Prospective, randomized, multi-institutional clinical trial of a silver alginate dressing to reduce lower extremity vascular surgery wound complications

Groin Complications Among Obese Patients Undergoing Vascular Procedures

OBJECTIVES

Groin incision wound complications (WC) are common among vascular surgery patients. Obesity is a known risk factor, but there is no consensus on the best way to prevent WC in obese patients after vascular procedures. The objective of this study was to identify risk factors for WC and strategies to prevent these complications specifically in obese patients.

METHODS

All patients who had longitudinal groin incisions at a single institution from 2021-2022 were included. The medical records were reviewed and all groin-related WC were identified. WC were stratified into major and minor WC where major WC were those requiring re-operation or hospital re-admission. Patients were stratified into obese (BMI>30kg/m2) and non-obese cohorts.

RESULTS

A total of 238 groin incisions were included. There were 46 (19.3%) obese and 192(80.7%) non-obese patients. 156 (65.5%) were closed with nylon, 49 (20.6%) were closed in a subcuticular fashion, and 32 (13.4%) were closed with staples. There were 45 (18.9%) WC; 15 (33.3%) major and 30 (66.7 %) minor. Obesity was associated with a higher WC rate (39.1% vs 14.1%, p<0.001), which was driven by minor WC (32.6% vs 7.8%, p<0.001) rather than major WC (6.5% vs 5.7%, p=0.873). On multivariable analysis, obesity remained a predictor for overall (OR 4.953, p<0.001) and minor WC (OR 7.389, p<0.001). Additionally, female sex was associated with a higher rate of WC on unadjusted (27.6% vs 12.8%, p=0.016) and adjusted analysis (OR 2.411, p=0.014). Among obese patients, subcuticular closure was associated with higher rates of minor complications (OR 8.454, p=0.044). Obese patients with major complications less frequently had close follow-up including rehab disposition, discharge with visiting nurse, or frequent office wound checks than those with minor complications (33.33% vs 86.67%, p=0.043).

CONCLUSIONS

Groin WC are more common in obese and female patients. Among obese patients, this difference is driven primarily by minor WC. Avoiding a subcuticular skin closure may reduce the risk of minor WC in obese patients. In addition, close postoperative follow up using rehab, visiting nurse services, and frequent office wound checks may prevent minor complications from escalating to major complications.

Enhanced recovery after surgery (ERAS) for vascular surgery: an evidence map and scoping review

BACKGROUND

Enhanced recovery after surgery (ERAS) interventions aim to improve patient outcomes. Vascular surgery patients have unique requirements and it is unclear which ERAS interventions are supported by an evidence base.

METHODS

We conducted a scoping review to identify ERAS randomized controlled trials (RCTs) published in the biomedical or nursing literature. We assessed interventions for applicability to vascular surgery and differentiated interventions given at preadmission, preoperative, intraoperative, and postoperative surgery stages. We documented the research in an evidence map.

RESULTS

We identified 76 relevant RCTs. Interventions were mostly administered in preoperative (23 RCTs; 30%) or intraoperative surgery stages (35 RCTs; 46%). The majority of studies reported mortality outcomes (44 RCTs; 58%), but hospital (27 RCTs; 35%) and intensive care unit (9 RCTs; 12%) length of stay outcomes were less consistently described.

CONCLUSION

The ERAS evidence base is growing but contains gaps. Research on preadmission interventions and more consistent reporting of key outcomes is needed.

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.

Evaluation of Cytotoxicity of Hyaluronic Acid/Chitosan/Bacterial Cellulose-Based Membrane

Novel wound dressing materials are required to non-cytotoxic with a viable cell ratio of above 92%. Herein, the cytotoxicity of hyaluronic acid/chitosan/bacterial cellulose-based (BC(CS/HA)) membranes are evaluated and compared to that of alginate/chitosan/bacterial cellulose-based (BC(CS/Alg)) membranes was investigated. Multilayer membranes with up to ten CS/HA or CS/Alg layers were prepared using the layer-by-layer (LBL) method. Scanning electron microscopy showed that the diameters of the fibers in the BC(CS/Alg) and BC(CS/HA) membranes were larger than those in a BC membrane. The cytotoxicity was analyzed using BALB-3T3 clone A31 cells (mouse fibroblasts, 1 × 10⁴ cells/well). The BC(CS/HA)₅ and BC(CS/HA)₁₀ membranes exhibited high biocompatibility, with the cell viabilities of 94% and 87% at 5 d, respectively, compared to just 82% for the BC(CS/Alg)₅ and BC(CS/Alg)₁₀ membranes with same numbers of layers. These results suggested that BC(CS/HA)₅ is a promising material for wound dressings.

American Society of Anesthesiologists-Physical Status Classification As An Independent Risk Factor of Surgical Site Infection After Infra-Inguinal Arterial Bypass

OBJECTIVES

The present study aimed to assess whether high-risk American Society of Anesthesiologists (ASA)-Physical Status was an independent risk factor for the development of surgical site infection (SSI) after infra-inguinal lower extremity bypass (LEB).

