Sternal wound infection after cardiac surgery: incidence and risk factors according to clinical presentation

Infectious Mediastinitis: A Retrospective Cohort Study

Background

This study aimed to characterize the demographics, microbiology, management and treatment outcomes of mediastinitis according to the origin of the infection.

Methods

This retrospective observational study enrolled patients who had mediastinitis diagnosed according to the criteria defined by the Centers for Disease Control and Prevention and were treated in Strasbourg University Hospital, France, between 1 January 2010 and 31 December 2020.

Results

We investigated 151 cases, including 63 cases of poststernotomy mediastinitis (PSM), 60 cases of mediastinitis due to esophageal perforation (MEP) and 17 cases of descending necrotizing mediastinitis (DNM). The mean patient age (standard deviation) was 63 (14.5) years, and 109 of 151 patients were male. Microbiological documentation varied according to the origin of the infection. When documented, PSM cases were mostly monomicrobial (36 of 53 cases [67.9%]) and involved staphylococci (36 of 53 [67.9%]), whereas MEP and DNM cases were mostly plurimicrobial (38 of 48 [79.2%] and 8 of 12 [66.7%], respectively) and involved digestive or oral flora microorganisms, respectively. The median duration of anti-infective treatment was 41 days (interquartile range, 21-56 days), and 122 of 151 patients (80.8%) benefited from early surgical management. The overall 1-year survival rate was estimated to be 64.8% (95% confidence interval, 56.6%-74.3%), but varied from 80.1% for DNM to 61.5% for MEP.

Conclusions

Mediastinitis represents a rare yet deadly infection. The present cohort study exhibited the different patterns observed according to the origin of the infection. Greater insight and knowledge on these differences may help guide the management of these complex infections, especially with respect to empirical anti-infective treatments.

Association Between Body Mass Index, Obesity, and Clinical Outcomes Following Coronary Artery Bypass Grafting in Brazil: An Analysis of One Year of Follow-up of BYPASS Registry Patients

OBJECTIVE

To investigate the association between body mass index (BMI), obesity, clinical outcomes, and mortality following coronary artery bypass grafting (CABG) in Brazil using a large sample with one year of follow-up from the Brazilian Registry of Cardiovascular Surgeries in Adults (or BYPASS) Registry database.

METHODS

A multicenter cohort-study enrolled 2,589 patients submitted to isolated CABG and divided them into normal weight (BMI 20.0-24.9 kg/m2), overweight (BMI 25.0-29.9 kg/m2), and obesity (BMI > 30.0 kg/m2) groups. Inpatient postoperative outcomes included the most frequently described complications and events. Collected post-discharge outcomes included rehospitalization and mortality rates within 30 days, six months, and one year of follow-up.

RESULTS

Sternal wound infections (SWI) rate was higher in obese compared to normal-weight patients (relative risk [RR]=5.89, 95% confidence interval [CI]=2.37-17.82; P=0.001). Rehospitalization rates in six months after discharge were higher in obesity and overweight groups than in normal weight group (χ=6.03, P=0.049); obese patients presented a 2.2-fold increase in the risk for rehospitalization within six months compared to normal-weight patients (RR=2.16, 95% CI=1.17-4.09; P=0.045). Postoperative complications and mortality rates did not differ among groups during time periods.

CONCLUSION

Obesity increased the risk for SWI, leading to higher rehospitalization rates and need for surgical interventions within six months following CABG. Age, female sex, and diabetes were associated with a higher risk of mortality. The obesity paradox remains controversial since BMI may not be sufficient to assess postoperative risk in light of more complex and dynamic evaluations of body composition and physical fitness.

Risk factors for surgical site infection following cardiac surgery in a region endemic for multidrug resistant organisms

OBJECTIVES

To identify risk factors for surgical site infections following cardiosurgery in an area endemic for multidrug resistant organisms.

DESIGN

Single-center, historical cohort study including patients who underwent cardiosurgery during a 6-year period (2014-2020).

SETTING

Joint Commission International accredited, multiorgan transplant center in Palermo, Italy.

MAIN OUTCOME MEASURES

Surgical site infection was the main outcome.

RESULTS

On a total of 3609 cardiosurgery patients, 184 developed surgical site infection (5.1 %). Intestinal colonization with multidrug resistant organisms was more frequent in patients with surgical site infections (69.6 % vs. 33.3 %; p < 0.001). About half of surgical site infections were caused by Gram-negative bacteria (n = 97; 52.7 %). Fifty surgical site infections were caused by multidrug resistant organisms (27.1 %), with extended-spectrum Beta-lactamase-producing Enterobacterales (n = 16; 8.7 %) and carbapenem-resistant Enterobacterales (n = 26; 14.1 %) being the predominant resistance problem. However, in only 24 of surgical site infections caused by multidrug resistant organisms (48 %), mostly carbapenem-resistant Enterobacterales (n = 22), a pathogen match between the rectal surveillance culture and surgical site infections clinical culture was demonstrated. Nevertheless, multivariate logistic regression analysis identified a rectal swab culture positive for multidrug resistant organisms as an independent risk factor for SSI (odds ratio 3.95, 95 % confidence interval 2.79-5.60). Other independent risk factors were female sex, chronic dialysis, diabetes mellitus, previous cardiosurgery, previous myocardial infarction, being overweight/obese, and longer intubation time.

CONCLUSION

In an area endemic for carbapenem-resistant Enterobacterales, intestinal colonization with multidrug resistant organisms was recognized as independent risk factor for surgical site infections.

IMPLICATIONS FOR CLINICAL PRACTICE

No causal relationship between colonization with resistant pathogens and subsequent infection could be demonstrated. However, from a broader epidemiological perspective, having a positive multidrug resistant organisms colonization status appeared a risk factor for surgical site infections. Therefore, strict infection control measures to prevent cross-transmission remain pivotal (e.g., nasal decolonization, hand hygiene, and skin antisepsis).

Sex differences in surgical site infections following coronary artery bypass grafting: a retrospective observational study

BACKGROUND

Surgical site infection (SSI) following cardiac surgery poses a significant challenge for healthcare providers. Despite advances in surgical techniques and infection control measures, SSI remains a leading cause of morbidity and mortality, in addition to being a significant economic burden on healthcare services. Current literature suggests there is a reproducible difference in the incidence of SSI following cardiac surgery between sexes. We aim to assess the sex-specific predictive risk factors for sternal SSI following coronary artery bypass grafting (CABG) in addition to identifying any differences in the causative organisms between groups.

METHODS

Adult patients undergoing isolated CABG between January 2012 and December 2022 in one UK hospital organization were included. In this 10-year, retrospective observational study, a total of 10,208 patients met the inclusion criteria. Pre-operative risk factors were identified using univariate analysis. To assess dependence between sex and organism or Gram stain, a Pearson Chi-squared test with Yates correction for continuity was performed.

RESULTS

In total there were 8457 males of which 181 developed a sternal SSI (2.14%) and 1751 females, 128 of whom had a sternal SSI (7.31%). Male patients were found to be significantly more likely to develop an SSI secondary to a Gram-positive organism, whereas female patients were more likely to have a Gram-negative causative organism (P<0.00001). Staphylococcus was statistically more likely to be the causative organism genus in male patients. Pseudomonas aeruginosa was found to be twice as common in the female cohort compared with the male group.

CONCLUSION

In our study, we found a statistically significant difference in the causative organisms and Gram stain for post-CABG sternal SSIs between males and females. Male patients predominately have Gram-positive associated SSIs, whereas female SSI pathogens are more likely to be Gram negative. The preoperative risk profiles of both cohorts are similar, including being an insulin-dependent diabetic and triple vessel coronary artery disease. Given these findings, it prompts the question, should we be tailoring our SSI treatment strategies according to sex and associated risk profiles?

The negative pressure wound therapy for prevention of sternal wound infection: Can we reduce infection rate after the use of bilateral internal thoracic arteries? A systematic literature review and meta-analysis

BACKGROUND

Negative pressure wound therapy (NPWT) is traditionally used to treat postoperative wound infections. However, its use in closed wound sternotomy post cardiac surgery in high-risk patients has become increasingly popular. The potential preventive benefit of reducing sternal wound infections has been recently acknowledged. Bilateral internal mammary artery (BIMA) grafts are used in coronary artery bypass grafting but have been associated with an increased risk of sternal wound infections (SWIs).

OBJECTIVES

This systematic analysis examines whether NPWT can reduce the incidence of SWI following BIMA grafts, leading to more patients benefiting from the better survival outcome associated with BIMA grafting.

METHOD

A comprehensive systematic search and meta-analysis were performed to identify studies on the use of NPWT in closed wound sternotomy. Ovid MEDLINE (in-process and other nonindexed citations and Ovid MEDLINE 1990 to present), Ovid EMBASE (1990 to present), and The Cochrane Library (Wiley), PubMed, and Google Scholar databases were searched from their inception to May 2022 using keywords and MeSH terms. Thirty-four articles from 1991 to May 2022 were selected.

