Negative pressure wound therapy induces early wound healing by increased and accelerated expression of vascular endothelial growth factor receptors

Biomaterials-Based Strategies to Enhance Angiogenesis in Diabetic Wound Healing

Amidst the present healthcare issues, diabetes is unique as an emerging class of affliction with chronicity in a majority of the population. To check and control its effects, there have been huge turnover and constant development of management strategies, and though a bigger part of the health care area is involved in achieving its control and the related issues such as the effect of diabetes on wound healing and care and many of the works have reached certain successful outcomes, still there is a huge lack in managing it, with maximum effect yet to be attained. Studying pathophysiology and involvement of various treatment options, such as tissue engineering, application of hydrogels, drug delivery methods, and enhancing angiogenesis, are at constantly developing stages either direct or indirect. In this review, we have gathered a wide field of information and different new therapeutic methods and targets for the scientific community, paving the way toward more settled ideas and research advances to cure diabetic wounds and manage their outcomes.

The Efficacy of Negative Pressure Wound Therapy (NPWT) on Healing of Diabetic Foot Ulcers: A Literature Review

BACKGROUND

Diabetes mellitus is a complex disorder that requires continuous management to control blood sugar levels and prevent complications. Diabetic foot ulcers (DFU) are the most common complication in diabetic patients. A popular therapy modality with considerable advantages in the management of diabetic foot ulcers today is negative pressure wound therapy (NPWT).

OBJECTIVE

This study aimed to review related articles about the efficacy as well as the complications or adverse effects of using NPWT on the healing of DFUs.

METHODS

Searching English databases from PubMed, Ebscohost, Proquest and Science Direct was done to identify relevant citations published between January 2017 and January 2022. A combination of terms was used with the boolean formulation of "negative pressure wound therapy OR NPWT" OR "vacuum-assisted closure or VAC" AND "diabetic foot ulcers OR diabetic foot wound" AND "wound healing" AND "Conventional dressings" and map terms were also used for the subject heading. Some potentially relevant citations of articles from the bibliographies are also reviewed.

RESULTS

This study included 8 related articles consisting of 6 RCTs, 1 cohort study and 1 Quasy experimental study. There were various methodological techniques for using NPWT and outcome measures among studies. The results of this literature review showed that NPWT was more efficacious than the other conventional or advanced moist dressings. This therapy revealed a faster healing time with complete wound healing and formation of granulation tissue and reduction in wound size. The complications or adverse effects of NPWT, such as amputation rate, bleeding and pain, were not different from conventional or advanced moist dressings, though.

CONCLUSION

NPWT was more efficacious than other conventional or advanced moist dressings for the healing of DFUs. However, complications or adverse effects of using this therapy showed no significant difference with other conventional or advanced moist dressings.

The Effect of Negative Pressure on Wound Healing and Regeneration in Closed Incisions under High Tension: Evidence from Animal Studies and Clinical Experience

Closed-incision negative-pressure wound therapy (iNPWT) is known to enhance wound healing and tissue regeneration. The main aim of the present study is to investigate its effectiveness on enhancing wound healing under tension. An animal study was designed using a swine model by removing a skin flap to create a wound that could be closed primarily under tension, and iNPWT was applied. The enhancement of angiogenesis, lymphangiogenesis, collagen deposition, and tissue proliferation with reduced inflammation by iNPWT was confirmed by histology. The effect of iNPWT was further verified in patients receiving a profunda artery perforator (PAP) free flap for breast reconstruction. iNPWT was applied on the transversely designed donor site in continuous mode for 7 days, in which the wound was always closed under tension. A significant improvement in off-bed time was noted with the application of iNPWT (4.6 ± 1.1st and 5.5 ± 0.8th postoperative days in the iNPWT and control groups, respectively, p = 0.028). The control group (without iNPWT treatment) presented more cases of poor wound healing in the acute (23.1% vs. 0%) and wound breakdown in the late (23.1% vs. 8.3%) stages. The treatment of closed incisions under tension with iNPWT clinically enhances wound healing and tissue regeneration and with histological evidence.

Negative Pressure Wound Therapy: Supra-Physiological or Just Physical Effects of Positive Pressure?

This communication provides a new insight into the unexplained physiology of beneficial effects of negative pressure wound therapy (NPWT). Possible mechanisms of beneficial effects of NPWT in failing replantation and free tissue transfer are discussed. Positive pressure generated by NPWT as well as its draining action creates exudate-free tight tissue-to-tissue interface, which may enhance neovascularization.

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.

