Surgical-site infection

Is barbed better? Evaluation of triclosan-coated barbed suture on wound complications following emergency laparotomy

INTRODUCTION

Emergent laparotomy is associated with significant wound complications including surgical site infections (SSIs) and fascial dehiscence. Triclosan-coated barbed (TCB) suture for fascial closure has been shown to reduce local complications but primarily in elective settings. We sought to evaluate the effect of TCB emergency laparotomy fascial closure on major wound complications.

METHODS

Adult patients undergoing emergency laparotomy were prospectively evaluated over 1 year. Patients were grouped into TCB versus polydioxanone (PDS) for fascial closure. Subanalysis was performed on patients undergoing single-stage laparotomy. Primary outcomes were SSI and fascial dehiscence. Multivariate analysis identified independent factors associated with SSI and fascial dehiscence.

RESULTS

Of the 206 laparotomies, 73 (35%) were closed with TCB, and 133 (65%) were closed with PDS. Trauma was the reason for laparotomy in 73% of cases; damage-control laparotomy was performed in 27% of cases. The overall rate of SSI and fascial dehiscence was 18% and 10%, respectively. Operative strategy was similar between groups, including damage-control laparotomy, wound vac use, skin closure, and blood products. Surgical site infection events trended lower with TCB versus PDS closure (11% vs. 21%, p = 0.07), and fascial dehiscence was significantly lower with TCB versus PDS (4% vs. 14%, p < 0.05). Subanalysis of trauma and nontrauma cases showed no difference in SSI or fascial dehiscence. Multivariable analysis found that TCB decreased the likelihood of fascial dehiscence (odds ratio, 0.07; p < 0.05) following emergency laparotomy. Increased odds of fascial dehiscence were seen in damage-control laparotomy (odds ratio, 3.1; p < 0.05).

CONCLUSION

Emergency laparotomy fascial closure with TCB showed significantly decreased rates of fascial dehiscence compared with closure with PDS and a strong trend toward lower SSI events. Triclosan-coated barbed suture was independently associated with decreased fascial dehiscence rates after emergency laparotomy.

LEVEL OF EVIDENCE

Therapeutic/Care Management; Level III.

Photoactive rhodamine-based photosensitizer eliminates Staphylococcus aureus via superoxide radical photosensitization

Due to the antibiotics abuse, bacterial infection has become one of the leading causes of human death worldwide. Novel selective antimicrobial agents are urgently needed, with the hope of maintaining the balance of the microbial environment. Photo-activated chemotherapeutics have shown great potential to eliminate bacteria with appealing spatiotemporal selectivity. In this work, we reported the structural modification to enhance the triplet excited state property of Rhodamine B, synthesizing a rhodamine-based photosensitizer RBPy. Upon light activation, RBPy exhibited much stronger photosensitization ability than the parent compound Rhodamine B both in solution and in bacteria. Importantly, RBPy can selectively inactivate Staphylococcus aureus and inhibit biofilm formation with high biocompatibility. This work provides a new strategy to develop rhodamine-based photoactive chemotherapeutics for antimicrobial photodynamic therapy.

Plus Sutures for preventing surgical site infection: a systematic review of clinical outcomes with economic and environmental models

BACKGROUND

Surgical site infections (SSIs) represent ~ 20% of all hospital-acquired infections in surgical patients and are associated with prolonged hospital stay, admission to intensive care, and mortality. We conducted a systematic review with economic and environmental models to assess whether triclosan-coated sutures (Plus Sutures) provide benefits over non-coated sutures in the reduction of SSI risk.

METHODS

Searches were conducted in fifteen databases. A total of 1,991 records were retrieved. Following deduplication and screening by two independent reviewers, 31 randomized controlled trials in adults and children were included in the review. Similarity of the studies was assessed by narrative review and confirmed by quantitative assessment. A fixed effects meta-analysis of SSI incidence model including all groups of patients estimated a risk ratio of 0.71 (95% confidence interval: 0.64 to 0.79) indicating those in the Plus Sutures group had a 29% reduction in the risk of developing an SSI compared with those in the control group (p < 0.001). Safety outcomes were analysed qualitatively.

RESULTS

The economic model estimated the use of Plus Sutures to result in average cost savings of £13.63 per patient. Plus Sutures remained cost-saving in all subgroup analyses with cost-savings ranging between £11 (clean wounds) and £140 (non-clean wounds). The environmental impact of SSI is substantial, and the model suggests that the introduction of Plus Sutures could result in potential environmental benefits.

CONCLUSIONS

The evidence suggests that Plus Sutures are associated with a reduced incidence of SSI across all surgery types alongside cost savings when compared with standard sutures.

Assessment of antimicrobial activity of melittin encapsulated in bicontinuous microemulsions prepared using renewable oils

The objective of this study is to demonstrate that melittin, a well-studied antimicrobial peptide (AMP), can be solubilized in an active form in bicontinuous microemulsions (BMEs) that employ biocompatible oils. The systems investigated consisted of Winsor-III and -IV BME phases composed of Water/Aerosol-OT (AOT)/Polysorbate 85/isopropyl myristate and a Winsor-IV BME employing Polysorbate 80 and limonene. We found that melittin resided in an α-helix-rich configuration and was in an apolar environment for the AOT/Polysorbate 85 Winsor-III system, suggesting that melittin interacted with the surfactant monolayer and was in an active conformation. An apolar environment was also detected for melittin in the two Winsor-IV systems, but to a lesser extent than the Winsor-III system. Small-angle X-ray scattering analysis indicated that melittin at a concentration of 1.0 g/Laq in the aqueous subphase of the Winsor-IV systems led to the greatest impact on the BME structure (e.g., decrease of quasi-periodic repeat distance and correlation length and induction of interfacial fluidity). The antimicrobial activity of the Polysorbate 80 Winsor-IV system was evaluated against several bacteria prominent in chronic wounds and surgical site infections (SSIs). Melittin-free BMEs inhibited the growth of all tested bacteria due to its oil, limonene, while the inclusion of 1.0 g/Laq of melittin in the BMEs enhanced the activity against several bacteria. A further increase of melittin concentration in the BMEs had no further enhancement. These results demonstrate the potential utility of BMEs as a delivery platform for AMPs and other hydrophilic and lipophilic drugs to inhibit antibiotic-resistant microorganisms in chronic wounds and SSIs.

