Management of poststernotomy mediastinitis: experience and results of different therapy modalities

BACKGROUND: Different primary treatment modalities have been utilized to treat poststernotomy mediastinitis (PM) following cardiac surgery. METHODS: A literature survey using the key phrases "treatment of deep sternal wound infection" and "poststernotomy-mediastinitis" was performed. Furthermore, a questionnaire regarding the primary treatment of PM was distributed to all 79 German heart surgery centers. RESULTS: The review of the literature shows that the current understanding is based purely on retrospective studies, not on evidence-based medicine. All 79 German heart centers replied to the questionnaire. Vacuum-assisted closure therapy (V. A. C.(R)) is used in 28/79 (35 %) heart centers as the "first-line" treatment, 22/79 (28 %) perform primary reclosure in conjunction with a double-tube irrigation/suction system, and in 29/79 (37 %) German heart centers both treatment options were used according to the intraoperative conditions. CONCLUSIONS: As a primary treatment for PM two treatment modalities are currently in use: primary reclosure coupled with a double-tube suction/irrigation system versus V. A. C.(R) therapy. Since prospective randomized studies have not yet been performed, controlled clinical trials comparing both treatment modalities are pivotal to define the evidence for patients presenting with PM.     

Mediastinitis after cardiac surgery in Madani Heart Center, Tabriz, Iran

Post-sternotomy infections are a kind of nosocomial infection involving the mediastinum space and the sternum, with a high morbidity and mortality rate. The present study was carried out to identify the incidence of mediastinitis following cardiac surgery and the most common risk factors. Cardic patients undergoing surgery were studied for suspicious mediastinitis infection at the Madani Heart Center, Tabriz, Iran from 2004 to 2006. The most common isolated agents included the coagulase-negative staphylococci, Staphylococcus aureus, Pseudomonas aeruginosa and Enterobacter spp. Incidence of postoperative mediastinitis after cardiac surgery was 1.2%. The mortality rate of postoperative mediastinitis was high (34.3%). Wound infection, especially mediastinitis following cardiac surgery, is rare but could be life-threatening. The most important step in the management of wound infections is prevention, and preventive measures could be strengthened by identifying the risk factors.     

Descending necrotizing mediastinitis: treatment by transcervical thoracic drainage

We report the case of a 29-year-old man with descending necrotizing mediastinitis and subcarinal spread secondary to oropharyngeal infection. The thoracic infection was treated by placement of a transcervical thoracic drain, which was removed 15 days after surgery. The outcome was satisfactory and no further invasive treatment was required. We believe that transcervical thoracic drainage is a useful initial treatment for descending necrotizing mediastinitis with subcarinal spread but no pleural cavity involvement.     

Suppurative mediastinitis after open heart surgery. A case control study of risk factors

Suppurative mediastinitis occurred in 68 of 9,965 patients (0.7 percent) who underwent median sternotomy at Emory University Hospital from 1973 through 1982. Case-control methodology was used to identify preoperative, intraoperative, and postoperative risk factors for the development of poststernotomy mediastinitis. The following 12 individually significant risk factors were identified by univariate analysis: preoperative factors: history of chronic obstructive pulmonary disease (COPD), history of prior sternotomy, pyuria, low ejection fraction, and high left ventricular end-diastolic pressure; intraoperative factors: valvular or aortic aneurysm surgery, prolonged bypass pump time, repeat placement on bypass, duration of surgery; and postoperative factors: surgical reexploration due to postoperative hemorrhage, cardiopulmonary resuscitation in the immediate postoperative period, prolonged time (greater than 48 hours) on mechanical ventilation. By logistic regression analysis, three of these factors were found to be associated independently with increased odds of developing mediastinitis: duration of surgery, history of COPD, and prolonged postoperative mechanical ventilation.     

