Mediastinitis After Congenital Heart Surgery: Epidemiology, Clinical Features and Outcomes.

Mediastinitis after surgery for congenital heart disease has a great impact on morbidity and mortality. However, there are scarce studies focused on the epidemiology of postsurgical mediastinitis in pediatric patients. In this 18-year period retrospective study, the cumulative incidence of mediastinitis was low: 0.64%, (95% confidence interval: 0.36-1.1). Gram-negative bacilli were common (35%). The mortality rate was 7.1%, associated with fungal infection.

Post-cardiac surgery fungal mediastinitis: clinical features, pathogens and outcome.

OBJECTIVES: The occurrence of mediastinitis after cardiac surgery remains a rare and severe complication associated with poor outcomes. Whereas bacterial mediastinitis have been largely described, little is known about their fungal etiologies. We report incidence, characteristics and outcome of post-cardiac surgery fungal mediastinitis. METHODS: Multicenter retrospective study among 10 intensive care units (ICU) in France and Belgium of proven cases of fungal mediastinitis after cardiac surgery (2009-2019). RESULTS: Among 73,688 cardiac surgery procedures, 40 patients developed fungal mediastinitis. Five were supported with left ventricular assist device and five with veno-arterial extracorporeal membrane oxygenation before initial surgery. Twelve patients received prior heart transplantation. Interval between initial surgery and mediastinitis was 38 [17-61] days. Only half of the patients showed local signs of infection. Septic shock was uncommon at diagnosis (12.5%). Forty-three fungal strains were identified: Candida spp. (34 patients), Trichosporon spp. (5 patients) and Aspergillus spp. (4 patients). Hospital mortality was 58%. Survivors were younger (59 [43-65] vs. 65 [61-73] yo; p = 0.013), had lower body mass index (24 [20-26] vs. 30 [24-32] kg/m2; p = 0.028) and lower Simplified Acute Physiology Score II score at ICU admission (37 [28-40] vs. 54 [34-61]; p = 0.012). CONCLUSION: Fungal mediastinitis is a very rare complication after cardiac surgery, associated with a high mortality rate. This entity should be suspected in patients with a smoldering infectious postoperative course, especially those supported with short- or long-term invasive cardiac support devices, or following heart transplantation.

Routine Mediastinal Drainage Fluid Culture for Early Diagnosis of Poststernotomy Mediastinitis.

BACKGROUND: Early diagnosis of poststernotomy mediastinitis (PSM) is challenging. Since 2016, we have routinely performed mediastinal drainage fluid culture (MDFC) in patients undergoing sternotomy. This study aimed to determine the utility of MDFC for early diagnosis of PSM. METHODS: Between November 2016 and April 2020, we conducted MDFC in 1,012 patients on the third postoperative day and prospectively observed for PSM occurrence for 3 months. If bacteria were identified, additional MDFC or blood culture was performed to reduce the possibility of false positives. Based on MDFC results, the decision for early treatment for PSM was at the attending physician's discretion. RESULTS: Bacteria were identified in MDFC of 29 patients, eight of whom subsequently developed PSM. Among 983 patients with negative MDFC, only 15 developed PSM. In multivariate analysis, previous sternotomy history and positive MDFC were predictors of PSM. Positive MDFC was regarded as true positive if (1) PSM occurred subsequently, and/or (2) the same bacteria were identified in additional MDFC/blood culture. Non-occurrence of PSM in the absence of antibiotic treatment was regarded as false-positive MDFC. The sensitivity, specificity, and positive and negative predictive values of routine MDFC for diagnosis of mediastinal infection were 46.4, 99.0, 56.5, and 98.5%, respectively. When categorizing cases with positive MDFC based on the identified bacteria, the positive predictive value was highest (76.9%) when Staphylococci were identified. CONCLUSION: Routine MDFC after sternotomy can facilitate early diagnosis of PSM. Early treatment for PSM may be indicated in patients in whom Staphylococci are identified in the MDFC.

Unveiling the Pathogenic Bacteria Causing Descending Necrotizing Mediastinitis.

