Closed incision negative pressure wound therapy versus standard dressings in obese women undergoing caesarean section: multicentre parallel group randomised controlled trial

A Systematic Review and Meta-analysis of Two Negative Pressure Wound Therapy Devices to Manage Cesarean Section Incisions

This paper aims to evaluate whether there is a device-dependent effect on the reduction of surgical site complications in obese patients (body mass index [BMI] ≥ 30 kg/m2) undergoing cesarean section (C-section). PubMed, Embase, Cochrane Library, and ClinicalTrials.gov were searched for the period, January 2011 to September 2021. English language articles describing a randomized controlled trial (RCT) that compared either a -80 or -125 mm Hg single-use negative pressure wound therapy (sNPWT) device to standard dressings in obese (BMI ≥ 30 kg/m2) patients undergoing C-section were included. Conference abstracts and "terminated" RCTs with published results were deemed eligible for inclusion. The primary outcome of interest was surgical site infection (SSI), classified as composite, superficial, or deep. Secondary outcomes assessed included seroma, dehiscence, hematoma, bleeding, reoperation, readmission, blistering, and (composite) wound complications. A total of 223 titles were identified, of which 129 were screened by full-text review. Eleven RCTs encompassing 5,847 patients met the inclusion criteria and were considered eligible for further analysis (-80 mm Hg: six studies; -125 mm Hg: five studies). A statistically significant improvement in the composite SSI (odds ratio [OR]: 0.69; 95% confidence interval [CI]: 0.54-0.89) and superficial SSI (OR: 0.66; 95% CI: 0.50-0.86) outcomes was observed with the -80 mm Hg device, compared with standard dressings. The same effect on SSI outcomes was not observed with the -125 mm Hg device (composite SSI-OR: 0.91; 95% CI: 0.64-1.28; superficial SSI-OR: 1.12; 95% CI: 0.70-1.78). There were no statistically significant differences in any of the other assessed outcomes. sNPWT devices may differ in their ability to reduce composite or superficial SSI after C-section. KEY POINTS: · Negative pressure benefits obese patients undergoing C-section.. · Negative pressure devices may differ in performance.. · A head-to-head clinical trial is needed..

Prospective evaluation of a closed-incision negative pressure wound therapy system in kidney transplantation and its association with wound complications

Introduction

Wound complications can cause considerable morbidity in kidney transplantation. Closed-incision negative pressure wound therapy (ciNPWT) systems have been efficacious in reducing wound complications across surgical specialties. The aims of this study were to evaluate the use of ciNPWT, Prevena™, in kidney transplant recipients and to determine any association with wound complications.

Material and methods

A single-center, prospective observational cohort study was performed in 2018. A total of 30 consecutive kidney transplant recipients deemed at high risk for wound complications received ciNPWT, and the results were compared to those of a historical cohort of subjects who received conventional dressings. Analysis for recipients with obesity and propensity score matching were performed.

Results

In total, 127 subjects were included in the analysis. Of these, 30 received a ciNPWT dressing and were compared with 97 subjects from a non-study historical control group who had conventional dressing. The overall wound complication rate was 21.3% (27/127). There was no reduction in the rate of wound complications with ciNPWT when compared with conventional dressing [23.3% (7/30) and 20.6% (20/97), respectively, p = 0.75]. In the obese subset (BMI ≥30 kg/m2), there was no significant reduction in wound complications [31.1% (5/16) and 36.8% (7/19), respectively, p = 0.73]. Propensity score matching yielded 26 matched pairs with equivalent rates of wound complications (23.1%, 6/26).

Conclusion

This is the first reported cohort study evaluating the use of ciNPWT in kidney transplantation. While ciNPWT is safe and well tolerated, it is not associated with a statistically significant reduction in wound complications when compared to conventional dressing. The findings from this study will be used to inform future studies associated with ciNPWT in kidney transplantation.