Mycotic ascending aortic pseudoaneurysm secondary to pseudomonas mediastinitis at the aortic cannulation site

During the last 5 years, postoperative Pseudomonas mediastinitis has occurred in 2 of the 3,072 patients in our institution who have undergone cardiopulmonary bypass cardiac operations via a sternotomy. To our knowledge, there is no prior report in the English-language literature of postoperative Pseudomonas mediastinitis that originated at the aortic cannulation site, yet that was the site of origin in both of these patients. The 1st patient developed a mycotic pseudoaneurysm of the ascending aorta at the cannulation site, secondary to the development of Pseudomonas mediastinitis following aortic valve replacement. This sequela was successfully treated by means of aneurysmectomy and closure of the aorta with a bovine pericardial patch, under cardiopulmonary bypass with circulatory arrest. The 2nd patient developed pseudoaneurysm and perforation of the aorta at the cardioplegia needle site, secondary to Pseudomonas mediastinitis following aortic and mitral valve replacement. This patient died. In both patients, the cannulation site and the cardioplegia needle site had been closed with pledgeted sutures. Pseudomonas aeruginosa was cultured from both sites. Once the diagnosis of Pseudomonas mediastinitis is made following heart surgery, the patient should undergo reoperation, if possible, for removal of the foreign bodies (pledgeted sutures). In addition, these patients should be monitored with chest magnetic resonance angiography every 3 months for 1 year, in order to diagnose early development of a mycotic pseudoaneurysm and subsequent complications.     

A Case of Aspergillus fumigatus Mediastinitis After Heart Surgery in Madani Heart Center, Tabriz, Iran

Reported here is the case of a 60-year-old male diabetic patient with mediastinitis caused by Aspergillus fumigatus following an open heart surgery that was successfully treated. A review of literature revealed that A. fumigatus as a cause of mediastinitis has been rarely described. Aspergillus infection should be considered in the differential diagnosis of mediastinitis after cardiac surgery, especially in a clinical setting of unexplained sepsis or nonhealing wound infection despite apparently adequate treatment.     

Autotransfusion of shed mediastinal blood: a risk factor for mediastinitis after cardiac surgery? Results of a cluster investigation

RATIONALE: After the introduction of autotransfusion of shed mediastinal blood following cardiac surgery, the incidence of mediastinitis increased. The role of autotransfusion in the increased occurrence of this serious complication was examined. METHODS: Using a case-control design, the preoperative, intraoperative, and postoperative characteristics of 11 patients with mediastinitis were compared to those of 33 randomly selected patients undergoing cardiac surgery between September 1, 2000, and April 15, 2001 (control subjects). RESULTS: Patients with mediastinitis were significantly more likely to have a body mass index > 30 (unadjusted odds ratio [OR], 9.9; 95% confidence interval [CI], 2.3 to 42.5), to have received antibiotic therapy during the 2 weeks prior to cardiac surgery (OR, 12.0; 95% CI, 1.1 to 131), or to have required re-exploration within 24 h of the original operation (OR, 8.3; 95% CI, 1.8 to 39). Patients with mediastinitis had 3.4 known risk factors for mediastinitis, compared to only 1.4 risk factors per control subject (p = 0.0001), and longer duration of autotransfusion. After adjustment for other risk factors, autotransfusion for > 6 h was significantly associated with the development of mediastinitis (adjusted OR, 11.9; 95% CI, 1.4 to 97.2). CONCLUSION: Retransfusion of shed mediastinal blood for > 6 h after cardiac surgery was an independent risk factor for mediastinitis.     

胸骨正中切口术后胸骨骨髓炎及纵隔感染的修复重建

目的:探讨应用胸大肌肌瓣转移,修复重建治疗经胸骨正中切口术后,胸骨骨髓炎及纵隔感染的临床疗效.方法:回顾性分析我科自2008年1月至2011年4月,应用胸大肌肌瓣转移手术治疗58例胸骨正中切口,术后胸骨骨髓炎及纵隔感染患者的临床资料.手术方法为彻底清创,用转移的胸大肌肌瓣将胸骨缺损区填实消灭残腔,放置带负压吸引装置的引...     

Mediastinitis and cardiac surgery--an updated risk factor analysis in 10,373 consecutive adult patients