The Role of Hyperbaric Oxygen Therapy in the Treatment of Surgical Site Infections: A Narrative Review

Surgical site infections (SSIs) are among the most prevalent postoperative complications, with significant morbidity and mortality worldwide. In the past half century, hyperbaric oxygen therapy (HBOT), the administration of 100% oxygen intermittently under a certain pressure, has been used as either a primary or alternative therapy for the management or treatment of chronic wounds and infections. This narrative review aims to gather information and evidence supporting the role of HBOT in the treatment of SSIs. We followed the Scale for the Quality Assessment of Narrative Review Articles (SANRA) guidelines and scrutinized the most relevant studies identified in Medline (via PubMed), Scopus, and Web of Science. Our review indicated that HBOT can result in rapid healing and epithelialization of various wounds and has potential beneficial effects in the treatment of SSIs or other similar infections following cardiac, neuromuscular scoliosis, coronary artery bypass, and urogenital surgeries. Moreover, it was a safe therapeutic procedure in most cases. The mechanisms related to the antimicrobial activity of HBOT include direct bactericidal effects through the formation of reactive oxygen species (ROS), the immunomodulatory effect of HBOT that increase the antimicrobial effects of the immune system, and the synergistic effects of HBOT with antibiotics. We emphasized the essential need for further studies, especially randomized clinical trials and longitudinal studies, to better standardize HBOT procedures as well as to determine its full benefits and possible side effects.

Peri-Operative Method of Applying Chlorhexidine and Iodine as Skin Preparation Solutions: Does It Matter? A Literature Review

Background: Surgical site infection (SSI) is an adverse event that can lead to increased pain, increased cost, risk of death, and decreased patient satisfaction. Studies have investigated the best solutions to prevent SSI. Chlorhexidine has been suggested as the most efficacious antiseptic. However, scant data exist on application of antiseptic solutions and effectiveness of concentric versus back-and-forth strokes. Because a specific method may result in better outcomes, we aimed to review the literature to compare these two techniques. Methods: PubMed-indexed articles were reviewed using specific keywords, including "back-and-forth," "concentric circle," "chlorhexidine," "iodine," "surgical site infection," "antiseptic," and "skin preparation." Because data showing the correlation between SSI and application method of skin preparation solutions were scant, studies that described skin preparation method but analyzed other types of infection, bacteremia, or colonization were also included in this review. Results: No consensus was found regarding the application method. Two articles showed the superiority of chlorhexidine applied using the back-and-forth technique, whereas one demonstrated the superiority of iodine applied in concentric circles. Conclusions: The method of applying antiseptic solution may be just as important as the choice of solution. More studies are needed to assess method of antiseptic application.

Risk Factors Analysis of Surgical Infection Using Artificial Intelligence: A Single Center Study

Background: Surgical site infections (SSIs) have a major role in the evolution of medical care. Despite centuries of medical progress, the management of surgical infection remains a pressing concern. Nowadays, the SSIs continue to be an important factor able to increase the hospitalization duration, cost, and risk of death, in fact, the SSIs are a leading cause of morbidity and mortality in modern health care. Methods: A study based on statistical test and logistic regression for unveiling the association between SSIs and different risk factors was carried out. Successively, a predictive analysis of SSIs on the basis of risk factors was performed. Results: The obtained data demonstrated that the level of surgery contamination impacts significantly on the infection rate. In addition, data also reveals that the length of postoperative hospital stay increases the rate of surgical infections. Finally, the postoperative length of stay, surgery department and the antibiotic prophylaxis with 2 or more antibiotics are a significant predictor for the development of infection. Conclusions: The data report that the type of surgery department and antibiotic prophylaxis there are a statistically significant predictor of SSIs. Moreover, KNN model better handle the imbalanced dataset (48 infected and 3983 healthy), observing highest accuracy value.

Reactivity Differences Enable ROS for Selective Ablation of Bacteria

An effective strategy to engineer selective photodynamic agents to surmount bacterial-infected diseases, especially Gram-positive bacteria remains a great challenge. Herein, we developed two examples of compounds for a proof-of-concept study where reactive differences in reactive oxygen species (ROS) can induce selective ablation of Gram-positive bacteria. Sulfur-replaced phenoxazinium (NBS-N) mainly generates a superoxide anion radical capable of selectively killing Gram-positive bacteria, while selenium-substituted phenoxazinium (NBSe-N) has a higher generation of singlet oxygen that can kill both Gram-positive and Gram-negative bacteria. This difference was further evidenced by bacterial fluorescence imaging and morphological changes. Moreover, NBS-N can also successfully heal the Gram-positive bacteria-infected wounds in mice. We believe that such reactive differences may pave a general way to design selective photodynamic agents for ablating Gram-positive bacteria-infected diseases.

Health care-associated infections: Controlled delivery of cationic antiseptics from polymeric excipients

Nowadays, the treatment of health care-associated infections represents a serious issue, due to the increasing number of bacterial strains resistant to traditional antibiotics. The use of antiseptics like quaternary ammonium salts and biguanides is a viable alternative to face these life-threatening infections. However, their inherent toxicity as well as the necessity of providing a sustained release to avoid the formation of pathogen biofilms are compelling obstacles towards their assessment in the hospitals. Within this framework, the role of polymeric drug delivery systems is fundamental to overcome the aforementioned problems. Biocompatibility, biodegradability and excipient-drug interactions are crucial properties determining the efficacy of the formulation. In this work, we provide an in-depth analysis of the polymer drug delivery systems that have been developed or are under development for the sustained release of positively charged antiseptics, highlighting the crucial characteristics that allowed to achieve the most relevant therapeutic effects. We reported and compared natural occurring polymers and synthetic carriers to show their pros and cons and applicability in the treatment of health care-associated infections. Then, the discussion is focused on a particularly relevant class of materials adopted for the scope, represented by polyesters, which gave rise, due to their biodegradability, to the field of resorbable drug delivery devices. Finally, a specific analysis on the effect of the polymer functionalization over the formulation performances for the different types of polymeric carriers is presented.