Effect of hydrocolloid dressings on preventing air leakage when applying negative pressure wound therapy to the perineum, buttocks, and sacrococcygeal region

Maintaining a vacuum when applying negative pressure wound therapy (NPWT) is the key to its function, which is a challenge in the perineum, buttocks, and sacrococcygeal region. A retrospective cohort study was conducted to assess the effect of hydrocolloid dressings on preventing air leakage when applying NPWT in these regions. There were 61 patients in Group A (without the aid of hydrocolloid dressings) and 65 patients in Group B (with the aid of hydrocolloid dressings). The hydrocolloid dressing-assisted NPWT significantly reduced the incidence of air leakage compared with conventional NPWT placement (24.6% vs. 7.7%; risk ratio, 3.20; 95% confidence interval, 1.24-8.27; p = 0.009), while decreasing the number of open NPWT applications (2.2 vs. 1.7; difference, 0.43; 95% confidence interval, 0.19-0.66; p < 0.001), shortening hospital stays (20.1 vs. 16.1; difference, 4.07; 95% confidence interval, 1.68-6.46; p = 0.01), and reducing the incidence of adverse skin events (18.0% vs. 4.6%; risk ratio, 3.91; 95% confidence interval, 1.14-13.34; p = 0.017). These findings support the routine use of hydrocolloid dressing-assisted NPWT placement in the perineum, buttocks, and sacrococcygeal region.

Cost-effectiveness of closed incision negative pressure wound therapy in preventing surgical site infection among obese women giving birth by caesarean section: An economic evaluation (DRESSING trial)

BACKGROUND

There is growing evidence regarding the potential of closed incision negative pressure wound therapy (ci-NPWT) to prevent surgical site infections (SSIs) in healing wounds by primary closure following a caesarean section (CS).

AIM

To assess the cost-effectiveness of ci-NPWT compared to standard dressings for prevention of SSI in obese women giving birth by CS.

MATERIALS AND METHODS

Cost-effectiveness and cost-utility analyses from a health service perspective were undertaken alongside a multicentre pragmatic randomised controlled trial, which recruited women with a pre-pregnancy body mass index ≥30 kg/m2 giving birth by elective/semi-urgent CS who received ci-NPWT (n = 1017) or standard dressings (n = 1018). Resource use and health-related quality of life (SF-12v2) collected during admission and for four weeks post-discharge were used to derive costs and quality-adjusted life years (QALYs).

RESULTS

ci-NPWT was associated with AUD$162 (95%CI -$170 to $494) higher cost per person and an additional $12 849 (95%CI -$62 138 to $133 378) per SSI avoided. There was no detectable difference in QALYs between groups; however, there are high levels of uncertainty around both cost and QALY estimates. There is a 20% likelihood that ci-NPWT would be considered cost-effective at a willingness-to-pay threshold of $50 000 per QALY. Per protocol and complete case analyses gave similar results, suggesting that findings are robust to protocol deviators and adjustments for missing data.

CONCLUSIONS

ci-NPWT for the prevention of SSI in obese women undergoing CS is unlikely to be cost-effective in terms of health service resources and is currently unjustified for routine use for this purpose.

A systematic review with meta-analysis on prophylactic negative pressure wound therapy versus standard dressing for obese women after caesarean section

AIMS

The purpose of this study is to assess the efficacy of prophylactic negative pressure wound therapy (NPWT) in obese women undergoing caesarean section.

DESIGN

An updated review and meta-analysis of randomized controlled trials following Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines.

METHODS

PubMed, Embase, Medline, Web of Science, and Cochrane Library were searched from inception up to March 2022 without restriction in language. We chose surgical site infection as the primary outcome.

RESULTS

NPWT resulted in a lower surgical site infection rate compared with conventional dressing (risk ratio [RR] = 0.76). The infection rate after low transverse incision was lower comparing the NPWT group with the control group ([RR] = 0.76). No statistically significant difference was detected in blistering([RR] = 2.91). The trial sequential analysis did not support the 20% relative decrease in surgical site infection in the NPWT group. (type II error of 20%).

Incisional negative pressure wound therapy for the prevention of surgical site infection: an up-to-date meta-analysis and trial sequential analysis

Background

The evidence on prophylactic use of negative pressure wound therapy on primary closed incisional wounds (iNPWT) for the prevention of surgical site infections (SSI) is confusing and ambiguous. Implementation in daily practice is impaired by inconsistent recommendations in current international guidelines and published meta-analyses. More recently, multiple new randomised controlled trials (RCTs) have been published. We aimed to provide an overview of all meta-analyses and their characteristics; to conduct a new and up-to-date systematic review and meta-analysis and Grading of Recommendations Assessment, Development and Evaluation (GRADE) assessment; and to explore the additive value of new RCTs with a trial sequential analysis (TSA).

