Preoperative evaluation of aortic calcification by computed tomography in thoracic aortic disease

Background Computed tomography (CT) is a useful tool for the identification of calcified lesions in the aorta. However, no quantitative evaluation has been established to assess the applicability of simple anastomosis preoperatively. We conducted this retrospective study to establish a reference range of maximal CT attenuation values for application of simple anastomosis. Methods A total of 122 consecutive patients underwent replacement of the thoracic aorta between 2007 and 2011, excluding those with acute aortic dissection. The patients were divided into two groups: those who underwent simple anastomosis (simple group: n = 105), and those who required endarterectomy before anastomosis (manipulation group: n = 17). The maximal CT attenuation values at the anastomosis site were calculated by imaging software. Results The mean maximal CT attenuation values (Hounsfield unit [HU]) was significantly higher in the manipulation group (638.1 +/- 269.5 [166-1304]) than in the simple group (94.7 +/- 171.5 [0-790]; p < .0001). The maximal CT attenuation values enabled us to predict the simple anastomosis with the area under the receiver operating characteristic curve of 0.96 (p < .0001). The cut-off value was 325 HU (sensitivity 94.1%, specificity 81.7%). The 10-year survival rate was significantly lower in the manipulation group (11.8%) than in the simple group (43.2%). In the multivariate analysis, age (hazard ratio [HR]: 1.073), hypertension (HR: 2.382), and maximal CT attenuation values (HR: 1.001) were independently associated with long-term mortality. Conclusions Preoperative evaluation of the maximal CT attenuation values is a useful tool in predicting whether simple anastomosis is applicable or not. Maximal CT attenuation values is a risk factor for long-term mortality.