The segmentation of the vertebral artery: An ambiguous anatomical concept

Area of Science:

• Anatomy
• Vascular Surgery
• Neurology

Background:

• The vertebral artery is divided into four segments (V1-V4).
• Current definitions of these segments lack consistency, particularly regarding the V2 segment's termination.
• This inconsistency impacts studies on vertebral artery disorders.

Purpose of the Study:

• To address the inconsistencies in vertebral artery segmentation.
• To propose a standardized definition for the V2 and V3 segments.
• To improve the reliability of anatomical studies and clinical management of vertebral artery pathologies.

Main Methods:

• Review of historical and current anatomical literature on vertebral artery segmentation.
• Analysis of discrepancies in defining the V2 segment's termination point (C2 vs. C1 transverse foramen).
• Evaluation of a proposed V3 segment definition extending from the C2 transverse foramen to the posterior atlanto-occipital membrane.

Main Results:

• Significant inconsistencies exist in the literature regarding the termination of the V2 segment.
• The segment between the C2 and C1 transverse foramina is variably assigned to V2 or V3.
• A proposed V3 segment definition (C2 transverse foramen to posterior atlanto-occipital membrane) offers a precise solution.

Conclusions:

• Standardizing vertebral artery segmentation, particularly the V3 segment, is crucial for accurate diagnosis and treatment of vertebral artery disorders.
• Adopting a consistent anatomical definition enhances the validity of research and clinical practice.
• A revised V3 segment definition provides a simple, precise, and reliable anatomical concept.