RESULT

Three studies reported on the outcome of NPWT following BIMA grafting. The pooled analysis did not show any significant difference in the incidence of sternal wound infection between NPWT and standard dressing (RR 0.48 95% CI 0.17-1.37; P = 0.17) with substantial heterogeneity (I2 65%). Another seven studies were found comparing the outcome of SWI incidence of negative pressure closed wound therapy with conventional wound therapy in patients undergoing adult cardiac surgery. The pooled analysis showed that NPWT was associated with a low risk of SWIs compared to conventional dressing (RR 0.47 95% CI 0.36-0.59; P < 0.00001), with low heterogeneity (I2 1%).

CONCLUSION

The literature identified that NPWT significantly decreased the incidence of sternal wound complications when applied to sutured sternotomy incisions in high-risk patients, and in some cases, it eliminated the risk. However, the inadequate number of randomized controlled trials assessing the effectiveness of NPWT in BIMA grafting emphasizes the need for further, robust studies.

A systematic review of right atrial bypass grafting in the management of central venous occlusive disease in patients undergoing hemodialysis

INTRODUCTION

Central venous occlusive disease (CVOD) is a complication that can occur in patients with end-stage renal disease who are receiving hemodialysis. When CVOD develops, patients often require multiple re-interventions to maintain their dialysis access. CVOD can be treated by various strategies such as balloon angioplasty, stenting, lower limb or extra-anatomical grafts, hybrid grafts or surgical bypasses such as right atrial (RA). In this systematic review, we aim to evaluate the indications, technical aspects, and outcomes after RA bypass grafting for the treatment of CVOD in hemodialysis patients.

METHODS

A systematic and comprehensive literature search was conducted using various electronic databases. We included articles that reported described and reported outcomes of RA bypass grafting for the treatment of CVOD in hemodialysis patients. A narrative review of the indications and technical aspects of RA bypass grafting was performed. We also pooled and reported the primary patency, secondary patency, postoperative complications, and 30-day mortality of RA bypass grafting.

RESULTS

A total of 21 studies with 55 patients who underwent RA bypass grafting were included in our systematic review. Follow-up period ranged from 0.5 to 84 months. The mean pooled primary patency and secondary patency of RA bypass grafting were 8.1 ± 4.9 and 21.7 ± 20.1 months, respectively. The incidence of early postoperative complications such as surgical site infection, bleeding, and access thrombosis was 0%, 4%, and 4%, respectively. The overall 30-day mortality was 4%.

CONCLUSIONS

This systematic review summarizes the patient characteristics, technical features and outcomes of RA bypass grafting in the treatment of hemodialysis-related CVOD. RA bypass grafting may be a viable last-resort option when less invasive or conventional treatment options have been exhausted.

Surgical site infection outcomes of two different closed incision negative pressure therapy systems in cardiac surgery: Systematic review and meta-analysis

Closed incision negative pressure therapy (ciNPT) system use compared with standard of care dressings (SOC) on surgical site infection (SSI) in cardiac surgery was assessed. A systematic literature review was conducted. Risk ratios (RR) and random effects models were used to assess ciNPT with foam dressing (ciNPT-F) or multilayer absorbent dressing (ciNPT-MLA) versus SOC. Health economic models were developed to assess potential per patient cost savings. Eight studies were included in the ciNPT-F analysis and four studies were included in the ciNPT-MLA analysis. For ciNPT-F, a significant reduction in SSI incidence was observed (RR: 0.507, 95% confidence interval [CI]: 0.362, 0.709; p < 0.001). High-risk study analysis reported significant SSI reduction with ciNPT-F use (RR: 0.390, 95% CI: 0.205, 0.741; p = 0.004). For ciNPT-MLA, no significant difference in SSI rates were reported (RR: 0.672, 95% CI: 0.276, 1.635; p = 0.381). Health economic modelling estimated a per patient cost savings of $554 for all patients and $3242 for the high-risk population with ciNPT-F use. Health economic modelling suggests ciNPT-F may provide a cost-effective solution for sternotomy incision management. However, limited high-quality literature exists. More high-quality evidence is needed to fully assess the impact of ciNPT use following cardiac surgery.

Efficacy of incisional negative pressure therapy in preventing post-sternotomy wound complications

BACKGROUND

Sternal wound infections represent a source of significant morbidity and mortality following median sternotomy. The use of incisional negative pressure wound therapy in prevention has yet to be elucidated.

METHODS

A retrospective study was conducted before and after a universal wound care protocol was implemented including the prophylactic use of negative pressure wound therapy (NPWT). The primary endpoint was sternal infections within 90 days of the index operation.

RESULTS

In the control period, there was a 3.0% rate of sternal infection within 90 days compared to 0.8% in the intervention period (p < 0.001). An odds ratio of 0.25 (95% confidence interval 0.11, 0.57; p < 0.001) in the intervention period as compared to the control period was demonstrated.

CONCLUSIONS

The use of a standardized wound care protocol including the universal application of NPWT for patients undergoing cardiac surgery with median sternotomy was an independent predictor of decreased rates of sternal infection.

Risk factors for sternal wound infection after open-heart operations: A systematic review and meta-analysis

We aimed to quantitatively and systematically elucidate the rationality of the examined variables as independent risk factors for sternal wound infection. We searched databases to screen studies, ascertained the variables to be analysed, extracted the data and applied meta-analysis to each qualified variable. Odds ratios and mean differences were considered to be the effect sizes for binary and continuous variables, respectively. A random-effects model was used for these procedures. The source of heterogeneity was evaluated using a meta-regression. Publication bias was tested by funnel plot and Egger's test, the significant results of which were then calculated using trim and fill analysis. We used a sensitivity analysis and bubble chart to describe their robustness. After screening all variables in the eligible literature, we excluded 55 because only one or no research found them significant after multivariate analysis, leaving 33 variables for synthesis. Two binary variables (age over 65 years, NYHA class >2) and a continuous variable (preoperative stay) were not significant after the meta-analysis. The most robust independent risk factors in our study were diabetes mellitus, obesity, use of bilateral internal thoracic arteries, chronic obstructive pulmonary disease, prolonged surgery time, prolonged ventilation and critical preoperative state, followed by congestive heart failure, atrial fibrillation, renal insufficiency, stroke, peripheral vascular disease and use of an intra-aortic balloon pump. Relatively low-risk factors were emergent/urgent surgery, smoking, myocardial infarction, combined surgery and coronary artery bypass grafting. Sternal wound infection after open-heart surgery is a multifactorial disease. The detected risk factors significantly affected the wound healing process, but some were different in strength. Anything that affects wound healing and antibacterial ability, such as lack of oxygen, local haemodynamic disorders, malnutrition condition and compromised immune system will increase the risk, and this reminds us of comprehensive treatment during the perioperative period.

A study on the preoperative risk factors for primary healing failure in the reconstruction of deep sternal wound infection with platelet-rich plasma and negative pressure trauma therapy

Deep sternal wound infection (DSWI) is a relatively complex wound in wound reconstruction surgery. Because plastic surgeons deal with DSWI patients late. The primary healing (healing by first intention) after reconstruction of DSWI is restricted by many preoperative risk factors. The purpose of this study is to explore and analyse the risk factors of primary healing failure in patients with DSWI treated with platelet-rich plasma (PRP) and negative pressure trauma therapy (NPWT). 115 DSWI patients treated with the PRP and NPWT (PRP + NPWT) modality were retrospectively (2013-2021) analysed. They were divided into two groups according to primary healing results after the first PRP + NPWT treatment. Univariate and multivariate analyses were used to compare the data of the two groups to find out the risk factors and their optimal cut-off values were identified by ROC analysis. The primary healing results, debridement history, wound size, sinus, osteomyelitis, renal function, bacterial culture, albumin (ALB), platelet (PLT) between the two groups were significantly different (P < 0.05). Binary logistic regression showed that osteomyelitis, sinus, ALB and PLT were the risk factors affecting primary healing outcomes (P < 0.05). ROC analysis showed that AUC for ALB in the non-primary healing group was 0.743 (95% CI: 0.650-0.836, P < 0.05) and its optimal cutoff value of 31 g/L was associated with primary healing failure with a sensitivity of 96.9% and specificity of 45.1%. AUC for PLT in the non-primary healing group was 0.670 (95% CI: 0.571 ~ 0.770, P < 0.05) its optimal cutoff value of 293 × 109 /L was associated with primary healing failure with a sensitivity of 72.5% and specificity of 56.3%. In the cases included in this study, the success rate of primary healing of DSWI treated with PRP + NPWT was not affected by the most common preoperative risk factors for wound non-union. It is indirectly confirmed that PRP + NPWT is an ideal treatment. However, it should be noted that it will still be adversely affected by sinus osteomyelitis, ALB and PLT. The patients need to be carefully evaluated and corrected before reconstruction.