SUMMARY OF BACKGROUND DATA

The ASA-Physical Status Classification System assesses the overall physical status preoperatively. ASA-Physical Status is associated with postoperative morbidity and mortality. However, limited data are available on how ASA-Physical Status Class affects the development of SSI after infra-inguinal LEB.

METHODS

Patients who had undergone infra-inguinal LEB from January 1, 2015 to December 31, 2018, for obliterative arteriopathy or popliteal aneurysm at our university hospital were included. SSI risk factors were identified using multivariable logistic regression. The length of hospital stay, major limb events (MALE), major adverse cardiovascular events (MACE), and all-cause mortality were compared for patients with SSI versus those without SSI 3 months and 1- year of follow-up after the index surgery.

RESULTS

Among the 267 patients included, 30 (11.2%) developed SSI during the 3-month period and 32 (12%) at 1 year. ASA-Physical Status ≥3 [odds ratio (OR): 3.7, 95% confidence interval CI) 1.5-11.1], emergency surgery (OR: 2.7, 95% CI 1.2-6.0), general anesthesia (OR: 2.8, 95% CI 1.3-6.1), and procedure performed by a junior surgeon (OR: 2.7, 95% CI 1.3-6.0) were independently associated with SSI. At 3 months and 1 year, SSI was significantly associated with MALE (including surgical wound debridement, subsequent thrombectomy, major amputation), length of hospital stay, and all-cause mortality.

CONCLUSION

The ASA-Physical Status should be considered in medical management when an infra-inguinal LEB is considered in frail patients, to prevent surgical complications.

Microwave-Assisted Incorporation of AgNP into Chitosan-Alginate Hydrogels for Antimicrobial Applications

Herein, improving the antibacterial activity of a hydrogel system of sodium alginate (SA) and basic chitosan (CS) using sodium hydrogen carbonate by adding AgNPs was investigated. SA-coated AgNPs produced by ascorbic acid or microwave heating were evaluated for their antimicrobial activity. Unlike ascorbic acid, the microwave-assisted method produced uniform and stable SA-AgNPs with an optimal reaction time of 8 min. Transmission electron microscopy (TEM) confirmed the formation of SA-AgNPs with an average particle size of 9 ± 2 nm. Moreover, UV-vis spectroscopy confirmed the optimal conditions for SA-AgNP synthesis (0.5% SA, 50 mM AgNO₃, and pH 9 at 80 °C). Fourier transform infrared (FTIR) spectroscopy confirmed that the -COO^- group of SA electrostatically interacted with either the Ag⁺ or -NH₃⁺ of CS. Adding glucono-δ-lactone (GDL) to the mixture of SA-AgNPs/CS resulted in a low pH (below the pKa of CS). An SA-AgNPs/CS gel was formed successfully and retained its shape. This hydrogel exhibited 25 ± 2 mm and 21 ± 1 mm inhibition zones against E. coli and B. subtilis and showed low cytotoxicity. Additionally, the SA-AgNP/CS gel showed higher mechanical strength than SA/CS gels, possibly due to the higher crosslink density. In this work, a novel antibacterial hydrogel system was synthesized via 8 min of microwave heating.

Effectiveness of moist dressings in wound healing after surgical suturing: A Bayesian network meta-analysis of randomised controlled trials

The moist healing theory proves that a moderately moist and airtight environment is conducive to wound healing. However, different moist dressings have different functions. We aim to evaluate the effects of moist dressings on wound healing after surgical suturing and identify superior moist dressings. Randomised controlled trials investigating the application of moist dressings were retrieved from electronic databases, including PubMed, EMBASE, Web of Science, and the Cochrane Library. Wound healing, surgical site infection (SSI), and times of dressing change were assessed. The values of the surface under the cumulative ranking (SUCRA) curve were calculated based on the Bayesian network meta-analysis. Inconsistency tests and funnel plots were applied to analyse the consistency and publication bias. All the analysis complies with the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) 2020 Checklist and AMSTAR (Assessing the Methodological Quality of Systematic Reviews) Guidelines. Sixteen randomised controlled trials involving 4444 patients were pooled in the network meta-analysis. The ionic silver dressing (SUCRA, 93%) ranked first in wound healing, the metallic silver dressing (SUCRA, 75.9%) ranked first in SSI, and the hydrocolloid dressing (SUCRA, 73.9%) ranked first in times of dressing change. Inconsistency was only observed in wound healing, and no publication bias was observed in this study. The effects of moist dressings are better than gauze dressings in the process of wound healing. The ionic silver dressing is effective in wound healing, whereas the metallic silver dressing is effective in SSI prevention. The hydrocolloid dressing requires the fewest times of dressing change. More high-quality RCTs are required to support the network meta-analysis.

