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)

Benign disorders of the mediastinum: a narrative review

Background and Objective

There are several benign processes that affect the mediastinum with considerable morbidity that may range from reactive entities to neoplastic disorders. This review article will focus on non-neoplastic benign mediastinal diseases which include large vessel vasculitis such as Takayasu and giant cell arteritis, mediastinal granulomas, fibrosing mediastinitis and mediastinal infections. These diseases can cause significant morbidity and mortality; therefore, we aim to familiarize readers with the pathophysiology, epidemiology and diagnosis of these mediastinal diseases and provide an update on the treatment options available.

Methods

We searched various databases such as PubMed and Google Scholar from August 2023 until January 2024 for the various benign mediastinal disorders we wanted to discuss. Relevant articles that were written in English were shortlisted and used to help write this narrative review.

Key Content and Findings

We will briefly discuss the anatomy of the mediastinum along with some of the more common benign mediastinal disorders. We will discuss epidemiology, etiology, clinical features, and treatment. Relevant laboratory, and imaging findings important to make the diagnosis will be included as well.

Conclusions

Prompt diagnosis of these diseases is of the utmost importance as delay in care may be associated with increased mortality. Our article aims to provide an up-to-date review and summarize the current literature regarding these diseases.

Association of adherence to individual components of Society of Thoracic Surgeons cardiac surgery antibiotic guidelines and postoperative infections

OBJECTIVES

The study objectives were to measure the association among the 4 components of Society of Thoracic Surgeons antibiotic guidelines and postoperative complications in a cohort of patients undergoing valve or coronary artery bypass grafting requiring cardiopulmonary bypass.

METHODS

In this retrospective observational study, adult patients undergoing coronary revascularization or valvular surgery who received a Surgical Care Improvement Project-compliant antibiotic from January 1, 2016, to April 1, 2021, at a single, tertiary care hospital were included. The primary exposures were adherence to the 4 individual components of Society of Thoracic Surgeons antibiotic best practice guidelines. The association of each component and a combined metric was tested in its association with the primary outcome of postoperative infection as determined by Society of Thoracic Surgeons data abstractors, controlling for several known confounders.

RESULTS

Of the 2829 included patients, 1084 (38.3%) received care that was nonadherent to at least 1 aspect of Society of Thoracic Surgeons antibiotic guidelines. The incidence of nonadherence to the 4 individual components was 223 (7.9%) for timing of first dose, 639 (22.6%) for antibiotic choice, 164 (5.8%) for weight-based dose adjustment, and 192 (6.8%) for intraoperative redosing. In adjusted analyses, failure to adhere to first dose timing guidelines was directly associated with Society of Thoracic Surgeons-adjudicated postoperative infection (odds ratio, 1.9; 95% confidence interval, 1.1-3.3; P = .02). Failure of weight-adjusted dosing was associated with both postoperative sepsis (odds ratio, 6.9; 95% confidence interval, 2.5-8.5; P < .01) and 30-day mortality (odds ratio, 4.3; 95% confidence interval, 1.7-11.4; P < .01). No other significant associations among the 4 Society of Thoracic Surgeons metrics individually or as a combination were observed with postoperative infection, sepsis, or 30-day mortality.

CONCLUSIONS

Nonadherence to Society of Thoracic Surgeons antibiotic best practices is common. Failure of antibiotic timing and weight-adjusted dosing is associated with odds of postoperative infection, sepsis, and mortality after cardiac surgery.

Early Wound and Sternal Management Following Pediatric Cardiac Surgery

Early postoperative wound management following congenital heart surgery remains an area without equipoise. Precautionary restrictions can impact quality of life, development, and delay access to other needed care. The influence of different practices on wound healing and complications is unknown. We surveyed Pediatric Acute Care Cardiology Collaborative member centers regarding postoperative wound closure, wound vacuum-assisted closure (VAC) use, sternal precautions, and restrictions in the early postoperative period. We analyzed responses using descriptive statistics. Responses were submitted by 35/46 (76%) centers. Most centers perform primary skin closure with subcutaneous sutures. Wound covers are removed after 48 h at 43% (15/35) of centers and after ≥72 h at 34% (12/35) of centers. For delayed sternal closure, 16 centers close skin with interrupted, externalized sutures, 5 utilize wound VAC-assisted closure, and 12 use variable practices. Generally, 33 centers use wound VACs for wound care. Patient selection for VAC use and length of therapy varies. We found great variability in duration of sternal precautions and in activity, bathing, and submersion restrictions. Finally, 29 centers require a waiting period between cardiothoracic surgery and other surgeries such as tracheostomy or gastrostomy tube placement. Postoperative wound and sternal management lack consistency across North American pediatric heart institutes. Some restrictive practices may prolong length of stay and/or negatively impact quality of life and neurodevelopment. Practices may also impact wound infection rates. Research linking practices with clinical outcomes is needed to better define standards of care and reduce potential negative consequences of overly conservative or aggressive practices.

