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

Prevention of infection in aortic or aortoiliac peripheral arterial reconstruction

BACKGROUND

Peripheral arterial disease (PAD) results from the narrowing of arteries. Aortic aneurysms - abnormal dilatations in artery walls - are a related concern. For severe cases, arterial reconstruction surgery is the treatment option. Surgical site infections (SSIs) are a feared and common complication of vascular surgery. These infections have a significant global healthcare impact. Evaluating the effectiveness of preventive measures is essential.

OBJECTIVES

To assess the effects of pharmacological and non-pharmacological interventions, including antimicrobial therapy, antisepsis, and wound management, for the prevention of infection in people undergoing any open or hybrid aortic or aortoiliac peripheral arterial reconstruction.

SEARCH METHODS

The Cochrane Vascular Information Specialist searched the Cochrane Vascular Specialised Register, CENTRAL, MEDLINE, Embase, and CINAHL databases, and the World Health Organization International Clinical Trials Registry Platform, LILACS, and ClinicalTrials.gov up to 11 November 2024.

SELECTION CRITERIA

We included all randomised controlled trials (RCTs) with a parallel (e.g. cluster or individual) or split-body design, and quasi-RCTs, which assessed any intervention to reduce or prevent infection following aortic or aortoiliac procedures for the treatment of aneurysm or PAD. There were no limitations regarding age and sex.

DATA COLLECTION AND ANALYSIS

We used standard Cochrane methodological procedures. Two review authors independently extracted the data and assessed the risk of bias of the trials. A third review author resolved disagreements when necessary. We assessed the evidence certainty for key outcomes using GRADE.

MAIN RESULTS

We included 21 RCTs with 4952 participants. Fifteen studies were assessed as having a high risk of bias in at least one domain, and 19 studies had an unclear risk of bias in at least one domain. We analysed 10 different comparisons for eight different outcomes. The comparisons were antibiotic versus placebo or no treatment; short-duration antibiotics (≤ 24 hours) versus long-duration antibiotics (> 24 hours); different types of systemic antibiotics (one versus another); antibiotic-bonded implant versus standard implant; Dacron graft versus stretch polytetrafluoroethylene graft; prophylactic closed suction drainage versus undrained wound; individualised goal-directed therapy (IGDT) versus fluid therapy based on losses, standard haemodynamic parameters and arterial blood gas values (standard care); comprehensive geriatric assessment versus standard preoperative care; percutaneous versus open-access technique; and negative pressure wound therapy (NPWT) versus standard dressing. The primary outcomes were graft infection rate and SSI rate. The secondary outcomes included all-cause mortality, arterial reconstruction failure rate, re-intervention rate, amputation rate, pain resulting from the intervention, and adverse events resulting from the interventions to prevent infection. We did not assess all the outcomes across the different comparisons. The main findings are presented below. Antibiotic versus placebo or no treatment (five studies) Very low-certainty evidence from five included studies suggests that antibiotic prophylaxis reduces SSI (risk ratio (RR) 0.33, 95% confidence interval (CI) 0.15 to 0.71; 5 studies, 583 participants; number needed to treat for an additional beneficial outcome (NNT) 9). With very low- to low-certainty evidence, there was little or no difference between the groups in the other assessed outcomes (graft infection rate, all-cause mortality, re-intervention rate, and amputation rate). We did not quantitatively assess other outcomes in this comparison. Short duration antibiotics (≤ 24 hours) versus long duration antibiotics (> 24 hours) (three studies) Very low-certainty evidence from three included studies suggests that there is little or no difference in graft infection rate (RR 2.74, 95% CI 0.11 to 65.59; 1 study, 88 participants) or SSI rate (RR 3.65, 95% CI 0.59 to 7.71; 1 study, 88 participants) between short- and long-duration antibiotic prophylaxis. We did not quantitatively assess other outcomes in this comparison. Different types of systemic antibiotics (one versus another) (seven studies) We grouped seven studies comparing one antibiotic to another into three subgroups that compared different classes of antibiotics amongst themselves. We found little or no difference between the groups analysed. Graft infection rate: beta-lactams versus cephalosporins (RR 0.36, 95% CI 0.02 to 8.71; 1 study, 88 participants; very low-certainty evidence); glycopeptides versus cephalosporins (RR 5.00, 95% CI 0.24 to 103.05; 1 study, 238 participants; low-certainty evidence); one cephalosporin versus another (RR not estimable, CI not estimable; 1 study; 69 participants; very low-certainty evidence); SSI rate: beta-lactams and cephalosporins (RR 0.27, 95% CI 0.03 to 2.53; 2 studies, 229 participants; very low-certainty evidence); glycopeptides versus cephalosporins (RR 2.17, 95% CI 0.65 to 7.23; 2 studies, 312 participants; very low-certainty evidence); and one cephalosporin versus another (RR 1.26, 95% CI 0.21 to 7.45; 3 studies, 625 participants; very low-certainty evidence). We could extract all-cause mortality data for the glycopeptide versus cephalosporin comparison; there was little or no difference between groups (RR 1.33, 95% CI 0.30 to 5.83; 1 study, 238 participants; low-certainty evidence). We did not quantitatively assess other outcomes in this comparison.

AUTHORS' CONCLUSIONS

Very low-certainty evidence suggests that the use of prophylactic antibiotics may prevent SSIs in aortic or aortoiliac peripheral arterial reconstruction. We found no superiority amongst specific antibiotics or differences in extended antibiotic use (over 24 hours) compared with shorter use (up to 24 hours), with low-certainty evidence. For other interventions, very low- to moderate-certainty evidence showed little or no difference across various outcomes. We advise interpreting these conclusions with caution due to the limited number of events in all groups and comparisons.

Artificial Intelligence Versus Human Systematic Literature Review Into Negative-pressure Wound Therapy in Plastic Surgery

Background

The potential of artificial intelligence (AI) to support physician evidence-based medicine is vast. We compared AI's ability to perform a systematic review of the literature to that of human investigators. Negative-pressure wound therapy (NPWT), a mainstay of wound management with a large but varied body of evidence, was therefore chosen as the subject of this investigation. Producing high-level evidence of NPWT's impact on wound healing has been challenging due to trial design issues, making a systematic review important and challenging. In this article, NPWT efficacy and the ability of AI to assess levels of evidence were evaluated.

Methods

A literature search was conducted using PubMed, SCOPUS, and CINAHL. The resulting articles were screened using Preferred Reporting Items for Systematic Reviews and Meta-Analysis guidelines. The Grading of Recommendations, Assessment, Development, and Evaluations criteria were applied by both humans and AI to analyze the quality and evidence of each article.

Results

Eighteen studies on 3131 patients were reviewed. Seven studies addressed length of stay; five showed shorter stays with NPWT. Fourteen studies examined infection rates. Eight found significant improvement with the use of NPWT. Twelve articles analyzed time to wound closure, and nine of those articles found reduced time when NPWT was utilized. AI generally assigned lower quality of evidence scores compared with humans.

Conclusions

AI is a promising tool but remains limited in accurately determining evidence quality. AI's lower scores may reflect reduced bias. Multiple confounders and the diversity of its application lead to a lack of high-level evidence of NPWT's efficacy.

Effectiveness of Negative Pressure Wound Therapy on Groin Surgical Site Infection After Lower Extremity Bypass for Chronic Limb-Threatening Ischemia

BACKGROUND

Surgical site infections (SSIs) are a common cause of patient morbidity, hospital readmission, and reoperation after lower extremity bypass (LEBs) surgery for chronic limb-threatening ischemia (CLTI). Recent studies on the use of incisional negative pressure wound therapy (NPWT) in LEB surgery have reported conflicting results. In this single-center study, we examined our experience on the impact of NPWT on groin SSI rates after LEB surgery.

METHODS

We retrospectively queried electronic medical records for all LEB operations performed for CLTI. Multivariate logistic regression analysis was used to identify risk factors associated with postoperative SSI. Using these risk factors, subset analysis was performed to determine whether NPWT was associated with reduced SSI in high-risk patients.

RESULTS

From 2018 to 2022, a total of 367 patients underwent LEB surgery for CLTI. Mean patient age was 66 years. Postoperative groin SSI was diagnosed in 22.9% (n = 84) of patients. Patients suffering SSI were more frequently morbidly obese (6.0% vs 1.8%, P = 0.03) and had higher rates of chronic obstructive pulmonary disease (35.7% vs 23.3%, P = 0.02). Other comorbidities and demographic data were similar between groups. NPWT was utilized in 19.6% (n = 72) of patients, with no baseline differences between SSI and no SSI cohorts (15.5% vs 20.9%, P = 0.28). On multivariate analysis, female sex (odds ratio [OR] 1.88, 95% confidence interval [CI] 1.06-3.35, P = 0.03), white race (OR 2.17, 95% CI 1.23-3.82, P = 0.007), morbid obesity (OR 3.67, 95% CI 0.93-14.4, P = 0.05), and active smoking (OR 4.07, 95% CI 1.20-13.8, P = 0.02) were independently associated with postoperative SSI. Subset analysis among patients at increased risk of SSI did not reveal any differences in wound infection with NPWT usage.

