Bilateral Asymmetry of the Intracranial Vertebral Artery in the Indian Population

Vertebral artery (VA), one of the feeder vessels to the brain is responsible for blood flow to posterior circulation of the brain. Reduction in the dimensions of the vessel because of atherosclerosis, or compression or stretching, may lead to hindbrain hypoxia with serious clinical manifestations. Because normative data for the intracranial vertebral artery in Indians are not readily available, it was the aim of the present study to measure the dimensions of these distal parts of the VA, to inform professional practice of the possible influence of different vessel dimensions on blood flow to the hindbrain. The length and outer diameter of intracranial vertebral arteries was measured in human bodies during routine autopsies from 100 bodies of both sexes and all age groups. The cases were grouped, Group I: Less than 20 years, Group II: 20 to 40 years and Group III: More than 40 years. Intracranial parts of the vertebral arteries obtained from the cranial cavity of 30 specimens were processed for light microscopic study and the left and right luminal and outer diameters were measured and compared by use of t-tests. The length of vertebral artery on the left side was significantly more in group II and group III. The outer diameter of the vertebral artery is significantly more on the left side in group II.