Improvement project to reduce surgical site infections: a retrospective cohort study

INTRODUCTION

Surgical site infections are one of the main problems related to health care. In Brazil, they are responsible for 14 to 16% of infections related to health care. This study sought to analyze the effect of implementing a package of measures to reduce surgical site infections (SSI) in heart surgeries, kidney transplants and herniorrhaphies and to evaluate adherence to the safe surgery checklist in a university hospital.

METHODS

this is a retrospective cohort study with data collection in a time series for the period from 2018 to 2020.

RESULTS

we analyzed 222 medical records referring to the surgeries under study performed in the year 2020, in which data were collected from the patients and the care package prevention measures. SSI data and adherence to the safe surgery checklist were analyzed in the years 2018, 2019 and 2020, totaling 268, 300 and 222 procedures analyzed, respectively.

CONCLUSION

the study showed a significant reduction in the SSI rate with greater adherence to the protocol, which was not maintained and was influenced by the COVID-19 pandemic. Thus, the sustainability of this action represents a challenge to be overcome, in order to establish a safer environment for the patient and a better quality of service.

Free Flaps in Sternal Osteomyelitis After Median Sternotomy: A Center's 12-Year Experience

BACKGROUND

 Adequate treatment of deep sternal wound infections (DSWIs) after open thoracic surgery still presents a major challenge. This study retrospectively analyzes the results of a single center's 12-year experience in treating DSWI, with special emphasis on free flap reconstruction.

METHODS

 In this single-center, retrospective study, all patients admitted with the diagnosis of DSWI after open thoracic surgery between 2009 and 2020 were included. A comparative analysis was performed between: (1) pedicled versus free flaps, (2) the center's two workhorse flaps-the pedicled latissimus dorsi (pLD) versus free anterolateral thigh (fALT) flaps, as well as (3) myocutaneous (MC) versus fasciocutaneous (FC) flaps. Primary endpoints were length of hospital stay (LOS) after reconstruction and in-hospital mortality.

RESULTS

 Of a total of 165 patients included, 152 underwent DSWI defect reconstruction with a total of 12 different reconstruction methods. Although the defect size was larger in patients who underwent free flap coverage, and the risk profile in the fALT and FC flap groups was higher, the LOS after reconstruction (in days) did not differ significantly between the groups (pedicled vs. free flaps: 23 vs. 28, p > 0.05; pLD vs. fALT: 24.5 vs. 26, p > 0.05; MC vs. FC flaps: 23 vs. 26, p > 0.05). Also, no significant differences were found in terms of in-hospital mortality when comparing the groups (pedicled vs. free flaps: 11.2 vs. 17.4%, p > 0.05; pLD vs. fALT: 11.5 vs. 12.5%, p > 0.05; MC vs. FC flaps: 12.9 vs. 12.5%, p > 0.05).

CONCLUSION

 With proper patient selection, free tissue transfer is a valuable alternative in the treatment of sternal dehiscence after a DSWI. Furthermore, our data demonstrate that MC flaps are not necessarily superior to FC flaps in the reconstruction of sternal osteomyelitis defects.

Topical skin adhesive PRINEO as the ideal wound closure system in cardiac surgery to limit surgical site infection

OBJECTIVE

Surgical site infections (SSIs) are a major source of morbidity after cardiac surgery, involving prolonged hospitalisation. Among the numerous techniques of skin closure and dressings available, the optimal method remains undetermined. The DERMABOND-PRINEO (PRINEO) (PRINEO, Ethicon, J&J) is the only skin closure system which combines a topical skin adhesive with a mesh. Other surgical disciplines have highlighted remarkable results with PRINEO. The aim of this study was to evaluate the effects of PRINEO, used as the final layer in sternotomy closure, in the incidence of postoperative SSIs.

METHOD

This was a retrospective single-centre cohort study including adult patients who underwent cardiac surgery between January 2015 and December 2018. Patients who had undergone heart transplantation or ventricular assist surgery were excluded. Included patients were divided into two groups depending on the type of post-operative wound care technique used. Group 1 consisted of patients who had their sternotomy closed with a standard dressing and group 2 consisted of patients who were treated with PRINEO. The primary endpoint of our study was the occurrence of SSIs and secondary outcomes were the length of hospitalisation and mortality.

RESULTS

A total of 1603 patients were reviewed with the occurrence of 44 SSIs. Both groups were homogeneous in terms of risk factors. The incidence of SSIs was significantly lower in group 2 (PRINEO) than in group 1 (standard dressing) (n=29, 3.8% vs n=15, 1.8%, respectively; p=0.042). However, there was no significant difference in the duration of hospitalisation and mortality.

CONCLUSION

In our practice, PRINEO has proven to be a safe wound closure system after sternotomy, with a reduced SSI rate compared to conventional wound care techniques.

Assessing the Patient Outcomes and Performance of a Cardiothoracic and Vascular Surgery (CTVS) Unit During Its First Two Years in a Tier-2 City in India: A Comprehensive Audit and Analysis

This detailed article presents a comprehensive overview of the initial two-year experience in establishing a new cardiothoracic vascular surgery (CTVS) facility in a tier-2 city in India. The article discusses various aspects of setting up and operating a specialized healthcare facility. The first two years of developing the CTVS facility were included in the study period. The manpower included one cardiothoracic vascular surgeon, one cardiac anesthesiologist, two perfusionists, and two physician assistants, along with four other ancillary staff to assist in the smooth functioning of the operation theater. The CTVS recovery staff included 15 nursing officers. There was only one modular operation theater reserved for cardiothoracic vascular surgeries, along with a five-bed recovery room (CTVS intensive care unit). One-hundred-seventy-two procedures were done, including 122 open heart surgeries, 36 vascular procedures, and 14 thoracic procedures. The majority of patients were discharged by the seventh day postoperatively. Overall complication and mortality rates were 8% and 4.6%, respectively. This article also discusses relevant hospital policy, challenges faced, and future recommendations for similar endeavors. The findings highlight the successful implementation of the facility and its impact on providing specialized cardiac care to the local population.

Effect of an E-Prescription Intervention on the Adherence to Surgical Chemoprophylaxis Duration in Cardiac Surgery: A Single Centre Experience

In our hospital, adherence to the guidelines for peri-operative antimicrobial prophylaxis (PAP) is suboptimal, with overly long courses being common. This practice does not offer any incremental benefit, and it only adds to the burden of antimicrobial consumption, promotes the emergence of antimicrobial resistance, and it is associated with adverse events. Our objective was to study the effect of an electronic reminder on the adherence to each element of PAP after cardiac surgery. We conducted a single center, before and after intervention, prospective cohort study from 1 June 2014 to 30 September 2017. The intervention consisted of a reminder of the hospital guidelines when ordering PAP through the hospital information system. The primary outcome was adherence to the suggested duration of PAP, while secondary outcomes included adherence to the other elements of PAP and incidence of surgical site infections (SSI). We have studied 1080 operations (400 pre-intervention and 680 post-intervention). Adherence to the appropriate duration of PAP increased significantly after the intervention [PRE 4.0% (16/399) vs. POST 15.4% (105/680), chi-square p < 0.001]; however, it remained inappropriately low. Factors associated with inappropriate duration of PAP were pre-operative hospitalization for <3 days, and duration of operation >4 h, while there were significant differences between the chief surgeons. Unexpectedly, the rate of SSIs increased significantly during the study (PRE 2.8% (11/400) vs. POST 5.9% (40/680), chi-square p < 0.019). The implemented intervention achieved a relative increase in adherence to the guideline-recommended PAP duration; however, adherence was still unacceptably low and further efforts to improve adherence are needed.

The Impact of Gender and Age in Obese Patients on Sternal Instability and Deep-Sternal-Wound-Healing Disorders after Median Sternotomy

OBJECTIVE

The aim of this study was to investigate the relationship between age and sex in regard to the development of deep sternal wound infections and sternal instability following median sternotomy.

METHODS

A propensity-score-matching analysis was conducted on 4505 patients who underwent cardiac surgery between 2009 and 2021, all of whom had a BMI of ≥30 kg/m². A total of 1297 matched pairs were determined in the sex group, and 1449 matched pairs we determined in the age group. The distributions of sex, age, diabetes mellitus, delirium, unstable sterna, wire refixation, wire removal, superficial vacuum-assisted wound closure, deep vacuum-assisted wound closure, clamp time, bypass time, logistic EuroSCORE, and BMI were determined.