BACKGROUND: Deep sternal wound infection (DSWI) remains a serious complication after cardiac surgery. New evolving techniques including the utilization of internal mammary arteries (IMA), beating heart procedures, and minimal invasive surgery (MIC) require an updated risk factor analysis to identify high risk patients in order to improve perioperative treatment. METHODS: 10,373 consecutive patients receiving cardiac surgery between May 1996 and August 1999 were evaluated: 9,303 underwent full sternotomy whereas a minimally invasive (MIC) approach using partial sternotomy or lateral thoracotomy was used in 1,070 patients. DSWI was defined as the evidence of mediastinitis seen at reoperation along with one or more of the following: positive culture of mediastinal fluid, positive blood culture or temperature higher than 38 degrees C and/or leukocytosis. RESULTS: The overall incidence of DSWI in the "full sternotomy" group was 1.44 % (134 of 9,303). Univariate risk factor analysis showed a significant influence of IMA use, ICU / IC treatment > 5 days, postoperative ventilator time > or = 72 h, need for reexploration, diabetes, surgery time > or = 180 min, assist device implantation (including use of IABP), peripheral vascular disease and increased body mass index. Multivariate analysis identified double IMA, ICU treatment > 5 days, single IMA, diabetes, reexploration and increased body mass as significant risk factors. No mediastinitis was observed in the MIC group. CONCLUSION: As DSWI is related to sternotomy, a MIC approach should be considered for patients at high risk for DSWI. IMA takedown as a pedicled graft should be especially avoided in patients with diabetes since the risk for postoperative mediastinitis is unacceptably high in this patient group.     

Anaerobic wound infection: Bacteroides mediastinitis after cardiovascular surgery

A case of postoperative anaerobic mediastinitis after coronary artery bypass grafting is reviewed. One of the causative organisms, Bacteroides oralis, has never previously been described as a pathogen causing mediastinitis after median sternotomy incision. There was associated Bacteroides fragilis bacteremia. Only three cases of Bacteroides species mediastinitis after open heart surgery have been reported. This anaerobic bacterium remains a rare pathogen in median sternotomy infections despite the increasing number of cases of mediastinitis seen in association with the burgeoning number of patients undergoing cardiac surgery. Multiple risk factors may contribute to mediastinal infections, which occur in about 2% of patients undergoing coronary artery surgery. When infection occurs, aerobic and anaerobic wound cultures should be made and appropriate antimicrobial and surgical therapy instituted.     

Comparison and evaluation of experimental mediastinitis models: precolonized foreign body implants and bacterial suspension inoculation seems promising

Background  

Post-sternotomy mediastinitis (PSM) is a devastating surgical complication affecting 1–3% of patients that undergo cardiac surgery. Staphylococcus aureus is one of the most commonly encountered bacterial pathogen cultured from mediastinal samples obtained from patients with PSM. A component of the membrane of the gram positive bacteria, lipoteichoic acid, stimulates the blood monocytes and macrophages to secrete cytokines, radicals and nitrogen species leading to oxido-inflammatory damage. This seems to be responsible for the high mortality rate in PSM. For the evaluation of the pathogenesis of infection or for the investigation of alternative treatment models in infection, no standard model of mediastinitis seems to be available. In this study, we evaluated four mediastinitis models in rats.     

Is Post-Sternotomy Mediastinitis Still Devastating after the Advent of Negative-Pressure Wound Therapy?

In this study, we reviewed a 15-year experience with the treatment of a severe sequela of cardiac surgery: post-sternotomy mediastinitis. We compared the outcomes of conventional treatment with those of negative-pressure wound therapy, focusing on mortality rate, sternal reinfection, and length of hospital stay.We reviewed data on 157 consecutive patients who were treated at our institution from 1995 through 2010 for post-sternotomy mediastinitis after cardiac surgery. Of these patients, 74 had undergone extensive wound débridement followed by negative-pressure wound therapy, and 83 had undergone conventional treatment, including primary wound reopening, débridement, closed-chest irrigation without rewiring, topical application of granulated sugar for recurrent cases, and final plastic reconstruction with pectoral muscle flap in most cases.The 2 study groups were homogeneous in terms of preoperative data and operative variables (the primary cardiac surgery was predominantly coronary artery bypass grafting). Negative-pressure wound therapy was associated with lower early mortality rates (1.4% vs 3.6%; P = 0.35) and significantly lower reinfection rates (1.4% vs 16.9%; P = 0.001). Significantly shorter hospital stays were also observed with negative pressure in comparison with conventional treatment (mean durations, 27.3 ± 9 vs 30.5 ± 3 d; P = 0.02), consequent to the accelerated process of wound healing with negative-pressure therapy.Lower mortality and reinfection rates and shorter hospital stays can result from using negative pressure rather than conventional treatment. Therefore, negative-pressure wound therapy is advisable as first-choice therapy for deep sternal wound infection after cardiac surgery.     