CONCLUSIONS

In our experience, NPWT does not appear to be more effective than standard dressings in preventing groin SSI after LEB surgery for CLTI, even among populations at heightened risk for wound infection.

Outcomes of Reconstructive Surgery Using Vacuum-Assisted Closure in Patients With Complex Wounds

This study aimed to assess the results of reconstructive surgery with vacuum-assisted closure (VAC) therapy in patients with complex wounds. The sample included 60 patients with a mean age of 53.03 years. The sample was ethnically diverse, with significant representation from various regions, including Khyber Pakhtunkhwa (KPK), Punjab, Sindh, Balochistan, Gilgit-Baltistan, and Kohistan. The most common comorbidities were obesity (26.7%), diabetes (25.0%), and cardiovascular disease (13.3%). Patients had varied wound types, including diabetic ulcers (26.7%) and pressure ulcers (23.3%) in the lower extremities, constituting 25.0%. VAC therapy was given to 53.3% of the patients with different parameters varying from continuous to intermittent mode with pressure between 50-149 mmHg. Pre- and post-operative laboratory results showed raised inflammatory markers and poor nutritional status, which are strongly related to delayed wound healing. The most common complications were infection (21.7%) and hemorrhage (15.0%). The type of surgical site was significantly associated with the complications. Surgical outcomes ranged from fully healed wounds to 23.3% to partially healed wounds and 28.3% of reopened wounds. While VAC therapy proves beneficial, comorbidities, as well as wound characteristics, play important roles in determining a greater degree of success. More research must be conducted to optimize VAC therapy protocols for more complex wounds.

The Role of the Omniflow II Biosynthetic Graft in Postoperative Wound Problems After Lower Limb Revascularization: A Single Center Prospective Registry

OBJECTIVE

To investigate the role of the Omniflow II prosthesis in the prevention of vascular graft infection (VGI) in patients with peripheral arterial disease and to report on short-and mid-term graft-related morbidity.

MATERIAL AND METHODS

Patients were included in prospective registry between October 2019 and March 2023. The primary endpoint was to report infection-related problems, operation-related wound problems, and short- and mid-term graft-related morbidity. Secondary endpoint was to report the bypass patency rates and limb salvage rates.

RESULTS

A total of 146 Omniflow II grafts were implanted in 125 patients. Sixty-seven patients (45.9%) received a femoral interposition graft, and 77 patients (52.7%) underwent ipsilateral bypass surgery (femoropopliteal or femorocrural). Forty-one patients (28.1%) underwent crural bypass surgery. Seventy-six patients (52.1%) had previous vascular operation in the groin. The mean follow-up time was 352 days (range 0-1108 days). 3.4% of the patients suffered a wound infection limited to the dermis, and in 8.2%, the subcutaneous tissue was involved. Five early VGI (3.4%) and one late VGI (0.7%) occurred. One year primary patency rate of above-the-knee bypass was significantly better compared to the bypass below the knee (74.5% ± 0.131 versus 54% ± 0.126 (P = 0.049)). This difference was not significantly different when below-the-knee bypass surgery was compared with crural bypass surgery (54% ± 0.126 versus 23.8% ± 0.080 (P = 0.098)).

CONCLUSIONS

The performance of the Omniflow II prosthesis in the preventive setting is highly influenced by the anatomic location of the distal anastomosis. No influence on the incidence of postoperative wound problems could be observed. The rate of Omniflow II VGI in a high-risk population is similar to reported outcomes in other prosthetic grafts.

Comparative analysis of negative pressure wound therapy (PICO) and standard dressing application after arterial vascular reconstructions

INTRODUCTION

Surgical site infections following arterial reconstructions with femoral exposures are common and potentially preventable. Negative pressure wound therapy has emerged as a potential solution to minimize groin wound complications. Our study evaluates efficacy of a negative pressure therapy (PICO dressing) in reducing groin wound complications after vascular reconstructions.

METHODS

A retrospective single center comparative analysis of vascular reconstructions involving common femoral artery dissection was performed between July 2021 and June 2023. Patients were divided into two groups: patients treated with PICO device and patients who received standard dressing (non-PICO). Patient demographics, comorbidities, vascular evaluation, and procedure indications were compared. Previous interventions, incision orientation and procedure types were noted. The wound complication categories were graded according to the Szilagyi classification: grade 1 (superficial infection/minor dehiscence), grade 2 (deep infection/major dehiscence), and grade 3 (artery or prosthetic involvement). Statistical significance level was determined at p < .05 for all analyses.

RESULTS

A total of 217 groin dissections in 184 patients were analyzed with 132 and 85 groin dissections in the PICO and non-PICO groups, respectively. The baseline characteristics were similar between the groups in terms of age, sex, BMI, and procedure indications. Prior endovascular procedures and re-operative groin surgeries were more prevalent in the PICO group. The use of antibiotics post-operatively for groin wound complication was greater in the non-PICO group. The incidence of wound complications was higher in the non-PICO group (29.4% vs 10.6%, p < .001). Multivariate logistic regression analysis determined that PICO dressing as well as hybrid and endovascular index procedures were associated with lower risks of groin complications.

CONCLUSION

PICO dressing decreased the incidence of groin wound complications in patients undergoing open vascular reconstructions. This study highlights the value of adjunctive negative pressure therapy in reduction of wound complications after arterial reconstructions in the inguinal region.

Comparison of negative pressure wound therapy against normal dressing after vascular surgeries for inguinal wounds: A systematic review and meta-analysis

Background

Negative Pressure Wound Therapy (NPWT) is a therapeutic technique of applying sub-atmospheric pressure to a wound to reduce inflammation, manage exudate, and promote the formation of granulation tissue. It aims to optimise the natural physiological processes of wound healing for more effective recovery, and NPWT has emerged as a promising alternative to traditional dressings.

Methods

The protocol followed in the study was prospectively registered. Appropriate search terms and Boolean operators were used to search electronic databases for relevant articles. Screening of articles was performed, and data extraction was done. The effect measure was chosen according to the nature of the variable, and the effect model was chosen as per heterogeneity. Forest plot was used to give visual feedback.

Results

This study included 11 randomized controlled trials (13 publications) with a total of 1310 patients (1497 inguinal wounds). The NPWT group had lesser odds of developing surgical site infection (OR: 0.40; 95 % CI: 0.29-0.54; n = 1491; I2 = 20 %; p-value ≤0.00001) and lesser odds of needing surgical wound revision (OR: 0.48; 95 % CI: 0.26-0.91; n = 856; I2 = 0 %; p-value = 0.02) as compared to the normal dressing group. No significant difference was observed in duration of hospital stay, cost of care, wound healing time, or other complications.

Conclusion

NPWT application in inguinal wounds significantly reduces the surgical site infection and the need for wound revision in patients who have undergone vascular surgery.

Closed Incision Negative Pressure Therapy Versus Standard of Care Over Closed Abdominal Incisions in the Reduction of Surgical Site Complications: A Systematic Review and Meta-Analysis of Comparative Studies

Background

Surgical site complications (SSCs) pose a significant risk to patients, potentially leading to severe consequences or even loss of life. While previous research has shown that closed incision negative pressure therapy (ciNPT) can reduce wound complications in various surgical fields, its effectiveness in abdominal incisions remains uncertain. To address this gap, a systematic review and meta-analysis were conducted to assess the impact of ciNPT on postsurgical outcomes and health care utilization in patients undergoing open abdominal surgeries.

Methods

A systematic literature search using PubMed, EMBASE, and QUOSA was performed for publications written in English, comparing ciNPT with standard of care dressings for patients undergoing abdominal surgical procedures between January 2005 and August 2021. Characteristics of study participants, surgical procedures, dressings used, duration of treatment, postsurgical outcomes, and follow-up data were extracted. Meta-analyses were performed using random-effects models. Dichotomous outcomes were summarized using risk ratios and continuous outcomes were assessed using mean differences.

Results

The literature search identified 22 studies for inclusion in the analysis. Significant reductions in relative risk (RR) of SSC (RR: 0.568, P = .003), surgical site infection (SSI) (RR: 0.512, P < .001), superficial SSI (RR: 0.373, P < .001), deep SSI (RR: 0.368, P =.033), and dehiscence (RR: 0.581, P = .042) were associated with ciNPT use. ciNPT use was also associated with a reduced risk of readmission and a 2.6-day reduction in hospital length of stay (P < .001).

Conclusions

These findings indicate that use of ciNPT in patients undergoing open abdominal procedures can help reduce SSCs and associated hospital length of stay as well as readmissions.A previous version of this abstract was presented at the 2023 Conference of the European Wound Management Association (EWMA) in Milan, Italy and posted online at the site listed below. EWMA permits abstracts to be republished with the complete manuscript. https://journals.cambridgemedia.com.au/application/files/9116/8920/7316/JWM_Abstracts_LR.pdf.