RESULTS

The 30-day in-hospital mortality was found to be similar in the older and younger groups (8.149% vs. 8.35%, p = 0.947), and diabetes mellitus was also equally distributed in both groups. However, postoperative delirium occurred significantly more often in the older group (29.81% vs. 17.46%, p < 0.001), and there was a significantly higher incidence in men compared with women (16.96% vs. 26.91%, p < 0.001). There were no differences found in the incidence of sternum instability, fractured sternum, superficial vacuum-assisted wound closure, and deep vacuum-assisted wound closure between the age and sex groups.

CONCLUSIONS

In conclusion, this study found that sternal instability and deep-wound-healing problems occur with equal frequency in older and younger patients and in men and women following median sternotomy. However, the likelihood of postoperative delirium is significantly higher in older patients and in men. These findings suggest that a higher level of monitoring and care may be required for these high-risk patient groups to reduce the incidence of postoperative delirium and improve outcomes following median sternotomy.

Incidence and predictors of sternal surgical wound infection in cardiac surgery: A prospective study

Sternal surgical wound infection (SSWI) in cardiac surgery is associated with increased morbidity. We investigated the incidence of SSWI, the main germs implicated and predictors of SSWI. Prospective study including patients undergoing full median sternotomy between January 2017 and December 2019. Patients were followed-up for 3 months after hospital discharge. All sternal wound infections up to 90 days after discharge were considered SSWI. 1004 patients were included. During follow-up, 68 (6.8%) patients presented SSWI. Patients with SSWI had a higher incidence of postoperative renal failure (29.4% vs 17.1%, P = .007), a higher incidence of early postoperative reoperation for non-infectious causes (42.6% vs 9.1%, P < .001), longer ICU stay (3 [2-9] days vs 2 [2-4] days, P = .006), and longer hospital stay (24.5 [14.8-38.3] days vs 10 [7-18] days, P < .001). Gram-positive germs were presented in 49% of the cultures, and gram-negative bacteria in 35%. Early reoperation for non-infectious causes (OR 4.90, 95% CI 1.03-23.7), and a longer ICU stay (OR 1.37 95% CI 1.10-1.72) were independent predictors of SSWI. SSWI is rare but leads to more postoperative complications. The need for early reoperation because of non-infectious cause and a longer ICU stay were independently associated with SSWI.

Association between type II diabetes mellitus and 90-day mortality in a large multicenter prospectively collected cohort. A FROG ICU post-hoc study

PURPOSE

Factors associated with adverse outcomes in ICU patients with type II (T2DM) are poorly defined. The main goal of this study is to determine the impact of pre-existing T2DM on 90-day mortality post ICU admission.

MATERIAL

Post-hoc analysis from the FROG-ICU cohort. All patients admitted to ICU who were ventilated and/or treated by a vasoactive agent for >24 h were included. Association between T2DM and 90-day mortality was analyzed in unmatched, and populations matched by propensity score (PS) method to balance confounders recorded before ICU admission. Analysis was performed in non-imputed and imputed datasets.

RESULTS

2002 patients were included, and 16% had a history of T2DM. The latter were at inclusion more severely ill (SAPSII score 51(39-67) vs 48(35-61), p < 0.0001; Charlson score 2(1-3) vs 0(0-2), p < 0.0001). In the unmatched cohort, T2DM patients had a higher 90-day risk of death compared to no-DM patients (HR 1.35(1.1-1.65)). The 90-day risk of death was not significantly different T2DM and no T2DM patients after PS matching (HR: 0.81 (0.56-1.18). Results were similar with the analysis performed on imputed datasets (pooled HR: 0.95 (0.69-1.30)).

CONCLUSIONS

In the present study, T2DM was not associated with 90-day mortality post ICU admission.

Impact of Antibiotic Prophylaxis on Surgical Site Infections in Cardiac Surgery

(1) Background: Cephalosporins (CA) are the first-line antibiotic prophylaxis recommended to prevent surgical site infection (SSI) after cardiac surgery. The combination of vancomycin/gentamicin (VGA) might represent a good alternative, but few studies have evaluated its efficacy in SSI prevention. (2) Methods: A single-centre retrospective study was conducted over a 13-year period in all consecutive adult patients undergoing elective cardiac surgery. Patients were stratified according to the type of antibiotic prophylaxis. CA served as the first-line prophylaxis, and VGA was used as the second-line prophylaxis. The primary endpoint was SSI occurrence at 90 days, which was defined as the need for reoperation due to SSI. (3) Results: In total, 14,960 adult patients treated consecutively from 2006 to 2019 were included in this study, of whom 1774 (12%) received VGA and 540 (3.7%) developed SSI. VGA patients had higher severity with increased 90-day mortality. Nevertheless, the frequency of SSI was similar between CA and VGA patients. However, the microbiological aetiologies were different, with more Gram-negative bacteria noted in the VGA group. (4) Conclusions: VGA seems to be as effective as CA in preventing SSI.

A single-patient-use ECG system for cardiothoracic surgery admissions in the UK: A cost-consequence analysis

Background

Deep sternal wound infections (DSWI) are severe complications in up to 1.36% of coronary artery bypass grafting (CABG) procedures in the United Kingdom. Each event adds between £4,000 and £11,000 in healthcare costs, owing primarily to prolonged hospitalisations. ECG devices have been shown to convey infection throughout perioperative CABG. On the other hand, single-patient ECG devices (spECG) can effectively reduce the incidence of surgical site infections (SSI), including DSWI, but no assessment of spECG impact in NHS cardiac units has been conducted.

Methods

To estimate the impact of spECG on NHS cardiac units, we conducted a cost-consequence analysis modeling the CABG care pathway in the United Kingdom using Simul8 software for a probabilistic, individual-patient simulation. The simulation time was 1 year, with each patient followed from admission through 30 days post-discharge. The base case simulation mirrors the cardiac unit of Bart Health NHS Trust, London. A total of 2,183 patients are generated with demographic and clinical attributes from probabilistic distributions informed by hospital-specific inputs from NHS Digital Data. The Brompton Harefield Infection Score (BHIS) is allocated to gauge the risk of SSI. Results are averaged across 50 independent and randomly seeded iterations.

Results

Simulation results indicate a base-case savings of £388 per patient, determined by the incidence of infections rather than the number of CABG procedures. In the base-case simulation, the mean cost of care with rECG was £13,096, whereas the mean cost with spECG was £12,708, resulting in a cost saving of £388 (2021 GBP). The simulation yielded an overall 8.6% SSI incidence rECG, whereas the incidence of SSIs with spECG was 6.9%. The model was most sensitive to changes in general ward and ICU costs, and infection incidence was a stronger predictor of potential per-patient savings than annual CABG volume.

Conclusion

Single-patient ECG is a sustainable and effective alternative to reusable ECG cables and lead wires in terms of patient safety and resource allocation.

Pyoderma Gangrenosum after Cardiac Surgery

BACKGROUND

Pyoderma gangrenosum after cardiac surgery is a rare, noninfectious ulcerating skin disease mimicking sternal wound infection.

METHODS

A systematic search of literature for pyoderma gangrenosum complicating cases of cardiac surgery was conducted between September 1985 and September 2020 on PubMed and Cochrane databases. A systematic review and detailed overview of clinical presentation, diagnostic, treatment, and outcome is provided.

RESULTS

A total of 15 studies enclosing 15 patients suffering from pyoderma gangrenosum following cardiac surgery were identified. Onset of symptoms was observed after a median of 5 days. Patients were predominantly male (81.3%) with a median age of 64 years. Typical clinical presentation mimicked sternal site infection, mainly by means of mediastinitis. Specific signs were rapid progression, erythematous to violaceous color of the wound border, accompanied by unspecific symptoms including fever, malaise, and severe pain. Additionally, pathergy (development of ulcers at the sites of minor cutaneous trauma) was reported frequently. Biopsy is mandatory with a cutaneous neutrophilic inflammation confirming the diagnosis. Initial treatment mostly (75.0% of reported cases) was misled, addressing suspicion of surgical site infection. After correct diagnosis, the treatment was switched to an immunosuppressive therapy. Full sternal wound closure took between 5 weeks and 5 months. Reported case mortality was 12.5% in actually low-risk surgeries.

CONCLUSION

Despite pyoderma gangrenosum has typical signs, it remains an exclusion diagnosis. The treatment is completely opposite to the main differential diagnosis-the typical surgical site infection. Knowledge about diagnosis and treatment is essential in the context of avoiding fatal mistreatment.

National Analysis of Sternal Wound Complications and Readmissions After Coronary Bypass Surgery

BACKGROUND

Wound complications are a cause for readmission after cardiac surgery. Health insurance status has been associated with poor postoperative outcomes. We investigate the association between health insurance status and post-CABG wound dehiscence or infection along with 30-day wound-related readmission using a national database.

METHODS

We queried the National Readmissions Database for the year 2018 for patients aged 18 years or more undergoing multivessel coronary artery bypass graft surgery (CABG). Patients were subcategorized by health insurance status (private, Medicaid, Medicare, uninsured). Our primary outcomes were wound dehiscence or infection during the index admission and 30-day readmission after discharge for wound-related complications.

