Asymmetric Sternotomy and Sternal Wound Complications: Assessment Using 3-Dimensional Computed Tomography Reconstruction

OBJECTIVE: Wound complications after midline sternotomy result in significant morbidity and mortality. Despite many known risk factors, the influence of sternal asymmetry has largely been ignored. The purpose of this study was to assess the utility of 3-dimensional computed tomographic scan reconstructions to assess sternal asymmetry and determine its relationship with sternal wound infection. METHODS: A retrospective chart review was conducted for patients who underwent midline sternotomy and received a postoperative computed tomographic scan between 2009 and 2010. Cases were composed of all patients who had a sternal wound infection after undergoing sternotomy. Controls were randomly selected from patients without poststernotomy wound complications. Sternal asymmetry was defined as the difference between the left and the right sternal halves and was expressed as a percentage of the total sternal volume. RESULTS: Twenty-six cases were identified and 32 controls were selected as described earlier. The patients were similar in baseline characteristics and risk factors including age, sex, smoking status, diabetes, chronic obstructive pulmonary disease, preoperative creatinine, and operative time. Univariate factors associated with sternal wound infection include an asymmetry of 10% or greater, body mass index, and internal mammary artery harvest. In a multivariate logistic regression, independent predictors of sternal wound infection included an asymmetry of 10% or greater (odds ratio, 3.6; P = 0.03) and diabetes (odds ratio, 3.3; P = 0.0442). CONCLUSIONS: Our data suggest an association between asymmetric sternotomy and sternal wound infections. We recommend an assessment of sternal asymmetry to be performed in patients with sternal wound infection and if it is found to be 10% or greater, the surgeon should implement measures that stabilize the sternum.