A systematic review of patient-reported outcome measures patients with chronic limb-threatening ischemia

Chronic limb-threatening ischemia (CLTI) causes significant morbidity with profound negative effects on health-related quality of life. As the prevalence of peripheral artery disease and diabetes continue to rise in our aging population, the public health impact of CLTI has escalated. Patient-reported outcome measures (PROMs) have become common and important measures for clinical evaluation in both clinical care and research. PROMs are important for the measurement of clinical effectiveness and cost effectiveness and for shared decision-making on treatment options. However, the PROMs used to describe the experience of patients with CLTI are heterogeneous, incomplete, and lack specific applicability to the underlying disease processes and diverse populations. For example, certain PROMs exist for patients with extremity wounds, and other PROMs exist for patients with pain, and still others exist for patients with vascular disease. Despite this multiplicity of tools, no single PROM encompasses all of the components necessary to describe the experiences of patients with CLTI. This significant unmet need is evident from both published reports and contemporary large-scale clinical trials in the field. In this systematic review, we review the current use of PROMs for patients with CLTI in clinical practice and in research trials and highlight the gaps that need to be addressed to develop a unifying PROM instrument for CLTI.

Waterproof dressing combined with sodium chloride to promote healing in acute wounds: a case report from an Indonesian hospital

In this case study, the wound healing process of a patient who had undergone an appendectomy and whose wound was treated with waterproof dressing was analysed, and the coverage of granulation tissue was tracked. This study aimed to re-evaluate the use of waterproof dressing, combined with sodium chloride, on acute wounds in an Indonesian hospital. Data were collected and evaluated through the use of the Nursing Outcomes Classification (NOC) observation method. A waterproof dressing and sodium chloride (NaCl) were administered once every 2 days to promote wound healing. After three rounds (14 days) of using waterproof dressing, granulation tissue formed over the surface of the wound base. The end result of healing by primary intention was complete return to function, with minimal scarring and loss of skin appendages. Waterproof dressing was considered to be effective and characterised by the formation of 93.2% granulation tissue; epithelialisation was observed covering between 75-100% of the wound area. No complications occurred during the intervention.

Clinical Relevance of Closed-Incision Negative Pressure Therapy (ciNPT) for SSI-Risk Reduction in Vascular Surgery Through a Groin Incision

BACKGROUND

Vascular surgery, especially lower limb revascularization surgery, has one of the highest rates of surgical complications, predominantly surgical site infections (SSI). Resulting in a significant burden of additional costs due to longer hospital stays, re-admissions and re-interventions, mainly attributable to deep incisional SSIs. Closed incisional negative pressure therapy (ciNPT) is a relatively new strategy in the postoperative management surgical wounds, aiming to reduce surgical wound complications. When discussing the clinical relevance of ciNPT, it is crucial to take into account the outcome of therapy as well as the additional costs related to ciNPT. Since, the additional costs must be justified by an associated decrease in the morbidity and costs associated with groin wound complications, which are particularly attributable to deep incisional SSIs. The current literature evaluating the beneficial effect of ciNPT in groin incisional vascular surgery, predominantly focusses on the decrease in superficial SSIs. Whereas this study aims to address and discuss the clinical relevance of ciNPT over conventional wound dressings, by separately evaluating and comparing the incidence of superficial and deep SSIs and their related re-admissions and re-interventions.

METHODS

In this single center prospective cohort study performed in a non-academic hospital in The Netherlands, 59 consecutive patients (67 incisions) were included between January and October 2019. All underwent elective vascular surgery with groin (access) incisions for either lower limb revascularization surgery or abdominal aortic aneurysm surgery. The study group was treated with six days ciNPT (PREVENA Incision Management System; KCI/3M, San Antonio, TX, USA) and matched for equal comparison to a historical retrospectively analysed cohort of 54 consecutive patients (60 incisions), all of whom have undergone elective vascular surgery for equal indications with groin (access) incisions in our center between January and October 2018. The standard-care group was treated following standard surgical wound care protocol with conventional surgical self-adhesive plaster (10 × 15cm, Mepore, Mölnlycke Health Care AB, Gothenburg, Sweden).

RESULTS

Study groups were comparable at baseline, except for Body Mass Index (BMI), which was significantly higher in the ciNPT-group (P =.021). No significant differences for formation of seroma, hematoma, as well as wound dehiscence and SSIs were found between both groups. Groin SSIs were seen in 12.1% of the patients in the ciNPT-group and in 13.0% in the Standard-care group (OR 0.80, CI ((0.26, 2.48)), deep SSI contributed for 4 out of 7 patients of total SSIs in the ciNPT-group and for 2 out of 7 patients in the standard of care group (P-value >0.05). Analysis for incidence of hospital re-admission and re-intervention in both study groups showed no significant difference. Subset analysis in both study groups for SSIs differentiated in superficial and deep SSIs showed that only deep SSIs resulted in re-interventions.

CONCLUSIONS

Based on the findings in the population of our single center study, we conclude that routine use of ciNPT was not effective in reducing groin wound complications, and therefore could not replicate the promising findings from some previous studies. Furthermore, we did not find a reduction in the incidence of deep SSIs, which comprise the highest morbidity and costs. Considering our findings as well as the associated additional expenses related to ciNPT, it might be superfluous at this stage to use ciNPT as the new standard of post-operative groin incision care for all lower limb revascularization and abdominal aortic aneurysm surgeries. In our opinion further research is warranted for establishing a risk-factor based model for determination of the indication of ciNPT. To be able to achieve a more substantiated decision for utilizing ciNPT compared to standard surgical wound care in groin incisional vascular surgical interventions.

