Morphometry of Arch of Aorta and its Branches- A Cadaveric Cross-sectional Study

Abstract

Introduction: The Arch of Aorta (AA) originates from the ascending aorta in the superior mediastinum, specifically at the level of the right 2nd costal cartilage, behind the lower half of the manubrium sterni. The AA typically gives rise to three major arteries, namely the brachiocephalic trunk, left common carotid, and left subclavian, which is the most common branching pattern. Aim: To investigate the morphometric parameters of the AA and its branches, including the diameters, angles formed by the branches with the AA, and the distance of origin of these branches from the mid vertebral line. Materials and Methods: This descriptive observational cross- sectional study was conducted in the Department of Anatomy at NRI Medical College, Guntur, Andhra Pradesh, India,, from June 2017 to August 2021. A total of 50 aortic arches, along with their branches, were examined from cadavers (45 males, 5 females) assigned to 1st-year MBBS students for regular dissection practicals. Measurements such as the diameter of the arch at its origin and termination, diameter of major vessels at their origin, angles made by major vessels at their origin with the convexity of the arch, and the distance of origin of major branches from the midvertebral line were recorded. Vernier calipers with an accuracy of 0.01 mm were used to measure various parameters, and angles were measured using a Goniometer. Mean and Standard Deviation (SD) were calculated for each parameter using an MS Excel sheet. Results: The distance of origin of the brachiocephalic trunk from the midvertebral line was found to be 1.86±5.13 mm to the right of the midline, while the distance of origin of the Left Common Carotid Artery (LCCA) and Left Subclavian Artery (LSA) from the midvertebral line were +12.68±6.43 mm and +26.31±6.73 mm, respectively. The diameters of the mentioned branches at their origin were 11.22±2.29 mm, 7.39±1.49 mm, and 8.38±2.15 mm, and the angles made by these branches with the aortic arch were 89.10±18.48, 73.52±14.55, and 73.93±16.80 degrees, respectively. Conclusion: The morphometric parameters of the AA and its branches, as observed in the present study, hold significant clinical importance and can be valuable for cardiothoracic and vascular surgeons working in this region.