Research on gradual change of ascending aorta diameter

Abstract

Objective To study the changes in the diameter of the ascending aorta at different levels. Methods A total of 287 patients were enrolled in this study from November 2016 to January 2017 at the Chinese People′s Liberation Army General Hospital in Beijing. Each patient had undergone enhanced computerized tomography scanning, and the systolic and diastolic images were reconstructed for each patient. Ten times distance accounts for percentage was calculated per 10% unit of ascending aorta. The maximal diameters of each level were measured by 3 mensio Vascular 8.1 software with curved planar reformation. Generalized additive mixed model with smoothing function and threshold saturation effect analysis with generalized estimating equations were used to analysis the changing regularity of ascending aortic diameters and its consistency using stratified analysis. Furthermore, stratified analyses were conducted aauording to sex, age, BMI, smoking status and history of chronic diseases. Results A nonlinear relationship between the maximal diameters and distance was observed. With the increase of distance, the maximal diameters of ascending aorta presented an inverted U shape. In the first half, the ascending aortic maximal diameter increased 1.16 mm while the distance increased ten percent of the ascending aortic length (P<0.001). In the second half, the ascending aortic maximal diameter reduced 0.47 mm while the distance increased ten percent of the ascending aortic length (P<0.001). The results showed that the changing regularity of ascending aortic diameter has no significant difference between systolic and diastolic periods. Conclusions With the increase of distance, the maximal diameters of ascending aorta increase and then decrease. The regularity of ascending aortic diameter between systole and diastole is consistent. In each subgroup, the regularity of ascending aortic diameter is not completely consistent, but the difference has not clinical significance. Key words: Aorta; Blood vessels; Periodicity, heart; Computer tomography