Aortic arch anatomical differences in male type B aortic dissection patients vs. healthy male individuals.

BACKGROUND

Understanding the distinct anatomical differences between patients with type B aortic dissection (TBAD) and control patients (CPs) can enhance our knowledge of normal and pathological aortic dimensions. This study aimed to deepen our knowledge of these dimensions by measuring and comparing the anatomical indices of the aortic arch in male patients with TBAD and non-TBAD male patients.

METHODS

In this cross-sectional observational study, 62 TBAD patients (TBADPs) and 43 CPs were assessed. Using a fit centerline approach, we identified three pivotal anatomical landmarks: Point A, Point B, and Point C. These landmarks represented intersections of the aortic arch with the brachiocephalic trunk, left common carotid artery, and left subclavian artery, respectively. These points defined Zones 1, 2, and 3, which collectively span the entire proximal aorta from the proximal end of the aortic valve to Point C. Our analyses compared key anatomical indices such as diameter of the circumscribed circle (Dcirc), ellipticity, curvature, tortuosity between TBADP and CP at critical points and regions.

RESULTS

TBADPs showed a more circular cross-sectional shape at Points A, B and C, as indicated by reduced values of Dcirc_A (P = 0.031), ellipticity_A (P = 0.034) and ellipticity_B (P = 0.048), together with a significant decrease in Dcirc_C (P = 0.015) and ellipticity_C (P = 0.007). The aortic arch in TBADPs showed enhanced tortuosity in Zone 1 (p = 0.002) and extended elongation in Zone 3 (p = 0.001).

CONCLUSIONS

The study found that the aortic arch in male TBAD patients is more circular near its primary branches, has greater tortuosity in Zone 1, and is longer in Zone 3 compared to male control patients.