The spectrum of cardiovascular infections due to Salmonella enterica: a review of clinical features and factors determining outcome

Cardiovascular infections due to Salmonella enterica are infrequently reported, so their clinical features, prognosis, and optimal treatment are not completely known. Mortality associated with aortitis and endocarditis caused by nontyphoidal Salmonella remains exceedingly high.In this review of cases of cardiovascular infections due to Salmonella enterica studied in 2 hospitals in Madrid, we tried to assess the clinical manifestations and the procedures leading to diagnosis in addition to treatment and outcome. To complete the spectrum of infections related to cardiovascular surgery, cases of postoperative mediastinitis, pericarditis, and infections associated with cardiac devices were also included.Twenty-three patients were reviewed: 11 had mycotic aneurysms; 7 had endocarditis; 2 had device-related infections; and 3 had pericarditis, mediastinitis, and infection of an arteriovenous fistula, respectively. The risk of endovascular infection in patients older than 60 years with bacteremia due to nontyphoidal Salmonella was 23%. Most patients with aortitis had risk factors for atherosclerosis, and 6 had preexisting atherosclerotic aortic aneurysms. All except 1 patient with endocarditis had underlying cardiac disorders. Acquired immunodeficiency disease (AIDS) was a major risk factor for salmonella bacteremia in 1 patient with aortitis and 1 with endocarditis. Fever, unremitting sepsis, "breakthrough" and relapsing bacteremia were the most common clinical findings. In addition, abdominal or thoracic pain and cardiac failure and pericarditis were common features in patients with aortitis and endocarditis respectively. Computed tomography (CT) scan, arteriography, and echocardiography were the main diagnostic tools.Mortality associated with mycotic aneurysms and endocarditis due to S. enterica was 45% and 28%, respectively. Thoracic aneurysms, rupture, and shock at the time of diagnosis were associated with increased mortality in patients with aortitis. In situ bypass grafting was successfully performed in most cases. After surgery, antimicrobial therapy was continued for 4-9 weeks. No relapses were observed after a mean follow-up of 64 months. Antimicrobial therapy alone or combined with valve replacement or excision of a ventricular aneurysm was successful treatment for most patients with salmonella endocarditis. Combined medical and surgical treatment was required for patients with mediastinitis and pericarditis, and patients with device-related infections needed removal of the complete device.Diagnosis of aortitis due to nontyphoidal Salmonella should be established as early as possible to reduce mortality. Patients older than 60 years who have positive blood cultures for Salmonella along with fever and back, abdominal, or chest pain should have an extensive workup for infective aortitis. Immediate bactericidal antimicrobial therapy should be started and a CT scan should be performed on an emergency basis. If a mycotic aneurysm is found, surgical resection should follow as soon as possible. Resection of the aneurysm with in situ bypass grafting is the procedure of choice. Postoperative antimicrobial therapy for 6-8 weeks seems enough to avoid relapses. Optimal treatment of patients with endocarditis occurring on ventricular aneurysms must include resection of the aneurysmal sac. Salmonella endocarditis can be successfully treated with antimicrobials alone. Valve replacement should be reserved for patients with cardiac failure or persisting sepsis, and for those who relapse after discontinuation of antimicrobial therapy.     

Sternotomy reconstruction with omentum followed by large diaphragmatic hernia

Poststernotomy mediastinitis carries significant morbidity and mortality. Aggressive wound debridement combined with a pedicled omental flap, with or without a pedicled muscle flap, has gained acceptance in the management of difficult sternal wound infections. Two cases of poststernotomy mediastinitis and sternal wound reconstruction with a pedicled omental flap were complicated by a large anterior diaphragmatic hernia containing the large bowel.     

A descriptive analysis of a series of patients diagnosed with acute mediastinitis

Acute mediastinitis is one of the most aggressive chest diseases. The mortality rate ranges between 14% and 42%. We present a retrospective analysis of a series of 26 cases (20 men and 6 women) treated between January 1994 and March 2002 and review the literature. Mediastinitis originated in the esophagus in 17 patients (8 postoperative, 4 due to iatrogenic perforation, 4 due to noniatrogenic perforation, and 1 due to a foreign body) and in the oropharynx in 6 patients; mediastinitis was secondary to median sternotomy in 3. Twenty-five patients were treated surgically. In addition to radical debridement and drainage, which were carried out on all the patients, 10 also underwent esophagectomy or resection of the esophago-gastric reconstruction, 5 received primary sutures of the esophagus, 1 received reconstructive surgery with a pectoral muscle flap, and 1 underwent sternectomy plus intrathoracic omental transposition. Four patients died within 30 days of surgery (15.4%). The mortality rate in our practice is similar to that described in the literature. The results argue for early, aggressive treatment.     