Emerging trends in aggregation induced emissive luminogens as bacterial theranostics

The emergence and spread of pathogenic bacteria, particularly antibiotic-resistant strains pose grave global concerns worldwide, which demand for the rapid development of highly selective and sensitive strategies for specific bacterial detection, identification, imaging and therapy. The fascinating feature of aggregation-induced emissive molecules (AIEgens) to display fluorescence in aggregate form can be suitably coupled with nanotechnology for developing theranostic AIE dots that can offer convenient and customised functions such as sensing, imaging, detection, discrimination and cell kill of different bacterial types. The initial section of the article reveals the necessity for incorporating diagnostic imaging with antibacterial therapy, while the latter part delivers mechanistic insights on the benefits of AIE fluorophores in theranostic applications. Further, the review illustrates the recent advancements of AIEgens as theranostic nanolights in bacterial detection, identification and eradication. The review is organised according to the different classes of AIE-active bacterial theranostics such as carrier-free nanoprodrugs, nanomachines for synergistic imaging-guided cancer treatment and bacterial kill, AIE polymers, bioconjugates and nanoparticle carriers. By elucidating their design principles and applications, as well as highlighting the recent trends and perspectives that can be further explored, we hope to instill more research interest in AIE bacterial theranostics for future translational research.HighlightsCombination of aggregation induced emissive fluorophores and nanotechnology for developing bacterial theranostics.AIE theranostics with customised functions for bacterial imaging, detection, discrimination and cell kill.

Heterogeneous ceramide distributions alter spatially resolved growth of Staphylococcus aureus on human stratum corneum

Contemporary studies have revealed dramatic changes in the diversity of bacterial microbiota between healthy and diseased skin. However, the prevailing use of swabs to extract the microorganisms has meant that only population 'snapshots' are obtained, and all spatially resolved information of bacterial growth is lost. Here we report on the temporospatial growth of Staphylococcus aureus on the surface of the human stratum corneum (SC); the outermost layer of skin. This bacterial species dominates bacterial populations on skin with atopic dermatitis (AD). We first establish that the distribution of ceramides naturally present in the SC is heterogeneous, and correlates with the tissue's structural topography. This distribution subsequently impacts the growth of bacterial biofilms. In the SC retaining healthy ceramide concentrations, biofilms exhibit no spatial preference for growth. By contrast, a depletion of ceramides consistent with reductions known to occur with AD enables S. aureus to use the patterned network of topographical canyons as a conduit for growth. The ability of ceramides to govern bacterial growth is confirmed using a topographical skin canyon analogue coated with the ceramide subcomponent d-sphingosine. Our work appears to explain the causal link between ceramide depletion and increased S. aureus populations that is observed in AD. It may also provide insight into disease transmission as well as improving pre-operative skin cleansing techniques.

The use of triclosan-coated sutures to prevent surgical site infections: a systematic review and meta-analysis of the literature

INTRODUCTION AND OBJECTIVES

Surgical site infections (SSIs) represent a common and serious complication of all surgical interventions. Microorganisms are able to colonise sutures that are implanted in the skin, which is a causative factor of SSIs. Triclosan-coated sutures are antibacterial sutures aimed at reducing SSIs. Our objective is to update the existing literature by systematically reviewing available evidence to assess the effectiveness of triclosan-coated sutures in the prevention of SSIs.

METHODS

A systematic review of EMBASE, MEDLINE, AMED (Allied and complementary medicine database) and CENTRAL was performed to identify full text randomised controlled trials (RCTs) on 31 May 2019.

INTERVENTION

Triclosan-coated sutures versus non-triclosan-coated sutures.

PRIMARY OUTCOME

Our primary outcome was the development of SSIs at 30 days postoperatively. A meta-analysis was performed using a fixed-effects model.

RESULTS

Twenty-five RCTs were included involving 11 957 participants. Triclosan-coated sutures were used in 6008 participants and non triclosan-coated sutures were used in 5949. Triclosan-coated sutures significantly reduced the risk of SSIs at 30 days (relative risk 0.73, 95% CI 0.65 to 0.82). Further sensitivity analysis demonstrated that triclosan-coated sutures significantly reduced the risk of SSIs in both clean and contaminated surgery.

CONCLUSION

Triclosan-coated sutures have been shown to significantly reduced the risk of SSIs when compared with standard sutures. This is in agreement with previous work in this area. This study represented the largest review to date in this area. This moderate quality evidence recommends the use of triclosan-coated sutures in order to reduce the risk of SSIs particularly in clean and contaminated surgical procedures.

PROSPERO REGISTRATION NUMBER

CRD42014014856.

Impact of blood transfusion on major infection after isolated coronary artery bypass surgery: Incidence and risk factors

Background/aim

Cardiac surgery is considered one of the conditions that require a transfusion of blood and blood products in large amount. Infections are one of the most common complications after cardiac surgery. The aim of this study is to assess the impact of blood transfusion on major infections after isolated coronary artery bypass surgery (CABG).

Methods

A retrospective cohort study was conducted at King Abdulaziz Cardiac Center. Eligible adult patients, aged >18 years, who underwent an isolated CABG from 2015 to 2016, were included. Patient demographic information, as well as pre-, intra-, and postoperative data were collected from the electronic hospital information system charts and perfusion records. For data analysis, categorical pre- and postoperative variables were summarized by frequencies and percentages, whereas for continuous variables, means and standard deviation or median and interquartile ranges were used.

Results

The sample size was 459 patients. Red blood cells (RBCs) were transfused in 60.1% of the patients, and the median number of units transfused per patient was 2. The mean hemoglobin threshold for transfusion was 8.2 (standard deviation ± 3.6) g/dL. The mean EuroSCORE of RBC recipients was 3.8 ± 5.9% and that of non-RBC recipients was 2.0 ± 2.0%. In both groups (RBC recipients and non-RBC recipients), the most frequent infections after CABG were pneumonia (12% and 8.7%, respectively), deep surgical site infection (3.6% and 0.5%, respectively), and superficial sternal infection (6.9% and 3.8%, respectively), with a statistically significant difference (all p < 0.05). Patients receiving a blood transfusion at any stage during the intraoperative or postoperative period were 2.6 times more likely to develop an infection compared with those who did not receive a blood transfusion. The recipients of a blood transfusion experienced a longer hospital stay compared with the non-recipients at 11.5 ± 9.8 days versus 8.7 ± 3.4 days, respectively.

