Clinically-relevant morphometric parameters and anatomical variations of the aortic arch branching pattern.

Introduction: The ever expanding advances in various domains of cardiac and endovascular interventions has drawn tremendous attention toward the importance of the anatomical variability and morphometric parameters of the aortic arch (AA) and its branches.

Methods: The current study delineates the morphometry and anatomical variations of the AA branches by evaluating coronal, axial and sagittal CT multiplanar reformatted three-dimensional angiograms. Correlations between morphometric data as well as the distribution of morphometric data in relation to the anatomical variations were also illustrated.

Results: 35% of the examined AA showed abnormal branching patterns, the most common of which was the "bovine arch" (24%), followed by common ostium variant (6%) and aberrant left vertebral artery arising directly from AA (5%). The outer diameter of AA at its origin and its end was 33.83 and 22.06 mm, respectively. The distance between the origin of AA and the origin of brachiocephalic trunk (BCT), left common carotid artery (LCCA) and left subclavian artery (LSA) was 19.59, 23.01 and 26.01 mm, respectively. The outer diameter of BCT, LCCA and LSA was 15.7, 11.42 and 14.02 mm, respectively. The angles between the AA and the BCT, LCCA and LSA were 59.01°, 68.59° and 59.92°, respectively. The mean distance between the BCT and LCCA was 19.59 mm and the distance between the LCCA and the LSA was 23.01 mm. Significant positive and negative correlations between morphometric data as well as the distribution of morphometric parameters in relation to the anatomical variations have been identified.

Conclusion: The illustrated anatomical variations and morphometric data provide cardinal information especially for patients undergoing aortic endovascular intervention, principally for choosing the size, shape and type of the angiographic catheters and devices to be delivered.