RESULTS

In all, 131,976 patients met inclusion criteria: 32.7% private, 7.6% Medicaid, 59.3% Medicare, and 0.4% uninsured. Compared with patients having private insurance, Medicaid patients had greater odds of readmission for superficial wound dehiscence (odds ratio [OR] 2.11; 1.11-4.00; P = .022) and deep wound dehiscence (OR 2.11; 95% CI, 1.09-4.10; P = .026), as did Medicare patients (OR 2.34; 95% CI, 1.29-3.88; P = .004; and OR 3.23; 95% CI, 1.76-5.90; P = .001, respectively). Medicaid patients additionally had higher odds of readmission for superficial wound infection (OR 1.59; 95% CI, 1.11-4.00; P = .014). Compared with patients with private insurance, Medicaid patients had higher odds of deep wound dehiscence on index admission (OR 1.97; 95% CI, 1.02-3.83; P = .044), and Medicare patients had higher odds of superficial wound dehiscence (OR 2.55; 95% CI, 1.28-5.06; P = .001).

CONCLUSIONS

Patients with Medicaid and Medicare had greater odds of readmission for wound complications and higher rates of wound dehiscence in their index admission. Further research is warranted to characterize factors driving readmission due to postsurgical wound complications in low socioeconomic status populations.

Surgical Site Infection in Cardiac Surgery

Surgical site infections (SSIs) are one of the most significant complications in surgical patients and are strongly associated with poorer prognosis. Due to their aggressive character, cardiac surgical procedures carry a particular high risk of postoperative infection, with infection incidence rates ranging from a reported 3.5% and 26.8% in cardiac surgery patients. Given the specific nature of cardiac surgical procedures, sternal wound and graft harvesting site infections are the most common SSIs. Undoubtedly, DSWIs, including mediastinitis, in cardiac surgery patients remain a significant clinical problem as they are associated with increased hospital stay, substantial medical costs and high mortality, ranging from 3% to 20%. In SSI prevention, it is important to implement procedures reducing preoperative risk factors, such as: obesity, hypoalbuminemia, abnormal glucose levels, smoking and S. aureus carriage. For decolonisation of S. aureus carriers prior to cardiac surgery, it is recommended to administer nasal mupirocin, together with baths using chlorhexidine-based agents. Perioperative management also involves antibiotic prophylaxis, surgical site preparation, topical antibiotic administration and the maintenance of normal glucose levels. SSI treatment involves surgical intervention, NPWT application and antibiotic therapy.

Risk factors for post sternotomy wound complications across the patient journey: A systematised review of the literature

BACKGROUND

Around 36,000 cardiac operations are undertaken in the United Kingdom annually, with most procedures undertaken via median sternotomy. Wound complications occur in up to 8% of operations, with an associated mortality rate of around 47% in late or undetected cases.

OBJECTIVE

To undertake a systematised literature review to identify pre-operative, peri-operative and post-operative risk factors associated with sternal wound complications.

METHODS

Healthcare databases were searched for articles written in the English language and published between 2013 and 2021. Inclusion criteria were quantitative studies involving patients undergoing median sternotomy for cardiac surgery; sternal complications and risk factors.

RESULTS

1360 papers were identified, with 25 included in this review. Patient-related factors included: high BMI; diabetes; comorbidities; gender; age; presenting for surgery in a critical state; predictive risk scores; vascular disease; severe anaemia; medication such as steroids or α-blockers; and previous sternotomy. Peri-operative risk increased with specific types and combinations of surgical procedures. Sternal reopening was also associated with increased risk of sternal wound infection. Post-operative risk factors included a complicated recovery; the need for blood transfusions; respiratory complications; renal failure; non-diabetic hyperglycaemia; sternal asymmetry and sepsis.

CONCLUSION

Pre, peri and post-operative risk factors increase the risk of sternal wound complications in cardiac surgery. Generic risk assessment tools are primarily designed to provide mortality risk scores, with their ability to predict risk of wound infection questionable. Tools that incorporate factors throughout the operative journey are required to identify patients at risk of surgical wound infection.

Surgical Complications of Lung Transplantation

Lung transplantation is a life-saving intervention and the most effective therapy for select patients with irreversible lung disease. Despite the effectiveness of lung transplantation, it is a major operation with several opportunities for complications. For example, recipient and donor factors, technical issues, early postoperative events, and immunology can all contribute to potential complications. This article highlights some of the key surgery-related complications that can undermine a successful lung transplantation. The authors offer their expert opinion and experience to help practitioners avoid such complications and recognize and treat them early should they occur.

Cardiac surgery in the morbidly obese

BACKGROUND

Obesity rates globally continue to rise and in turn the body mass index (BMI) of patients undergoing cardiac surgery is set to mirror this. Patients who are Class III obese (BMI ≥ 40) pose significant challenges to the surgical teams responsible for their care and are also at high risk of complications from surgery and even death. To improve outcomes in this population, interventions carried out in the preoperative, operative, and postoperative periods have shown promise. Despite this, there are no defined best practice national guidelines for perioperative management of obese patients undergoing cardiac surgery.

AIM

This review is aimed at clinicians and researchers in the field of cardiac surgery and aims to form a basis for the future development of clinical guidelines for the management of obese cardiac surgery patients.

METHODS

The PubMed database was utilized to identify relevant literature and strategies employed at various stages of the surgical journey were analyzed.

CONCLUSIONS

Data presented identified the benefits of preoperative respiratory muscle training, off-pump coronary artery bypass grafting where possible, and early extubation. Further randomized controlled trials are required to identify optimal operative and perioperative management strategies before the introduction of such guidance into clinical practice.

Extracorporeal Membrane Oxygenation Cannula-Related Infections: Epidemiology and Risk Factors

Although being a potential major source of infection in extracorporeal membrane oxygenation (ECMO) patients, data regarding cannula-related infections (CRI) remain scarce. We therefore aimed at describing the epidemiology of CRI among critically ill patients supported by ECMO. Between October 2017 and November 2019, adult patients supported by either venoarterial (VA), venopulmonary arterial, or venovenous (VV) ECMO for more than 24 hours were prospectively enrolled. When CRI was suspected, cannula swab and subcutaneous needle aspirate samples were obtained for microbiological culture. Cannula tips were systematically sent for culture at the time of ECMO removal. Primary end-point was CRI, which was defined by sepsis or local sign of cannula infection and at least one positive culture among swab, subcutaneous needle aspirate or tip. Multivariate analysis was performed to identify risk factors of CRI. Hundred patients were included, including 77 VA, 12 venopulmonary arterial, and 11 VV ECMO. Cannula-related infections were diagnosed after a median duration of ECMO of 10 [7-13] days. Rate of CRI was 24%, including 10% with bacteremia. Most frequent involved pathogens were Enterobacteriaceae (n = 14), Enterococci (n = 8), and coagulase-negative Staphylococci (n = 7). By multivariate analysis, diabetes and ECMO duration were independently associated with CRI.

A bundle of infection control measures reduces post-operative sternal wound infection due to Staphylococcus aureus but not Gram-negative bacteria: a retrospective analysis of 6,903 patient episodes

BACKGROUND

Prevention of cardiac surgical site infection has largely focused on reducing infection due to Staphylococcus aureus although other bacteria also play an important role in this complication.

AIM

We assess the impact of an evolving infection control program on the incidence of sternal wound infection (SWI) and the changing incidence of non-staphylococcal infections.

METHODS

We conducted a retrospective cohort study of all patients who underwent primary sternotomy at a single UK centre between September 2010 and May 2018. Data were collated from two-years prior to the stepwise introduction of a broad-ranging infection control program, including S. aureus decolonisation.

FINDINGS

6,903 primary sternotomies were performed of which 2.6% (n=178) were complicated by SWI. Gram-negative bacteria (GNB) and S. aureus were most commonly identified as causative pathogens (45.5% and 30.3% respectively). Following program introduction there was a reduction in the rate of SWI from 3.9 to 1.8 cases/100 patients/month. This was mainly due to a sustained reduction in S. aureus infected cases with no discernible impact on GNB. Multivariable logistic regression analysis identified coronary artery bypass grafting, procedural urgency and procedures performed in the 3rd quarter as independent risk factors for post-operative infection.

CONCLUSION

A multifaceted infection control program was successful at reducing the rate of SWI primarily due to a reduction in S. aureus infections. GNB also play an important role in SWI and traditional preventative measures fail to address these. Future intervention and impact assessments should consider Gram negative infection when measuring effectiveness.

Anaesthesia Challenges during Sternal Wound Debridement

A 50-year-old female weighing 80 kg is posted for a deep sternal wound debridement, post mitral valve replacement (MVR), and post-CABG (Coronary Artery Bypass Grafting) (left internal mammary artery (LIMA)→left anterior descending (LAD)). She had sternal osteomyelitis and had wound debridement thrice before. She had also history of cardiac injury repair during second wound debridement.