Conclusions

Blood transfusion appears to increase the risk of infection post-CABG. However, increased understanding of the role of other potential clinical confounding variables that may impact the infection rate is required. We recommend management strategies that limit RBC transfusion.

Predictors of surgical site infection after radical cystectomy: should we enhance surgical antibiotic prophylaxis?

PURPOSE

To compare surgical site infections (SSI) rate after radical cystectomy (RC) over time and ascertain whether antibiotic prophylaxis should be enhanced.

METHODS

All medical records of RC patients in a single tertiary uro-oncology center between 2007 and 2017 were analyzed. SSI was defined using the criteria of the US Centers for Disease Control and Prevention. All bacterial culture results and antimicrobial resistance rates were recorded. Lastly, multivariable logistic regression analysis was performed to ascertain SSI predictors.

RESULTS

RC was performed in 405 patients, of which 96 (23.7%) developed SSI. No differences were demonstrated in the mean age, gender, NIDDM prevalence, neoadjuvant chemotherapy, positive preoperative urine culture, bowel preparation, and surgery time between both groups. However, statistically significant higher median BMI, age-adjusted Charlson Comorbidity score, usage of ceftriaxone preoperatively, and intensive care unit (ICU) hospitalization were noted in SSI patients. Overall, 62/96 (63.5%) SSI patients had a positive wound culture, with only 16.7% of the pathogens being sensitive to their perioperative antibiotics. Lastly, on multivariable analysis rising BMI, preoperative ceftriaxone and ICU hospitalization were associated with a higher SSI rate.

CONCLUSIONS

Preoperative BMI reduction, and maximal preoperative medical optimization in an attempt to lower ICU admittance rates, should be part of the ideal strategy for lowering SSI rates. Additionally, preoperative antibiotics should be enhanced to harbor-wide spectrum coverage, based on local resistance rates.

A multifunctional luminogen with aggregation-induced emission characteristics for selective imaging and photodynamic killing of both cancer cells and Gram-positive bacteria

The increasing impact of bacteria on cancer progression and treatments has been witnessed in recent years. Insufficient attention to cancer-related bacteria may lead to distant metastasis, poor therapeutic efficiency and low survival rates for cancers. Exploiting new approaches that enable selective imaging and effective killing of cancer cells and bacteria are thus of great value for the battle against cancers. Herein, we report an aggregation-induced emission (AIE) luminogen, namely TPPCN, with intense emission and efficient reactive oxygen species production for fluorescence imaging and killing cancer cells and Gram-positive bacteria. This work not only demonstrates the potential of AIE luminogens in comprehensive cancer treatments but also stimulates the enthusiasm of scientists to design more multifunctional AIE systems for both cancer and bacteria theranostics.

Three-Dimensional Printing Antimicrobial and Radiopaque Constructs

Three-dimensional (3D) printing holds tremendous potential as a tool for patient-specific devices. This proof-of- concept study demonstrated the feasibility, antimicrobial properties, and computed tomography(CT) imaging characteristics of iodine/polyvinyl alcohol (PVA) 3D meshes and stents. Under scanning electron microscopy, cross-linked PVA displays smoother and more compacted filament arrangements. X-ray and transaxial CT images of iodized PVA vascular stents show excellent visibility and significantly higher Hounsfield units of radiopacity than control prints. Three-dimensional PVA prints stabilized by glutaraldehyde cross-linking and loaded with iodine through sublimation significantly suppressed Escherichia coli and Staphylococcus aureus growth in human blood agar disk diffusion assays. It is suggested that PVA 3D printing with iodine represents an important new synthetic platform for generating a wide variety of antimicrobial and high-visibility devices.

Viable adhered Staphylococcus aureus highly reduced on novel antimicrobial sutures using chlorhexidine and octenidine to avoid surgical site infection (SSI)

BACKGROUND

Surgical sutures can promote migration of bacteria and thus start infections. Antiseptic coating of sutures may inhibit proliferation of adhered bacteria and avoid such complications.

OBJECTIVES

This study investigated the inhibition of viable adhering bacteria on novel antimicrobially coated surgical sutures using chlorhexidine or octenidine, a critical factor for proliferation at the onset of local infections. The medical need, a rapid eradication of bacteria in wounds, can be fulfilled by a high antimicrobial efficacy during the first days after wound closure.

METHODS

As a pretesting on antibacterial efficacy against relevant bacterial pathogens a zone of inhibition assay was conducted with middle ranged concentrated suture coatings (22 μg/cm). For further investigation of adhering bacteria in detail the most clinically relevant Staphylococcus aureus (ATCC®49230™) was used. Absorbable braided sutures were coated with chlorhexidine-laurate, chlorhexidine-palmitate, octenidine-laurate, and octenidine-palmitate. Each coating type resulted in 11, 22, or 33 μg/cm drug content on sutures. Scanning electron microscopy (SEM) was performed once to inspect the coating quality and twice to investigate if bacteria have colonized on sutures. Adhesion experiments were assessed by exposing coated sutures to S. aureus suspensions for 3 h at 37°C. Subsequently, sutures were sonicated and the number of viable bacteria released from the suture surface was determined. Furthermore, the number of viable planktonic bacteria was measured in suspensions containing antimicrobial sutures. Commercially available sutures without drugs (Vicryl®, PGA Resorba®, and Gunze PGA), as well as triclosan-containing Vicryl® Plus were used as control groups.

RESULTS

Zone of inhibition assay documented a multispecies efficacy of novel coated sutures against tested bacterial strains, comparable to most relevant S. aureus over 48 hours. SEM pictures demonstrated uniform layers on coated sutures with higher roughness for palmitate coatings and sustaining integrity of coated sutures. Adherent S. aureus were found via SEM on all types of investigated sutures. The novel antimicrobial sutures showed significantly less viable adhered S. aureus bacteria (up to 6.1 log) compared to Vicryl® Plus (0.5 log). Within 11 μg/cm drug-containing sutures, octenidine-palmitate (OL11) showed the highest number of viable adhered S. aureus (0.5 log), similar to Vicryl® Plus. Chlorhexidine-laurate (CL11) showed the lowest number of S. aureus on sutures (1.7 log), a 1.2 log greater reduction. In addition, planktonic S. aureus in suspensions were highly inhibited by CL11 (0.9 log) represents a 0.6 log greater reduction compared to Vicryl® Plus (0.3 log).

