Posterior communicating artery:: From microsurgical, endoscopic and radiological perspective

Objective: The main objective of this study was to display the morphological characteristics of the posterior communicating artery and its perforating branches in various configurations of the circle of Willis and their relationship with neighbouring anatomic structures by microscopic examination of the brain hemispheres and endoscopic examination of cadaver specimens. A secondary aim was to investigate the possibility of detecting the posterior communicating artery and its variations in cerebral MR angiographies performed for various reasons. Methods: The posterior communicating artery was examined under the microscope in 24 cerebral hemisphere specimens, by endoscopy in 5 cadavers and by 3D TOF MRI in 62 patients. Results: The posterior communicating artery had a hypoplastic configuration in 28%, whereas it was transitional in 14%, fetal in 28% and adult in 30% of cerebral hemisphere specimens. While no posterior communicating artery and transitional configuration could be detected in 11 % of the MR angiography examinations, 34 % had a hypoplastic configuration, 10% a fetal configuration and 45% an adult configuration. The percentage of infundibular dilatation was 22 % and the premamillary artery was the thickest perforating branch. The diameter of the posterior communicating artery varied between 0.5 and 3.03 mm. Discussion: A detailed knowledge on the variations of the posterior communicating artery and the morphological characteristics of the perforators arising from this artery in various configurations of the circle of Willis is an important factor affecting the results of surgical interventions.