Short-Term Pre-Operative Protein Caloric Restriction in Elective Vascular Surgery Patients: A Randomized Clinical Trial

(1) Background: Vascular surgery operations are hampered by high failure rates and frequent occurrence of peri-operative cardiovascular complications. In pre-clinical studies, pre-operative restriction of proteins and/or calories (PCR) has been shown to limit ischemia-reperfusion damage, slow intimal hyperplasia, and improve metabolic fitness. However, whether these dietary regimens are feasible and safe in the vascular surgery patient population remains unknown. (2) Methods: We performed a randomized controlled trial in patients scheduled for any elective open vascular procedure. Participants were randomized in a 3:2 ratio to either four days of outpatient pre-operative PCR (30% calorie, 70% protein restriction) or their regular ad-libitum diet. Blood was drawn at baseline, pre-operative, and post-operative day 1 timepoints. A leukocyte subset flow cytometry panel was performed at these timepoints. Subcutaneous/perivascular adipose tissue was sampled and analyzed. Follow-up was one year post-op. (3) Results: 19 patients were enrolled, of whom 11 completed the study. No diet-related reasons for non-completion were reported, and there was no intervention group crossover. The PCR diet induced weight loss and BMI decrease without malnutrition. Insulin sensitivity was improved after four days of PCR (p = 0.05). Between diet groups, there were similar rates of re-intervention, wound infection, and cardiovascular complications. Leukocyte populations were maintained after four days of PCR. (4) Conclusions: Pre-operative PCR is safe and feasible in elective vascular surgery patients.

The Society for Vascular Surgery Objective Performance Goals for Critical Limb Ischemia are attainable in select patients with ischemic wounds managed with wound care alone

BACKGROUND

To set therapeutic benchmarks, in 2009 the Society for Vascular Surgery defined objective performance goals (OPG) for treatment of patients with chronic limb threatening ischemia (CLTI) with either open surgical bypass or endovascular intervention. The goal of these OPGs are to set standards of care from a revascularization standpoint and to provide performance benchmarks for 1 year patency rates for new endovascular therapies. While OPGs are useful in this regard, a critical decision point in the treatment of patients with CLTI is determining when revascularization is necessary. There is little guidance in the comprehensive treatment of this patient population, especially in the nonoperative cohort. Guidelines are needed for the CLTI patient population as a whole and not just those revascularized, and our aim was to assess whether CLTI OPGs could be attained with nonoperative management alone.

METHODS

Our cohort included patients with an incident diagnosis of CLTI (by hemodynamic and symptomatic criteria) at our institution from 2013-2017. The primary outcome measured was mortality. Secondary outcomes were limb loss and failure of amputation-free survival. Descriptive statistics were used to define the 2 groups - patients undergoing primary revascularization and patients undergoing primary wound management. The risk difference in outcomes between the 2 groups was estimated using collaborative-targeted maximum likelihood estimation.

RESULTS

Our cohort included 349 incident CLTI patients; 60% male, 51% white, mean age 63 +/- 13 years, 20% Rutherford 4, and 80% Rutherford 5. Most patients (277, 79%) underwent primary revascularization, and 72 (21%) were treated with wound care alone. Demographics and presenting characteristics were similar between groups. Although the revascularized patients were more likely to have femoropopliteal disease (72% vs. 36%), both groups had a high rate of infrapopliteal disease (62% vs. 57%). Not surprisingly, the patients in the revascularization group were less likely to have congestive heart failure (34% vs. 42%), complicated diabetes (52% vs. 79%), obesity (19% vs. 33%), and end stage renal disease (14% vs. 28%). In the wound care group, 2-year outcomes were 65% survival, 51% amputation free survival, 19% major limb amputation, and 17% major adverse cardiac event. The wound care cohort had a 13% greater risk of death at 2 years; however, the risk of limb loss at 2 years was 12% less in the wound care cohort.

CONCLUSIONS

A comprehensive set treatment goals and expected amputation free survival outcomes can guide revascularization, but also assure that appropriate outcomes are achieved for patients treated without revascularization. The 2-year outcomes achieved in this cohort provide an estimate of outcomes for nonrevascularized CLTI patients. Although multi-center or prospective studies are needed, we demonstrate that equal, even improved, limb salvage rates are possible.

Chitosan/Hyaluronic acid/Alginate and an assorted polymers loaded with honey, plant, and marine compounds for progressive wound healing-Know-how

