decision making process, whether to amputate or save a limb, is very difficult. Several scoring systems have been developed in order to determine the fate of crushed extremities, but they are not always predictive when patients are children. In the past few years, advances in bone and soft tissue reconstruction techniques have improved outcomes, even in the most extreme cases. Negative Pressure Wound Therapy has become an accepted option in the treatment of crushed limbs. We report a 6-year-old child with a crushed left foot from the running chain of his father's motorcycle. Early revascularization and stabilization along with multiple debridement and the application of Negative Pressure Wound Therapy leaded to salvage of the child's limb. At the end of one year follow up, he presented a very good functional and aesthetic result.

LEVEL OF CLINICAL EVIDENCE

"4".

[Effectiveness of Drawtex hydroconductive dressing in treatment of early implantation-associated infection and soft tissue defect after internal fixation of tibial fracture]

Objective

To investigate the feasibility of Drawtex hydroconductive dressing in treatment of early implantation-associated infection and soft tissue defect after internal fixation of tibial fracture.

Methods

Thirty-six New Zealand rabbits were used to prepare the model of early implantation-associated infection after internal fixation of tibial fracture, and randomly divided into 3 groups ( n=12) . The infected wounds were covered with Drawtex hydroconductive dressing (group A), chitosan solution gauze (group B), and normal saline gauze (group C), respectively. The dressing was changed every 2 days. X-ray films were performed at 1, 14, and 21 days. The gross observation, microbiological evaluation, and histological observation were done at 21 days.

Results

There was no significant difference in the wound grading according to the James' grading criteria between groups at 21 days ( χ2=3.713, P=0.156). X-ray films showed no bone destruction in all groups at 1 day; and there was no significant difference in radiographic scores between groups ( P>0.05). At 14 days, the mild osteolysis was observed in group B; the radiographic score was significantly lower in groups A and C than in group B ( P<0.05), but there was no significant difference between groups A and C ( P>0.05). At 21 days, the osteolysis and osteomyelitis were observed in groups B and C; the radiographic score was significantly lower in group A than in groups B and C ( P<0.05), but there was no significant difference between groups B and C ( P>0.05). Also, the microorganism in bone tissue of group A was less than that of groups B and C ( P<0.05); and the difference between group B and group C was not significant ( P>0.05). Histological observation showed the mild inflammatory cell infiltration in group A and many inflammatory cells in groups B and C. The Smeltzer histological score was significant lower in group A than in groups B and C ( P<0.05); and there was no significant difference between groups B and C ( P>0.05).

Conclusion

Drawtex hydroconductive dressing can be used for the implantation-associated infection after tibial fracture internal fixation. And the effectiveness of Drawtex hydroconductive dressing is better than that of chitosan solution gauze and normal saline gauze.

Comparative study of abdominal cavity temporary closure techniques for damage control

The damage control surgery, with emphasis on laparostomy, usually results in shrinkage of the aponeurosis and loss of the ability to close the abdominal wall, leading to the formation of ventral incisional hernias. Currently, various techniques offer greater chances of closing the abdominal cavity with less tension. Thus, this study aims to evaluate three temporary closure techniques of the abdominal cavity: the Vacuum-Assisted Closure Therapy - VAC, the Bogotá Bag and the Vacuum-pack. We conducted a systematic review of the literature, selecting 28 articles published in the last 20 years. The techniques of the bag Bogotá and Vacuum-pack had the advantage of easy access to the material in most centers and low cost, contrary to VAC, which, besides presenting high cost, is not available in most hospitals. On the other hand, the VAC technique was more effective in reducing stress at the edges of lesions, removing stagnant fluids and waste, in addition to acting at the cellular level by increasing proliferation and cell division rates, and showed the highest rates of primary closure of the abdominal cavity. RESUMO A cirurgia de controle de danos, com ênfase em peritoneostomia, geralmente resulta em retração da aponeurose e perda da capacidade de fechar a parede abdominal, levando à formação de hérnias ventrais incisionais. Atualmente, várias técnicas oferecem maiores chances de fechamento da cavidade abdominal, com menor tensão. Deste modo, este estudo tem por objetivo avaliar três técnicas de fechamento temporário da cavidade abdominal: fechamento a vácuo (Vacuum-Assisted Closure Therapy - VAC), Bolsa de Bogotá e Vacuum-pack. Realizou-se uma revisão sistemática da literatura com seleção de 28 artigos publicados nos últimos 20 anos. As técnicas de Bolsa de Bogotá e Vacuum-pack tiveram como vantagem o acesso fácil ao material, na maioria dos centros, e baixo custo, ao contrário do que se observa na terapia a vácuo, VAC, que além de apresentar alto custo, não está disponível em grande parte dos hospitais. A técnica VAC, por outro lado, foi mais eficaz na redução da tensão nas bordas das lesões, ao remover fluidos estagnados e detritos, além de exercer ação a nível celular, aumentando as taxas de proliferação e divisão celular, e apresentou as maiores taxas de fechamento primário da cavidade abdominal.