Methods

PubMed, Embase and Cochrane CENTRAL databases were searched from database inception to October 24, 2022. We identified existing meta-analyses covering all surgical specialties and RCTs studying the effect of iNPWT compared with standard dressings in all types of surgery on the incidence of SSI, wound dehiscence, reoperation, seroma, hematoma, mortality, readmission rate, skin blistering, skin necrosis, pain, and adverse effects of the intervention. We calculated relative risks (RR) with corresponding 95% confidence intervals (CI) using a Mantel-Haenszel random-effects model. We assessed publication bias with a comparison-adjusted funnel plot. TSA was used to assess the risk of random error. The certainty of evidence was evaluated using the Cochrane Risk of Bias-2 (RoB2) tool and GRADE approach. This study is registered with PROSPERO, CRD42022312995.

Findings

We identified eight previously published general meta-analyses investigating iNPWT and compared their results to present meta-analysis. For the updated systematic review, 57 RCTs with 13,744 patients were included in the quantitative analysis for SSI, yielding a RR of 0.67 (95% CI: 0.59-0.76, I2 = 21%) for iNPWT compared with standard dressing. Certainty of evidence was high. Compared with previous meta-analyses, the RR stabilised, and the confidence interval narrowed. In the TSA, the cumulative Z-curve crossed the trial sequential monitoring boundary for benefit, confirming the robustness of the summary effect estimate from the meta-analysis.

Interpretation

In this up-to-date meta-analysis, GRADE assessment shows high-certainty evidence that iNPWT is effective in reducing SSI, and uncertainty is less than in previous meta-analyses. TSA indicated that further trials are unlikely to change the effect estimate for the outcome SSI; therefore, if future research is to be conducted on iNPWT, it is crucial to consider what the findings will contribute to the existing robust evidence.

Funding

Dutch Association for Quality Funds Medical Specialists.

Topical negative pressure wound therapy to prevent wound complications following caesarean delivery in high-risk obstetric patients: A randomised controlled trial

BACKGROUND AND AIMS

We investigated whether the use of a prophylactic negative pressure wound therapy (NPWT) system in women undergoing caesarean would decrease wound complications in a high-risk population.

MATERIALS AND METHODS

A randomised controlled trial was performed. Women with risk factors for wound complications undergoing caesarean delivery were randomised to a standard dressing or NPWT placed over their caesarean wound. We standardised the closure of the subcutaneous fat and skin layers, both with Vicryl. Patients were followed for wound complications for up to 6 weeks after their caesareans. The incidence of wound complications was the primary outcome. The single-use NPWT system, PICO, was provided by Smith and Nephew for use in this trial. The trial was registered on clinicaltrials.gov, # NCT03082664.

RESULTS

We report here on 154 women randomised to either a standard dressing or to the NPWT. Wound complication rates were equivalent between groups, with 19.4 and 19.7% (P = 0.43) of women with follow-up information available experiencing wound complications.

CONCLUSION

We found no difference in wound complications in women with risk factors treated with a prophylactic NPWT system or standard wound dressing at the time of caesarean birth.

Meta-analysis of prophylactic negative pressure wound therapy for surgical site infections (SSI) in caesarean section surgery

Introduction

Negative pressure wound therapy (NPWT) has been used in reducing the incidence of surgical site infections (SSIs) and wound complications across various surgical categories. SSIs are a common post-surgical complication following caesarean section (CS) births, making it necessary to use prophylactic interventions to reduce SSI and wound complication incidences.

Aim

To conduct an updated meta-analysis on randomized controlled trials (RCTs) comparing SSI incidence and wound complications in women undergoing C-sections receiving NPWT or standard dressings after wound closure.

Material and methods

A systematic literature review was conducted using MEDLINE and CENTRAL databases, and clinical trial registries for RCTs that involved NPWT versus standard dressings in participants undergoing C-section procedures. The primary outcome was surgical site infection (SSI) and other wound complications (haematoma, dehiscence, seroma.