CONCLUSIONS

Novel antimicrobial sutures can potentially limit surgical site infections caused by multiple pathogenic bacterial species. Therefore, a potential inhibition of multispecies biofilm formation is assumed. In detail tested with S. aureus, the chlorhexidine-laurate coating (CL11) best meets the medical requirements for a fast bacterial eradication. This suture coating shows the lowest survival rate of adhering as well as planktonic bacteria, a high drug release during the first-clinically most relevant- 48 hours, as well as biocompatibility. Thus, CL11 coatings should be recommended for prophylactic antimicrobial sutures as an optimal surgical supplement to reduce wound infections. However, animal and clinical investigations are important to prove safety and efficacy for future applications.

Sustained tobramycin release from polyphosphate double network hydrogels

Sustained local delivery of antibiotics from a drug reservoir to treat or prevent bacterial infections can avoid many of the drawbacks of systemic administration of antibiotics. Prolonged local release of high concentrations of antibiotics may also be more effective at treating bacteria in established biofilm populations that are resistant to systemic antibiotics. A double network hydrogel comprising an organic polyphosphate pre-polymer network polymerized within a polyacrylamide network de-swelled to about 50% of its initial volume when the polyphosphate network was crosslinked with polycationic tobramycin, an aminoglycoside antibiotic. The antibiotic-loaded hydrogels contained approximately 200mg/ml of tobramycin. The hydrogels continuously released daily amounts of tobramycin above the Pseudomonas aeruginosa minimal bactericidal concentration for greater than 50days, over the pH range 6.0-8.0, and completely eradicated established P. aeruginosa biofilms within 72h in a flow cell bioreactor. The presence of physiological concentrations of Mg²⁺ and Ca²⁺ ions doubled the cumulative release over 60days. The polyphosphate hydrogels show promise as materials for sustained localized tobramycin delivery to prevent post-operative P. aeruginosa infections including infections established in biofilms.

STATEMENT OF SIGNIFICANCE

Polyphosphate hydrogels were loaded with high concentrations of tobramycin. The hydrogels provided sustained release of bactericidal concentrations of tobramycin for 50days, and were capable of completely eradicating P. aeruginosa in established biofilms. The hydrogels have potential for localized prevention or treatment of P. aeruginosa infections.

Prevention of postsurgical wound dehiscence after abdominal surgery with NPWT: a multicentre randomised controlled trial protocol

OBJECTIVE

The effectiveness of negative pressure wound therapy (NPWT) in the prevention of postoperative surgical wound dehiscence (SWD) is the subject of much debate and remains to be determined. This study will identify individuals at risk of postoperative SWD and trial the use of NPWT as a prophylactic measure against the occurrence of SWD, compared with a non-NPWT standard surgical dressing (SSD).

METHOD

A prospective multicentre randomised controlled trial comparing NPWT dressing against standard surgical dressings (SSD) will be conducted. An intention-to-treat (ITT) approach will be used for the trial.

AIMS

The primary outcome is the prevention of postoperative SWD up to and including day 30 postoperative. Secondary outcomes are: prevention of surgical site infection (SSI) and economic analysis of treatment groups.

CONCLUSION

This study will determine the effectiveness of NPWT in the prevention of postoperative abdominal SWD in a predefined level of risk population. This level 1 study will provide further data for abdominal SWD risk classification, which is anticipated to inform preventive postoperative management. The study design uses a prospective real-world scenario in order to identify clinically significant differences between the intervention and control groups.

TRIAL REGISTRATION

This trial was prospectively registered on 10 December 2012 with Australian and New Zealand Clinical Trials Network (ANZCTR): 12612001275853.

Perioperative Allogeneic Blood Transfusion Is Associated With Surgical Site Infection After Abdominoperineal Resection-a Space for the Implementation of Patient Blood Management Strategies

Allogeneic blood transfusion (ABT) has been reported as a major risk factor for surgical site infection (SSI) in patients undergoing colorectal surgery. However, the association of ABT with SSI in patients undergoing abdominoperineal resection (APR) and total pelvic exenteration (TPE) still remains to be evaluated. Here, we aim to elucidate this association. The medical records of all patients undergoing APR and TPE at our institution in the period between January 2000 and December 2012 were reviewed. Patients without SSI (no SSI group) were compared with patients who developed SSI (SSI group), in terms of clinicopathologic features, including ABT. In addition, data for 262 patients who underwent transabdominal rectal resection at our institution in the same period were also enrolled, and their data on differential leukocyte counts were evaluated. Multivariate analysis showed that intraoperative transfusion was an independent predictive factor for SSI after APR and TPE (P = 0.004). In addition, the first-operative day lymphocyte count of patients undergoing APR, TPE, and transabdominal rectal resection was significantly higher in nontransfusion patients compared with transfusion ones (P = 0.026). ABT in the perioperative period of APR and TPE may have an important immunomodulatory effect, leading to an increased incidence of SSI. This fact should be carefully considered, and efforts to avoid allogeneic blood exposure while still achieving adequate patient blood management would be very important for patients undergoing APR and TPE as well.

Systematic review and meta-analysis of sutures coated with triclosan for the prevention of surgical site infection after elective colorectal surgery according to the PRISMA statement

BACKGROUND

Several randomized clinical trials (RCTs) conducted to evaluate the effect of triclosan-coated suture on surgical site infection (SSI) yield to controversial results. The primary purpose of this systematic review and meta-analysis was to analyze the available RCTs, comparing the effect of triclosan-coated suture with uncoated suture on the incidence of SSI after elective colorectal operations. As secondary endpoint of the analysis, we considered length of hospital stay after surgery.

METHODS

We performed a systematic literature review through Medline, Embase, Pubmed, Scopus, Ovid, ISI Web of Science, and the Cochrane Controlled Trials Register searching for RCTs published from 1990 to 2015. To conduct these meta-analyses, we followed the guidelines and the Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement. Study inclusion criteria were as follows: parallel-group RCTs in adult populations reporting the closure of the abdominal wall after elective colorectal operation with triclosan-coated suture or noncoated suture, and reporting the outcomes considered in the meta-analysis.