Negative pressure wound therapy inhibits inflammation and upregulates activating transcription factor-3 and downregulates nuclear factor-κB in diabetic patients with foot ulcerations

BACKGROUND

Negative pressure wound therapy (NPWT) is one of the most important treatments for diabetic foot, but the underlying mechanisms of its benefits still remain elusive. This study aims to evaluate the inflammatory signals involved in the effects of negative pressure therapy on diabetic foot ulcers.

METHODS

We enrolled 22 patients with diabetic foot ulceration, 11 treated with NPWT and the other 11 treated with traditional debridement. All patients were treated and observed for 1 week. Granulation tissues were harvested and analyzed in both groups, and then were histologically and immunohistochemically analyzed. Enzyme-linked immunosorbent assay, Western blot analysis, and real-time PCR were performed to evaluate the expression of interleukin-6 (IL-6), tumor necrosis factor α (TNF-α), inducible nitric oxide synthase (iNOS), nuclear factor-κB (NF-κB) p65, I_k B-α, and activating transcription factor-3 (ATF-3).

RESULTS

After 7 days of treatment, NPWT could obviously promote diabetic wound healing because of the mild inflammation and the dense cell-deposited matrix. Meanwhile, NPWT significantly decreased the expression of TNF-α, IL-6, and iNOS (all P < .05). The result of Western blotting and real-time PCR indicated that NPWT obviously decreased the level of I_k B-α and NF-κB p65, and increased the level of ATF-3 (all P < .05).

CONCLUSION

NPWT exerts an anti-inflammatory effect, possibly through the suppression of proinflammatory enzymes and cytokines resulting from I_k B-α inhibition and ATF-3 activation, which may prevent the activation of the NF-κB pathway in human diabetic foot wounds.

Negative pressure wound therapy

iabetic foot disease is a major global burden. Foot ulcers frequently develop complications and become chronic, representing a considerable challenge as these are typically very difficult to treat. New therapies are needed to address these wounds and there is an increasing focus on negative pressure wound therapy (NPWT). This technique has been shown to accelerate wound healing and although its costs are significant, there is also evidence to show that it compares favourably with more conventional alternatives. However, most studies to date have been small, and larger trials are needed before NPWT becomes more routine. In the meantime, the procedure may be most suitable for large, chronic, heavily exuding wounds that do not respond to established therapies.

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

Introducation

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

Presentation of case

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

Discussion

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

Conclusion

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

•

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

•

Within 4 days bacterial culture was negative.

•

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

•

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

Evaluation of Vacuum Assisted Closure Therapy for Soft Tissue Injury in Open Musculoskeletal Trauma

INTRODUCTION

The application of controlled levels of negative or sub atmospheric pressure for a prolonged period of time on a wound had shown to accelerate removal of excess fluid and promote hyperaemia, which eventually promote wound healing.

AIM

The study was conducted with the aim to evaluate the effectiveness of Vacuum Assisted Closure (VAC) therapy for soft tissue injury in open musculoskeletal trauma.

MATERIALS AND METHODS

Twenty cases of complex musculoskeletal wound involving different parts of body were included in this progressive randomized study. In patients, aggressive debridement was done before the application of VAC therapy. Controlled negative pressure was uniformly applied to the wound. Dressings were changed after every 4 to 5 days. The evaluation of results included healing rate of the wound, eradication of infection, complication rate, and number of secondary procedures.

RESULTS

VAC therapy over the wound was administered for an average of 20.4 days ±6.72 days (range 14 to 42 days). There was decrease in wound size attained by VAC therapy ranged from 2.6 to 24.4cm(2), with an average reduction of 10.55 cm(2). Three wounds were infected at the start of VAC therapy. However, all patients were cleared of bacterial infection by the end of VAC therapy.

