Morphometric and Clinical Analysis of the Azygos Anterior Cerebral Artery: Insights From a Cadaveric Case Report Study

The azygos anterior cerebral artery (ACA) is an uncommon anatomical variation with important clinical implications. This study presents an in-depth morphometric analysis of a single brain specimen displaying this variant. The goal is to improve the understanding of its anatomical characteristics and its influence on cerebral vascular health. Through precise dissection and measurement, the study highlights the structural features of the azygos ACA and its potential role in clinical conditions, particularly in relation to aneurysm formation and associated risks. The brain specimen was sourced from the Laboratory of Microsurgical Anatomy of the Central Nervous System, Faculty of Medicine, National Autonomous University of Mexico (UNAM). The donor did not have a history of neurological disease or neurosurgical procedures, ensuring the integrity of the vascular structures for analysis. To facilitate analysis, red latex was injected into the specimen, which was then preserved in 10% formalin for two months. Morphometric assessments were carried out using a Mitutoyo Model CD-8" CX digital caliper with a resolution of 0.0005"/0.01mm, along with detailed photographic documentation. The study examined the brain of a 38-year-old male, which weighed 1,310 grams. Symmetry was observed in the A1 segments: the right A1 segment measured 11 mm in length and 3 mm in diameter, while the left A1 segment measured 10 mm in length and 2.4 mm in diameter. The anterior communicating artery (ACoA) was absent, and only a single A2 trunk was identified. This trunk had an initial diameter of 4 mm, which tapered to 3 mm over a length of 33 mm until it bifurcated. Common anatomical variations of the A1-ACoA complex include absence, bifurcation, hypoplasia, plexal arrangement, and fenestration. A thorough understanding of anterior cerebral circulation variants is essential for optimizing the treatment of vascular pathologies.