Segmental anatomy of cerebellar arteries: a proposed nomenclature. Laboratory investigation.

Abstract

The conceptual division of intracranial arteries into segments provides a better understanding of their courses and a useful working vocabulary. Segmental anatomy of cerebral arteries is commonly cited by a numerical nomenclature, but an analogous nomenclature for cerebellar arteries has not been described. In this report, the microsurgical anatomy of the cerebellar arteries is reviewed, and a numbering system for cerebellar arteries is proposed. Cerebellar arteries were designated by the first letter of the artery's name in lowercase letters, distinguishing them from cerebral arteries with the same first letter of the artery's name. Segmental anatomy was numbered in ascending order from proximal to distal segments. The superior cerebellar artery was divided into 4 segments: s(1), anterior pontomesencephalic segment; s(2), lateral pontomesencephalic segment; s(3), cerebellomesencephalic segment; and s(4), cortical segment. The anterior inferior cerebellar artery was divided into 4 segments: a(1), anterior pontine segment; a(2), lateral pontine segment; a(3), flocculopeduncular segment; and a(4), cortical segment. The posterior inferior cerebellar artery was divided into 5 segments: p(1), anterior medullary segment; p(2), lateral medullary segment; p(3), tonsillomedullary segment; p(4), telovelotonsillar segment; and p(5), cortical segment. The proposed nomenclature for segmental anatomy of cerebellar artery complements established nomenclature for segmental anatomy of cerebral arteries. This nomenclature is simple, easy to learn, and practical. The nomenclature localizes distal cerebellar artery aneurysms and also localizes an anastomosis or describes a graft's connections to donor and recipient arteries. These applications of the proposed nomenclature with cerebellar arteries mimic the applications of the established nomenclature with cerebral arteries.