CONCLUSION

VAC therapy using negative pressure promote Wound healing by increasing local capillary perfusion and increased rate of granulation tissue formation, decreases the duration of wound healing and requires fewer painful dressing change.

Use of vacuum-assisted closure to maintain viability of a skin flap in a dog

CASE DESCRIPTION

A 4-year-old sexually intact male Labrador Retriever-Poodle mix was admitted to the hospital for treatment of a wound in the left thoracic region. The wound had been debrided and primary closure had been performed by the referring veterinarian 4 days previously.

CLINICAL FINDINGS

The dog had a 20-cm-long wound covered by a large flap of skin that extended caudally from the scapula over the left side of the thorax. A 3-cm defect was evident at the cranioventral aspect of the wound, from which purulent material was being discharged. The skin flap was necrotic, and the skin surrounding the flap was bruised. Signs of pain were elicited when the wound and surrounding region were palpated. Other findings, including those of thoracic radiography, were unremarkable.

TREATMENT AND OUTCOME

The wound was debrided, and vacuum-assisted closure (VAC) was initiated for 3 days until a healthy bed of granulation tissue developed. A reconstructive procedure was performed with a rotation flap 3 days after VAC dressing removal. The VAC process was reinitiated 2 days following reconstruction because of an apparent failing of the skin flap viability. After 5 days of VAC, the flap had markedly improved in color and consistency and VAC was discontinued. Successful healing of the flap occurred without the need for debridement or additional intervention.

CLINICAL RELEVANCE

Use of VAC led to a good overall outcome for the dog, with complete healing achieved. Additional evaluation of this technique for salvaging failing skin flaps is warranted in dogs, particularly considering that no reliable method for flap salvage in veterinary species has been reported to date.

A preliminary study of the effect of closed incision management with negative pressure wound therapy over high-risk incisions

Background

Certain postoperative wounds are recognised to be associated with more complications than others and may be termed high-risk. Wound healing can be particularly challenging following high-energy trauma where wound necrosis and infection rates are high. Surgical incision for joint arthrodesis can also be considered high-risk as it requires extensive and invasive surgery and postoperative distal limb swelling and wound dehiscence are common. Recent human literature has investigated the use of negative pressure wound therapy (NPWT) over high-risk closed surgical incisions and beneficial effects have been noted including decreased drainage, decreased dehiscence and decreased infection rates. In a randomised, controlled study twenty cases undergoing distal limb high-energy fracture stabilisation or arthrodesis were randomised to NPWT or control groups. All cases had a modified Robert-Jones dressing applied for 72 h postoperatively and NPWT was applied for 24 h in the NPWT group. Morphometric assessment of limb circumference was performed at six sites preoperatively, 24 and 72 h postoperatively. Wound discharge was assessed at 24 and 72 h. Postoperative analgesia protocol was standardised and a Glasgow Composite Measure Pain Score (GCPS) carried out at 24, 48 and 72 h. Complications were noted and differences between groups were assessed.

Results

Percentage change in limb circumference between preoperative and 24 and 72 h postoperative measurements was significantly less at all sites for the NPWT group with exception of the joint proximal to the surgical site and the centre of the operated bone at 72 h. Median discharge score was lower in the NPWT group than the control group at 24 h. No significant differences in GCPS or complication rates were noted.

Conclusions

Digital swelling and wound discharge were reduced when NPWT was employed for closed incision management. Larger studies are required to evaluate whether this will result in reduced discomfort and complication rates postoperatively.

Curbing Inflammation in Skin Wound Healing: A Review

Wound healing is a complex regulated process that results in skin scar formation in postnatal mammals. Chronic wounds are major medical problems that can confer devastating consequences. Currently, there are no treatments to prevent scarring. In the early fetus wounds heal without scarring and the healing process is characterized by relatively less inflammation compared to adults; therefore, research aimed at reducing the inflammatory process related to wound healing might speed healing and improve the final scar appearance.