Results

A total of 11 RCTs were included in the meta-analysis with information from 5,693 patients. A reduction in overall SSI incidence (RR = 0.79, 95% CI: 0.66-0.95, p = 0.01, I2 = 0%) and wound complication rate (RR = 0.86, 0.75 to 0.98, p = 0.02, I2 = 5%) was found with all studies pooled together. Subgroup analyses showed that NPWT did not significantly reduce SSI incidence when stratified by the type of C-section (emergency/elective) whereas the type of NPWT device had a differential effect on SSI reduction, with PICO NPWT systems showing a beneficial effect (RR = 0.72, 0.58 to 0.91, p = 0.006, I2 = 0%) in comparison to the PREVENA closed-incision device (RR = 0.94, 0.68 to 1.29, p = 0.73, I2 = 0%).

Conclusions

Prophylactic NPWT is useful in reducing the incidence of SSIs in women undergoing C-sections based on synthesis of results from RCTs in obese women (BMI > 30 kg/m2).

Prevention of Postoperative Surgical Site Infection Following Cesarean Delivery

Cesarean delivery is the most common major surgical procedure performed among birthing persons in the United States, and surgical-site infection is a significant complication. Several significant advances in preventive measures have been shown to reduce infection risk, while others remain plausible but not yet proven in clinical trials.

Use of closed incision negative pressure wound therapy on C-section wounds in obese women

Rates of obesity in pregnant women are increasing. Obesity is linked to increased patient risk of developing postoperative wound complications such as surgical site infection, wound dehiscence and haematoma formation. Closed incision negative pressure wound therapy (ciNPWT) has been introduced as a prophylactic intervention to reduce caesarian section (C-section) wound complications. Evidence from randomised controlled trials and retrospective studies has shown variable rates of success in reducing risk of SSI. The studies reviewed in this article found that ciNPWT had no statistically significant impact in reducing rates of wound dehiscence and haematoma formation or increasing long-term satisfaction with the appearance of scar tissue following C-section. Further research into the use of cINPWT to prevent surgical site infection is needed to determine the effectiveness of this therapy in reducing this wound complication.

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

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

Implementation of an evidence-based bundle to reduce surgical site infection after caesarean section - Review of the interventions

BACKGROUND

Surgical site infection (SSI) is the most common complication post caesarean section (CS) with a significant impact on women and health services. A bundle approach incorporating previously studied individual interventions has shown increased reductions in SSI.

AIM

To assess compliance with a SSI intervention bundle and to examine readmission rates for SSI.

METHODS

A retrospective audit of women who underwent CS at a regional hospital in Queensland, Australia pre-intervention (February 2015-January 2017) and post-intervention (February 2018-December 2020).

RESULTS

There was good compliance with vaginal cleansing (27.7% vs 84.8%), chlorhexidine skin preparation (90.4% vs 98.4%), BMI-based antibiotic dose adjustment (48.8% vs 74.3%), and Alexis retractor use (9.9% vs 66%), pre and post-implementation periods respectively. There was a reduction in documented hair shaving (2.1% vs 0.5%). There was a trend towards less admission for SSI, a trend that could have been even better had there not been an increasing number of women with high BMI over the years. Fewer cases needed return to theatre post-implementation. Endometritis rates were unchanged.

CONCLUSIONS

Good compliance can be achieved with good collaboration. There was a reduction in admission rates for SSI. Larger prospective studies are needed to further examine these findings.

Incidence and risk factors for surgical wound complications in women with body mass index >30 kg/m2 following cesarean delivery: a secondary analysis

BACKGROUND

OBJECTIVE

STUDY DESIGN

RESULTS

CONCLUSION

Emerging Paradigms in the Prevention of Surgical Site Infection: The Patient Microbiome and Antimicrobial Resistance

This article summarizes new scientific evidence on the pathogenesis of surgical site infection, including the roles of the patient microbiome and antimicrobial resistance, and reviews changes in guidelines and clinical practices for prevention.

Prophylactic negative pressure wound therapy on wound complications after cesarean delivery in women with obesity: a meta-analysis of randomized controlled trials

OBJECTIVE

This systematic review and meta-analysis of randomized controlled trials aimed to assess whether negative pressure wound therapy affects the rate of wound complications when applied to women with obesity after cesarean delivery compared with standard postoperative dressings.

DATA SOURCES

This research used PubMed, Scopus, ClinicalTrials.gov, and the Cochrane Central Register of Controlled Trials as electronic databases, from the inception of each database to January 2021, with randomized controlled trial as the publication type. There was no restriction applied for language or geographic location.

