SynthesisJournal of anatomy2022
A new classification system for the anatomical variations of the human circle of Willis: A systematic review.
Synthesis in Journal of anatomy, 2022. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 16 papers, 1 of them a synthesis that pooled it.
What it found
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The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.
The trial behind it
Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.
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Who cites it
16 citing papers in PubMed, 1 synthesis or guideline pooled it, 46 citations in OpenAlex.
- A new classification system for the anatomical variations of the human circle of Willis: A systematic review.Journal of anatomy · 2022Pooled it
- Reclaiming Anatomy as Method: From Morphological Reasoning to Clinical Relevance.Clinical anatomy (New York, N.Y.) · 2026Review
- Human cerebral arterial morphogenesis explored by 3D microscopic imaging of cleared embryos: Bridging the gap between embryonic and adult anatomy.Journal of anatomy · 2026Article
- Vascular Neuroembryology: The Genesis of the Intracranial Arterial System and the Circle of Willis.Life (Basel, Switzerland) · 2026Article
- Atypical variants of the cerebral arterial circle beyond the Lazorthes classification: a retrospective morphologic and neuroradiologic study.Surgical and radiologic anatomy : SRA · 2026Article
- An unusual variant of the anterior cerebral and anterior communicating arterial system: anatomical description with clinical and radiological implications.Surgical and radiologic anatomy : SRA · 2026Article
- A Historic Review of the Three-Century Journey of the Circulus Arteriosus Cerebri: Then and Now.Cureus · 2025Review
- Right aortic arch with aberrant left subclavian artery and anomalous Circle of Willis supply.Radiology case reports · 2025Article
- Review
- Association of circle of willis variants with stroke and aneurysm: insights from a tertiary hospital in Ethiopia.BMC neurology · 2025Article
- Distinct Circle of Willis anatomical configurations in healthy preterm born adults: a 3D time-of-flight magnetic resonance angiography study.BMC medical imaging · 2025Article
- Human cerebral blood supply via circulus arteriosus cerebri: A scoping review on its variations and clinical implications.Heliyon · 2024Article
- Geometry and Symmetry of Willis' Circle and Middle Cerebral Artery Aneurysms Development.Journal of clinical medicine · 2024Article
- Exploring the anatomical configurations of the cerebral arteries in a cohort of South African patients.Scientific reports · 2024Article
- Anatomy of the pontine arteries and perforators of the basilar artery in humans.Journal of anatomy · 2023Article
- Hyperacute ischemic stroke treated with carotid-carotid artery bypass surgery "case report".Heliyon · 2023Article
Corrections and comments
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Authors and funding
5 authors at 1 institution in 1 country.
Funding
No grant is acknowledged in the PubMed record.
Abstract
The circle of Willis (CoW) is an anastomotic arterial network located on the base of the brain. Studies have shown that it demonstrates considerable anatomical variation in humans. This systematic review aimed to identify and catalogue the described anatomical variations of the CoW in humans to create a new, comprehensive variation classification system. An electronic literature search of five databases identified 5899 studies. A two-phase screening process was performed, and studies underwent quality assessment. A total of 42 studies were included in the review. Data were extracted and circles were reconstructed digitally using graphics software. The classification system contains 82 CoW variations in five continuous groups. Group one contains 24 circles with one or more hypoplastic segments only. Group two contains 11 circles with one or more absent segments only. Group three contains 6 circles with hypoplastic and absent segments only. Group four contains 26 circles with one or more accessory segments. Group five contains 15 circles with other types of anatomical variation. Within each group, circles were subcategorised according to the number or type of segments affected. An original coding system was created to simplify the description of anatomical variations of the CoW. The new classification system provides a comprehensive ontology of the described anatomical variations of the CoW in humans. When used with the coding system, it allows the description and categorisation of recorded and unrecorded variants identified in past and future studies. It is applicable to current clinical practice and the anatomical community, including human anatomy education and research.
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Registered trials
Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.