Negative pressure wound therapy as an adjunct in healing of chronic wounds

Negative pressure wound therapy (NPWT) has emerged as a cutting-edge technology and provides an alternative solution to the problem of wounds. This study was undertaken to assess the efficacy of this technique in the treatment of chronic wounds. A prospective clinical study was used to evaluate our experience in use of NPWT in the healing of pressure ulcers and chronic wounds over 2 years. The primary end point of the study group was the time taken for appearance of healthy granulation tissue and full reepithelialisation without drainage. All patients with sepsis were excluded from the study. The statistical analysis of the data was carried out. Of the 60 patients studied, 41 had associated comorbidities including diabetes mellitus. The commonest site of occurrence was the lower limb. Coverage in the form of a flap was required at presentation in 63·33% of patients. However, after initiation of NPWT, none of them required the procedure and they healed spontaneously either by secondary intention or by skin grafting. The time taken for appearance of healthy granulation tissue was 14·36 ± 4·24 days. Complete healing of wounds occurred by 33·1 ± 10·22 days. There was a statistically significant difference in the volume of the wounds before and after the intervention (P = 0·000). Complications resulting from NPWT were minimal. This technique is an excellent adjunct to surgical debridement.

Treatment of traumatically cutaneous necrosis of buttocks using vacuum sealing drainage combined with ileostomy

PURPOSE

The purpose of this study is to evaluate the surgical technique and review the therapeutic effect of vacuum sealing drainage combined with ileostomy treating patients of traumatically buttock skin necrosis.

METHODS

26 patients with buttock wounds were dressed and 6-12 days later, buttock skin necrosis boundaries were clear and debridement was performed. General surgeons were invited to perform the ileostomy. Thorough debridement was conducted and vacuum sealing drainage (VSD) devices were used to cover buttock wounds. Debridement and VSD were operated every 5-7 days until the granulation tissue of buttock wound was fresh. Then epidermal skin graft from thigh was performed to cover the granulation wound. About 3 months later after skin graft survival completely, the ileum was reversed by general surgeons and the patients recovered defecation using anus.

RESULTS

The granulation tissues of all patients were fresh after debridement and VSD 2-3 times. In 20 cases, transplanted epidermal skin grew well. In six cases, necrosis was observed at the margins of the flap and further debridement and skin graft were conducted. During the follow-up period of approximate 6 months, the flaps grew well and the patients defecated normally from anus.

CONCLUSIONS

Treating traumatically cutaneous necrosis of buttocks with vacuum sealing drainage and ileostomy can gain good therapeutic effect.

Vacuum-assisted close versus conventional treatment for postlaparotomy wound dehiscence

Purpose

The conventional treatment for postlaparotomy wound dehiscence usually involves surgical revision. Recently, vacuum-assisted closure has been successfully used in postlaparotomy wound dehiscence. The aim of the present study was to compare the clinical outcome of 207 patients undergoing vacuum-assisted closure therapy or conventional treatment for postlaparotomy wound dehiscence.

Methods

Two hundred and seven consecutive patients underwent treatment for postlaparotomy wound dehiscence: vacuum-assisted closure therapy (January 2007 through August 2012, n = 25) or conventional treatment (January 2001 through August 2012, n = 182).

Results

The failure rate to first-line treatment with vacuum-assisted closure and conventional treatment were 0% and 14.3%, respectively (P = 0.002). There was no statistically significant difference in the enterocutaneous fistulas and hospital stay after vacuum-assisted closure therapy or conventional treatment respectively.

Conclusion

Our findings support that vacuum-assisted closure therapy is a safe and reliable option in postlaparotomy wound dehiscence with very low failure rate in surgical revision compared with conventional treatment.

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.

Science supporting negative pressure wound therapy with instillation

A new method (V.A.C.ULTA Therapy System, KCI USA, Inc., San Antonio, TX) combines the benefits of negative pressure wound therapy (NPWT; V.A.C. Therapy, KCI USA, Inc.) with regulated, periodic instillation of user-selected topical wound solutions (V.A.C. VeraFlo Therapy, KCI USA, Inc.). In simulated wound model studies comparing solution distribution using NPWT with and without a soak phase, the instillation soak phase allowed for uniform solution distribution across the wound bed, whereas continuous (no soak) irrigation resulted in uneven coverage. Additional in vitro work illustrated that bacterial particle aerosolisation during wound cleansing was significantly decreased using NPWT with instillation (NPWTi) versus commercially available low-pressure wound cleansers (P < 0·05). In porcine studies, NPWT with saline instillation induced 43% more granulation tissue versus NPWT (P < 0·05) and was as effective at wound cleansing as pulsed lavage. These studies have demonstrated that NPWTi may be an effective wound management therapy that provides both wound cleansing and NPWT benefits.

