Anatomy of Vertebral and Posterior Inferior Cerebellar Artery.
- Author:
Jun Seok KOH
1
;
Gook Ki KIM
Author Information
1. Department of Neurosurgery School of Medicine, Kyung-Hee University, Seoul, Korea. neurokoh@medigate.net
- Publication Type:Original Article
- Keywords:
Vertebral artery;
Posterior inferior cerebellar artery;
Vertebrobasilar junction;
Anatomy
- MeSH:
Anatomic Variation;
Aneurysm;
Arteries*;
Brain Stem;
Choroid;
Humans;
Membranes;
Meningeal Arteries;
Pica;
Running;
Subclavian Artery;
Vertebral Artery
- From:Korean Journal of Cerebrovascular Disease
2000;2(2):118-125
- CountryRepublic of Korea
- Language:Korean
-
Abstract:
Vertebral artery(VA) and posterior inferior cerebellar artery(PICA) have complex and variable anatomic configuration of origin and running course in its exctracranial and intracranial pathway. VA has four main segments: the first portion from their origin to the entry into the foramen transversarium of C6, V1; the second portion from the C6 foramen to the C1 foramen, V2; the third portion from the exit from the C1 foramen to their entry through the atlanto-occipital membrane, V3; and the fourth portion from the entry through the dura to the vertebrobasilar junction, V4 after usual origin from proximal subclavian artery. Anatomic variations including aplasia, hypoplasia, duplication, and fenestration have been reported and careful consideration and examination must be needed because these variations tend to have another vascular anomalies such as arteriorvenous malformation or aneurysm. Tortuosity of VA is not a unusual finding especially in the aged people and the branches of VA are composed of meningeal, spinal, muscular, and radicular artery. PICA is most prominent artery from VA and its trunk is divided into five segments: anterior medullary, lateral medullary, tonsilomedullary, telovellotonsillar, and cortical. The running pathway of this vessel is pretty various in each person. The branches of this vessel are composed of perforating, terminal (cortical), choroidal, and meningeal artery. The extradural origin of PICA is infrequent; however, awareness of the presence of such an anatomic variation may be a helpful adjunct to avoid injury to this vessel. Around the vertebrobasilar junction (VBJ), the anatomy of the main arteries was variable. In contrast, the perforators penetrated the adjoining brain stem at specific locations regardless of caliber of the main artery. The four major point of entry to brain stem are the lateral medullary area just caudal to the posterior olivary sulcus (Group I), the posterior olivary sulcus(Group II), the small lateral fossa at the superior olivary groove(Group III), and the foramen caecum(Group IV). Despite a small VA or its major branches, the perforators penetrating the brain stem are very important and may effect the outcomes of operation or neurointerventional procedure of VBJ unless careful manipulation and consideration was performed.