Biomaterials are being extensively used in regenerative medicine including tissue engineering applications, as these enhance tissue development, repair, and help in the process of angiogenesis. Wound healing is a crucial biological process of regeneration of ruptured tissue after getting injury to the skin and other soft tissue in humans and animals. Besides, the accumulation of microbial biofilms around the wound surface can increase the risk and physically obstruct the wound healing activity, and may even lead to amputation. Hence, in both acute and chronic wounds, prominent biomaterials are required for wound healing along with antimicrobial agents. This review comprehensively addresses the antimicrobial and wound healing effects of chitosan, chitin, cellulose acetate, hyaluronic acid, pullulan, bacterial cellulose, fibrin, alginate, etc. based wound dressing biomaterials fabricated with natural resources such as honey, plant bioactive compounds, and marine-based polymers. Due to their excellent biocompatibility and biodegradability, bioactive compounds derived from honey, plants, and marine resources are commonly used in biomedical and tissue engineering applications. Different types of polymer-based biomaterials including hydrogel, film, scaffold, nanofiber, and sponge dressings fabricated with bioactive agents including honey, curcumin, tannin, quercetin, andrographolide, gelatin, carrageenan, etc., can exhibit significant wound healing process in, diabetic wounds, diabetic ulcers, and burns, and help in cartilage repair along with good biocompatibility and antimicrobial effects. Among the reviewed biomaterials, carbohydrate polymers such as chitosan-based biomaterials are prominent and widely used for wound healing applications followed by hyaluronic acid and alginate-based biomaterials loaded with honey, plant, and marine compounds. This review first provides an overview of the vast natural resources used to formulate different biomaterials for the treatment of antimicrobial, acute, and chronic wound healing processes.

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.

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.

Three wound-dressing strategies to reduce surgical site infection after abdominal surgery: the Bluebelle feasibility study and pilot RCT

BACKGROUND

Surgical site infection (SSI) affects up to 20% of people with a primary closed wound after surgery. Wound dressings may reduce SSI.

OBJECTIVE

To assess the feasibility of a multicentre randomised controlled trial (RCT) to evaluate the effectiveness and cost-effectiveness of dressing types or no dressing to reduce SSI in primary surgical wounds.

DESIGN

Phase A - semistructured interviews, outcome measure development, practice survey, literature reviews and value-of-information analysis. Phase B - pilot RCT with qualitative research and questionnaire validation. Patients and the public were involved.

SETTING

Usual NHS care.

PARTICIPANTS

Patients undergoing elective/non-elective abdominal surgery, including caesarean section.

INTERVENTIONS

Phase A - none. Phase B - simple dressing, glue-as-a-dressing (tissue adhesive) or 'no dressing'.

MAIN OUTCOME MEASURES

Phase A - pilot RCT design; SSI, patient experience and wound management questionnaires; dressing practices; and value-of-information of a RCT. Phase B - participants screened, proportions consented/randomised; acceptability of interventions; adherence; retention; validity and reliability of SSI measure; and cost drivers.

DATA SOURCES

Phase A - interviews with patients and health-care professionals (HCPs), narrative data from published RCTs and data about dressing practices. Phase B - participants and HCPs in five hospitals.

RESULTS

Phase A - we interviewed 102 participants. HCPs interpreted 'dressing' variably and reported using available products. HCPs suggested practical/clinical reasons for dressing use, acknowledged the weak evidence base and felt that a RCT including a 'no dressing' group was acceptable. A survey showed that 68% of 1769 wounds (727 participants) had simple dressings and 27% had glue-as-a-dressing. Dressings were used similarly in elective and non-elective surgery. The SSI questionnaire was developed from a content analysis of existing SSI tools and interviews, yielding 19 domains and 16 items. A main RCT would be valuable to the NHS at a willingness to pay of £20,000 per quality-adjusted life-year. Phase B - from 4 March 2016 to 30 November 2016, we approached 862 patients for the pilot RCT; 81.1% were eligible, 59.4% consented and 394 were randomised (simple, n = 133; glue, n = 129; no dressing, n = 132); non-adherence was 3 out of 133, 8 out of 129 and 20 out of 132, respectively. SSI occurred in 51 out of 281 participants. We interviewed 55 participants. All dressing strategies were acceptable to stakeholders, with no indication that adherence was problematic. Adherence aids and patients' understanding of their allocated dressing appeared to be key. The SSI questionnaire response rate overall was 67.2%. Items in the SSI questionnaire fitted a single scale, which had good reliability (test-retest and Cronbach's alpha of > 0.7) and diagnostic accuracy (c-statistic = 0.906). The key cost drivers were hospital appointments, dressings and redressings, use of new medicines and primary care appointments.

LIMITATIONS

Multiple activities, often in parallel, were challenging to co-ordinate. An amendment took 4 months, restricting recruitment to the pilot RCT. Only 67% of participants completed the SSI questionnaire. We could not implement photography in theatres.

CONCLUSIONS

A main RCT of dressing strategies is feasible and would be valuable to the NHS. The SSI questionnaire is sufficiently accurate to be used as the primary outcome. A main trial with three groups (as in the pilot) would be valuable to the NHS, using a primary outcome of SSI at discharge and patient-reported SSI symptoms at 4-8 weeks.

TRIAL REGISTRATION

Phase A - Current Controlled Trials ISRCTN06792113; Phase B - Current Controlled Trials ISRCTN49328913.

FUNDING

This project was funded by the National Institute for Health Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 23, No. 39. See the NIHR Journals Library website for further project information. Funding was also provided by the Medical Research Council ConDuCT-II Hub (reference number MR/K025643/1).

Silver in Wound Care-Friend or Foe?: A Comprehensive Review

Due to its strong antimicrobial activity, silver is a commonly used adjunct in wound care. However, it also has the potential to impair healing by exerting toxic effects on keratinocytes and fibroblasts. The published literature on the use of silver in wound care is very heterogeneous, making it difficult to generate useful treatment guidelines.