Clinical evidences, personal experiences, recent applications

Management of difficult wounds can be a complex, challenging and expensive task, especially for wounds showing a slow healing process. Topical negative pressure (TNP) therapy has greatly improved difficult wounds treatment. It allows to treat patient on an outpatient management, to reduce the complication rate with shorter hospital stay, to avoid frequent dressings with expensive advanced materials and allow a lower commitment of health professionals. Vacuum Assisted Closure^® (VAC^®) system is a therapeutic device based on the administration of a controlled TNP introduced by Morykwas and Argenta in 1997. It is indicated in different kinds of wound, but clinical evidences are present only for few of them. In this work we summarize indications and recommendations for VAC^® therapy and we analyze the actual better choice of treatment based on evidences and personal experience in order to stimulate further studies. Finally we introduce recent applications of VAC^® system such as Prevena^®, VAC Instill^® and VAC Via^®. Prevena^® is a system based on TNP indicated in the management of closed wounds that present risk factors for dehiscence. VAC Instill^® is a system that allows to associate TNP and topical administration of solutions, such as antibiotics or disinfectants, to treat specific type of wounds. VAC Via^® is a device based on TNP, characterized by little dimension and a preset system that allow the treatment of little wounds for 7 d, with no impairment for the patient. The aim of our paper is to describe a report of VAC^® therapy use in order to stimulate further studies and to define the level of evidence of VAC^® therapy.

Negative pressure wound therapy literature review of efficacy, cost effectiveness, and impact on patients' quality of life in chronic wound management and its implementation in the United kingdom

This is a paper reviewing the National Health Service (NHS) agenda in relation to the use of Negative Pressure Wound Therapy (NPWT) in chronic wound management and assesses the evidence behind it, its cost effectiveness and the outcome it has on patients' satisfaction and life style. Multiple studies over the last 10 years looking at clinical efficacy of NPWT with its cost effectiveness and the implementation of this service in the UK were reviewed. NPWT has showed a reasonable body of evidence to support its usage in chronic wounds with potential positive outcomes on finance and patients' satisfaction. However, the NHS system shows significant variations in the availability and implementation of this useful tool, depending on care providers and resources availabilities. The paper concluded that the NPWT can be a useful source of cutting down costs of chronic wound managements and saving money by its effect on expediting wound healing, which can address a part of the financial crises facing the NHS, however, has to be considered according to specific case needs. There should also be a national standard for the availability and indication of this tool to assure equal opportunities for different patients in different areas in the country.

[Vacuum assisted closure in open abdomen and deferred closure: experience in 23 patients]

INTRODUCTION

We analyse our experience and the results obtained with the use of vacuum assisted closure (VAC(®), KCI Clinic Spain SL) in the management of open abdomen.

MATERIAL AND METHODS

We retrospectively reviewed the laparostomies performed between June 2006 and March 2011 using VAC(®) treatment in the Hospital Xeral-Cíes, Vigo.

RESULTS

We included 23 consecutive patients (18 males and 5 females) on whom the VAC(®) was used in the open abdomen due to different indications (abdominal trauma, peritonitis, pancreatitis, ischaemic disease or abdominal compartmental syndrome). The VAC(®) needed changing a mean of 3.1 times per patient (range 1-7), with total mean treatment duration of 14.8 days (2-43) until closure, primary closure being achieved in 18 out of 21 patients (86%). The mean hospital stay was 110.1 days (8-163) and 6 patients (26%) died during their hospital stay due to problems related to their underlying disease. Seven cases (30%) had complications during the VAC® therapy: 3 intra-abdominal abscesses (13%), 4 fistulas or suture dehiscence (17%), and 1 evisceration (4%).

CONCLUSIONS

VAC(®) therapy is simple to manage, with an acceptable rate of complication, particularly of intestinal fistulas, and a reduced mortality. Of the various systems available for the deferred closure of the abdomen, the VAC(®) has made considerable progress in the past few years, mainly due to its adaptable material, and its numerous advantages. Its use will possibly increase in the future.

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.

Negative pressure wound therapy for recurrent pilonidal disease: a review of the literature

Pilonidal disease arises from hair follicles of the gluteal cleft and may result in a chronic exudative disorder. The management of pilonidal disease following surgical excision remains controversial, despite an abundance of research into different treatment options. Negative pressure wound therapy is an emerging treatment option for complex or recurrent pilonidal disease. We performed a comprehensive literature search, using the electronic databases MEDLINE, Cochrane library, CINAHL, PubMed, and Web of Knowledge. All studies, case reports, and multiple case series evaluating the use of negative pressure wound therapy for treatment of pilonidal disease were included. Despite the breadth of our search parameters, we identified limited studies addressing this issue; all were published between 2003 and 2007. Findings of 5 case reports or multiple case series tentatively suggest that negative pressure wound therapy may be an emerging treatment option for pilonidal disease management. However, we recommend that more rigorous research, including randomized controlled trials, be conducted before implications can be drawn for evidence-based practice.