STUDY ELIGIBILITY CRITERIA

The selection criteria included only randomized controlled trials comparing the effect of negative pressure wound therapy with that of standard dressings on wound complications in women with obesity undergoing cesarean delivery.

METHODS

The primary outcome was a wound complication composite outcome (wound infection, separation or dehiscence, hematoma, seroma, or readmission secondary to a wound concern). The wound complication composite was analyzed by counting events once per patient. The summary measures were reported as relative risk or as mean difference with 95% confidence intervals using the random-effects model of DerSimonian and Laird. An I-squared (Higgins I²) value of >0% was used to identify heterogeneity.

RESULTS

Overall, 11 randomized controlled trials, which included 5746 participants with obesity undergoing cesarean delivery, were included. Of those participants, 2869 (49.9%) were randomized to the intervention group (negative pressure wound therapy), and 2877 (50.1%) were randomized to the control group (standard dressing). Prophylactic negative pressure wound therapy was not associated with a significant change in the rate of wound complications (relative risk, 1.00; 95% confidence interval, 0.81-1.23) compared with standard postoperative dressings. However, the use of negative pressure wound therapy decreased the rate of wound infections (relative risk, 0.79; 95% confidence interval, 0.66- 0.96) and increased the frequency of skin reactions (relative risk, 4.59; 95% confidence interval, 1.29-16.38). Negative pressure wound therapy did not result in a significant difference in the rate of dehiscence, hematoma, seroma, readmission, reoperation, and antibiotic use for wound infection.

CONCLUSION

Compared with standard postoperative incision dressings, negative pressure wound therapy did not affect the rate of wound complications but decreased the frequency of wound infections when applied to women with obesity after cesarean delivery. However, results should be interpreted with caution, as wound infection outcome includes different definitions per the individual trials.

CONDENSATION

Prophylactic negative pressure wound therapy has no effect on overall wound complications in women with obesity after cesarean delivery compared with standard dressings.

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.

Overweight, obesity and excessive weight gain in pregnancy as risk factors for adverse pregnancy outcomes: a narrative review

The global prevalence of overweight and obesity in pregnancy is rising and this represents a significant challenge for the management of pregnancy and delivery. Women who have a pre‐pregnancy body mass index greater than 25 kg m^–2 are more likely than those with a body mass index in the ideal range (20–24.99 kg m^–2) to have problems conceiving a child and are at greater risk of miscarriage and stillbirth. All pregnancy complications are more likely with overweight, obesity and excessive gestational weight gain, including those that pose a significant threat to the lives of mothers and babies. Labour complications arise more often when pregnancies are complicated by overweight and obesity. Pregnancy is a stage of life when women have greater openness to messages about their lifestyle and health. It is also a time when they come into greater contact with health professionals. Currently management of pregnancy weight gain and the impact of overweight tends to be poor, although a number of research studies have demonstrated that appropriate interventions based around dietary change can be effective in controlling weight gain and reducing the risk of pregnancy complications. The development of individualised and flexible plans for avoiding adverse outcomes of obesity in pregnancy will require investment in training of health professionals and better integration into normal antenatal care.

Overweight and obesity before pregnancy and excessive gestational weight gain are major determinants of risk for pregnancy loss, gestational diabetes, hypertensive conditions, labour complications and maternal death.

Pregnancy is regarded as a teachable moment when women are at their most receptive to messages about their health. However, unclear guidance on diet and physical activity, weight stigma from health professionals, inexperience and reluctance among professionals about raising issues about weight, and stretched resources put the health of women and babies at risk.

Excessive weight gain in pregnancy and post‐partum weight retention compromise future fertility and increase risk for future pregnancies.

Large randomised controlled trials have had little success in addressing excessive gestational weight gain or antenatal complications. Individualised, culturally sensitive and responsive interventions appear to have greater success.