METHODS

A search of high-quality studies on the use of silver in wound care was performed on PubMed. A detailed qualitative analysis of published articles was performed to evaluate the evidence for the use of silver in infected wounds, clean wounds, burns, and over closed surgical incisions.

RESULTS

Fifty-nine studies were included in this qualitative analysis. We found that, overall, the quality of the published research on silver is poor. While there is some evidence for short-term use of dressings containing nanocrystalline silver in infected wounds, the use of silver-containing dressings in clean wounds and over closed surgical incisions is not indicated. Negative-pressure wound therapy accelerates the healing of contaminated wounds, especially when silver is used as an adjunct. For burns, silver sulfadiazine slows healing and should not be used. Instead, nanocrystalline silver, or alternatives such as octenidine and polyhexanide, lead to less infection and faster healing.

CONCLUSIONS

In infected wounds, silver is beneficial for the first few days/weeks, after which nonsilver dressings should be used instead. For clean wounds and closed surgical incisions, silver confers no benefit. The ideal silver formulations are nanocrystalline silver and silver-coated polyurethane sponge for negative-pressure wound therapy. Silver sulfadiazine impairs wound healing. Proper use of silver-containing dressings is essential to optimize wound healing.

Dermabond and Tegaderm: A Better Surgical Incision Dressing

Surgical site infections (SSIs) are a common source of morbidity with vascular surgery incisions, especially in the groin. Single institution case series have widely varying, but high incidences of groin wound infection after open lower extremity revascularization. Optimally, a dressing that did not require changes, had low cost, and was water resistant would be optimal in these patients. We developed and validate a new dressing utilizing Dermabond (Ethibond™) and Tegaderm™ for vascular surgery incisions that could simplify and reduce postoperative SSIs. In this initial experience, we reviewed 94 patients. Of the 94 patients, 0 had signs of infection superficial or deep, dehiscence, or evidence of nonhealing. Gluing a Tegaderm to an incision using Dermabond is a novel and easy way to perform dressing that reduces wound infection, increases patient comfort, avoids dressing changes, and allows visualization of the wound.

Evidence for silver in wound care - meta-analysis of clinical studies from 2000-2015

BACKGROUND

Given that the scientific evidence for silver in wound care is generally considered insufficient, there is uncertainty among users regarding its clinical use.

MATERIAL AND METHODS

A group of experts evaluated the clinical studies on silver in wound management published from 2000-2015.

RESULTS

Overall, 851 articles were identified, 173 of which were included and categorized. There were 31 randomized controlled trials (RCTs) and eight cohort studies. Twenty-eight of these studies showed statistically significant outcome parameters in support of silver. While nine of these studies investigated burn injuries, 20 addressed other indications (venous leg ulcers: 9; pressure ulcers: 3; chronic wounds: 2; diabetic foot ulcer: 1; other types of wounds: 5). In 16 studies, the primary parameter was wound healing, whereas quality of life including pain was assessed in twelve studies; cost-effectiveness, in eight studies; reduction of bacterial load, in three studies. Based on these results, a treatment algorithm for the clinical use of silver in wound care has been developed.

CONCLUSIONS

The present meta-analysis shows that the evidence base for silver in wound management is significantly better than perceived in the current scientific debate. Thus, if used selectively and for a limited period of time, silver not only has antimicrobial effects but is also characterized by an improvement in quality of life and good cost-effectiveness.

Silver-containing dressing for surgical site infection in clean and clean-contaminated operations: a systematic review and meta-analysis of randomized controlled trials

BACKGROUND

Silver-containing dressings for the prevention of surgical site infections (SSIs) remained controversial, and accumulating evidence was lacking, so a meta-analysis was conducted to systematically assess the effectiveness and safety of silver-containing dressings for clean and clean-contaminated surgical incisions.

METHODS

Pubmed, Embase, and the Cochrane Library were searched from the inception to February 2016 for randomized controlled trials (RCTs), which explored silver-containing dressings for the prevention of SSIs in clean and clean-contaminated operations. Relative risk (RR) with 95% confidence interval (CI) was pooled using random effects model. Predefined subgroup analyses, sensitivity analyses, and influence analyses were further undertaken.

RESULTS

Nine RCTs totaling 2196 patients (1141 in silver-containing group and 1055 in control group) were included. Silver-containing dressings did not effectively prevent the incidence of SSIs (9 RCTs; RR: 0.92; 95% CI: 0.66-1.29; I2 = 40%), superficial SSIs (5 RCTs; RR: 0.67; 95% CI: 0.36-1.24; I2 = 36%), and deep SSIs (5 RCTs; RR: 0.78; 95% CI: 0.41-1.49; I2 = 0). Subgroup analyses, sensitivity analyses, and influence analyses confirmed the robustness of the pooled estimate.

CONCLUSIONS

The current available evidence indicated that silver-containing dressing as compared with silver-free dressing was not associated with lower incidence of SSIs. Considering the quality of evidence ranking very low, further studies with higher quality should be warranted.