A clinical review of infected wound treatment with Vacuum Assisted Closure (V.A.C.) therapy: experience and case series

Over the last decade Vacuum Assisted Closure((R)) (KCI Licensing, Inc., San Antonio, TX) has been established as an effective wound care modality for managing complex acute and chronic wounds. The therapy has been widely adopted by many institutions to treat a variety of wound types. Increasingly, the therapy is being used to manage infected and critically colonized, difficult-to-treat wounds. This growing interest coupled with practitioner uncertainty in using the therapy in the presence of infection prompted the convening of an interprofessional expert advisory panel to determine appropriate use of the different modalities of negative pressure wound therapy (NPWT) as delivered by V.A.C.((R)) Therapy and V.A.C. Instill((R)) with either GranuFoam() or GranuFoam Silver() Dressings. The panel reviewed infected wound treatment methods within the context of evidence-based medicine coupled with experiential insight using V.A.C.((R)) Therapy Systems to manage a variety of infected wounds. The primary objectives of the panel were 1) to exchange state-of-practice evidence, 2) to review and evaluate the strength of existing data, and 3) to develop practice recommendations based on published evidence and clinical experience regarding use of the V.A.C.((R)) Therapy Systems in infected wounds. These recommendations are meant to identify which infected wounds will benefit from the most appropriate V.A.C.((R)) Therapy System modality and provide an infected wound treatment algorithm that may lead to a better understanding of optimal treatment strategies.

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

Negative pressure wound therapy (NPWT) contracts the wound and alters the pressure in the tissue of the wound edge, which accelerates wound healing. The aim of this study was to examine the effect of the type (foam or gauze) and size (small or large) of wound filler for NPWT on wound contraction and tissue pressure. Negative pressures between --20 and --160 mmHg were applied to a peripheral porcine wound (n = 8). The pressure in the wound edge tissue was measured at distances of 0·1, 0·5, 1·0 and 2·0 cm from the wound edge and the wound diameter was determined. At 0·1 cm from the wound edge, the tissue pressure decreased when NPWT was applied, whereas at 0·5 cm it increased. Tissue pressure was not affected at 1·0 or 2·0 cm from the wound edge. The tissue pressure, at 0·5 cm from the wound edge, was greater when using a small foam than when using than a large foam. Wound contraction was greater when using a small foam than when using a large foam during NPWT. Gauze resulted in an intermediate wound contraction that was not affected by the size of the gauze filler. The use of a small foam to fill the wound causes considerable wound contraction and may thus be used when maximal mechanical stress and granulation tissue formation are desirable. Gauze or large amounts of foam result in less wound contraction which may be beneficial, for example when NPWT causes pain to the patient.

The influence of low and high pressure levels during negative-pressure wound therapy on wound contraction and fluid evacuation

BACKGROUND

Negative-pressure wound therapy promotes healing by drainage of excessive fluid and debris and by mechanical deformation of the wound. The most commonly used negative pressure, -125 mmHg, may cause pain and ischemia, and the pressure often needs to be reduced. The aim of the present study was to examine wound contraction and fluid removal at different levels of negative pressure.

METHODS

Peripheral wounds were created in 70-kg pigs. The immediate effects of negative-pressure wound therapy (-10 to -175 mmHg) on wound contraction and fluid removal were studied in eight pigs. The long-term effects on wound contraction were studied in eight additional pigs during 72 hours of negative-pressure wound therapy at -75 mmHg.

RESULTS

Wound contraction and fluid removal increased gradually with increasing levels of negative pressure until reaching a steady state. Maximum wound contraction was observed at -75 mmHg. When negative-pressure wound therapy was discontinued, after 72 hours of therapy, the wound surface area was smaller than before therapy. Maximum wound fluid removal was observed at -125 mmHg.

CONCLUSIONS

Negative-pressure wound therapy facilitates drainage of wound fluid and exudates and results in mechanical deformation of the wound edge tissue, which is known to stimulate granulation tissue formation. Maximum wound contraction is achieved already at -75 mmHg, and this may be a suitable pressure for most wounds. In wounds with large volumes of exudate, higher pressure levels may be needed for the initial treatment period.