Prophylactic negative pressure wound therapy on surgical site infection in obese women after cesarean section: A systematic review and meta-analysis

Prevention of surgical site infection (SSI) is a public health challenge. The objective of the study was to evaluate the efficacy of negative pressure wound therapy (NPWT) for preventing SSI and other wound complications in obese women undergoing cesarean section. The search terms included "negative pressure wound therapy", "obesity" and "cesarean section/delivery". Randomized controlled trials were used to compare the use of NPWT to standard dressings in preventing SSI in obese women after cesarean section. A comprehensive literature search of four databases was performed up to June 2021. The primary outcome was SSI. Secondary outcomes were seroma, hematoma, overall wound complications, and adverse skin reactions. Ten RCTs involving 5586 patients met the inclusion criteria. The use of NPWT reduced SSI (RR = 0.76, 95%CI: 0.63-0.92, P = 0.004). No statistically significant difference was detected in the incidence of overall wound complications (RR = 0.93, P = 0.48), seroma (RR = 1.10, P = 0.79), hematoma (RR = 0.63, P = 0.36) and hospital readmission (RR = 1.41, P = 0.15). NPWT significantly increased the occurrence of skin blistering with a RR of 4.60 (P = 0.04). Use of prophylactic NPWT after cesarean delivery among obese women is associated with a significant reduction of surgical site infection.

Effect of negative-pressure wound therapy on wound complications in obese women after caesarean birth: a systematic review and meta-analysis

BACKGROUND

Obesity is associated with increased surgical-site infection (SSI) following caesarean section (CS).

OBJECTIVE

To summarise the evidence on the effectiveness of negative-pressure wound therapy (NPWT) for preventing SSI and other wound complications in obese women after CS.

SEARCH STRATEGY

MEDLINE, Embase, CINAHL, Cochrane CENTRAL databases and ClinicalTrials.gov were systematically searched in March 2021.

SELECTION CRITERIA

Randomised controlled trials (RCTs) of NPWT compared with standard dressings after CS birth.

DATA COLLECTION AND ANALYSIS

Pooled effect sizes were calculated using either fixed or random effects models based on heterogeneity. The Cochrane risk of bias and Grading of Recommendations Assessment, Development and Evaluation tools were used to assess the quality of studies and overall quality of evidence.

MAIN RESULTS

Ten RCTs with 5583 patients were included; studies were published between 2012 and 2021. Nine RCTs with 5529 patients were pooled for the outcome SSI. Meta-analysis results suggest a significant difference favouring the NPWT group (relative risk [RR] 0.79, 95% CI 0.65-0.95, P < 0.01), indicating an absolute risk reduction of 1.8% among those receiving NPWT compared with usual care. The risk of blistering in the NPWT group was significantly higher (RR 4.13, 95% CI 1.53-11.18, P = 0.005). All studies had high risk of bias relative to blinding of personnel/participants. Only 40% of studies reported blinding of outcome assessments and 50% had incomplete outcome data.

CONCLUSIONS

The decision to use NPWT should be considered both in terms of its potential benefits and its limitations.

TWEETABLE ABSTRACT

NPWT was associated with fewer SSI in women following CS birth but was not effective in reducing other wound complications.

Incidence and predictors of surgical site infection in women who are obese and give birth by elective caesarean section: A secondary analysis

BACKGROUND

Surgical site infection (SSI) after a caesarean section is of concern (CS) is of concern to both clinicians and women themselves.

AIMS

The aim of this study is to identify the cumulative incidence and predictors of SSI in women who are obese and give birth by elective CS.

MATERIALS AND METHODS

The method used was planned secondary analysis of data from women with a pre-pregnancy body mass index (BMI) ≥30 kg/m² giving birth by elective CS in a multicentre randomised controlled trial of a prophylactic closed-incision negative pressure wound therapy dressing. Data were collected from medical records, direct observations of the surgical site and self-reported signs and symptoms from October 2015 to December 2019. The Centers for Disease Control and Prevention definition was used to identify SSI. Women were followed up once in hospital just before discharge and then weekly for four weeks after discharge. Blinded outcome assessors determined SSI. After the cumulative incidence of SSI was calculated, multiple variable logistic regression models were used to identify independent risk factors for SSI.

RESULTS

SSI incidence in 1459 women was 8.4% (122/1459). Multiple variable-adjusted odds ratios (OR) for SSI were BMI ≥40 kg/m² (OR 1.55, 95% confidence interval (CI) 1.30-1.86) as compared to BMI 30-34.9 0 kg/m² , ≥2 previous pregnancies (OR 1.38, 95% CI 1.00-1.80) as compared to no previous pregnancies and pre-CS vaginal cleansing (OR 0.55, 95% CI 0.33-0.99).

CONCLUSIONS

Our findings may inform preoperative counselling and shared decision-making regarding planned elective CS for women with pre-pregnancy BMI ≥30 kg/m² .