Reevaluation of the morphological parameters according to 11 different duplications of the fetal vertebral artery at prevertebral (V1) and intracranial (V4) parts.

It is noted that the vertebral artery lies buried in a sea of generalities, prejudices, fear, and ignorance in the clinical literature. This fact is the reason why this observation is based on 11 cases, selected from 206 fetal cases, of various duplications of the vertebral artery. Aberrant or anastomotic vessels are illustrated and their definition is largely modified according to the recent anatomic terminology. Duplications of the vertebral artery indicate the 'segmental duplication' as a first form, and the presence of an abnormal 'fenestra' in the vessel's trunk as a second form of duplication. There are 9 (5 at prevertebral and 4 at intracranial parts) or 4.36% cases of 'segmental duplication' of the vertebral artery and 2 or 0.98% 'arteria vertebralis unifenestrata' at the intracranial part of all 206 cases. Successive morphological parameters of aberrant or anastomotic vessels are described and discussed according to personal cases and cases in the literature. Copyright 2004 S. Karger AG, Basel