Her initial three tissue cultures showed Acinetobacter positive. Her fourth tissue culture shows Staphylococcus haemolyticus positive. Histopathology shows necrotizing granuloma. Two-dimensional Echocardiography (ECHO) shows post-MVR, no Mitral regurgitation (MR), mild Tricuspid Regurgitation (TR) (right ventricular systolic pressure (RVSP)-24 + Retrograde autologous priming (RAP)), Inferior Vena Cava #x0028;IVC) 1.6 cm with respiratory collapse, no pericardial effusion, no Left atrium (LA) clot/veg, and normal biventricular function.

Trends in per-operative parameters and postoperative complications associated with coronary artery bypass graft surgery (CABG); A four-year retrospective study

Objective:

To determine the patterns of per-operative parameters and early outcomes of patients that underwent CABG surgery during a four-year period.

Methods:

This is a cross-sectional descriptive study conducted in a tertiary care of hospital from November 2020 to January 2021. All the patients that underwent the isolated coronary artery bypass grafting (CABG) procedure were included in the study from June 2017 till June 2020. Data was collected on a data extraction form and stored in SPSS format which was analyzed for qualitative statistics keeping p<0.05 as significant. All the results were represented in the form of tables.

Results:

A total of 1,613 patients were operated upon for Coronary Artery Bypass Grafting (CABG) procedure during the study period with 1,222 (75.8%) males and 391 (24.2%) females. Dyslipidemia (71.8%) was the most common risk factor. The average perfusion time decreased only slightly (~1 minute) from 96.01 minutes to 95.07 minutes (2017 to 2020). This change however was not significant (p=0.301). The rate of Left Internal Mammary Artery (LIMA) use stayed relatively stable over the 4-year period fluctuating between 88.7% and 92.9% (p=0.360). The average initial ICU stay (in hours), drain at 12 hours and 24 hours stays almost the same. The rate of mortality peaked in 2018 (4.76%) and subsequently fell to 3.57% by 2020.

Conclusion:

More males underwent CABG surgery at this tertiary care hospital and the overall complication rate and per-operative parameters improved over the years. The non-risk stratified mortality in this study was found to be higher than developed nations.

The value of prophylactic antibiotics in coronary artery bypass graft surgery: A review of literature

Infections have a significant impact on increasing both the morbidity and mortality rate of patients who have undergone coronary artery bypass graft (CABG) surgery. Infection after CABG imposes a clinical and economic burden on patients and health care organizations; therefore, prevention should be on the agenda. This review will focus on the value of using prophylactic antibiotics in coronary artery bypass graft surgery (CABG). Prophylactic antibiotics like cephalosporin and vancomycin are more commonly used antibiotics and are strongly associated with reduced infection risk in patients. The results showed that using antibiotics during the perioperative period and after CABG is an effective strategy for reducing post-infection problems without compromising the patients' clinical outcomes. Diabetic patients are prone to postoperative infection after CABG, however, prophylactic antibiotics should not be the only strategy used to reduce the risk of postoperative infection in diabetic patients. Perioperative glycaemic control is essential for diabetic patients undergoing CABG. Appropriate antibiotic prophylaxis has a great impact on preventing infection after CABG but duration and selecting appropriate antibiotic is important. Standardizing the use of antibiotic prophylaxis reduces the rate of infection and unwanted bacterial resistance, which could subsequently reduce economic costs to patients and public health.

Prevention, Diagnosis and Management of Post-Surgical Mediastinitis in Adults Consensus Guidelines of the Spanish Society of Cardiovascular Infections (SEICAV), the Spanish Society of Thoracic and Cardiovascular Surgery (SECTCV) and the Biomedical Research Centre Network for Respiratory Diseases (CIBERES)

This is a consensus document of the Spanish Society of Cardiovascular Infections (SEICAV), the Spanish Society of Thoracic and Cardiovascular Surgery (SECTCV) and the Biomedical Research Centre Network for Respiratory Diseases (CIBERES). These three entities have brought together a multidisciplinary group of experts that includes anaesthesiologists, cardiac and cardiothoracic surgeons, clinical microbiologists, infectious diseases and intensive care specialists, internal medicine doctors and radiologists. Despite the clinical and economic consequences of sternal wound infections, to date, there are no specific guidelines for the prevention, diagnosis and management of mediastinitis based on a multidisciplinary consensus. The purpose of the present document is to provide evidence-based guidance on the most effective diagnosis and management of patients who have experienced or are at risk of developing a post-surgical mediastinitis infection in order to optimise patient outcomes and the process of care. The intended users of the document are health care providers who help patients make decisions regarding their treatment, aiming to optimise the benefits and minimise any harm as well as the workload.

Diagnosis of infection after cardiovascular surgery (DICS): a study protocol for developing and validating a prediction model in prospective observational study

INTRODUCTION

Postoperative infection (PI) is one of the main severe complications after cardiovascular surgery. Therefore, antibiotics are routinely used during the first 48 hours after cardiovascular surgery. However, there is no effective method for early diagnosis of infection after cardiovascular surgery, particularly, to determine whether postoperative patients need to prolong the use of antibiotics after the first 48 hours. In this study, we aim to develop and validate a diagnostic model to help identify whether a patient has been infected after surgery and guide the appropriate use of antibiotics.

METHODS AND ANALYSIS

In this prospective study, we will develop and validate a diagnostic model to determine whether the patient has a bacterial infection within 48 hours after cardiovascular surgery. Baseline data will be collected through the electronic medical record system. A total of 2700 participants will be recruited (n=2000 for development, n=700 for validation). The primary outcome of the study is the newly PI during the first 48 hours after cardiovascular surgery. Logistic regression penalised with elastic net regularisation will be used for model development and bootstrap and k-fold cross-validation aggregation will be performed for internal validation. The derived model will be also externally validated in patients who are continuously included in another time period (N=700). We will evaluate the calibration and differentiation performance of the model by Hosmer-Lemeshow good of fit test and the area under the curve, respectively. We will report sensitivity, specificity, positive predictive value and negative predictive value in the validation data-set, with a target of 80% sensitivity.

ETHICS AND DISSEMINATION

Ethical approval was obtained from Medical Ethics Committee of Affiliated Nanjing Drum Tower Hospital, Nanjing University Medical College (2020-249-01).

TRIAL REGISTRATION NUMBER

Chinese Clinical Trial Register (www.chictr.org.cn, ChiCTR2000038762); Pre-results.

Does Age Affect the Short- and Long-Term Outcomes of Coronary Bypass Grafting?

The etiology of coronary artery disease (CAD) is multifactorial, stemming from both modifiable and nonmodifiable risk factors such as age. Several studies have reported the effects of age on various outcomes of coronary artery bypass grafting (CABG). This article reviews age-related outcomes of CABG and offers direction for further studies in the field to create comprehensive, evidence-based guidelines for the treatment of CAD. Ninety-two primary sources were analyzed for relevance to the subject matter, of which 17 were selected for further analysis: 14 retrospective cohort studies, 2 randomized clinical trials, and 1 meta-analysis. Our review revealed four broad age ranges into which patients can be grouped: those with CAD (1) below the age of 40 years, (2) between the ages of 40 and 60 years, (3) between the ages of 60 and 80 years, and (4) at or above 80 years. Patients below the age of 40 years fare best overall with total arterial revascularization (TAR). Patients between the ages of 40 and 60 years also fare well with the use of multiarterial grafts (MAGs) whereas either MAGs or single-arterial grafts may be of significant benefit to patients at or above the age of 60 years, with younger and diabetic patients benefitting the most. Arterial grafting is superior to vein grafting until the age of 80 years, at which point there is promising evidence supporting the continued use of the saphenous vein as the favored graft substrate. Age is a factor affecting the outcomes of CABG but should not serve as a barrier to offering patients CABG at any age from either a cost or a health perspective. Operative intervention starts to show significant mortality consequences at the age of 80 years, but the increased risk is countered by maintenance or improvement to patients' quality of life.

The Economic Implications of Introducing Single-Patient ECG Systems for Cardiac Surgery in Australia

Introduction

Sternal wound infections (SWIs) are severe adverse events of cardiac surgery. This study aimed to estimate the economic burden of SWIs following coronary artery bypass grafts (CABG) in Australia. It also aimed to estimate the national and hospital cost-benefit of adopting single-patient electrocardiograph (spECG) systems for CABG monitoring, a measure that reduces the rate of surgical site infections (SSIs).

Material and Methods

A literature review, which focused on CABG-related SSIs, was conducted to identify data which were then used to adapt a published Markov cost-effectiveness model. The model adopted an Australian hospital perspective.