The combination of maxillofacial infections (MI) with descending necrotizing mediastinitis (DNM) is a complex disease characterized by rapid development and high mortality. Here, we performed metagenomic next-generation sequencing (mNGS) using samples from 21 patients with MI and eight patients with DNM. In this study, we found that the species richness of the DNM group was higher than that of the MI group, and the species diversity of the DNM group was higher than that of the MI group, with no statistically significant differences between groups (P > 0.05). LefSE analysis revealed that the main species differing between groups were Bacillus, Lactobacillus, Streptococcaceae, and Streptococcus (S. constellatus and S. anginosus). In addition, the PLS-DA analysis revealed that the dominant groups in the DNM group at the species level were S. constellatus, S. anginosus, Streptococcus intermedius, Prevotella oris, Mogibacterium timidum, and Eubacterium nodatum. Next, we correlated the clinical characteristics of the patients with the relative abundance of the pathogens identified in the LefSe and PLS-DA analyses. The relative abundance of S. anginosus was positively correlated with C-reactive protein (CRP) and calcitoninogen (PCT) but negatively correlated with the percentage of lymphocytes (Lymph%) (P < 0.05). On the other hand, M. timidum was positively correlated with the percentage of neutrophils (Neut%) and glycated hemoglobin (GLU) (P < 0.05), and Parvimonas micra was positively correlated with CRP (P < 0.05).

Fibrosing Mediastinitis Associated With Tuberculosis in Children.

Two children developed fibrosing mediastinitis following past tuberculosis disease. Both were microbiologically negative for tuberculosis at presentation. One was treated with steroids and supportive therapy, but developed active tuberculosis with complications. He ultimately succumbed to healthcare-associated infection. The other recovered with steroids, administered along with antituberculosis treatment.

Kazachstania slooffiae: An unexpected journey to a human pleural sample.

We report a case of a 50-year-old shepherd hospitalized in intensive care unit for hiatal hernia complicated by an occlusive syndrome. In post-surgery, an acute respiratory distress occurs due to mediastinitis with large pleural effusion. At the laboratory, direct examination of the pleural sample revealed the presence of pseudohyphae. Kazachstania slooffiae was identified by Mass Spectrometry and confirmed by DNA sequencing. This uncommon yeast has never been previously described in human infections. Although its pathogenicity is not well known, K. slooffiae should be considered in the case of critically ill patients.

Prevention of Sternal Wound Infections in Women Using an External Sternum Fixation Corset.

PURPOSE: Deep sternal wound infection (DSWI) and mediastinitis are devastating complications after median sternotomy. Previous studies demonstrated an effective prevention of sternal wound infection (SWI) using an external sternal corset in high-risk cardiac surgery patients. The aim of this study is to assess the preventive effect of the Stern-E-Fix corset in high-risk poststernotomy female patients. METHODS: A total of 145 high-risk female patients undergoing cardiac surgery through median sternotomy were retrospectively analyzed. Patients were divided into group A (n = 71), who received the Stern-E-Fix corset (Fendel & Keuchen GmbH, Aachen, Germany), and group B (n = 74), who received the elastic thorax bandage (SanThorax) postoperatively for 6 weeks. The mean follow-up period was 12 weeks. RESULTS: Incidence of SWI was 7% in group A vs. 17.6% in group B (p = 0.025). One patient presented with DSWI in group A vs. seven patients in group B (p = 0.063). No patient developed mediastinitis in group A vs. four patients in group B (p = 0.121). In all, 4.2% of group A patients required operative wound therapy vs. 16.2% of group B patients (p = 0.026). The length of hospital stay was significantly longer in group B (p = 0.006). CONCLUSION: Using an external supportive sternal corset (Stern-E-Fix) yields a significantly better and effective prevention against development of sternal dehiscence, DSWI, and mediastinitis in high-risk poststernotomy female patients.

Descending Necrotizing Mediastinitis: Analysis of 9 Cases in Our Hospital.