The Utility of Prevena Negative Pressure Wound Therapy on Groin Incisions for Critical Limb-Threatening Ischemia: A Single Institution Experience

BACKGROUND

Incisional negative pressure wound therapy (iNPWT) is an adjunctive treatment that uses constant negative pressure suction to facilitate healing. The utility of this treatment modality on vascular operations for critical limb-threatening ischemia (CLTI) has yet to be elucidated. This study compares the incidence of postoperative wound complications between the Prevena Incision Management System, a type of iNPWT, and standard wound dressings for vascular patients who also underwent plastic surgery closure of groin incisions for CLTI.

METHOD

We performed a retrospective cohort study of 40 patients with CLTI who underwent 53 open vascular surgeries with subsequent sartorius muscle flap closure. Patient demographics, intraoperative details, and wound complications were measured from 2015 to 2018 at the University of California San Francisco. Two cohorts were generated based on the modality of postoperative wound management and compared on wound healing outcomes.

RESULTS

Of the 53 groin incisions, 29 were managed with standard dressings, and 24 received iNPWT. Patient demographics, comorbidities, and operative characteristics were similar between the 2 groups. Patients who received iNPWT had a significantly lower rate of infection (8.33% vs 31.0%, P = 0.04) and dehiscence (0% vs 41.3%, P < 0.01). Furthermore, the iNPWT group had a significantly lower rate of reoperation (0% vs 17.2%, P = 0.03) for wound complications within 30 days compared with the control group and a moderately reduced rate of readmission (4.17% vs 20.7%, P = 0.08).

CONCLUSIONS

Rates of infection, reoperation, and dehiscence were significantly reduced in patients whose groin incisions were managed with iNPWT compared with standard wound care. Readmission rates were also decreased, but this difference was not statistically significant. Our results suggest that implementing iNPWT for the management of groin incisions, particularly in patients undergoing vascular operations for CLTI, may significantly improve clinical outcomes.

Effectiveness of Closed Incision Negative Pressure Wound Therapy for Infrainguinal Bypass in the Vascular Quality Initiative

BACKGROUND

To analyze surgical site infections (SSIs) after infrainguinal bypass for standard dressings versus closed incision negative pressure wound therapy (ciNPWT) in the Society for Vascular Surgery's Vascular Quality Initiative (VQI).

METHODS

We retrospectively analyzed SSI after infrainguinal bypass procedures in the VQI from December 2019 to December 2021 comparing ciNPWT and standard dressings. The primary outcome of any superficial or deep wound infection at 30 days was analyzed in a subset of procedures with 30-day follow-up data (cohort A, n = 1,575). Secondary outcomes including in-hospital SSI, return to the operating room (OR) for infection, and length of stay (LOS) were analyzed for all procedures (cohort B, n = 9,288). Outcomes were analyzed in propensity-matched cohorts.

RESULTS

Patients who received ciNPWT (n = 1,389) were more likely to be female (34% vs. 32%, P = 0.04) with a higher rate of smoking history (90% vs. 86%, P = 0.003), diabetes (54% vs. 50%, P = 0.007), obesity (34% vs. 26%, P < 0.001), prior peripheral vascular intervention (57% vs. 51%, P < 0.001), and to prosthetic conduit (55% vs. 48%, P < 0.001) compared to patients with standard dressings (n = 7,899). After propensity matching of cohort A (n = 1,256), the 30-day SSI rate was 4% (12/341) in the ciNPWT and 6% (54/896) in the standard dressing group (P = 0.07, 95% CI 0.03-1.06). In the propensity-matched in-hospital cohort B (n = 5,435), SSI was 3% (35/1,371) in the ciNPWT group and 2% (95/4,064) in the standard dressing group (P = 0.66). There was no difference in the rate of return to the OR for infection, 1% (36/4,064) vs. 1% (19/1,371) (P = 0.13) or LOS, 9.0 vs. 9.0 days (P = 0.86) for the standard versus ciNPWT groups.

CONCLUSIONS

In this analysis of the VQI registry, the use of ciNPWT after infrainguinal bypass did not result in a statistically significant decrease in 30-day SSI. We recommend that surgeons consider the use of ciNPWT as part of a bundled process of care for high risk rather than all patients, as it may reduce SSI after infrainguinal bypass.

Multicenter parallel randomized trial evaluating incisional negative pressure wound therapy for the prevention of surgical site infection after lower extremity bypass

OBJECTIVE

Incisional negative pressure wound therapy (iNPWT) applied over all incisions after lower extremity bypass in the prevention of surgical site infections (SSIs) is unclear. The primary and secondary aims of this study were to investigate if prophylactic iNPWT after the elective lower extremity bypass prevents SSI and other surgical wound complications.

METHODS

This was a multicenter, parallel, randomized controlled trial. Patients undergoing elective lower extremity bypass in 3 hospitals were randomized to either iNPWT or standard dressings. SSIs or other wound complications were assessed within the first 90 days by wound care professionals blinded to the randomized result. The validated Additional treatment, Serous discharge, Erythema, Purulent exudate, Separation of deep tissues, Isolation of bacteria, and Stay (ASEPSIS) score was used to objectively assess the wounds. ASEPSIS score ≥21 is defined as an SSI. Unilateral and bilateral groups were analyzed with the Fisher exact test and the McNemar test, respectively.

RESULTS

In the unilateral group (n = 100), the incidence of SSI in the iNPWT group was 34.9% (15/43), compared with 40.3% (23/57) in the control group, according to the ASEPSIS score (P = .678). In the bilateral group (n = 7), the SSI rate was 14.3% (1/7) in the iNPWT group compared with 14.3% (1/7) in the control group (P = 1.00). In the unilateral group, there was a higher wound dehiscence rate in the control group (43.9%) compared with the iNPWT group (23.3%) (P = .0366). No serious iNPWT-related adverse events were recorded.

CONCLUSIONS

There was no reduction of SSI rates in leg incisions with iNPWT compared with standard dressings in patients undergoing elective lower extremity bypass, whereas iNPWT reduced the incidence of wound dehiscence.

Effectiveness of negative-pressure wound therapy to standard therapy in the prevention of complications after vascular surgery

Wound complications are common after vascular surgery and many may be preventable. Negative pressure wound therapy (NPWT) dressings may be able to reduce wound complications relating to closed incisions following vascular surgery and several devices are currently available along with a large body of literature. This review article will describe the use of NPWT dressings in vascular surgery. We will summarize the currently available systems, the likely mechanism of action of NWPT, the published studies to date and we will give our recommendations regarding the priorities for future research on this topic.

Effect of closed incision negative pressure wound treatment in vascular surgery: A meta-analysis

The meta-analysis aimed to assess and compare the effect of closed-incision negative pressure wound (NPW) treatment in vascular surgery. Using dichotomous or contentious random or fixed effect models, the outcomes of this meta-analysis were examined, and the odds Ratio (OR) and the mean difference (MD) with 95% confidence intervals (CIs) were computed. Ten examinations from 2017 to 2022 were enrolled for the present meta-analysis, including 2082 personals with vascular surgery. Closed-incision NPW treatment had significantly lower infection rates (OR, 0.39; 95% CI, 0.30-0.51, p < 0.001), grade I infection rates (OR, 0.33; 95% CI, 0.20-0.52, p < 0.001), grade II infection rates (OR, 0.39; 95% CI, 0.21-0.71, p = 0.002), and grade III infection rates (OR, 0.31; 95% CI, 0.13-0.73, p = 0.007), and surgical re-intervention (OR, 0.49; 95% CI, 0.25-0.97, p = 0.04) compared to control in personal with vascular surgery. However, no significant differences were found between closed-incision NPW treatment and control in the 30-day mortality (OR, 0.54; 95% CI, 0.29-1.00, p = 0.05), antibiotic treatment (OR, 0.53; 95% CI, 0.24-1.19, p = 0.12), and length of hospital stay (MD, -0.02; 95% CI, -0.24-0.19, p = 0.83) in personnel with vascular surgery. The examined data revealed that closed-incision NPW treatment had significantly lower infection rates, grade I infection rates, grade II infection rates, and grade III infection rates, surgical re-intervention, however, there were no significant differences in 30-day mortality, antibiotic treatment, or length of hospital stay compared to control group with vascular surgery. Yet, attention should be paid to its values since some comparisons had a low number of selected studies.

Impact of closed-incision negative pressure wound dressings on surgical site infection following groin incisions in vascular surgery; a single-centre experience

OBJECTIVES

Surgical site infection (SSI) is a common complication in vascular surgery, and is associated with increased patient morbidity, readmission and reintervention. The aim of this study was to assess the impact of closed-incision negative pressure wound therapy (CiNPWT) upon rate of SSI and length of hospital stay.

