Intraoperative Observations of Anatomic Variations of the Posterior Communicating Artery: A Microsurgical Approach

Background: Course and territory supplied by the posterior communicating artery (PCoA) are well known but its origin and calibre are quite variable. ncreasing incidence of microsurgical operations in the areas that are supplied by PCoA requires detailed knowledge about the anatomic variations of this artery. The aim of the present study is to examine the anatomical variability of the PCoA, with special emphasis on patients that underwent surgery via the pterional approach.Methods: The variability of the PCoA was studied intraoperatively in 30 patients selected from a series of 130 individuals that were operated via the pterional approach at our center. Skull base surgery was performed via either the right or left pterional approach. The findings were recorded during surgical intervention and documented by slides and videotapes of the operations. The commencement and dimension of the PCoA were examined.Results: In all individuals selected, the PCoA constantly arose from the internal carotid artery (ICA). In 70% of the patients, it arose from the posteromedial aspect, in 23.3% from the posterolateral aspect, and 6.6% from the anterolateral aspect of the ICA, respectively. In terms of its diameter, the PCoA showed a considerable amount of variation. Thus, the adult (regular) type was present in 66.6%, the fetal (hyperplastic) type was observed in 26.6%, and the hypoplastic type was seen in 6.7% of the patients.Conclusion: Knowledge of the variations of PCoA will help the neurosurgeon in design of aneurysm surgery and of reconstruction and revascularization procedures concerning the posterior cerebral circulation.