RESULTS

Six trials including 2168 patients (1102 treated and 1066 controls) provided data on SSIs. The overall rate was 11.7% (129/1102) in the triclosan group and 13.4% (143/1066) in the control group (odds ratio 0.81, 95% confidence interval [CI] 0.58-1.13, P = 0.220). Heterogeneity among studies was moderate (I = 44.9%). No evidence of publication bias was detectable. Five RCTs (1783 patients; 914 treated and 689 controls) described hospital length of stay with no significant effect (mean difference: -0.02, 95% CI -0.11 to -0.07, P = 0.668). The I test for heterogeneity was 0% (P = 0.836). Moderator analyses showed no significant differences were detected in analyses comparing the suture materials (polydioxanone vs polyglactin). In open-label trials, the odds ratio for SSI risk was 0.62 (95% CI 0.20-1.93, P = 0.413), 0.77 in single-blind (95% CI 0.31-1.95, P = 0.583) and 0.85 in double-blind trials (95% CI 0.46-1.54, P = 0.582).

CONCLUSIONS

Our findings failed to demonstrate a significant protective effect of triclosan-coated sutures on the occurrence of SSI after elective colorectal resections. Further large RCTs are needed before introducing this technology into clinical practice.

Wound management for the 21st century: combining effectiveness and efficiency

Treatment of wounds of different aetiologies constitutes a major part of the total health care budget. It is estimated that 1·5-2 million people in Europe suffer from acute or chronic wounds. These wounds are managed both in hospitals and in community care. The patients suffering from these wounds report physical, mental and social consequences of their wounds and the care of them. It is often believed that the use of wound dressings per se is the major cost driver in wound management, whereas in fact, nursing time and hospital costs are together responsible for around 80-85% of the total cost. Healing time, frequency of dressing change and complications are three important cost drivers. However, with the use of modern, advanced technology for more rapid wound healing, all these cost drivers can be substantially reduced. A basic understanding of the terminology and principles of Health Economics in relation to wound management might therefore be of interest.

Improving Surveillance for Surgical Site Infections Following Total Hip and Knee Arthroplasty Using Diagnosis and Procedure Codes in a Provincial Surveillance Network

OBJECTIVE

To evaluate hospital administrative data to identify potential surgical site infections (SSIs) following primary elective total hip or knee arthroplasty.

DESIGN

Retrospective cohort study.

SETTING

All acute care facilities in Alberta, Canada.

METHODS

Diagnosis and procedure codes for 6 months following total hip or knee arthroplasty were used to identify potential SSI cases. Medical charts of patients with potential SSIs were reviewed by an infection control professional at the acute care facility where the patient was identified with a diagnosis or procedure code. For SSI decision, infection control professionals used the National Healthcare Safety Network SSI definition. The performance of traditional surveillance methods and administrative data–triggered medical chart review was assessed.

RESULTS

Of the 162 patients identified by diagnosis or procedure code, 46 (28%) were confirmed as an SSI by an infection control professional. More SSIs were identified following total hip vs total knee arthroplasty (42% vs16%). Of 46 confirmed SSI cases, 20 (43%) were identified at an acute care facility different than their procedure facility. Administrative data–triggered medical chart review with infection control professional confirmation resulted in a 1.1- to 1.7-fold increase in SSI rate compared with traditional surveillance. SSIs identified by administrative data resulted in sensitivity of 90% and specificity of 99%.

CONCLUSION

Medical chart review for cases identified through administrative data is an efficient supplemental SSI surveillance strategy. It improves case-finding by increasing SSI identification and making identification consistent across facilities, and in a provincial surveillance network it identifies SSIs presenting at nonprocedure facilities.

Infect Control Hosp Epidemiol 2016;37:699–703

Meta-analysis of local gentamicin for prophylaxis of surgical site infections in colorectal surgery

PURPOSE

Surgical site infections (SSIs) following colorectal surgery is common, and local application of gentamicin for SSIs in the surgery remains controversial.

OBJECTIVE

To identify whether local application of gentamicin reduces incidence of SSIs in colorectal surgery.

METHODS

PubMed, Embase, the Cochrane Library, and Science Citation Index were searched for relevant randomized controlled trials (RCTs) and reference list up to November 2014. Two independent reviewers screened the records from the electronic databases, selected relevant studies, assessed the methodological quality, and extracted the data from included articles. Stata 12.0 was used to conduct a pooled analysis for main outcomes.

RESULTS

Eight relevant randomized controlled trials with a total of 1685 patients were included in the meta-analysis. All included studies were of moderate to high quality by the Cochrane Collaboration's tool for assessing risk of bias. There was no significant difference being found in the total pooled results for wound infection (relative risk (RR) 0.73, 95% confidence interval (CI) 0.47 to 1.12) and organ space infection (RR 0.90, 95% CI 0.51 to 1.59). However, subgroup analysis showed that the significant decrease of wound infection was associated with the population in the Western Europe (RR 0.60, 95% CI 0.42 to 0.87) and follow-up periods of 30 days (RR 0.63, 95% CI 0.42 to 0.94).

CONCLUSIONS

Local application of gentamicin significantly reduced incidence of wound infection following colorectal surgery in Western Europe, and it was also associated with lower risk of wound infection during follow-up period of 30 days. However, its effectiveness on prophylaxis of perineal wound infection and organ space infection still lacked evidence.

High inspired oxygen versus low inspired oxygen for reducing surgical site infection: a meta-analysis

To perform a meta-analysis of published literature to assess the role of high-concentration inspired oxygen in reducing the incidence of surgical site infections (SSIs) following all types of surgery, a comprehensive search for published randomized controlled trials (RCTs) comparing high- with low-concentration inspired oxygen for SSIs was performed. The related data were extracted by two independent authors. The fixed and random effects methods were used to combine data. Twelve RCTs involving 6750 patients were included. Our pooled result found that no significant difference in the incidence of SSIs was observed between the two groups, but there was high statistic heterogeneity across the studies [risk ratio (RR): 0·91; 95% confidence interval (CI): 0·72-1·14; P = 0·40; I² = 54%]. The sensitivity analysis revealed the superiority of high-concentration oxygen in decreasing the SSI rate (RR: 0·86; 95% CI: 0·75-0·98; P = 0·02). Moreover, a subgroup analysis of studies with intestinal tract surgery showed that patients experienced less SSI when high-concentration inspired oxygen was administrated (RR: 0·53; 95% CI: 0·37-0·74; P = 0·0003). Our study provided no direct support for high-concentration inspired oxygen in reducing the incidence of SSIs in patients undergoing all types of surgery.