Impact of body mass index and gender on wound complications after lower extremity arterial surgery

OBJECTIVE

Wound complications (WCs) after lower extremity arterial surgery (LEAS) are common, resulting in readmissions and reinterventions. Whereas diabetes and obesity are known risk factors for WCs, gender-specific variability in body fat distribution (android vs gynoid) may drive differential risks of WCs after LEAS. We analyzed the independent and synergistic effects of gender and body mass index (BMI) on WCs.

METHODS

We performed a retrospective review of prospectively collected data from a published, randomized, multicenter trial assessing the incidence of WCs (dehiscence, surgical site infections, seroma, and hematoma) after LEAS. Postoperative outcomes were compared between genders. A multivariable regression model assessed the impact of gender and BMI on WCs. Subanalysis focused on the synergy of gender and body habitus, groin-only incisions, and clinical outcomes.

RESULTS

There were 502 patients who underwent LEAS between October 2010 and September 2013. The cohort was elderly (67.6 ± 10.5 years), mostly male (72%), and overweight (BMI, 27.6 ± 5.7); 225 (45%) patients had a groin-only incision. In 171 patients (37.9%), a WC developed within 30 days, 85% of which were infectious in etiology. On multivariable regression, obesity (odds ratio [OR], 2.10; 95% confidence interval [CI], 1.17-3.77), morbid obesity (OR, 2.87; 95% CI, 1.32-6.23), and female gender (OR, 1.17; 95% CI, 1.06-2.75) were independent predictors of infectious WCs at 30 days. When stratified by groin-only incision, BMI was no longer significant, but female gender (OR, 2.70; 95% CI, 1.24-5.87) was predictive of infectious WCs at 30 days. There was no synergistic effect of BMI and gender on WCs.

CONCLUSIONS

WCs are common after LEAS. BMI is an independent risk factor for the development of any WC. Female gender, a potential surrogate for high hip to waist ratio body habitus, is also an independent predictor of groin WCs, suggesting the clinical importance of gynoid vs android fat distribution.

Dressings for the prevention of surgical site infection

BACKGROUND

Surgical wounds (incisions) heal by primary intention when the wound edges are brought together and secured, often with sutures, staples, or clips. Wound dressings applied after wound closure may provide physical support, protection and absorb exudate. There are many different types of wound dressings available and wounds can also be left uncovered (exposed). Surgical site infection (SSI) is a common complication of wounds and this may be associated with using (or not using) dressings, or different types of dressing.

OBJECTIVES

To assess the effects of wound dressings compared with no wound dressings, and the effects of alternative wound dressings, in preventing SSIs in surgical wounds healing by primary intention.

SEARCH METHODS

We searched the following databases: the Cochrane Wounds Specialised Register (searched 19 September 2016); the Cochrane Central Register of Controlled Trials (CENTRAL; the Cochrane Library 2016, Issue 8); Ovid MEDLINE (including In-Process & Other Non-Indexed Citations, MEDLINE Daily and Epub Ahead of Print; 1946 to 19 September 2016); Ovid Embase (1974 to 19 September 2016); EBSCO CINAHL Plus (1937 to 19 September 2016).There were no restrictions based on language, date of publication or study setting.

SELECTION CRITERIA

Randomised controlled trials (RCTs) comparing wound dressings with wound exposure (no dressing) or alternative wound dressings for the postoperative management of surgical wounds healing by primary intention.

DATA COLLECTION AND ANALYSIS

Two review authors performed study selection, 'Risk of bias' assessment and data extraction independently.

MAIN RESULTS

We included 29 trials (5718 participants). All studies except one were at an unclear or high risk of bias. Studies were small, reported low numbers of SSI events and were often not clearly reported. There were 16 trials that included people with wounds resulting from surgical procedures with a 'clean' classification, five trials that included people undergoing what was considered 'clean/contaminated' surgery, with the remaining studies including people undergoing a variety of surgical procedures with different contamination classifications. Four trials compared wound dressings with no wound dressing (wound exposure); the remaining 25 studies compared alternative dressing types, with the majority comparing a basic wound contact dressing with film dressings, silver dressings or hydrocolloid dressings. The review contains 11 comparisons in total.

PRIMARY OUTCOME

SSIIt is uncertain whether wound exposure or any dressing reduces or increases the risk of SSI compared with alternative options investigated: we assessed the certainty of evidence as very low for most comparisons (and low for others), with downgrading (according to GRADE criteria) largely due to risk of bias and imprecision. We summarise the results of comparisons with meta-analysed data below:- film dressings compared with basic wound contact dressings following clean surgery (RR 1.34, 95% CI 0.70 to 2.55), very low certainty evidence downgraded once for risk of bias and twice for imprecision.- hydrocolloid dressings compared with basic wound contact dressings following clean surgery (RR 0.91, 95% CI 0.30 to 2.78), very low certainty evidence downgraded once for risk of bias and twice for imprecision.- hydrocolloid dressings compared with basic wound contact dressings following potentially contaminated surgery (RR 0.57, 95% CI 0.22 to 1.51), very low certainty evidence downgraded twice for risk of bias and twice for imprecision.- silver-containing dressings compared with basic wound contact dressings following clean surgery (RR 1.11, 95% CI 0.47 to 2.62), very low certainty evidence downgraded once for risk of bias and twice for imprecision.- silver-containing dressings compared with basic wound contact dressings following potentially contaminated surgery (RR 0.83, 95% CI 0.51 to 1.37), very low certainty evidence downgraded twice for risk of bias and twice for imprecision. Secondary outcomesThere was limited and low or very low certainty evidence on secondary outcomes such as scarring, acceptability of dressing and ease of removal, and uncertainty whether wound dressings influenced these outcomes.