METHODS

This study was reported in line with the STROBE guidelines. We assessed the baseline incidence of SSI from a 12-month retrospective cohort and, following a change in practice intervention with CiNPWT, compared to a 6-month prospective cohort. The primary endpoint was incidence of SSI (according to CDC-NHSN guidelines) while secondary endpoints included length of hospital stay, readmission, reintervention and Days Alive and Out of Hospital (DAOH) to 90-days.

RESULTS

A total of 127 groin incisions were performed: 76 (65 patients) within the retrospective analysis and 51 (42 patients) within the prospective analysis (of whom 69% received CiNPWT). The primary endpoint of SSI was seen in 21.1% of the retrospective cohort and 9.8% of the prospective cohort (p = .099). Readmission was found to be significantly associated with the retrospective cohort (p = .016) while total admission (inclusive of re-admission) was significantly longer in those in the retrospective cohort (p = .013). DAOH-90 was 83 days (77-85) following introduction of the CiNPWT protocol as compared to the retrospective cohort (77 days (64-83), p = .04).

CONCLUSION

Introduction of CiNPWT was associated with a reduced length of hospital stay and improved DAOH-90. Further trials on CINPWT should include patient-centred outcomes and healthcare cost analysis.

Efficacy of Strategies Intended to Prevent Surgical Site Infection After Lower Limb Revascularization Surgery: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

OBJECTIVE

The objective of this study is to evaluate the efficacy of strategies intended to prevent surgical site infection (SSI) after lower limb revascularization surgery.

BACKGROUND

SSIs are common, costly complications of lower limb revascularization surgery associated with significant morbidity and mortality.

METHODS

We searched MEDLINE, EMBASE, CENTRAL, and Evidence-Based Medicine Reviews (inception to April 28, 2022). Two investigators independently screened abstracts and full-text articles, extracted data, and assessed the risk of bias. We included randomized controlled trials (RCTs) that evaluated strategies intended to prevent SSI after lower limb revascularization surgery for peripheral artery disease. We used random-effects models to pool data and GRADE to assess certainty.

RESULTS

Among 6258 identified citations, we included 26 RCTs (n=4752 patients) that evaluated 12 strategies to prevent SSI. Preincision antibiotics [risk ratio (RR)=0.25; 95% CI, 0.11-0.57; n=4 studies; I2 statistic=7.1%; high certainty] and incisional negative-pressure wound therapy (iNPWT) (RR=0.54; 95% CI, 0.38-0.78; n=5 studies; I2 statistic=7.2%; high certainty) reduced pooled risk of early (≤30 days) SSI. iNPWT also reduced the risk of longer-term (>30 days) SSI (pooled-RR=0.44; 95% CI, 0.26-0.73; n=2 studies; I2 =0%; low certainty). Strategies with uncertain effects on risk of SSI included preincision ultrasound vein mapping (RR=0.58; 95% CI, 0.33-1.01; n=1 study); transverse groin incisions (RR=0.33; 95% CI, 0.097-1.15; n=1 study), antibiotic-bonded prosthetic bypass grafts (RR=0.74; 95% CI, 0.44-1.25; n=1 study; n=257 patients), and postoperative oxygen administration (RR=0.66; 95% CI, 0.42-1.03; n=1 study) (low certainty for all).

CONCLUSIONS

Preincision antibiotics and iNPWT reduce the risk of early SSI after lower limb revascularization surgery. Confirmatory trials are required to determine whether other promising strategies also reduce SSI risk.

The wound adjuncts effect of closed incision negative pressure wound therapy on stopping groin surgical site wound infection in arterial surgery: A meta-analysis

A meta-analysis study was conducted to assess the influence of the wound adjuncts therapy of closed incision negative pressure wound therapy (ciNPWT) on stopping groin site wound infection (SWSI) in arterial surgery. A comprehensive literature examination till January 2023 was implemented and 2186 linked studies were appraised. The picked studies contained 2133 subjects with groin surgical wounds of arterial surgery in the picked studies' baseline, 1043 of them were using ciNPWT, and 1090 were using standard care. Odds ratio (OR) in addition to 95% confidence intervals (CIs) were used to calculate the consequence of the wound adjuncts therapy of ciNPWT on stopping groin SWSI in arterial surgery by the dichotomous and continuous styles and a fixed or random model. The ciNPWT had a significantly lower SWSI (OR, 0.42; 95% CI, 0.33-0.55, P < .001), superficial SWSI (OR, 0.46; 95% CI, 0.33-0.66, P < .001), and deep SWSI (OR, 0.39; 95% CI, 0.25-0.63, P < .001) compared with the standard care in groin surgical wound of arterial surgery. The ciNPWT had a significantly, lower SWSI, superficial SWSI, and deep SWSI compared with the standard care in groin surgical wounds of arterial surgery. Although precautions should be taken when commerce with the consequences because some of the picked studies for this meta-analysis was with low sample sizes.

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.

Closed Incision Negative Pressure Therapy vs Standard of Care Over Closed Knee and Hip Arthroplasty Surgical Incisions in the Reduction of Surgical Site Complications: A Systematic Review and Meta-analysis of Comparative Studies

Background

Total hip arthroplasty (THA) and total knee arthroplasty (TKA) are common surgical procedures but carry a risk of harmful and costly surgical site complications (SSCs). This systematic review and meta-analysis examined the impact of closed incision negative pressure therapy (ciNPT) on the risk of SSCs following THA and TKA.

Methods

A systematic literature review identified studies published between January 2005 and July 2021 comparing ciNPT (Prevena Incision Management System) to traditional standard-of-care dressings for patients undergoing THA and TKA. Meta-analyses were performed using a random effects model. A cost analysis was conducted using inputs from the meta-analysis and cost estimates from a national database.

Results

Twelve studies met the inclusion criteria. Eight studies evaluated SSCs, where a significant difference was seen in favor of ciNPT (relative risk [RR]: 0.332, P < .001). Significant benefits in favor of ciNPT were also observed for surgical site infection (RR: 0.401, P = .016), seroma (RR: 0.473, P = .008), dehiscence (RR: 0.380, P = .014), prolonged incisional drainage (RR: 0.399, P = .003), and rate of return to the operating room (RR: 0.418, P = .001). The estimated cost savings attributed to ciNPT use was $932 per patient.

Conclusions

The use of ciNPT after TKA and THA was associated with a significant reduction in the risk of SSCs, including surgical site infections, seroma, dehiscence, and prolonged incisional drainage. The risk of reoperation was reduced as were the costs of care in the modeled cost analysis, suggesting a potential for both economic and clinical advantages for ciNPT over standard-of-care dressings, particularly in high-risk patients.

Closed Incision Negative Pressure Therapy versus Standard of Care in Reduction of Surgical Site Complications: A Systematic Review and Meta-analysis

Closed incision negative pressure therapy (ciNPT) has been utilized to help manage closed incisions across many surgical specialties. This systematic review and meta-analysis evaluated the effect of ciNPT on postsurgical and health economic outcomes.

Methods

A systematic literature search using PubMed, EMBASE, and QUOSA was performed for publications written in English, comparing ciNPT to standard-of-care dressings between January 2005 and August 2021. Study participant characteristics, surgical procedure, dressings used, treatment duration, postsurgical outcomes, and follow-up data were extracted. Meta-analyses were performed using random-effects models. Risk ratios summarized dichotomous outcomes. Difference in means or standardized difference in means was used to assess continuous variables reported on the same scale or outcomes reported on different scales/measurement instruments.

Results

The literature search identified 84 studies for analysis. Significant reductions in surgical site complication (SSC), surgical site infection (SSI), superficial SSI, deep SSI, seroma, dehiscence, skin necrosis, and prolonged incisional drainage were associated with ciNPT use (P < 0.05). Reduced readmissions and reoperations were significant in favor of ciNPT (P < 0.05). Patients receiving ciNPT had a 0.9-day shorter hospital stay (P < 0.0001). Differences in postoperative pain scores and reported amounts of opioid usage were significant in favor of ciNPT use (P < 0.05). Scar evaluations demonstrated improved scarring in favor of ciNPT (P < 0.05).

Discussion

For these meta-analyses, ciNPT use was associated with statistically significant reduction in SSCs, SSIs, seroma, dehiscence, and skin necrosis incidence. Reduced readmissions, reoperation, length of hospital stay, decreased pain scores and opioid use, and improved scarring were also observed in ciNPT patients.

Systematic Review of Groin Incision Surgical Site Infection Preventative Measures in Vascular Surgery

OBJECTIVE

Groin surgical site infections (SSIs) after open revascularization can lead to devastating consequences in patients. As a result, prevention has been crucial in minimizing the rate of SSIs. This review aims to evaluate the current body of literature regarding prevention techniques including: prophylactic flaps, incision technique, topical antibiotic use, closed-incision negative pressure wound therapy and adhesive drapes METHODS: This review was conducted and reported in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement. A systematic review was conducted utilizing the Google Scholar ©, PubMed, and Cochrane Review databases regarding the five prevention topics. The authors identified 1,371 potential studies with 33 studies selected and analyzed after systematic review regarding the five preventative topics.