Results

The average SWI-related cost of care increase per patient was estimated at 1022 Australian dollars (AUD), and the annual burden to the Australian health care system at AUD 9.2 million. SWI burden comprised 360 additional intensive care unit (ICU) days; 1979 additional general ward (GW) days; and 186 readmissions. Implementing spECG resulted in 103 fewer ICU days, 565 fewer GW days, 48 avoided readmissions, and a total national cost saving of AUD 2.5 million, annually. A hospital performing 200 yearly CABGs was estimated to save AUD 54,830.

Conclusion

SWIs cause substantial costs to the Australian health care system. Implementing new technologies shown to reduce the SWI rate is likely to benefit patients and reduce costs.

An Outcomes Review of 330 Sternal Wound Reconstructions: Timing of Closure Does Make a Difference

BACKGROUND

Sternal wound infection and dehiscence following cardiac surgery remain difficult clinical problems with high morbidity. Older classification systems regarding timing to reconstruction do not take into account recent improvements in critical care, wound vacuum-assisted closure use, or next-generation antibiotic therapies, which may prolong time to reconstruction.

METHODS

Records of patients undergoing sternal wound reconstruction performed by the senior author (J.A.A.) from 1996 to 2018 at a high-volume cardiac surgery center were reviewed. Indications included sternal wound infection or dehiscence. All patients underwent single-stage removal of hardware, débridement, and flap closure. Patients were divided into two groups based on timing of wound closure after cardiac surgery: less than 30 days or greater than or equal to 30 days.

RESULTS

Of the 505 patients identified during the study period, 330 had sufficient data for analysis. Mean time to sternal wound surgery was 15.7 days in the early group compared to 64.4 days (p < 0.01) beyond 30 days. Postdébridement cultures were positive in 72 percent versus 62.5 percent of patients (p = 0.11), whereas rates of postoperative infection were significantly higher in the delayed group: 1.9 percent versus 9.5 percent (p < 0.01). Partial wound dehiscence rates were also higher after 30 days (1.9 percent versus 11.3 percent; p < 0.01), whereas total length of stay was decreased. Use of wound vacuum-assisted closure was significantly associated with reconstruction beyond 30 days (p < 0.01).

CONCLUSIONS

Although performing sternal wound reconstruction more than 30 days after initial cardiac surgery was associated with a shorter overall hospital length of stay and higher extubation rates in the operating room, these patients also had elevated postoperative infection and wound complication rates. The authors thus recommend not delaying definitive surgical reconstruction when possible.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Therapeutic, III.

A nomogram prediction model for sternal incision problems

Presently, the incidence and mortality rates of sternal incision problems (SIPs) after thoracotomy remain high, and no effective preventive measures are available. The data on 23 182 patients at Xinqiao Hospital, Army Medical University treated with median sternotomy from 1 August 2009 to 31 July 2019 were retrospectively reviewed. A prediction model of SIPs after median thoracotomy was established using R software and then validated using the bootstrap method. Next, the validity and accuracy of the model were tested and evaluated. In total, 15 426 cases met the requirements of the present study, among which 309 cases were diagnosed with SIPs, with an incidence rate of 2%. The body mass index (BMI), intensive care unit (ICU) time, diabetes mellitus, and revision for bleeding were identified as independent risk factors for postoperative SIPs. The nomogram model achieved good discrimination (73.9%) and accuracy (70.2%) in predicting the risk of SIPs after median thoracotomy. Receiver operating characteristic curve analysis showed that the area under curve of the model was 0.705 (95% confidence interval [CI]: 0.746-0.803); the Hosmer-Lemeshow test showed that χ²  = 6.987 and P = 0.538, and the fitting degree of the calibration curve was good. Additionally, the clinical decision curve showed that the net benefit of the model was greater than 0, and the clinical application value was high. The nomogram based on BMI, ICU time, diabetes mellitus, and revision for bleeding can predict the individualised risk of SIPs after median sternotomy, showing good discrimination and accuracy, and has high clinical application value. It also provides significant guidance for screening high-risk populations and developing intervention strategies.

The effects of showering in 48-72 h after coronary artery bypass graft surgery through median sternotomy on wound infection, pain, comfort, and satisfaction: randomized controlled trial

AIMS 

Time of showering after surgery is still a controversial issue for surgical patients and health professionals. We evaluated the effects of showering in 48-72 h after median sternotomy on sternal wound infections, pain due to sternotomy, patient comfort, and satisfaction levels.

METHODS AND RESULTS 

The study was a randomized controlled clinical trial. Fifty-one patients were randomly allocated (1:1) to the shower (n = 26) or non-shower group (n = 25). The patients in the shower group (intervention group) showered in the first 48-72 h after surgery and the patients in the non-shower group (control group) were not allowed to shower until their chest tube sutures were removed. They were instructed to shower on the next day after removal of the chest tube sutures. The rate of sternal wound infections was significantly lower in the shower group (n = 2, 7.7%) than in the non-shower group patients (n = 8, 32.0%; P = 0.038). A logistic regression analysis showed that early post-operative showering was protective and significantly reduced the risk of sternal wound infections independently of other variables [odds ratio (OR): 0.177; 95% confidence interval (CI): 0.033-0.940; P = 0.042]. The pain severity score was significantly lower in the shower group patients. Also, comfort and satisfaction scores were significantly higher in this group (P < 0.05).

CONCLUSION 

Early showering after sternotomy was found to be protective against sternal wound infections and had a positive effect on pain, comfort, and satisfaction.

TRIAL REGISTRATION 

Clinical Trials.gov registration number NCT04250961 (https://clinicaltrials.gov/ct2/show/NCT04250961).

The association between preoperative length of hospital stay and deep sternal wound infection: A scoping review

BACKGROUND

Deep sternal wound infection (DSWI) is a serious complication of cardiac surgery, associated with a significantly longer hospital stay, an increased mortality, and an almost doubling of treatment costs. The preoperative length of hospital stay has been suggested in a small number of studies as a modifiable risk factor yet is not included in surgical site infection prevention guidelines. The aim of this scoping review was to review the existing evidence on the association between preoperative length of hospital stay and DSWI, and to identify established risk factors for DSWI.

METHODS

A literature search of six electronic databases yielded 2297 results. Titles concerning risk factors for DSWI, sternal or surgical wound infection, or poststernotomy complications were included. Abstracts relating to preoperative length of stay as a risk factor for DSWI proceeded to full article review. Articles regarding paediatric surgery, DSWI management or unavailable in English were excluded.

RESULTS

The review identified 11 observational cohort studies. DSWI prevalence was between 0.9% and 6.8%. Preoperative length of stay ranged from 0-15.5 days and was found to be associated with DSWI in all studies. Preoperative length of stay and DSWI were inconsistently defined. Other risk factors for DSWI included diabetes, obesity, respiratory disease, heart failure, renal impairment, complex surgery, and reoperation (p < 0.05).

CONCLUSION

In this scoping review, an association between preoperative length of stay and the development of DSWI following cardiac surgery was identified. Thus, preoperative length of stay as a modifiable risk factor for DSWI should be considered for inclusion in cardiothoracic surgical infection prevention guidelines.

Eradication of Staphylococcus aureus post-sternotomy mediastinitis following the implementation of universal pre-operative nasal decontamination with mupirocin: an interrupted time-series analysis

BACKGROUND

Although pre-surgical nasal decontamination with mupirocin (NDM) has been advocated as a measure for preventing post-surgical mediastinitis (PSM) due to Staphylococcus aureus, this strategy is not universally recommended due to the lack of robust supporting evidence. We aimed to evaluate the role of pre-operative NDM in the annual incidence of S. aureus PSM at our institution.

METHODS

An interrupted time-series analysis, with autoregressive error model, was applied to our single-center cohort by comparing pre-intervention (1990-2003) and post-intervention period (2005 to 2018). Logistic regression was performed to analyze risk factors for S. aureus PSM.

FINDINGS

12,236 sternotomy procedures were analyzed (6,370 [52.1%] and 5,866 [47.9%] in the pre-intervention and post-intervention periods, respectively). The mean annual percentage adherence to NDM estimated over the post-interventional period was 90.2%. Only four out of 127 total cases of S. aureus PSM occurred during the 14-years post-intervention period (0.68/1,000 sternotomies vs. 19.31/1,000 in pre-interventional period [p<0.0001]). Interrupted time-series analysis demonstrated a statistically significant annual reduction of S. aureus PSM trend of -9.85 cases per 1,000 sternotomies (-13.17 to -6.5, P-value< 0·0001) in 2005, with a decreasing trend maintained over the following five years with an estimated relative reduction of 84.8% (95% CI: 89·25 to 74·09). Chronic obstructive pulmonary disease was the single independent risk factor for S. aureus PSM (odds ratio: 3.7; 95% CI: 1.72-7.93) and was equally distributed in patients undergoing sternotomy during pre or post-intervention periods.