OBJECTIVES: Descending necrotizing mediastinitis (DNM) is a serious and progressive infection involving the neck and chest and with high mortality if not treated quickly and properly. The aim of this study is to share our practices for managing this condition. METHODS: We retrospectively evaluated 9 patients diagnosed with DNM in our hospital between January 2006 and October 2019. Age, gender, origin of infection, length of hospital stay, microorganisms present, type of surgical treatment, and clinical outcomes were reviewed. RESULTS: All patients underwent surgery to drain neck and mediastinal secretions and collections. Three (33.3%) patients were treated with transcervical drainage alone, and 6 (66.7%) patients were treated with combined transcervical and transthoracic drainage. Reoperations were reported in 3 (33.3%) cases. The average length of hospital stay was 22.78 ± 10.05 days (range: 9-40 days). The average length of intensive care unit stay was 6.44 ± 10.10 days (range: 0-25 days). There were no in-hospital deaths, and all patients were discharged home with good outcomes. CONCLUSIONS: To improve the prognosis of DNM, we suggest early and adequate debridement of all affected areas along with the proper use of antibiotics. A multidisciplinary approach involving both cardiothoracic and ENT surgeons is also required.

Emerging trends in mediastinitis: National Veterans Health Administration experience with methicillin-resistant Staphylococcus aureus prevention.

OBJECTIVES: Perioperative bacterial decolonization and prophylactic antibiotic therapy at the Veterans Affairs Health Care System have changed over the past decade. Our objectives were to identify associated changes in the microbiology of mediastinitis and to perform a contemporary survival analysis in patients with mediastinitis after isolated coronary artery bypass grafting procedure. METHODS: From January 2006 to December 2015, 45,323 consecutive patients underwent coronary artery bypass grafting at 83 medical centers. The Veterans Affairs Health Care System nationwide administrative database was queried to identify patients with postoperative mediastinitis and obtain patient-level data. Simple descriptive statistics and multivariable logistic regression were used to analyze microbiologic data and identify risk factors for infection. Poisson regression was used to determine yearly incidence estimates. Cox proportional hazard model identified predictors of long-term survival from date of operation. RESULTS: During the study period, 348 patients (0.78%) developed postoperative mediastinitis-with a stable rate of incidence (Cochrane-Armitage test, P = .69). Of patients with microbiologic data, 75.5% of infections (n = 188) were caused by gram-positive and 24.5% (n = 61) gram-negative organisms. The incidence of methicillin-resistant Staphylococcus aureus mediastinitis decreased during the study period (Cochrane-Armitage test, P = .013). Gram-negative mediastinitis occurred earlier than gram-positive mediastinitis (median, 15.0 vs 25.0 days; P < .0001). Patients with mediastinitis did not have increased 30-day mortality (2.0% vs 1.9%; P = .9), but had worse long-term survival compared with uninfected patients (P < .0001). CONCLUSIONS: The incidence of methicillin-resistant S aureus mediastinitis has decreased over the past decade. Gram-negative bacteria are responsible for 1 in 4 cases of mediastinitis and infection is diagnosed earlier in the postoperative period than gram-positive mediastinitis. These findings highlight the need for efforts to prevent gram-negative and methicillin-susceptible S aureus mediastinitis.

Staphylococcus aureus Descending Necrotizing Mediastinitis in a Healthy Adult.

Descending necrotizing mediastinitis (DNM) is a severe form of mediastinitis with high mortality rates due to the rapid progression of infection into the mediastinum through tissue planes, often from a dental or pharyngeal source. We present a case of monomicrobial methicillin-resistant Staphylococcus aureus DNM in a healthy young man who was initially misdiagnosed with strep throat. This is well described in the pediatric literature; however, DNM in adults is typically polymicrobial and occurs in those with comorbidities such as diabetes mellitus and older age. Survival is excellent with early identification of mediastinitis, prompt surgical intervention, and appropriate antibiotics.

Deep Neck Infection Complicated by Phlegmonous Esophagitis and Mediastinitis.