RESULTS

The primary outcome of interest was how the rate of SSI was affected with each preventative technique. As a result, the recommendations are: - We suggest prophylactic flaps be considered in high-risk surgical patients undergoing open arterial exposure of the groin. [Grade 2C] - We suggest consideration of transverse incisions for open arterial exposure of the groin as a means of SSI prevention. [Grade 2C] - Given the lack of data regarding topical antibiotics no recommendation can be made regarding its use. - We suggest closed-incision negative pressure wound therapy be utilized in groin surgical incisions at high risk for SSI. [Grade 2B] - Given the paucity of data regarding adhesive drapes, such as Ioban ®, no recommendation can be made regarding its use.

CONCLUSIONS

This review highlights the effects of various preventative techniques and their potential benefit in prevention of SSI in the groin. However, there is a glaring deficit in the available data emphasizing the need for additional robust studies to better delineate their effectiveness and implementation into surgical practice. While the use of endovascular techniques continues to increase thus limiting the amount of open arterial procedures and the potential for further studies to be conducted. In order to provide the high-quality studies needed to better evaluate these prevention techniques, large multi-institutional collaboration will likely be necessary to provide the appropriate number of patients to evaluate true effectiveness.

Effect of prophylactic negative pressure treatment for post-surgery groin wounds management in vascular surgery: A meta-analysis

We performed a meta-analysis to evaluate the effect of prophylactic negative pressure treatment for post-surgery groin wounds management in vascular surgery. A systematic literature search up to April 2022 was performed and 1537 total number of groin vascular surgery incisions at the baseline of the studies; 729 of them were using the prophylactic negative pressure treatment, and 808 were using control. Odds ratio (OR) and mean difference (MD) with 95% confidence intervals (CIs) were calculated to assess the effect of prophylactic negative pressure treatment for post-surgery groin wounds management in vascular surgery using the dichotomous, and contentious methods with a random or fixed-effect model. The prophylactic negative pressure treatment subjects had a significantly lower surgical site wound infection (OR, 0.26; 95% CI, 0.16-0.42, P < .001) in subjects after vascular surgery compared with control. However, prophylactic negative pressure treatment did not show any significant difference in revision surgery (OR, 0.73; 95% CI, 0.52-1.00, P = .05), readmission (OR, 0.93; 95% CI, 0.66-1.32, P = .69), mortality in hospital (OR, 0.54; 95% CI, 0.29-1.01, P = .05), and length of hospital stay (MD, -0.24; 95% CI, -0.91-0.44, P = .49) compared with control in subjects after vascular surgery. The prophylactic negative pressure treatment subjects had a significantly lower surgical site wound infection and no significant difference in revision surgery, readmission, mortality in hospital, and length of hospital stay compared with control in subjects after vascular surgery. The analysis of outcomes should be with caution because of the low sample size of 2 out of 10 studies in the meta-analysis and a low number of studies in certain comparisons.

Controlling the controls: what is negative pressure wound therapy compared to in clinical trials?

AIM

Surgical site infections (SSIs) are common following colorectal operations. Clinical trials suggest that closed incision negative pressure wound therapy (ciNPWT) may reduce SSIs compared to a 'standard of care' group. However, wound management in the standard of care group may vary. The aim of this review was to assess the control arms in trials of ciNPWT for potential confounding variables that could influence the rates of SSI and therefore the trial outcomes.

METHODS

A mapping review of the PubMed database was undertaken in the English language for randomized controlled trials that assessed, in closed surgical wounds, the use of ciNPWT compared to standard of care with SSI as an outcome. Data regarding wound care to assess potential confounding factors that may influence SSI rates were compared between the ciNPWT and standard of care groups. Included were the method of wound closure, control dressing type, frequency of dressing changes and postoperative wound care (washing).

RESULTS

Twenty-seven trials were included in the mapping review. There was heterogeneity in ciNPWT duration. There was little control in the comparator standard of care groups with a variety of wound closure techniques and different control dressings used. Overall standard of care dressings were changed more frequently than the ciNPWT dressing and there was no control over wound care or washing. No standard for 'standard of care' was apparent.

CONCLUSION

In randomized trials assessing the intervention of ciNPWT compared to standard of care there was considerable heterogeneity in the comparator groups and no standard of care was apparent. Heterogeneity in dressing protocols for standard of care groups could introduce potential confounders impacting SSI rates. There is a need to standardize care in ciNPWT trials to assess potential meaningful differences in SSI prevention.

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 Cost-Utility Analysis of the Use of Closed-Incision Negative Pressure System in Vascular Surgery Groin Incisions

OBJECTIVE

Closed-incision negative pressure therapy (CINPT) with the Prevena system has been used and clinically evaluated in high-risk groin incisions to reduce the risk of postoperative complications. We performed a cost-effectiveness analysis evaluating CINPT in femoral-popliteal bypass with prosthetic graft.

METHODS

A literature review looking at prospective randomized trials determined the probabilities and outcomes for femoral-popliteal bypass with and without CINPT. Reported utility scores were used to estimate the quality adjusted life years (QALYs) associated with a successful procedure and postoperative complications. Medicare current procedure terminology and diagnosis-related group codes were used to assess the costs for a successful surgery and associated complications. A decision analysis tree was constructed with rollback analysis to highlight the more cost-effective strategy. An incremental cost-effectiveness ratio (ICER) analysis was performed with a willingness to pay at $50,000. Deterministic and probabilistic sensitivity analyses were performed to validate the robustness of the results, and to accommodate for the uncertainty in the literature.

RESULTS

Femoral-popliteal bypass with CINPT is less costly ($40,138 vs $41,774) and more effective (6.14 vs 6.13) compared to without CINPT. This resulted in a negative ICER of -234,764.03, which favored CINPT, indicating a dominant strategy. In one-way sensitivity analysis, surgery without CINPT was more cost-effective if the probability of successful surgery falls below 84.9% or if the cost of CINPT exceeds $3139. Monte Carlo analysis showed a confidence of 99.07% that CINPT is more cost-effective.

CONCLUSIONS

Despite the added device cost of CINPT, it is cost-effective in vascular surgical operations using groin incisions.

Meta-analysis of prophylactic closed-incision negative pressure wound therapy for vascular surgery groin wounds

OBJECTIVE

Previous meta-analysis of randomized control trials evaluating the efficacy of closed incision negative pressure wound therapy (ciNPWT) on vascular surgery groin wounds reported a reduction in surgical site infections (SSI). Our aim was to perform a comprehensive, updated meta-analysis after the largest multicenter randomized control trial (RCT) on the subject to date reported no benefit of ciNPWT.

METHODS

A systematic review identified RCTs that compared the primary outcome of incidence of postoperative SSIs of groin incisions treated with ciNPWT or standard dressings. Secondary outcomes included wound dehiscence, composite incidence of seroma / lymph leak / hematoma, need for reoperation, in-hospital mortality, need for readmission and hospital length of stay. Odds ratios were compared across studies using random effects meta-analysis. Risk of bias was assessed using the Cochrane Risk of Bias tool, Harbord test and trim-and-fill analysis.

RESULTS

Eight RCTs comprised of 1125 incisions (n = 555 [49.3%] ciNPT, n = 570 [50.7%] control) were included. RCTs included 3 studies inside and 5 outside of the United States. ciNPWT was associated with a significant reduction in rate of SSIs (OR 0.39; 95% CI 0.24-0.63; p < 0.001). There was no significant difference in rate of wound dehiscence (OR 1.11, 95% CI 0.67-1.83, p = 0.68), composite incidence of seroma, lymph leak or hematoma (OR 0.49, 95% CI 0.13-1.76, p= 0.27), need for reoperation (OR 0.68, 95% CI 0.40-1.16, p = 0.16), or need for readmission (OR 0.60, 95% CI 0.30-1.21, p = 0.15). It was not possible to quantitatively evaluate in-hospital mortality or hospital length of stay. Risk of bias assessment identified high risk of bias regarding participant blinding in all studies, low risk in randomization and outcome reporting, and variability between studies in other methodologies. There was no evidence of publication bias.

CONCLUSIONS

Meta-analysis of pooled data suggest prophylactic use of ciNPWT for vascular groin incisions is associated with reduced rates of SSIs, with the greatest benefits seen in trials with higher baseline rates of infection in the control group.

How to Prevent Surgical Site Infection in Vascular Surgery: A Review of the Evidence

BACKGROUND

This review aims to identify and review the current evidence for preventing postoperative surgical site infections in abdominal aortic aneurysm surgery or infrainguinal arterial surgery.