Salivary VEGF and post-extraction wound healing in type 2 diabetic immediate denture wearers

OBJECTIVE

Oral wound healing in healthy could be promoted by VEGF in saliva, and immediate denture wearing, but data in type 2 diabetes are lacking. Aims were to investigate the timeline of extraction wound healing in diabetic participants wearing immediate dentures and its correlation to salivary VEGF, as well as to examine the impact of the palatal plate on tissue VEGF during palatal wound healing in rat diabetic model.

MATERIAL AND METHODS

Healthy (42) and type 2 diabetic (36) denture wearers, candidates for teeth extractions were included. Extraction wound healing was followed via measurements of socket closure, gingival hyperaemia, pain and presence of necrosis on 3^rd, 7^th, 14^th and on 21^st-day post-extraction. Salivary VEGF was measured before and on the 3^rd and 21^st day after the extraction. In streptozotocin-induced diabetic (30) as well as non-diabetic rats (30), tissue VEGF was measured in palatal wounds healing under or without a palatal plate.

RESULTS

Type 2 diabetic prosthetic patients exhibit delayed socket closure, with pronounced hyperaemia, pain and necrosis. Salivary VEGF is increased in diabetes and positively correlates to socket closure while negatively with pain on 21^st day after the extraction. Palatal incision induced VEGF increase in non-diabetic and diabetic, but less pronounced in diabetic rats. Wound healing under the palatal plate exhibit higher tissue VEGF.

CONCLUSION

Type 2 diabetes-induced increase in salivary VEGF may mitigate diabetes-induced detrimental effects on extraction wound healing. Lack of adequate tissue VEGF response to injury may underly dysregulation of diabetic oral wound healing.

Mechanotransduction in Wound Healing: From the Cellular and Molecular Level to the Clinic

GENERAL PURPOSE

To review the various mechanical forces that affect fibroblasts, keratinocytes, endothelial cells, and adipocytes at the cellular and molecular level as well as scar-reducing mechanical devices currently in clinical use.

TARGET AUDIENCE

This continuing education activity is intended for physicians, physician assistants, nurse practitioners, and nurses with an interest in skin and wound care.

LEARNING OBJECTIVES/OUTCOMES

After participating in this educational activity, the participant will:1. Compare and contrast the responses of various types of cells to mechanical forces.2. Identify the mechanical devices and techniques that can help restore skin integrity.

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.

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.

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.

Effect of negative-pressure wound therapy on the circulating number of peripheral endothelial progenitor cells in diabetic patients with mild to moderate degrees of ischaemic foot ulcer

Objective

To investigate the effect of negative-pressure wound therapy (NPWT) on the circulating number of endothelial progenitor cells (EPCs) in diabetic patients with mild to moderate degrees of ischemic foot ulcer.

Methods

We selected 84 diabetic patients who had a foot ulcer with a duration of at least four weeks and who had an ankle-brachial index of 0.5–0.9. Patients were assigned to one two groups according to 2:1 randomization: NPWT group ( n = 56) and non-NPWT (patients who did not receive NPWT) group ( n = 28). The control group (NC group) was composed of 18 patients who had normal glucose tolerance and lower extremity ulcer without arteriovenous disease. NPWT was performed on the ulcer after debridement for one week for patients in both the NPWT group and the NC group, and the patients in the non-NPWT group received conventional treatment process. The circulating number of EPCs was measured before and after various treatments, and the factors influencing their changes were analysed.

Results

After NPWT, the circulating number of EPCs significantly increased in both the NPWT group and the NC group ((85.3 ± 18.1) vs. (34.1 ± 12.5)/106 cells; (119.9 ± 14.4) vs. (66.1 ± 10.6)/106 cells, both P < 0.05). In contrast, the circulating number of EPCs had no significant change in the non-NPWT group ((45.2 ± 19.4) vs. (34.7 ± 16.8)/106 cells, P > 0.05). In addition, the circulating levels of vascular endothelial growth factor (VEGF) and the protein expressions of VEGF and stromal cell-derived factor-1α (SDF-1α) in the granulation tissue significantly increased after NPWT in both the NPWT and the NC group, but there was no significant change in the non-NPWT group. Compared with the non-NPWT group, the changes in VEGF and SDF-1α levels in the sera and granulation tissue were all significantly higher in both the NPWT and NC groups ( P < 0.05, P < 0.01, respectively). There was no significant difference in changes in the circulating number of EPCs in the peripheral blood and levels of VEGF and SDF-1α in the sera and granulation tissue between the NPWT and NC groups. Correlation analysis showed that the change in the circulating number of EPCs was correlated with the changes of VEGF and SDF-1α levels in the sera and granulation of the NPWT and NC groups ( P < 0.05).