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.

A Randomized Study Evaluating Clinical Efficacy and Safety of Trusteel® and Ethisteel® Surgical Steel Sutures for Sternal Closure in Subjects Undergoing Surgical Procedures by Sternotomy

INTRODUCTION

Sternal dehiscence and other post-sternotomy complications, viz. superficial and deep sternal wound infection, mediastinitis, and sternal instability increase the risk of mortality. Sternotomy closure with steel sutures results in a low complication rate. Therefore, this study compared the clinical equivalence of Trusteel® (Healthium Medtech Limited, Bengaluru, India) and Ethisteel® (Ethicon, Johnson & Johnson, Cincinnati, USA) surgical steel sutures for sternal closure following median sternotomy.

METHODS

The primary endpoint of this prospective, single-blind, multicentric, two-arm, randomized (1:1) study (April 2021-April 2023) was a comparison of the proportion of subjects having sternal dehiscence within 26 weeks of the median sternotomy closure between Trusteel® (n=33) and Ethisteel® (n=34) groups. Secondary endpoints comprised an assessment of intraoperative suture handling, the incidence of mortality and other complications of sternal closure, operative time, intensive care unit (ICU)/hospital stay, return to normal day-to-day activities and work, subject satisfaction and general well-being, and adverse events in both groups. A statistically significant result between the groups was considered at p<0.05.

RESULTS

No incidence of sternal dehiscence or other post-operative complications were recorded. A significant difference (p<0.05) in the stretch capacity of Trusteel® and Ethisteel® sutures was noted; otherwise, ease of passage, knot holding, knot security, knot tie-down smoothness, and memory of both sutures had comparable ratings. Operative time, ICU/hospital stay, and return to normal day-to-day activities and work were comparable between the groups. Improvement in post-operative functional abilities, quality of life, and health status was evident in both groups and was comparable.

CONCLUSION

Trusteel® surgical steel suture is clinically equivalent to Ethisteel® surgical steel suture and is safe and effective for sternal closure following median sternotomy.

Infectious complications following major heart surgery from the day of the surgery to hospital discharge

BACKGROUND

At some point in their lives, many people will require major heart surgery (MHS). Patients are generally older adults with various risk factors for infection. However, the incidence of infection after MHS is poorly known, as reported infection data are frequently biased due to different factors like the surgical procedure, postoperative timing, and infectious syndromes or etiologic agents, among others. In addition, most patient data are retrospectively obtained.

PURPOSE AND METHODS

Data were prospectively collected regarding the incidence of all nosocomial infections produced from the time of surgery to hospital discharge in a cohort of 800 adults consecutively undergoing a MHS procedure.

RESULTS

During postoperative hospitalization, 124 of the 800 participants developed one or more infections (15.5%): during their ICU stay in 68 patients (54.8%), during their stay on the general ward post ICU in 50 (40.3%), and during their stay in both wards in 6 (4.8%). The most common infections were pneumonia (related or not to mechanical ventilation), surgical site and bloodstream. As etiological agents, 193 pathogens were isolated: mostly Gram-negative bacilli (54.4%), followed by Gram-positive bacteria (30%), viruses (4.6%) and fungi (1.5%). In our cohort, all-cause mortality was recorded in 33 participants (4.1%) and 9 infection-related deaths (1.1%) were produced. Among subjects who developed infections, overall mortality was 13.7% and in those who did not, this was only 2.3%.

CONCLUSION

Infection following MHS remains frequent and severe. Our data suggest that hospital-acquired infection studies should consider episodes of infection in all populations during their entire hospital stay and not only those related to specific clinical syndromes or acquired while the patient is in intensive care.

The role of negative pressure wound therapy in the treatment of poststernotomy mediastinitis in Asians: A single-center, retrospective cohort study

Introduction

Poststernotomy mediastinitis (PSM) is a critical and life-threatening complication that can arise after cardiac surgery. The aim of this study was to evaluate and compare the outcomes of negative pressure wound therapy (NPWT) and conventional methods in the management of mediastinitis following heart surgery with a focus on Asian populations.

Methods

For this retrospective study, we included and evaluated a total of 34 patients who had undergone cardiac operations between January 2011 and September 2021 and developed PSM. The patients were divided into two groups, the NPWT group (n = 16, 47.1%) and the conventional treatment group (n = 18, 52.9%), and compared.

Results

The two groups showed no significant differences in terms of patient characteristics, PSM wound classification based on the El Oakley classification, and wound closure methods, but there was a higher incidence of diabetes mellitus in the NPWT group. With regard to mediastinal cultures, a higher prevalence of Staphylococcus epidermidis was observed in the NPWT group. However, we found no significant differences between the two groups regarding the time interval from diagnosis to wound closure, hospitalization duration, and re-exploration rate. Notably, the NPWT group exhibited a significantly higher in-hospital mortality rate than the conventional treatment group (p = 0.024).