AUTHORS' CONCLUSIONS

It is uncertain whether covering surgical wounds healing by primary intention with wound dressings reduces the risk of SSI, or whether any particular wound dressing is more effective than others in reducing the risk of SSI, improving scarring, reducing pain, improving acceptability to patients, or is easier to remove. Most studies in this review were small and at a high or unclear risk of bias. Based on the current evidence, decision makers may wish to base decisions about how to dress a wound following surgery on dressing costs as well as patient preference.

Negative-pressure wound therapy for prevention and treatment of surgical-site infections after vascular surgery

BACKGROUND

Indications for negative-pressure wound therapy (NPWT) in vascular surgical patients are expanding. The aim of this review was to outline the evidence for NPWT on open and closed wounds.

METHODS

A PubMed, EMBASE and Cochrane Library search from 2007 to June 2016 was performed combining the medical subject headings terms 'wound infection', 'abdominal aortic aneurysm (AAA)', 'fasciotomy', 'vascular surgery' and 'NPWT' or 'VAC'.

RESULTS

NPWT of open infected groin wounds was associated with shorter duration of wound healing by 47 days, and was more cost-effective than alginate dressings in one RCT. In one RCT and six observational studies, NPWT-related major bleeding and graft preservation rates were 0-10 and 83-100 per cent respectively. One retrospective comparative study showed greater wound size reduction per day, fewer dressing changes, quicker wound closure and shorter hospital stay with NPWT compared with gauze dressings for lower leg fasciotomy. NPWT and mesh-mediated fascial traction after AAA repair and open abdomen was associated with high primary fascial closure rates (96-100 per cent) and low risk of graft infection (0-7 per cent). One retrospective comparative study showed a significant reduction in surgical-site infection, from 30 per cent with standard wound care to 6 per cent with closed incisional NPWT.

CONCLUSION

NPWT has a central role in open and infected wounds after vascular surgery; the results of prophylactic care of closed incisions are promising.

New WHO recommendations on intraoperative and postoperative measures for surgical site infection prevention: an evidence-based global perspective

Surgical site infections (SSIs) are the most common health-care-associated infections in developing countries, but they also represent a substantial epidemiological burden in high-income countries. The prevention of these infections is complex and requires the integration of a range of preventive measures before, during, and after surgery. No international guidelines are available and inconsistencies in the interpretation of evidence and recommendations in national guidelines have been identified. Considering the prevention of SSIs as a priority for patient safety, WHO has developed evidence-based and expert consensus-based recommendations on the basis of an extensive list of preventive measures. We present in this Review 16 recommendations specific to the intraoperative and postoperative periods. The WHO recommendations were developed with a global perspective and they take into account the balance between benefits and harms, the evidence quality level, cost and resource use implications, and patient values and preferences.

Local perivascular adiponectin associates with lower extremity vascular operative wound complications

BACKGROUND

Wound complication rates after lower extremity vascular operative procedures stand as high as 40% and represent a major cause of morbidity, mortality, and cost. In view of increasing recognition of adipose tissue involvement in homeostasis and the response to injury, we hypothesized that adipose phenotype is linked to operative wound outcomes.

METHODS

Clinical history, peripheral blood, and subcutaneous and perivascular adipose tissue were prospectively collected at the time of operation in patients undergoing lower extremity revascularization and lower extremity amputations. Nine biologic mediators (adiponectin; interleukin [IL]-1β, IL-6, and IL-8; leptin; monocyte chemoattractant protein-1; plasminogen activator inhibitor-1; resistin; and tumor necrosis factor) were assayed in the adipose tissues and plasma. The 30-day wound complications were captured in real time. Logarithmic transformation of mediator levels was performed based on positively skewed, non-Gaussian distribution, and data were compared using the Student t test. Bonferroni correction was used for multiple comparisons.

RESULTS

Sixty-six patients undergoing lower extremity revascularization or lower extremity amputations for severe peripheral arterial disease were enrolled. The 30-day follow-up was 92.4%. In total, 19 (29%) patients developed wound complications. Patients who developed wound complications had elevated perivascular adiponectin levels (mean ± standard error, 2,372.45 ± 648.64 ng/mL vs 832.53 ± 180.54 ng/mL, P = .004). Perivascular IL-1β levels were lower among patients with wound dehiscence (0.41 ± 0.004 pg/mL vs 0.73 ± 0.09 pg/mL, P = .001).

CONCLUSION

Local adipose tissue mediator levels at the time of operation demonstrate a previously undescribed compartment-specific relationship to wound outcomes in patients undergoing lower extremity vascular operative procedures. These associations provide fertile directives for defining the mechanisms underlying the pathogenesis of wound complications and their prevention.