In vitro evaluation of novel antimicrobial coatings for surgical sutures using octenidine

BACKGROUND

Sutures colonized by bacteria represent a challenge in surgery due to their potential to cause surgical site infections. In order to reduce these type of infections antimicrobially coated surgical sutures are currently under development. In this study, we investigated the antimicrobial drug octenidine as a coating agent for surgical sutures. To achieve high antimicrobial efficacy and required biocompatibility for medical devices, we focused on optimizing octenidine coatings based on fatty acids. For this purpose, antimicrobial sutures were prepared with either octenidine-laurate or octenidine-palmitate at 11, 22, and 33 μg/cm drug concentration normalized per length of sutures. Octenidine containing sutures were compared to the commercial triclosan-coated suture Vicryl® Plus. The release of octenidine into aqueous solution was analyzed and long-term antimicrobial efficacy was assessed via agar diffusion tests using Staphylococcus aureus. For determining biocompatibility, cytotoxicity assays (WST-1) were performed using L-929 mouse fibroblasts.

RESULTS

In a 7 days elution experiment, octenidine-palmitate coated sutures demonstrated much slower drug release (11 μg/cm: 7%; 22 μg/cm: 5%; 33 μg/cm: 33%) than octenidine-laurate sutures (11 μg/cm: 82%; 22 μg/cm: 88%; 33 μg/cm: 87%). Furthermore sutures at 11 μg/cm drug content were associated with acceptable cytotoxicity according to ISO 10993-5 standard and showed, similar to Vicryl® Plus, relevant efficacy to inhibit surrounding bacterial growth for up to 9 days.

CONCLUSIONS

Octenidine coated sutures with a concentration of 11 μg/cm revealed high antimicrobial efficacy and biocompatibility. Due to their delayed release, palmitate carriers should be preferred. Such coatings are candidates for clinical testing in regard to their safety and efficacy.

Multi-Center Randomized Controlled Trial on the Effect of Triclosan-Coated Sutures on Surgical Site Infection after Colorectal Surgery

BACKGROUND

Surgical site infection (SSI) remains the most frequent complication after colorectal resection. The role of sutures coated with antimicrobial agents such as triclosan in reducing SSI is controversial.

METHODS

This was a multi-center randomized controlled trial with patients and outcome assessors blinded to treatment. The study was performed in four university referral hospitals. Patient candidates for elective colorectal resection were assigned randomly to abdominal incision closure with polyglactin 910 triclosan-coated sutures (triclosan group) or with polyglactin 910 without triclosan (control group). The primary outcome was the rate of SSI within 30 d after hospital discharge. The secondary outcomes were the overall rate of incision complications and length of hospital stay (LOS).

RESULTS

Two hundred eighty-one patients (triclosan group: 140; control group: 141) were analyzed after randomization. The rate of SSI was 12.9% (18/140) in the triclosan group versus 10.6% (15/141) in the control group (odds ratio: 1.24; 95% confidence interval: 0.60-2.57; p=0.564). Secondary outcome analysis showed an overall incision complication rate of 38.3% in the control group versus 45.7% in the triclosan group (odds ratio: 1.36; 95% confidence interval: 0.84-2.18; p=0.208). Median LOS was 11 d in both groups (p=0.55).

CONCLUSIONS

Surgical sutures coated with triclosan do not appear to be effective in reducing the rate of SSI.

The right skin preparation technique: a literature review

Recent debates and guidelines are suggesting back and forth motion to be the optimal preoperative technique for skin preparation. There is a lack of conclusive evidence showing this to be the case, but it may be reasonable to follow this technique, in preference to the widely used concentric circles motion, as the antiseptic agent will reach deeper cell layers of the skin where most of the microbes are found.

Sutures in abdominal surgery: biomechanical study and clinical application

The aim of this study is to improve treatment results and SSI prevention by differential usage of the contemporary suture materials and choice of proper suturing technique. To simulate suturing process and compared two suturing techniques, two FE models were developed. Finite-element analysis (FEA) was based on experimental data of contemporary commercial sutures and soft tissue properties. We applied obtained results for abdominal wall closure in rats and compared non-absorbable suture (capron) with absorbable suture (PDS Plus) for chosen technique. Cross-sections were examined by lighting electron microscope. Afterwards, the results of patients’ treatment are also presented. It was shown that running sew was more appropriate for aponeurosis suturing compared to interrupted sew. The optimal parameters of suturing techniques were computed. Single-row running sew by PDS Plus was proved to hold wound edges for 90 days with less inflammatory response compared to other suture in the result of histological analysis. Application of contemporary synthetic absorbable suture materials with antibacterial coating for laparotomic wounds closure and anastomosis decreases local inflammatory reaction and provides the successful tissue regeneration. Application of advanced SSI prophylactics algorithm was shown to decrease risk of post-operative suppurative complications from 14.2 to 1.6 %.

'This wound has spoilt everything': emotional capital and the experience of surgical site infections

In this article we explore the experience of suffering from a surgical site infection, a common complication of surgery affecting around 5 per cent of surgical patients, via an interview study of 17 patients in the Midlands in the UK. Despite their prevalence, the experience of surgical site infections has received little attention so far. In spite of the impairment resulting from these iatrogenic problems, participants expressed considerable stoicism and we interpret this via the notion of emotional capital. This idea derives from the work of Pierre Bourdieu, Helga Nowotny and Diane Reay and helps us conceptualise the emotional resources accumulated and expended in managing illness and in gaining the most from healthcare services. Participants were frequently at pains not to blame healthcare personnel or hospitals, often discounting the infection's severity, and attributing it to chance, to 'germs' or to their own failure to buy and apply wound care products. The participants' stoicism was thus partly afforded by their refusal to blame healthcare institutions or personnel. Where anger was described, this was either defused or expressed on behalf of another person. Emotional capital is associated with deflecting the possibility of complaint and sustaining a deferential and grateful position in relation to the healthcare system.