METHODS

Extended literature review of clinical trials that examined the prevention of postoperative surgical site infections in abdominal aortic aneurysm or infrainguinal arterial surgery. Searches were conducted on Ovid MEDLINE (1950 - 13 March 2020) using key terms for vascular surgery, surgical site infections and specific preventative techniques. Articles were included if they discussed a relationship between a preventative technique and surgical site infections in abdominal aortic aneurysm or infrainguinal arterial surgery. The GRADE guidelines were used to assess the quality of evidence.

RESULTS

21 techniques and 81 studies were included. Prophylactic antibiotics and negative pressure wound therapy have a high quality of evidence for the prevention of surgical site infections in abdominal aortic aneurysm or infrainguinal arterial surgery. A moderate quality evidence base was identified for gentamicin containing collagen implant (confined to high surgical site infection risk centers). Currently, there is a low or very low quality of evidence to suggest a reduction in the surgical site infection rate for combination therapy, glycaemic control, Methicillin-resistant Staphylococcus aureus screening and absorbable suture. Evidence suggests no beneficial effect for nutritional supplementation, chlorhexidine bath, hair removal therapy, Staphylococcus aureus nasal eradication, cyanoacrylate microsealant, silver grafts, rifampicin bonded grafts, triclosan coated suture and postoperative wound drains. Endoscopic saphenous vein harvest may reduce surgical site infection rate (very low quality of evidence) but may lower long-term patency. Autologous vein grafts may increase surgical site infections (very low quality of evidence) but may provide better long-term patency rates in above-knee infrainguinal bypass surgery. There was no identified evidence for perioperative normothermia, electrosurgical bipolar vessel sealer or Dermabond and Tegaderm for surgical site infection prevention in vascular surgery.

CONCLUSIONS

Prophylactic antibiotics and postoperative negative pressure wound therapy are effective in the prevention of postoperative surgical site infection in abdominal aortic aneurysm or infrainguinal arterial surgery. There exists a significant risk of bias in the literature for many preventative techniques and further studies are required to investigate the efficacy of gentamicin containing collagen implant, and specific combination therapies.

Benefit of Negative Pressure Dressings in Vascular Surgery Patients with Infra-Inguinal 1 Incisions after short-term followupAssessing the Benefit of Incisional Negative Pressure 2 Dressings in Community-Based Vascular Surgery Patients with Infra-Inguinal Incisions

OBJECTIVES

Within the vascular patient population there is increased risk of developing wound complications especially in infra-inguinal incisions. There has been increasing interest in using closed incisional negative pressure dressings to decrease the risk of wound complications. To assess the efficacy of these incisional wound dressings we studied surgical site infections and seroma rates of infrainguinal incisions in our vascular patient population.

METHODS

This was a multi-institutional, retrospective study from July 2015- June 2019. In 2017 our institution began using the Prevena incisional wound system. Wound complication rates were compared to the non Prevena group prior to 2017. There was a total of 100 infrainguinal incisions (left and right combined) that received the Prevena wound system and 138 infrainguinal incisions that had not. The primary endpoint was to assess for wound complication rates including surgical site infections and seroma formation. Surgical site infections were graded based on the ACS-NSQIP SSI criteria. Seroma formation was diagnosed based on clinical diagnosis, imaging studies (ultrasound, CT) or needle aspiration of fluid collection.

RESULTS

Analysis showed a statistically significant decrease in the rate of SSIs in the Prevena group when compared to the non Prevena group (p=0.012). There was no statistical difference between the two groups in the rate of seroma formation (p=0.155). Of the 100 incisions that received the Prevena wound system 1.2% (1/82) had a femoral SSI and 22% (4/18) had a popliteal SSI. For seroma formation 24.4% (20/82) had a femoral seroma and 11.1% (2/18) had a popliteal seroma. Of the 138 incisions that did not have the Prevena wound system, 9.6% (10/104) had a femoral SSI, and 8.8% (3/34) had a popliteal SSI. For seroma formation 24.0% (25/104) had a femoral seroma and 8.8% (3/34) had a popliteal seroma. Comorbid conditions were assessed in the two study groups and there was no statistical significance regarding rates of surgical site infections between the groups.

CONCLUSIONS

The use of an incisional negative pressure dressing decreases the rate of surgical site infections in infrainguinal incisions. Regarding the use of these wound systems for seromas; our study did not show a statistical significance in decreasing seroma rates.

Negative pressure wound therapy: device design, indications, and the evidence supporting its use

Introduction: Negative pressure wound therapy (NPWT) has become a mainstay in the armamentarium for wound care. Since the initial commercial vacuum-assisted closure device became available in 1995, subsequent research has confirmed the positive physiological effects of negative pressure on wound healing. Traditionally, NPWT has been used to improve healing of open nonsurgical wounds by secondary intention. However, the clinical applications of NPWT have significantly broadened, and now also include use in open surgical wounds, closed surgical incisions, and skin graft surgery. In addition, devices have evolved and now include functionality and features such as instillation, antimicrobial sponges, and portability.Areas covered: This article reviews the history, background, and physiology underlying NPWT, as well as the most commonly used devices. In addition, an evidence-based discussion of the current clinical applications of NPWT is presented, with a focus on those with high levels of evidence.Expert opinion: Future directions for device development include modifications to increase ease of use by patients and to allow its use in a broader array of anatomic areas. Lastly, more research with high levels of evidence is needed to better define the outcomes associated with NPWT, including in relation to specific clinical applications and cost.

A multicenter, prospective randomized trial of negative pressure wound therapy for infrainguinal revascularization with a groin incision

BACKGROUND

Wound complications after open infrainguinal revascularization are a frequent cause of patient morbidity, resulting in increased healthcare costs. The purpose of the present study was to assess the effects of closed incision negative pressure therapy (ciNPT) on groin wound complications after infrainguinal bypass and femoral endarterectomy.

METHODS

A total of 242 patients who had undergone infrainguinal bypass (n = 124) or femoral endarterectomy (n = 118) at five academic medical centers in New England from April 2015 to August 2019 were randomized to ciNPT (PREVENA; 3M KCI, St Paul, Minn; n = 118) or standard gauze (n = 124). The primary outcome measure was a composite endpoint of groin wound complications, including surgical site infections (SSIs), major noninfectious wound complications, or graft infections within 30 days after surgery. The secondary outcome measures included 30-day SSIs, 30-day noninfectious wound complications, readmission for wound complications, significant adverse events, and health-related quality of life using the EuroQoL 5D-3L survey.

RESULTS

The ciNPT and control groups had similar demographics (age, 67 vs 67 years, P = .98; male gender, 71% vs 70%, P = .86; white race, 93% vs 93%, P = .97), comorbidities (previous or current smoking, 93% vs 94%, P = .46; diabetes, 41% vs 48%, P = .20; renal insufficiency, 4% vs 7%, P = .31), and operative characteristics, including procedure type, autogenous conduit, and operative time. No differences were found in the primary composite outcome at 30 days between the two groups (ciNPT vs control: 31% vs 28%; P = .55). The incidence of SSI at 30 days was similar between the two groups (ciNPT vs control: 11% vs 12%; P = .58). Infectious (13.9% vs 12.6%; P = .77) and noninfectious (20.9% vs 17.6%; P = .53) wound complications at 30 days were also similar for the ciNPT and control groups. Wound complications requiring readmission also similar between the two groups (ciNPT vs control: 9% vs 7%; P = .54). The significant adverse event rates were not different between the two groups (ciNPT vs control: 13% vs 16%; P = .53). The mean length of the initial hospitalization was the same for the ciNPT and control groups (5.2 vs 5.7 days; P = .63). The overall health-related quality of life was similar at baseline and at 14 and 30 days postoperatively for the two groups. Although not powered for stratification, we found no differences among the subgroups in gender, obesity, diabetes, smoking, claudication, chronic limb threatening ischemia, bypass, or endarterectomy. On multivariable analysis, no differences were found in wound complications at 30 days for the ciNPT vs gauze groups (odds ratio, 1.4; 95% confidence interval, 0.8-2.6; P = .234).

CONCLUSIONS

In contrast to other randomized studies, our multicenter trial of infrainguinal revascularization found no differences in the 30-day groin wound complications for patients treated with ciNPT vs standard gauze dressings. However, the SSI rate was lower in the control group than reported in other studies, suggesting other practice patterns and processes of care might have reduced the rate of groin infections. Further study might identify the subsets of high-risk patients that could benefit from ciNPT.

Final results of the PräVAC trial: prevention of wound complications following inguinal lymph node dissection in patients with penile cancer using epidermal vacuum-assisted wound closure

PURPOSE

Inguinal lymphadenectomy in penile cancer is associated with a high rate of wound complications. The aim of this trial was to prospectively analyze the effect of an epidermal vacuum wound dressing on lymphorrhea, complications and reintervention in patients with inguinal lymphadenectomy for penile cancer.