Conclusion

NPWT may increase the circulating number of EPCs in diabetic patients with mild to moderate ischaemic foot ulcer as in non-diabetic controls, which may be attributed to the upregulation of systemic and local VEGF and SDF-1α levels.

Outpatient Negative-Pressure Wound Therapy Following Surgical Debridement: Results and Complications

OBJECTIVE

To present results and complications in a case series of outpatients with diabetic and neuropathic foot ulcers with exposed bone following surgical debridement treated with negative-pressure wound therapy (NPWT).

METHODS

Retrospective data were obtained from digital medical records from the Maccabi Health Services High Risk Foot Clinic in Tel Aviv, Israel, between 2009 and 2014. Medical records examined were those of clinic outpatients with exposed bone following partial foot amputation or selective bone debridement (University of Texas grade III-A) treated with NPWT.

MAIN OUTCOME MEASURES

Wound area, closure rate, and adverse events.

MAIN RESULTS

There were 66 patients provided NPWT in a total of 77 treatment courses. Mean patient age was 62 ± 10 years, 82% were male, and mean diabetes mellitus duration was 14 ± 8 years. Mean HbA1C levels were 8.1% ± 1.7%. Mean treatment course duration was 16 days (range, 2-42 days). Wound area decreased significantly (from 11.3 ± 16.8 cm to 8.0 ± 13.3 cm, P < .0001). Ulcer curing was noted in 7% of the cases, and healing progression was noted in 54%. Seven serious adverse events were recorded.

CONCLUSIONS

Outpatient NPWT is a relatively safe and effective adjuvant to surgical debridement of neuropathic foot ulcers. In an outpatient setting, one can expect serious adverse events to occur in 10% of cases, but this seems unavoidable in patients with diabetic foot ulcers when taking into account their comorbidities and patient resources. Strict protocols to promote early recognition of complications and appropriate response to minimize deterioration must be implemented.

Negative pressure wound therapy in the treatment of diabetic foot ulcers may be mediated through differential gene expression

AIMS

Negative pressure wound therapy (NPWT) has been successfully used as a treatment for diabetic foot ulceration (DFU). Its mechanism of action on the molecular level, however, is not fully understood. We assessed the effect of NPWT on gene expression in patients with type 2 diabetes (T2DM) and DFU.

METHODS

We included two cohorts of patients-individuals treated with either NPWT or standard therapy. The assignment to NWPT was non-randomized and based on wound characteristics. Differential gene expression profiling was performed using Illumina gene expression arrays and R Bioconductor pipelines based on the 'limma' package.

RESULTS

The final cohort encompassed 21 patients treated with NPWT and 8 with standard therapy. The groups were similar in terms of age (69.0 versus 67.5 years) and duration of T2DM (14.5 versus 14.4 years). We identified four genes differentially expressed between the two study arms post-treatment, but not pre-treatment: GFRA2 (GDNF family receptor alpha-2), C1QBP (complement C1q binding protein), RAB35 (member of RAS oncogene family) and SYNJ1 (synaptic inositol 1,4,5-trisphosphate 5-phosphatase 1). Interestingly, all four genes seemed to be functionally involved in wound healing by influencing re-epithelialization and angiogenesis. Subsequently, we utilized co-expression analysis in publicly available RNA-seq data to reveal the molecular functions of GFRA2 and C1QBP, which appeared to be through direct protein-protein interactions.

CONCLUSIONS

We found initial evidence that the NPWT effect on DFUs may be mediated through differential gene expression. A discovery of the specific molecular mechanisms of NPWT is potentially valuable for its clinical application and development of new therapies.

Hardware removal or preservation? Decision making based on a newly developed rating scale

Hardware exposure following open reduction and internal fixation (ORIF) surgery is a tricky problem. It is always hard for surgeons to decide whether to keep or remove the hardware. In this study, a rating scale and corresponding clinical path is developed based on former published paper as well as our own experience. New admitted patients are first evaluated and scored once they enter the department. Based on the score they get, patients are assigned to different therapeutic schedule, i.e. (1) hardware preservation with pedicel flap transplantation, (2) debridement for further reevaluation and (3) hardware removal with external fixation. Satisfying clinical outcome is achieved that is characterized with high osseous consolidation rate and low complication rate. The result showed that this newly developed rating scale and the related therapeutic schedule could be an available tool to help surgeons to make decisions in the treatment of hardware exposure.