Origin-entry geometry and left-sided V1 vertebral artery tortuosity: a retrospective cross-sectional CT angiography study
In brief
Left V1 vertebral artery is about 15% more tortuous than right
20 on the right in 82% of patients, a difference of roughly 15%. Greater tortuosity correlated with older age and with a more cranial (higher) vertebral artery origin, but not with which side was larger. The finding suggests that an origin-entry geometric mismatch, not dominance, explains the common left-side twist, prompting clinicians to consider anatomy when planning cervical interventions.
- Journal
- Neuroradiology (Q1)
- Published
- 3 September 2026
- Study design
- Cross-sectional study
- Evidence level
- Level 3, Low (CEBM 3b)
- Authors
- Răzvan Costin Tudose, Rodica Narcisa Calotă, Mugurel Constantin Rusu
- PMID
- 42690340
- DOI
- 10.1007/s00234-026-04180-9
Why clinicians should know about it
- Picked for Anatomy (paper of the day, 6 September 2026): Quantifies V1 vertebral artery tortuosity and origin‑entry geometry, a key
Abstract
PURPOSE: V1 vertebral artery (VA) tortuosity is associated with cervical artery dissection, stent fracture, and endovascular access difficulty, and predominates on the left; its anatomical basis and its relationship to VA dominance have not been quantitatively tested on CT angiography (CTA). METHODS: Bilateral V1 morphometric analysis was performed on 50 cervical CTAs (24 men, 26 women; 63.2 ± 15.5 years). The tortuosity index (TI) was computed as the centreline-to-straight-line length ratio; VA dominance was determined at two segmental levels. RESULTS: Left V1 was more tortuous than right (TI 1.37 ± 0.26 vs. 1.20 ± 0.15; Wilcoxon p < 0.0001; d_z = 0.74) in 82% of patients. TI correlated with age (Spearman ρ = 0.599, p < 0.001 for left; ρ = 0.439, p = 0.001 for right) but not with sex, and showed no association with calibre-based dominance (p = 0.53). A more cranial VA origin was associated with higher TI (Spearman ρ = -0.64, p < 0.001 for left; ρ = -0.37, p = 0.009 for right) and remained a significant predictor in multivariable linear regression adjusted for age and sex (left V1 β = -0.0408 per ordinal step toward a more caudal origin, 95% CI - 0.0683 to - 0.0133, p = 0.005) against a conserved bilateral C6 transverse-foraminal entry (76%). We refer to this configuration as the origin-entry mismatch. CONCLUSION: Left-sided V1 tortuosity was associated with an origin-entry geometric mismatch; no association with calibre-defined dominance was detected.
Abstract as published, via PubMed.
For healthcare professionals. The summary is generated by AI from the published abstract, and the evidence level is assigned automatically from the study design on the Oxford CEBM hierarchy. Neither is medical advice. Read the full paper before changing practice.