PATIENTS AND METHODS

Prospective, multicenter, randomized, investigator-initiated study in two German university hospitals (2013-2017). Thirty-one patients with penile cancer and indication for bilateral inguinal lymph node dissection were included and randomized to conventional wound care on one side (CONV) versus epidermal vacuum wound dressing (VAC) on the other side.

RESULTS

A smaller cumulative drainage fluid volume until day 14 (CDF) compared to contralateral side was observed in 15 patients (CONV) vs. 16 patients (VAC), with a median CDF 230 ml (CONV) vs. 415 ml (VAC) and a median maximum daily fluid volume (MDFV) of 80 ml (CONV) vs. 110 ml (VAC). Median time of indwelling drainage: 7 days (CONV) vs. 8 days (VAC). All grade surgery-related complications were seen in 74% patients (CONV) vs. 74% patients (VAC); grade 3 complications in 3 patients (CONV) vs. 6 patients (VAC). Prolonged hospital stay occurred in 32% patients (CONV) vs. 48% patients (VAC); median hospital stay was 11.5 days. Reintervention due to complications occurred in 45% patients (CONV) vs. 42% patients (VAC).

CONCLUSIONS

In this prospective, randomized trial we could not observe a significant difference between epidermal vacuum treatment and conventional wound care.

Editor's Choice - Systematic Review and Meta-Analysis of Wound Adjuncts for the Prevention of Groin Wound Surgical Site Infection in Arterial Surgery

OBJECTIVE

Groin incision surgical site infections (SSIs) following arterial surgery are common and are a source of considerable morbidity. This review evaluates interventions and adjuncts delivered immediately before, during, or after skin closure, to prevent SSIs in patients undergoing arterial interventions involving a groin incision.

DATA SOURCES

MEDLINE, EMBASE, and CENTRAL databases were searched.

REVIEW METHODS

This review was undertaken according to established international reporting guidelines and was registered prospectively with the International prospective register of systematic reviews (CRD42020185170). The MEDLINE, EMBASE, and CENTRAL databases were searched using pre-defined search terms without date restriction. Randomised controlled trials (RCTs) and observational studies recruiting patients with non-infected groin incisions for arterial exposure were included; SSI rates and other outcomes were captured. Interventions reported in two or more studies were subjected to meta-analysis.

RESULTS

The search identified 1 532 articles. Seventeen RCTs and seven observational studies, reporting on 3 747 patients undergoing 4 130 groin incisions were included. A total of seven interventions and nine outcomes were reported upon. Prophylactic closed incision negative pressure wound therapy (ciNPWT) reduced groin SSIs compared with standard dressings (odds ratio [OR] 0.34, 95% CI 0.23 - 0.51; p < .001, GRADE strength of evidence: moderate). Local antibiotics did not reduce groin SSIs (OR 0.60 95% CI 0.30 - 1.21 p = .15, GRADE strength: low). Subcuticular sutures (vs. transdermal sutures or clips) reduced groin SSI rates (OR 0.33, 95% CI 0.17 - 0.65, p = .001, GRADE strength: low). Wound drains, platelet rich plasma, fibrin glue, and silver alginate dressings did not show any significant effect on SSI rates.

CONCLUSION

There is evidence that ciNPWT and subcuticular sutures reduce groin SSI in patients undergoing arterial vascular interventions involving a groin incision. Local antibiotics did not reduce groin wound SSI, although the strength of this evidence is lower. No other interventions demonstrated a significant effect.

Contemporary Review to Reduce Groin Surgical Site Infections in Vascular Surgery

Surgical site infection (SSIs) in lower extremity vascular procedures is a major contributor to patient morbidity and mortality. Despite previous advancements in preoperative and postoperative care, the surgical infection rate in vascular surgery remains high, particularly when groin incisions are involved. However, successfully targeting modifiable risk factors reduces the surgical site infection incidence in vascular surgery patients. We conducted an extensive literature review to evaluate the efficacy of various preventive strategies for groin surgical site infections. We discuss the role of preoperative showers, preoperative and postoperative antibiotics, collagen gentamicin implants, iodine impregnated drapes, types of skin incisions, negative pressure wound therapy, and prophylactic muscle flap transposition in preventing surgical site infection in the groin after vascular surgical procedures.

Effects of vacuum sealing drainage to improve the therapeutic effect in patients with orthopedic trauma and to reduce post-operative infection and lower-limb deep venous thrombosis

The present study investigated the effects of vacuum sealing drainage (VSD) to improve the therapeutic efficacy in patients with orthopedic trauma (OT) and reduce post-operative infection and lower-limb deep venous thrombosis (DVT) through a retrospective analysis. A total of 76 patients with OT treated at our hospital were selected for observation. The patients were divided into the control group (CG; n=37) and the experimental group (EG; n=39) according to the treatment administered. For patients in the CG, routine dressing changes were applied. Patients in the EG underwent VSD treatment. The dressing change frequency, time between the first and second operation, hospital stay, treatment efficacy, wound healing time, interleukin-6 (IL-6) serum level, tumor necrosis factor-α (TNF-α) serum level, incidence of post-operative infection and incidence of lower-limb DVT were compared between the two groups. The dressing change frequency in the EG was less than that in the CG. The time between the first and second operation and hospital stay were shorter in the EG than in the CG (P<0.05). The total effective rate in the EG was 97.44%, which was higher than that in the CG (78.38%; P<0.05). The wound healing time in the EG was 1.72±0.73 weeks and shorter than that in the CG (2.23±0.85 weeks; P<0.05). With the progression of treatment, the serum IL-6 and TNF-α levels decreased in the two groups, but the levels in the EG were lower than those in the CG (P<0.05). The incidence of post-operative infection and lower-limb venous thrombosis in the EG were 7.69 and 0.00%, respectively, and lower than those in the CG (27.03 and 13.01%, respectively; P<0.05). In the treatment of OT, VSD may reduce the dressing change frequency, shorten the operation time and hospital stay, accelerate wound healing and reduce post-operative infection and lower-limb DVT. Thus, the VSD treatment method is worthy of promotion and implementation in clinic.

Closed-incision negative-pressure wound management in surgery—literature review and recommendations

Background

Wound healing deficits and subsequent surgical site infections are potential complications after surgical procedures, resulting in increased morbidity and treatment costs. Closed-incision negative-pressure wound therapy (ciNPWT) systems seem to reduce postoperative wound complications by sealing the wound and reducing tensile forces.

Materials and methods

We conducted a collaborative English literature review in the PubMed database including publications from 2009 to 2020 on ciNPWT use in five surgical subspecialities (orthopaedics and trauma, general surgery, plastic surgery, cardiac surgery and vascular surgery). With literature reviews, case reports and expert opinions excluded, the remaining 59 studies were critically summarized and evaluated with regard to their level of evidence.

Results

Of nine studies analysed in orthopaedics and trauma, positive results of ciNPWT were reported in 55.6%. In 11 of 13 (84.6%), 13 of 15 (86.7%) and 10 of 10 (100%) of studies analysed in plastic, vascular and general surgery, respectively, a positive effect of ciNPWT was observed. On the contrary, only 4 of 12 studies from cardiac surgery discovered positive effects of ciNPWT (33.3%).

Conclusion

ciNPWT is a promising treatment modality to improve postoperative wound healing, notably when facing increased tensile forces. To optimise ciNPWT benefits, indications for its use should be based on patient- and procedure-related risk factors.

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.

Deep Learning-Based Risk Model for Best Management of Closed Groin Incisions After Vascular Surgery

BACKGROUND

Reduced surgical site infection (SSI) rates have been reported with use of closed incision negative pressure therapy (ciNPT) in high-risk patients.

METHODS

A deep learning-based, risk-based prediction model was developed from a large national database of 72,435 patients who received infrainguinal vascular surgeries involving upper thigh/groin incisions. Patient demographics, histories, laboratory values, and other variables were inputs to the multilayered, adaptive model. The model was then retrospectively applied to a prospectively tracked single hospital data set of 370 similar patients undergoing vascular surgery, with ciNPT or control dressings applied over the closed incision at the surgeon's discretion. Objective predictive risk scores were generated for each patient and used to categorize patients as "high" or "low" predicted risk for SSI.

RESULTS

Actual institutional cohort SSI rates were 10/148 (6.8%) and 28/134 (20.9%) for high-risk ciNPT versus control, respectively (P < 0.001), and 3/31 (9.7%) and 5/57 (8.8%) for low-risk ciNPT versus control, respectively (P = 0.99). Application of the model to the institutional cohort suggested that 205/370 (55.4%) patients were matched with their appropriate intervention over closed surgical incision (high risk with ciNPT or low risk with control), and 165/370 (44.6%) were inappropriately matched. With the model applied to the cohort, the predicted SSI rate with perfect utilization would be 27/370 (7.3%), versus 12.4% actual rate, with estimated cost savings of $231-$458 per patient.

CONCLUSIONS

Compared with a subjective practice strategy, an objective risk-based strategy using prediction software may be associated with superior results in optimizing SSI rates and costs after vascular surgery.