Descending necrotizing mediastinitis is a life-threatening disease that extends into the pretracheal, perivascular, retrovisceral, and/or prevertebral spaces, generally sparing the esophagus. We report a case of deep neck abscess complicated by phlegmonous esophagitis and mediastinitis. The patient was successfully treated with antibiotics and surgery, combining transcervical and bilateral thoracoscopic transthoracic mediastinal drainage. However, a pseudo-lumen with a large amount of pus remained in the esophagus. The septum between the true and the pseudo-lumen was cut endoscopically, after which the patient recovered well without any complications.

Aspergillus mediastinitis in a post-operative immunocompetent child.

Post-operative Aspergillus mediastinitis is regarded to be a devastating infection, usually affecting patients undergoing cardiothoracic surgery with specific predisposing factors characterised by a high mortality and chronic morbidity. Patient outcome after such a complication is extremely poor despite antifungal therapy and surgery. We describe the case of an immunocompetent 2-month-old child with obstructed supracardiac total anomalous pulmonary venous circulation (TAPVC) and severe pulmonary artery hypertension, who underwent TAPVC repair through median sternotomy and developed post-operative mediastinitis due to Aspergillus flavus.

[Infectious and inflammatory complications occurring after cardiac surgery in cardiac rehabilitation centres]. / Complications infectieuses et inflammatoires après chirurgie cardiaque survenues dans les services de réadaptations cardiaques.

Patients undergoing cardiac surgery are older, have complex pathologies and several comorbidities, but need to leave the hospital quickly! Therefore, the mission of cardiac rehabilitation centres has substantially changed. Indeed, if 15 to 25% of patients undergoing cardiac surgery will have a postoperative complication requiring a hospital management (infectious, pericardial, rhythmic, neurologic, pulmonary, digestive, etc.), more than 2/3 of these acute events could be managed by cardiac rehabilitation centres for a lower cost. Therefore, the quickest the patient is transferred to a cardiac rehabilitation centre, the easier the cardiac surgery centre could manage his beds. Infectious complications are the most dreadful, particularly mediastinitis.

Mediastinal tissue friability-An unreported complication from Mycobacterium chimaera infection post-cardiac surgery.

Mycobacterium chimaera can cause disseminated infection following cardiac surgery with cardiopulmonary bypass and contaminated heater-cooler devices. We discuss a 41-year-old man with a disseminated M. chimaera infection following surgery for a type A aortic dissection. His presentation included cachexia and dorsalgia with a work-up revealing vertebral osteomyelitis with an epidural abscess, bone marrow, and pulmonary infiltration, and fluid collection around his aortic graft. He received 1 month of antibiotics before the explantation of infected foreign material, mediastinal debridement, and aortic reconstruction. Complications included septic shock, respiratory and renal failure, mediastinitis, and four distal aortic anastomotic dehiscences from friable tissue and persistent infection.

Spontaneous community-acquired PVL-producing Staphylococcus aureus mediastinitis in an immunocompetent adult - a case report.

BACKGROUND: Mediastinitis caused by hematogenous spread of an infection is rare. We report the first known case of community-acquired mediastinitis from hematogenous origin in an immunocompetent adult. This rare invasive infection was due to Panton-Valentine Leucocidin-producing (PVL+) methicillin-susceptible Staphylococcus aureus (MSSA). CASE PRESENTATION: A 22-year-old obese man without other medical history was hospitalized for febrile precordial chest pain. He reported a cutaneous back abscess 3 weeks before. CT-scan was consistent with mediastinitis and blood cultures grew for a PVL+ MSSA. Intravenous clindamycin (600 mg t.i.d) and cloxacillin (2 g q.i.d.), secondary changed for fosfomycin (4 g q.i.d.) because of a related toxidermia, was administered. Surgical drainage was performed and confirmed the presence of a mediastinal abscess associated with a fistula between the mediastinum and right pleural space. All local bacteriological samples also grew for PVL+ MSSA. In addition to clindamycin, intravenous fosfomycin was switched to trimethoprim-sulfamethoxazole after 4 weeks for a total of 10 weeks of antibiotics. CONCLUSIONS: We present the first community-acquired mediastinitis of hematogenous origin with PVL+ MSSA. Clinical evolution was favorable after surgical drainage and 10 weeks of antibiotics. The specific virulence of MSSA PVL+ strains played presumably a key role in this rare invasive clinical presentation.

