Preoperative Evaluation of Aortic Calcification by Computed Tomography
in Thoracic Aortic Disease
Abstract
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 the maximal CT value for
application of simple anastomosis. Methods: 122 consecutive patients
underwent replacement of the thoracic aorta between 2007-2011, excluding
those with acute aortic dissection. The patients were divided into two
groups: those who could undergo simple anastomosis (Simple group:n=105),
and those who required endarterectomy prior to anastomosis (Manipulation
group:n=17). The maximal CT value at the anastomosis site was calculated
by an imaging software. Results: The mean maximal CT value (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<0.0001). The maximal CT value enabled us to
predict the simple anastomosis with the area under the receiver
operating characteristic curve of 0.96 (p<0.0001). The cut-off
value was 325 HU (sensitivity 94.1%, specificity 81.7%). The 10-year
survival rate was significant lower in the Manupilation 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
value (HR:1.001) were independently associated with long-term mortality.
Conclusions: Preoperative evaluation of the maximal CT value is a useful
tool in predicting whether simple anastomosis is applicable or not, in
the thoracic aortic surgery. Maximal CT value is a risk factor for
long-term mortality.