A systematic review and meta-analysis of randomized controlled trials for the reduction of surgical site infection in closed incision management versus standard of care dressings over closed vascular groin incisions

OBJECTIVE

Surgical site infection after groin incision is a common complication and a financial burden to patients and healthcare systems. Closed incision negative pressure therapy (ciNPT) has been associated with decreased surgical site infection rates in published literature. This meta-analysis examines the effect of ciNPT (PREVENA™ Incision Management System; KCI, San Antonio, TX) versus traditional postsurgical dressing use in reducing surgical site infection rates over closed groin incisions following vascular surgery.

METHODS

A systematic literature search using PubMed, OVID, EMBASE, and QUOSA was performed on 3 January 2019, by two independent researchers and focused on publications between 1 January 2005 and 31 December 2018. The review conformed to the statement and reporting check list of the Preferred Reporting Items for Systematic Reviews and Meta Analyses. Inclusion criteria included abstract or manuscript written in English, published studies, conference abstracts, randomized controlled trials (RCTs), ciNPT usage over closed groin incisions in vascular surgery, comparison of ciNPT use and traditional dressings, study endpoint/outcome of surgical site infection, and study population of >10. Characteristics of study participants, surgical procedure, type of dressing used, duration of treatment, incidence of surgical site infection, and length of follow-up were extracted. Weighted odds ratios and 95% confidence intervals were calculated to pool study and control groups in each publication for analysis. Treatment effects were combined using Mantel-Haenszel risk ratios, and the Chi-Square test was used to assess heterogeneity. Overall, high-risk patients, normal-risk patients, and Szilagyi I, II, III outcomes were assessed between ciNPT and control groups. The Cochrane Collaboration tool was utilized to assess the risk of bias for all studies included in the analysis.

RESULTS

A total of 615 articles were identified from the literature search. After removal of excluded studies and duplicates, six RCT studies were available for analysis. In these studies, a total of 362 patients received ciNPT, and 371 patients received traditional dressings (control). Surgical site infection events occurred in 41 ciNPT patients and 107 control patients. The heterogeneity test was nonsignificant (p > 0.05). The overall RCT meta-analysis showed a highly significant effect in favor of ciNPT (OR = 3.06, 95% CI [2.05, 4.58], p < 0.05). High-risk, normal-risk, Szilagyi I, and Szilagyi II meta-analyses were also statistically significant in favor of ciNPT use (p < 0.05). The varying RCT inclusion/exclusion criteria, such as differences in procedure types, and patient populations form the major limitations of this study.

CONCLUSIONS

A statistically significant reduction in the incidence of surgical site infection was seen following ciNPT usage in patients undergoing vascular surgery with groin incisions.

Closed Incision Negative Pressure Therapy: Review of the Literature

Surgical site infection and other common surgical site complications (dehiscence, hematoma, and seroma formation) can lead to serious and often life-threatening complications. Gauze, adhesive dressings, and skin adhesives have traditionally been utilized for incision management. However, the application of negative pressure wound therapy over clean, closed surgical incisions (closed incision negative pressure therapy, ciNPT), has become a recent option for incision management. A brief review of ciNPT clinical evidence and health economic evidence are presented. A brief literature review was performed using available publication databases (PubMed, Ovid®, Embase®, and QUOSA™) for articles in English reporting on the use of ciNPT between October 1, 2016, to March 31, 2019. The successful application of ciNPT over clean, closed wounds has been reported in a broad spectrum of patients and operative interventions, resulting in favorable clinical results. Four of the five studies that examined health economics following the use of ciNPT reported a potential reduction in the cost of care. The authors' own experience and published results suggest that patients at high risk for developing a surgical site complication may benefit from the use of ciNPT during the immediate postoperative period. Additional studies are needed across various surgical disciplines to further assess the safety, and cost-effectiveness of ciNPT use in patient populations.

Meta-analysis Comparing Outcomes of Two Different Negative Pressure Therapy Systems in Closed Incision Management

BACKGROUND

Closed incision negative pressure therapy (ciNPT) is an emerging approach to managing closed incisions of patients at risk of postoperative complications. There are primarily 2 different commercially available ciNPT systems. Both systems consist of a single-use, battery-powered device and foam- or gauze-based peel-and-place dressing designed for closed incisions. These systems vary in design, and there are no data comparing outcomes between the 2 systems.

METHODS

We performed 2 separate meta-analyses to compare surgical site infection (SSI) rates postuse of (1) ciNPT with foam dressing (FOAM) versus conventional dressings and (2) ciNPT with multilayer absorbent dressing (MLA) versus conventional dressings.

RESULTS

Seven articles and 2 abstracts met inclusion criteria in the FOAM group (n = 489) versus the control group (n = 489) in meta-analysis 1; 7 articles and 1 abstract met inclusion criteria in the MLA group (n = 532) versus the control group (n = 540) in meta-analysis 2. Meta-analysis 1 showed that patients in the control group were 3.17 times more likely to develop an SSI compared with patients in the FOAM group [weighted mean odds ratios of FOAM group versus control group was 3.17 (P < 0.0001) with the 95% confidence intervals of 2.17-4.65]. Meta-analysis 2 showed no significant difference in SSI rates between patients in the MLA group and patients in the control group [weighted mean odds ratios of MLA group versus control group was 1.70 (P = 0.08) with the 95% confidence intervals of 0.94-3.08].

CONCLUSIONS

Comparing outcomes of two different ciNPT systems with a common comparator (conventional dressings) may provide an interim basis for comparing ciNPT systems until further comparative evidence is available. More comparative research is required to determine outcomes in clinical practice.

Meta-analysis and trial sequential analysis of prophylactic negative pressure therapy for groin wounds in vascular surgery

BACKGROUND

Negative pressure therapy has been proposed as a prophylactic measure to promote surgical wound healing and reduce surgical site complications.

METHODS

We conducted a systematic review of the literature to identify randomized controlled trials (RCTs) comparing prophylactic negative pressure therapy with standard practice in closed groin incisions in vascular surgery. We calculated the pooled odds ratio (OR) or risk difference and 95% confidence interval (CI) with the use of the fixed-effect model. To control the risk of type I error, we adjusted the thresholds for the Z-values with the use of the O'Brien-Fleming α-spending function, and the risk of type II error was controlled with the use of the β-spending function and futility boundaries.

RESULTS

We selected six RCTs reporting on a total of 733 groin wounds. Patients with negative pressure wound therapy had a lower risk of developing surgical site infection (OR, 0.36; 95% CI, 0.24-0.54; P < .001), a lower risk of revision surgery (OR, 0.44; 95% CI, 0.22-0.88; P = .02) and a shorter hospital stay (weighted mean difference, -2.14; 95% CI, -3.78 to 0.49; P = .01). There was no difference in in-hospital mortality (risk difference, 0.01; 95% CI, -0.02 to 0.05; P = .53) or readmission (OR, 0.46; 95% CI, 0.17-1.29; P = .14). The Z-curve for surgical site infection crossed the O'Brien-Fleming significance boundaries for superiority (before the required information size was reached).

CONCLUSIONS

Prophylactic negative pressure wound therapy confers improved outcomes in patients undergoing arterial surgery via a groin incision compared with standard surgical wound care.

Meta-Analysis of Comparative Trials Evaluating a Single-Use Closed-Incision Negative-Pressure Therapy System

BACKGROUND

Surgical site infections (SSIs) pose a significant surgical complication. Application of closed-incision negative-pressure therapy (ciNPT) has been associated with reduced SSI rates in published literature. This meta-analysis examines the effect of ciNPT use over closed incisions in reducing SSIs versus traditional dressings.

METHODS

A systematic literature search using PubMed, The Cochrane Library, OVID, EMBASE, ScienceDirect, and QUOSA was performed focusing on publications between January 1, 2005, and April 30, 2018. Characteristics of study participants, surgical procedure, type of dressing used, duration of treatment, incidence of SSI, and length of follow-up were extracted. Weighted odds ratios and 95% CIs were calculated to pool study and control groups in each publication for analysis. Treatment effects were combined using Mantel-Haenszel odds ratios as the summary statistics, and a fixed-effects model was used for each analysis performed. The chi-square test was used to statistically assess heterogeneity. For each meta-analysis performed, the more conservative random-effects models were conducted as sensitivity analyses.

RESULTS

For all meta-analyses (randomized controlled trial only, observational studies only, colorectal/abdominal, obstetrics, lower extremity, groin/vascular, cardiac), heterogeneity tests were nonsignificant (P > 0.05). All fixed-effects meta-analyses were significant in favor of ciNPT use over traditional dressings (P < 0.05). When the random-effects analyses were performed, all analyses except obstetrics remained significant (P < 0.05).

CONCLUSION

For all meta-analyses performed using the fixed-effects approach, ciNPT usage demonstrated a statistically significant reduction in incidence of SSI relative to traditional 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). 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.