[Rare case of left vertebral artery agenesia in man].

At the post-mortem examination of 74 years old male subject it was found that his left vertebral artery was missing. A circle of Willis was formed by two carotid internal arteries and the right vertebral artery. Both cerebellar inferior posterior arteries as well as posterior spinal arteries were also missing. The vessels network of the medulla oblongata and medulla spinalis was composed of multiple cervical ramifications of the right vertebral artery. The latter one passed into the basal cerebral artery and divided in its distal segment into two posterior cerebral arteries. The other arteries of the circle of Willis were normal. There was no history of any CNS disturbances in the patient during his life.