Acute mediastinitis associated with tracheobronchial tuberculosis and aspergillosis: a case report and literature review.

Acute mediastinitis (AM) is a rare but life-threatening disease. Here, we report a case of AM secondary to endobronchial tuberculosis (EBTB) and pseudomembranous Aspergillus tracheobronchitis (PMATB) co-infection. EBTB was confirmed by tissue culture for Mycobacterium tuberculosis and GeneXpert MTB/RIF (Cepheid, Sunnyvale, CA, USA) detection (simultaneous detection of M. tuberculosis and resistance to rifampin) using endobronchial biopsies; PMATB was confirmed by histopathology. Even with antibiotic treatment and systemic support treatment, the patient died of massive hemoptysis on day 10 after admission. When immunocompromised hosts have AM, especially with central airway involvement, EBTB and aspergillosis should be considered potential causes. Bronchoscopy is helpful for rapid diagnosis and administering precise treatment.

[Clinical analysis of 61 cases of deep neck infection].

Objective: To explore the clinical experience in care for deep neck infection (DNI) and to analyze the factors influencing surgical treatment outcome. Methods: A retrospective analysis was conducted on 61 patients with DNI admitted to the Department of Otorhinolaryngology Head and Neck Surgery of Yantai Yuhuangding Hospital from March 2013 to April 2019, including 33 males and 28 females, aged from 6 months to 81 years with a median age of 49 years. Patients were divided into two groups, 31 cases with localized infection (neck abscess) in Group A and 30 cases with diffuse infection (neck necrotizing fasciitis) in Group B. Patients in two groups were compared for sex, age, hospital stay, diabetes, tracheostomy, drainage methods, mediastinal infection, and pathogenic bacteria. The influence of different drainage methods on hospital stay in Group A was analyzed. SPSS 25.0 software was used for statistical analysis. Results: Of the 61 patients, 45 patients underwent surgical incision and drainage (21 cases in Group A and 24 cases in Group B), 23 patients underwent ultrasound-guided fine needle aspiration (UG-FNA) and catheter drainage (10 cases in Group A and 13 cases in Group B), and 7 patients in Group B were treated with both drainage methods. Pathogens were cultured in 31 cases (50.82%). There were significant differences in hospital stay, drainage method and mediastinal infection (χ(2) values were 26.890, 8.687 and 6.035, respectively, P<0.05), but no significant difference was found in sex, age, diabetes, tracheotomy and pathogenic bacteria (χ(2) values were 0.157, 3.685, 2.434, 3.631 and 0.807, respectively, P>0.05) between the two groups. There was no significant difference in hospital stay between two drainage methods in patients in Group A (χ(2)=1.560, P>0.05). Conclusions: There were significant differences in hospital stay, drainage method and mediastinal infection between patients with localized infection and diffuse infection, as diffuse infection is often associated with serious complications. UG-FNA and catheter drainage is an optional method for the treatment of localized infection, with minimal invasion and no influence on hospital stay.

Descending necrotizing mediastinitis caused by Streptococcus constellatus in an immunocompetent patient: case report and review of the literature.

Descending necrotizing mediastinitis is a severe infection of the mediastinum. This syndrome manifests as fever and chest pain following cough and sputum production. A 49-year-old woman presented with fever and a 14-day history of pneumonia. CT showed mediastinal abscesses with a giant calcified mediastinal lymph node (21 × 18 mm) and pneumonia. Bronchoscopy by EBUS-TBNA under general anesthesia was performed. The pathogen found in the puncture culture was Streptococcus constellatus, and antibiotics (mezlocillin/sulbactam 3.375 IVGTT q8h) was administered. A proximal right main bronchial neoplasm, suspected lung cancer, was found and conformed to inflammatory granuloma. A total of 22 months post-discharge the patient was clinically stable. We also conducted a review of the literature for all Streptococcus constellatus descending necrotizing mediastinitis infections between 2011 and 2017.