Conclusions

Our findings suggest that the use of NPWT might not lead to improved medical outcomes for patients with PSM when compared to conventional treatment methods. As a result, it becomes imperative to exercise great care when choosing patients for NPWT. To obtain more definitive and conclusive results and identify the most appropriate cases for NPWT, conducting larger randomized clinical trials is necessary.

Sepsis in postcardiotomy cardiogenic shock patients supported with veno- arterial extracorporeal membrane oxygenation

BACKGROUND

Sepsis could affect the outcomes of patients with postcardiotomy cardiogenic shock supported with extracorporeal membrane oxygenation (ECMO). Our objectives were to characterize sepsis patients with ECMO support for postcardiotomy cardiogenic shock and assess its predictors and effect on patients' outcomes.

METHODS

This retrospective study included 103 patients with ECMO for postcardiotomy cardiogenic shock from 2009 to 2020. Patients were divided according to the occurrence and timing of sepsis into three groups. Group 1 included patients with no sepsis (n = 67), Group 2 included patients with ECMO-related sepsis (n = 10), and Group 3 included patients with non-ECMO-related sepsis (n = 26).

RESULTS

Lactate level before ECMO was highest in the ECMO-associated sepsis group (Group 1 and 2 p = 0.003 and Group 2 and 3 p = 0.003). Dialysis and gastrointestinal bleeding were highest in ECMO-associated sepsis (p = 0.03 and 0.04, respectively). Blood transfusion was higher in ECMO-associated sepsis than in patients with no sepsis (p = 0.01). Mortality was nonsignificantly higher in patients with ECMO-associated sepsis. High BMI (OR: 1.11; p = 0.004), preoperative dialysis (OR: 7.35; p = 0.02), preoperative IABP (OR: 9.9.61; p = 0.01) and CABG (OR: 6.29; p = 0.01) were significantly associated with sepsis. Older age (OR: 1.08; p = 0.004), lower BSA (OR: 0.004; p = 0.003), peripheral cannulation (OR: 29.82; p = 0.03), and high pre ECMO lactate level (OR: 1.24; p = 0.001) were associated with increased mortality. Sepsis did not predict mortality (OR: 1.83; p = 0.21).

CONCLUSIONS

Sepsis is a dreaded complication in patients with postcardiotomy cardiogenic shock, especially ECMO-associated sepsis. Preoperative risk factors could predict postoperative sepsis in ECMO patients.

Predictors of sternal wound infection post cardiac surgery in a Saudi Centre: a case control study

BACKGROUND

Sternal wound infection (SWI) post cardiac surgery remains an important cause of extra morbidity, mortality and cost. The objective was to identify risk factors for SWI in a cardiac centre in Eastern Saudi Arabia as part of the investigation into Surveillance variance in the local rates of SWI.

METHODS

We included cases and controls from a cross section of patients who underwent major cardiac surgery between 2017 and 2020 matched for age, sex and time of surgery. An explanatory logistic regression model was fitted to estimate the risk factors.

RESULTS

N = 204 (51 cases and 153 controls matching ratio 1:3, from a source population of 985 patients). factors significantly associated with SWI in the final multivariate model: hospital stay OR (1.05, Cl 1.01-1.10), Graft Conduit BIMA versus No Graft OR (10.94, Cl 1.60-74.63), transfusion of both packed cells plus other blood products versus no transfusion OR (3.53, Cl 93-13.44), HbA1c OR (1.09 Cl 0.84-1.41), BMI OR (1.25, Cl 1.04-1.50), perioperative blood glucose OR (1.02, Cl 1.004-1.03), surgery time OR (1.19, Cl 1.00-1.58).

CONCLUSIONS

The diverse aetiology, cross-disciplinary nature of SWI prevention, and despite improved prevention and control practices, including related care bundles with their proven value, SWI remain a serious challenge in cardiac surgery. Multidisciplinary consensus guidelines are well overdue.

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.

Nosocomial Extracardiac Infections After Cardiac Surgery

Purpose of Review

Nosocomial extracardiac infections after cardiac surgery are a major public health issue affecting 3–8.2% of patients within 30–60 days following the intervention.

Recent Findings

Here, we have considered the most important postoperative infective complications that, in order of frequency, are pneumonia, surgical site infection, urinary tract infection, and bloodstream infection. The overall picture that emerges shows that they cause a greater perioperative morbidity and mortality with a longer hospitalization time and excess costs. Preventive interventions and corrective measures, diminishing the burden of nosocomial extracardiac infections, may reduce the global costs. A multidisciplinary team may assure a more appropriate management of nosocomial extracardiac infections leading to a reduction of hospitalization time and mortality rate.

Summary

The main and most current data on epidemiology, prevention, microbiology, diagnosis, and management for each one of the most important postoperative infective complications are reported. The establishment of an antimicrobial stewardship in each hospital seems to be, at the moment, the more valid strategy to counteract the challenging problems.