Descending spinal vascular axis in contact with the artery of Adamkiewicz: Anterior spinal artery or descending branch of the artery of Adamkiewicz?

Abstract

Objective: This study aims to determine whether the descending vascular axis distal to the Adamkiewicz loop is a continuation of the AKA or the ASA, using both morphological and statistical analyses.

Method: A cadaveric study was conducted on 15 adult male specimens. Following posterior access and removal of the spinal cord en bloc, low-pressure injections were performed into the ASA to visualize spinal vasculature. In several cases, the AKA was identifiable without injection due to its prominent calibre. Using digital callipers, morphometric measurements were obtained for the ascending branch, arch, and descending segment of the AKA, as well as the ASA segment proximal to the AKA loop.

Results: The mean diameter of the ASA was 1.0 mm (range: 0.5–1.86 mm), with 80% of specimens exhibiting a calibre under 1 mm. The ASA occupied less than 10% of the spinal cord’s ventral surface. The AKA had a mean diameter of 1.14 mm, while the descending vascular axis measured 1.69 mm on average (range: 0.8–2.1 mm). In all specimens, the AKA presented as a continuous single trunk with ascending, arching, and descending components. The descending vascular axis showed greater morphological similarity in calibre to the AKA than to the ASA.

Conclusion: Morphometric evidence suggests that the descending spinal axis beyond the AKA loop more closely resembles a continuation of the Adamkiewicz artery rather than the anterior spinal artery.