Post-sternotomy chronic osteomyelitis: is sternal resection always necessary?

OBJECTIVES: The goal of this study was to investigate alternative strategies to the sternal resection in the treatment of post-sternotomy osteomyelitis. We report our experience in the treatment of chronic infection of median sternotomy following open heart surgery without sternal resection. METHODS: A 4-year retrospective study was performed, consisting of 70 patients affected by post-sternotomy sternocutaneous fistulas due to chronic osteomyelitis: 45 patients underwent only medical treatment and 25 underwent steel wire removal and surgical debridement (conservative surgery). Of the 25, 7 patients underwent an additional vacuum assisted closure (VAC) therapy due to widespread infected subcutaneous tissue. The diagnosis of osteomyelitis was supported via 3D CT scan images. RESULTS: Complete wound healing was achieved in 67 patients including a patient who achieved healing after being affected by a fistula for over 24 years before coming under our observation, another, affected by mycobacteria other than tuberculosis osteomyelitis, who needed antimicrobial treatment for a period of 30 months and 2 who were affected by Aspergillus infection and needed radical cartilage removal. Fistula relapses were observed in 6 patients of the total 70, possibly due to the too short-term antibiotic therapy used in the presence of coagulase-negative Staphylococcus (CoNS) with multiple resistances and in the presence of Corynebacterium species. CONCLUSIONS: Post-sternotomy chronic osteomyelitis can be successfully treated mainly by systemic antimicrobial therapy alone, without mandatory surgical treatments, provided that accurate microbiological and radiological studies are performed. The presence of CoNS and Corynebacterium species seemed to be associated with a need for a prolonged combined antimicrobial therapy with a minimum of 6 months up to a maximum of 18 months. The CT scan and the 3D reconstruction of the sternum proved to be a good method to evaluate the status of the sternum and support the treatments. The VAC therapy was not useful in treating osteomyelitis, although, if used appropriately in the postoperative deep sternal wound infection with the sponge fitted between the sternal edges, it seems to be an effective method to eradicate the infection in the sternum and to prevent chronic osteomyelitis.

Improved results of the vacuum assisted closure and Nitinol clips sternal closure after postoperative deep sternal wound infection.

OBJECTIVE: Postoperative deep sternal wound infection is a severe complication of cardiac surgery, with a high mortality rate and a high morbidity rate. The objective of this prospective study is to report our experience with the vacuum assisted closure (VAC) system for the management of deep wound infection. We also devised an innovative closure technique post VAC therapy using thermo reactive clips. The advantage of this technique is that the posterior face of the sternum does not have to be separated from the mediastinal structures thus minimising the risk of damage. METHODS: From October 2006 to October 2008, we prospectively evaluated 21 patients affected by mediastinitis after sternotomy. Nineteen patients had sternotomy for coronary artery bypass grafting (CABG), one patient for aortic valve replacement (AVR) and another one for ascending aortic replacement (AAR). All patients were treated with the VAC system at the time of infection diagnosis. When the wound tissue appeared viable and the microbiological cultures were negative, the chest was closed using the most suitable procedure for the patient in question; nine patients were closed using pectoralis flaps, nine patients using Nitinol clips, one patient with a combined technique (use of Nitinol clips and muscle flap), one patient with a direct wound closure and another patient, who needed AAR with a homograft performed in another institution, was closed using sternal wires. RESULTS: We had no mortality; wound healing was successfully achieved in all patients. In more than 50% of the patients, the VAC therapy allowed direct sternal resynthesis. The average duration of the vacuum therapy was 26 days (range 14-37 days). CONCLUSIONS: VAC is a safe and effective option in the treatment of post-sternotomy mediastinitis, with excellent survival and immediate improvement of local wound conditions; furthermore, the use of Nitinol clips after VAC therapy demonstrated to be a safe and non-invasive option for sternal resynthesis. After VAC therapy, a reduction in number of muscular flaps used and an increase of direct sternal resynthesis were observed.

Diagnostic difficulties of Lactobacillus casei bacteraemia in immunocompetent patients: a case report.

INTRODUCTION: Lactobacilli are currently proposed as probiotic agents in several dietary products. In blood cultures, they are usually considered as contaminants, but in recent years they have been recognized as causal infectious agents of endocarditis, urinary tract infections, meningitis, intra-abdominal infections and bacteraemia. CASE PRESENTATION: We report a case of Lactobacillus casei bacteraemia in a 66-year-old immunocompetent man with a history of fever of unknown origin. Leuconostoc bacteraemia was demonstrated by blood culture, but a later polymerase chain reaction analysis with sequencing of 16S ribosomal RNA identified Lactobacillus casei and a successful antibiotic therapy was performed. CONCLUSION: Bacteraemia caused by probiotic organisms is rare but underestimated, since they are normally regarded as contaminants and their role as primary invaders is not always easily established. Although the consumption of probiotic products cannot be considered a risk factor in the development of diseases caused by usually non-pathogenic bacteria, specific individual clinical histories should be taken into account. This report should alert both clinicians and microbiologists to the possibility of unusual pathogens causing serious illnesses and to the use of 16S ribosomal RNA sequencing for molecular identification as a powerful tool in confirming the diagnosis of infrequent pathogens.