INTERPRETATION

Our experience suggests that the implementation of pre-operative NDM reduces significantly the incidence of S. aureus PSM.

Higher Surgery and Recovery Room Air Pressures Associated with Reduced Surgical Site Infection Risk

BACKGROUND

Incisional surgical site infections (SSIs) following coronary artery bypass grafting (CABG) prolong hospital stays, elevate healthcare costs and increase likelihood of further complications. High air pressure deactivates bacteria and is utilized for commercial food preservation, assuring microbiologically safe pharmaceuticals and sanitizing instruments. However, research on utilizing air pressure deactivation thresholds in surgical and postoperative rooms to reduce rates of SSIs is lacking.

METHODS

A case-control study of 801 CABG patients, 128 SSI cases and 673 controls was conducted from January 1, 2006 through March 31, 2009 in Yerevan, Armenia. Patient and surgery characteristics, air pressure measurements and seasons were selected as independent variables with SSI rates as the outcome. The novel threshold regression analysis was used to determine potential air pressure bacterial deactivation thresholds. A final multivariate logistic regression model adjusted for confounders.

RESULTS

Overall, bacterial deactivation air pressure threshold was 694.2 mmHg, with the presence of infection for higher air pressure values not statistically significant from zero. Individual deactivation thresholds for Staphylococcus epidermidis (threshold = 694.2 mmHg) and Escherichia coli (threshold = 689.2) showed similar patterns. Multivariate logistic regression showed air pressure above the deactivation threshold was highly protective against SSIs with adjOR = 0.27 (p-value = 0.009, 95%CI: 0.10-0.72). Other SSI risk factors included female sex, adjOR = 2.12 (p-value = 0.006, 95%CI: 1.24-3.62), diabetes, adjOR = 2.61 (p-value < 0.001, 95%CI: 1.72-3.96) and longer time on ventilator, adjOdds = 1.01 (p-value = 0.012, 95%CI: 1.00-1.02).

CONCLUSION

Maintaining air pressures in operating and postoperative rooms exceeding bacterial-deactivation thresholds might substantially reduce SSI rates following surgery. Further research should identify specific bacterial-deactivation air pressure thresholds in surgical and postoperative rooms to reduce SSI rates, especially for drug-resistant bacteria.

Obesity and Preoperative Anaemia as Independent Risk Factors for Sternal Wound Infection After Coronary Artery Bypass Graft Surgery with Pedicled (Non-Skeletonized) Internal Mammary Arteries: The Role of Thoracic Wall Ischemia?

Purpose

Obesity remains statistically associated with coronary artery disease, for which coronary artery bypass graft surgery (CABG) remains the standard of care. However, obesity is also associated with sternal wound infection (SWI) which is a severe complication of CABG despite advances in surgery and in infection prevention and control. Strategies to reduce the incidence of SWI are still being investigated, and we therefore conducted a retrospective study to revisit factors other than obesity associated with SWI after CABG.

Patients and Methods

Data were extracted from the medical records of 182 patients who underwent elective on-pump CABG using one or both pedicled internal mammary artery grafts in Reims University Hospital between May 2015 and May 2016. All preoperative or perioperative variables with a p value<0.10 in univariate analysis were entered into a stepwise logistic regression model.

Results

Among the 182 patients (145 male (79.6%), median age 68.0 [45.0-87.0] years), 138 (75.8%) underwent CABG using bilateral internal mammary artery grafts. Median BMI was 27.7 [18.7-50.5] kg/m², and there were 51 (28.0%) and 79 (43.4%) patients with obesity and overweight, respectively. Twenty-three out of the 182 patients (12.6%) developed SWI. In-hospital mortality was not statistically different between patients with and without SWI but the median length of stay was (6.0 [2.0-38.0] versus 5.0[3.0-21.0] days in the intensive care unit, p=0.03, and 26.0 [9.0-134.0] versus 9.0 [7.0-51.0] days in hospital, p<0.0001). Obesity and preoperative anaemia were independently associated with SWI, as was the number of red blood cell (RBC) units transfused (OR 14.61 [2.64-80.75], OR 4.64 [1.61-13.34] and OR 1.27 [1.02-1.58], respectively).

Conclusion

The independent association of SWI with the number of RBC units transfused and the existence of preoperative anaemia and obesity suggests a mechanism of thoracic wall ischemia in SWI after CABG, thus leaving insufficient perfusion of the thoracic wall in patients with obesity. Medical strategies are warranted to try to prevent this costly complication.

Impact of Pre-operative Hemoglobin A1C Level and Microbiological Pattern on Surgical Site Infection After Cardiac Surgery

Background Surgical site infection (SSI) after cardiac surgery is a major concern. A limited number of studies have addressed the relationship of preoperative glycemic control on the risk of developing SSI after cardiac surgery. We aim to determine the incidence, microbiological pattern, and impact of preoperative hemoglobin A1C (Hgb A1C) on the development of SSI after cardiac surgery. Methods This is a single-center retrospective chart review that was performed on adult patients undergoing cardiac surgery from January 2017 to December 2018. Results Two hundred and twenty-nine patients underwent 233 procedures. The median age was 60 years; 71% males, 64% were diabetic, and 67% had a Hb A1C above 7% preoperatively. Around 7% of patients developed deep SSI. For patients that developed SSI, 63% had gram-negative bacteria. Hb A1C >7% was not found to be associated with an increased incidence of SSI. Conclusion Our results show that there is no apparent relationship between pre-operative Hgb A1C levels and SSI after cardiac surgery. Although we follow a comprehensive SSI perioperative bundle based on international guidelines that advocates using antibiotics to cover gram-positive organisms, it is interesting that the rate of gram-negative organisms in our patients' cohort is unexpectedly high. We believe that adjusting the perioperative antibiotic regimen based on local microbiological patterns seems to be a reasonable and easily achievable target to decrease the incidence of SSI.

Novel device prototyping for endoscopic cell sheet transplantation using a three-dimensional printed simulator

Introduction

Considering higher risks of candidates for cardiac regenerative therapy with compromised cardiac function, it is anticipated to develop less invasive surgical procedures. In the present study, we aimed to develop a prototype of totally endoscopic cell sheet delivery device and evaluate the surgical technique for epicardial cell sheet placement using three-dimensional (3D) printed simulators based on human computed tomography data.

Methods

We designed an endoscopic cell sheet delivery device with outer and inner frame with self-expandable applicator which can be opened in thoracic cavity. We launched spout line to provide liquids on the applicator surface and tension line to gently bend the applicator dorsally. We prepared human mesenchymal stem cell (MSC) sheets and compared wet/dry conditions of 3D printed heart/porcine heart and applicator to identify suitable conditions for cell sheet transplantation. Finally we validated the feasibility of endoscopic transplantation to anterior and lateral wall of left ventricle using 3D printed simulators.

Results

Moist condition of both 3D printed heart/porcine heart surface and applicator at transplantation yielded highest successful rate (100%, p = 0.0197). For both endoscopic transplantation sites, MSC sheets were successfully deployed. The procedure duration was 157 ± 23 s for anterior wall and 123 ± 13 s for the lateral wall in average, respectively.

Conclusions

We developed a novel prototype of endoscopic cell sheet delivery device for minimally-invasive cardiac regenerative therapy utilizing a 3D printed simulator. The commercialization of the prototype may provide a safe minimally-invasive method to deliver potential cardiac regenerative therapy in the future.

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We invented a novel device for endoscopic cell sheet transplantation.

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We optimized the transplantation procedure using three-dimensional printed simulator.

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Commercialization of the device may provide standardized cardiac regenerative therapy.

Healthcare-Associated Infections in a Cardiac Surgery Service in Brazil

Objectives

The study aimed to determine the incidence of healthcare-associated infections (HAI) and their sites in a cardiac surgery service, as well as to determine if gender and age were risk factors for infection and to quantify mortality and increase in the hospital length of stay (LOS) due to HAI.

Methods

Medical records of patients who underwent cardiac surgery from January 2012 to January 2018 were retrospectively analyzed. Data on age, gender, mortality, occurrence of HAI during hospitalization, and LOS were collected. Continuous variables were analyzed using Student's t-test, while categorical variables were compared using Fisher's exact test or chi-square test.

Results

Among the 195 patients available, the HAI rate in our service was 22.6%, with female gender being a risk factor for infections (odds ratio [OR]=2.23; P=0.015). Age was also a significant risk factor for infections, with a difference in the mean age between the group with and without infection (P=0.02). The occurrence of an infectious process increased the LOS in 14 days (P<0.001) and resulted in higher mortality rates (P=0.112). A patient who has HAI was approximately 19 times more likely to remain hospitalized for more than nine days (P<0.001).

Conclusion

Age and gender were risk factors for the development of HAI and the occurrence of an infectious process during hospitalization significantly increases the LOS. These findings may guide future actions aimed at reducing the impact of HAI on the health system.