Creative solutions in order to treat sternal wound complications in cardiac surgery

Abstract

I read with great interest the article by Kalab and colleagues about their successful results with regard to the reconstruction of massive sternum defects following cardiac surgery [1]. They used allogenic bone transplantation in order to substitute tissue loss due to mediastinitis. Mechanical instability of the sternum is an untoward complication with significant morbidity in the field of cardiac surgery. The risk factors for sternal nonunion are broadly classified as preoperative, intraoperative, and postoperative [2]. Preoperative factors are related to the pre-existing factors in the patients, such as diabetes mellitus, obesity, chronic obstructive pulmonary disease, osteoporosis, and radiation to the chest. The intraoperative risk factors for sternal nonunion are mainly associated with technical errors, such as paramedian sternotomy, harvest of bilateral internal thoracic arteries for grafting, and mechanical failure. Postoperatively, prolonged mechanical ventilation, impaired cardiac output and infectious aetiologies are the most important risk factors associated with increased sternal complications. Several methods, devices and substitution material have been reported in literature. The biological substitution material as emphasized by Kalab et al. have the major advantage of optimal mechanical properties, biocompatibility, lower risk of infection as compared to synthetic materials and the ability for new tissue formation by osteoprogenitor cells in the allografts.