Novel high efficient coatings for anti-microbial surgical sutures using chlorhexidine in fatty acid slow-release carrier systems

Sutures can cause challenging surgical site infections, due to capillary effects resulting in bacteria permeating wounds. Anti-microbial sutures may avoid these complications by inhibiting bacterial pathogens. Recently, first triclosan-resistances were reported and therefore alternative substances are becoming clinically relevant. As triclosan alternative chlorhexidine, the “gold standard” in oral antiseptics was used. The aim of the study was to optimize novel slow release chlorhexidine coatings based on fatty acids in surgical sutures, to reach a high anti-microbial efficacy and simultaneously high biocompatibility. Sutures were coated with chlorhexidine laurate and chlorhexidine palmitate solutions leading to 11, 22 or 33 µg/cm drug concentration per length. Drug release profiles were determined in aqueous elutions. Antibacterial efficacy against Staphylococcus aureus was assessed in agar diffusion tests. Biocompatibility was evaluated via established cytotoxicity assay (WST-1). A commercially triclosan-containing suture (Vicryl Plus), was used as anti-microbial reference. All coated sutures fulfilled European Pharmacopoeia required tensile strength and proved continuous slow drug release over 96 hours without complete wash out of the coated drug. High anti-microbial efficacy for up to 5 days was observed. Regarding biocompatibility, sutures using 11 µg/cm drug content displayed acceptable cytotoxic levels according to ISO 10993-5. The highest potential for human application were shown by the 11 µg/cm chlorhexidine coated sutures with palmitic acid. These novel coated sutures might be alternatives to already established anti-microbial sutures such as Vicryl Plus in case of triclosan-resistance. Chlorhexidine is already an established oral antiseptic, safety and efficacy should be proven for clinical applications in anti-microbial sutures.

Factors affecting the risk surgical site infection and methods of reducing

According to estimates by the National Audit Office (NAO) hospital acquired infections (HAl), in particular surgical site infections (SSls), cost the NHS on average 3200 pounds per SSI and cause a mortality rate of at least five thousand patients a year (Leaper 2010). Despite practitioners' knowledge of safe working technique and control of infection, reported cases of nosocomial infections are still high, despite a reduction in-rate from 9% in 1993/4 to 8.2% in 2006 (Roberts & Cookson 2009).

Patients’ experiences of surgical site infection

The qualitative experience of having a surgical site infection (SSI) is often overlooked. The aim of this study was to present a description of how SSIs affect the lives of patients and their families. Seventeen former patients from three hospitals in England were interviewed to explore their experience of having an SSI. The interview data was transcribed and analysed into the following themes – horror stories, physical effects, psychological effects, effect on families, feelings of relief, not blaming the hospital, and lack of support after discharge. Numerous articles describe SSIs as being ‘distressing’ for patients. This study reveals the extent of the distress, with patients describing feeling ‘utter despair’ and ‘wanting to die’. These symptoms continued for months after patients had been discharged from hospital.

Risk factors for surgical site infection after elective resection for rectal cancer. A multivariate analysis on 2131 patients

AIM

Surgical site infection (SSI) is the most common cause of morbidity after colorectal surgery. The aim of this study was to analyze risk factors for SSI in patients who had undergone surgery for rectal cancer.

METHOD

A multicentre observational study was carried out on 2131 patients operated on for rectal cancer between May 2006 and May 2009. Twenty-nine centres were involved. SSI included wound infection and organ space infection within 30 days after the operation. Univariate and multivariate analyses were carried out to study possible risk factors for SSI.

RESULTS

Wound infection and organ space infection were diagnosed in 8.9% and 10%, respectively, of patients. The anastomotic leakage rate was 8%. Multivariate analysis showed that wound infection was related to tumour stage, a converted laparoscopic procedure and open surgery. Organ space infection was related to Stage IV tumour, a tumour < 11 cm from the anal verge, low anterior resection and Hartmann's procedure.

CONCLUSION

Rectal surgery for malignant disease is associated with a considerable rate of SSI. Wound infection and organ space infection are related to different factors and therefore should be evaluated separately.

Randomized trial of antimicrobial-coated sutures to prevent surgical site infection after breast cancer surgery

BACKGROUND

Surgical site infection (SSI) is the fourth commonest healthcare-associated infection and complicates at least 5% of open operations. In a randomized clinical trial, antimicrobial-coated sutures were compared with their conventional counterparts, polyglactin and poliglecaprone, for skin closure after breast cancer surgery to assess their role in reducing the rate of SSI.

METHODS

Between November 2008 and February 2011, 150 female patients presenting with breast cancer to a single center were randomized to skin closure with antimicrobial-coated or plain sutures. Postoperatively, SSI was defined using the U.S. Centers for Disease Control and Prevention (CDC) definitions and scored using the ASEPSIS or Southampton systems by trained, blinded observers with close post-discharge surveillance and patient diaries. Surgeons and patients were blinded to the type of suture used.

RESULTS

Using CDC criteria, the overall rate of SSI was 18.9% at six weeks. Six patients (4.7%) needed intervention or readmission for SSI. Skin closure with antimicrobial sutures showed a non-statistically significant reduction in the SSI rate, to 15.2%, compared with conventional sutures (22.9%). A uniform tendency for fewer SSIs in the antimicrobial-coated suture group was found using ASEPSIS and Southampton scores, but again, the difference was not statistically significant.

CONCLUSION

The previously reported high rate of SSI related to breast surgery was confirmed. Using statistical modeling and earlier reports, the study was powered to show a difference using ASEPSIS scores, but the modification used in this trial failed to find a difference. Finding a statistically significant difference would have needed two to three times the number of patients recruited. Further evaluation of antimicrobial-coated sutures is merited, particularly if used as part of a care bundle to reduce SSI after breast cancer surgery.

[Surgical infections as patient safety problems]

Surgical infections are severe complications of surgical interventions and one of the most important patient safety issues. These are associated with increased morbidity, mortality, costs and decreased quality of life. Prevention of infections is essential, while one has to consider pre-, intra- and postoperative factors and procedures in the clinical practice. In this article we summarize the latest recommendations for clinicians based on the relevant published literature.