Cervical necrotizing fasciitis associated with descending necrotizing mediastinitis

ABSTRACT: We report a case of potentially fatal cervical necrotizing fasciitis and descending necrotizing mediastinitis due to deep neck infection in a 66-year-old male patient with no history or evidence of immunocompromising disorders. On admission, he had painful neck movements and the skin over his neck was red, hot and tender. A computerized tomography (CT) scan of his neck and chest showed evidence of air collection in soft tissues. He was treated with broad-spectrum intravenous antibiotics and early massive cervical drainage. Prompt diagnosis by CT of the neck and chest enabled an early surgical treatment of cervical necrotizing fasciitis. Although acute mediastinitis is a fatal infection involving the connective tissues that fill the interpleural spaces and surround the median thoracic organs, an extensive cervicotomy combined with appropriate antibiotics can prevent the need for mediastinal drainage.     

Perfusionist-transmitted bacterial mediastinitis in a heart transplant recipient

We report the case of a 56-year-old man who developed bacterial mediastinitis with methicillin-resistant Staphylococcus aureus after undergoing heart transplantation. He had a history of insulin-dependent diabetes mellitus and prior cardiac surgery. To find the source of nosocomial infection, we cultured nasal swab specimens from all hospital personnel involved in this operation. We used antibiotic sensitivity profiling and pulsed-field gel electrophoresis to subtype the involved microorganism. The S. aureus isolates from the patient and the perfusionist were identical to each other and were different from the strains previously found in our hospital. It is almost certain that the S. aureus mediastinitis in this patient was transmitted from the perfusionist. We recommend obtaining cultures from hospital staff members when there is an outbreak of staphylococcal infection.     

Omental flap for recurrent deep sternal wound infection and mediastinitis after cardiac surgery

BACKGROUND: Unsuccessful surgical treatment of deep sternal wound infection (DSWI) and mediastinitis may lead to sepsis, multiorgan failure and death. Omental flap transposition (OFT) may, in this situation, be the only effective therapy. METHODS: Twenty-seven patients with DSWI and mediastinitis after one or more unsuccessful surgical attempts to cure the infection were treated by OFT. Forty-one interventions (1.5/patient) consisting of closed irrigation technique, bilateral pectoralis flap reconstruction and vacuum-assisted therapy were performed before carrying out OFT. RESULTS: Operative mortality was 0. Mean postoperative ventilation time was 1.38 days and mean time in the intensive care unit was 4.7 days. Hospital mortality was 7.4 % (n = 2). Mean follow-up time was 2 years. One patient (4 %) died one year after discharge. During follow-up, abdominal wall hernia occurred in one patient (4 %) and presternal fistula resection was necessary in another patient (4 %). CONCLUSION: OFT is, in our experience, the most effective procedure for the treatment of recurrent DSWI and mediastinitis after cardiac surgery. Early mortality is acceptable, morbidity is low and late results are very good.     

Cardiopulmonary function following post-cardiac surgical mediastinitis

Eleven survivors of bacterial mediastinitis, which followed cardiac surgery through a median sternotomy approach, underwent noninvasive cardiopulmonary evaluation to determine whether clinically apparent mediastinal fibrosis had developed. Compared to preoperative values, forced vital capacity was reduced by 9.75 percent of predicted; the greatest reduction occurred in those patients with Gram-negative mediastinitis. In one patient, an abnormal jugular venous wave form and apex cardiogram were consistent with constrictive cardiac physiology, but this was not associated with an abnormal echocardiogram or impaired functional status. In this small series, no serious abnormalities in cardiopulmonary function were detected which could be attributed to prior mediastinal infection.     

Management of purulent mediastinitis with sternal dehiscence - a case report

The authors report the case of 70-year-old female who underwent urgent CABG for unstable angina. The post-operative course was complicated by Staphylococcal mediastinitis, which was treated with chest irrigation system and antibiotics. Because of extensive tissue destruction caused by the infection, the steel sternal wires were not placed. Interestingly, one year after surgery the sternal wound was completely healed and there were no paradoxical respiratory movements.