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.

Use of a collagen-elastin matrix for hard to treat soft tissue defects

As deep soft tissue defects with exposed bone, cartilage or tendons are not suitable for wound closure with skin mesh grafts, other techniques are needed. We report on six patients, one female and five males, aged between 32 and 89 years, and deep soft tissue defects with exposed tendons, cartilage or bone. The aetiology of these defects was vascular (n = 3), tumour surgery (2), and post-traumatic (1). Wounds were treated with a collagen-elastin matrix applied above the exposed structures. In five patients, the procedure was combined with mesh graft transplantation in the same setting. Follow-up varied between 12 and 40 weeks. Wound healing was uncomplicated in all transplanted patients until first dressing change after 7 days. All but one transplant showed a 100% take rate and the transplant was stable within 10-14 days. A complete wound closure was also achieved without transplantation, but this took 8 weeks. No adverse effects were noted. There was no skin contracture of the skin grafts. Collagen-elastin matrix with split-thickness skin grafts is a useful tool in deep soft tissue. The time to heal can be reduced.

Influence on pressure transduction when using different drainage techniques and wound fillers (foam and gauze) for negative pressure wound therapy

Pressure transduction to the wound bed in negative pressure wound therapy (NPWT) is crucial in stimulating the biological effects ultimately resulting in wound healing. In clinical practice, either foam or gauze is used as wound filler. Furthermore, two different drainage techniques are frequently employed. One involves the connection of a non-perforated drainage tube to the top of the dressing, while the other involves the insertion of perforated drains into the dressing. The aim of this study was to examine the efficacy of these two different wound fillers and drainage systems on pressure transduction to the wound bed in a challenging wound (the sternotomy wound). Six pigs underwent median sternotomy. The wound was sealed for NPWT using different wound fillers (foam or gauze) and drainage techniques (see earlier). Pressures between 0 and -175 mmHg were applied and the pressure in the wound was measured using saline-filled catheters sutured to the bottom of the wound (over the anterior surface of the heart) and to the side of the wound (on the thoracic wall). The negative pressure on the wound bed increased linearly with the negative pressure delivered by the vacuum source. In a dry wound, the pressure transduction was similar when using the different wound fillers (foam and gauze) and drainage techniques. In a wet wound, pressure transduction was better when using a perforated drainage tube inserted into the wound filler than a non-perforated drainage tube connected to the top of the dressing (-116 ± 1 versus -73 ± 4 mmHg in the wound at a delivered pressure of -125 mmHg for foam, P < 0·01), regardless of the type of wound filler. Gauze and foam are equally effective at delivering negative pressure to the wound bed. Perforated drainage tubes inserted into the wound filler are more efficient than a non-perforated drainage tubes connected to the top of the dressing. The choice of drainage technique may be particularly important in wounds with a large volume of exudate.

Effectiveness of Vacuum-assisted Closure (VAC) Therapy in the Healing of Chronic Diabetic Foot Ulcers

Introduction: This is the first prospective study done locally to determine the effectiveness of vacuum-assisted closure (VAC) therapy in the healing of chronic diabetic foot ulcers. Materials and Methods: An electronic vacuum pump was used to apply controlled negative pressure evenly across the wound surface. Changes in wound dimension, presence of wound granulation and infection status of diabetic foot ulcers in 11 consecutive patients with diabetes were followed over the course of VAC therapy. Results: Healing was achieved in all wounds. Nine wounds were closed by split-skin grafting and 2 by secondary closure. The average length of treatment with VAC therapy was 23.3 days. Ten wounds showed reduction in wound size. All wounds were satisfactorily granulated and cleared of bacterial infection at the end of VAC therapy. Conclusions: VAC therapy was useful in the treatment of diabetic foot infection and ulcers, which after debridement, may present with exposed tendon, fascia and/or bone. These included ray amputation wounds, wounds post-debridement for necrotising fasciitis, wounds post-drainage for abscess, a heel ulcer and a sole ulcer. It was able to prepare ulcers well for closure via split-skin grafting or secondary closure in good time. This reduced cost of VAC therapy, as therapy was not prolonged to attain greater reduction in wound area. VAC therapy also provides a sterile, more controlled resting environment to large, exudating wound surfaces. Large diabetic foot ulcers were thus made more manageable. Key words: Diabetic foot wound, Negative pressure dressing, Wound healing