Prevalence and Clinical Implications of the Primitive Trigeminal Artery and its Variants: A Meta-Analysis.
BACKGROUND
The primitive trigeminal artery (PTA) is the most common and the largest persistent carotid-basilar anastomosis. Primitive trigeminal artery variants (PTAVs) are anastomoses between the internal carotid artery and cerebellar arteries. These vessels pose a risk of hemorrhagic or ischemic complications during neurosurgical procedures in the parasellar and intrasellar regions. The aim of this study was to determine the prevalence of both PTA and PTAVs and their clinically important anatomic features.


METHODS
Major electronic databases were thoroughly searched for studies on PTA and PTAV. References in the included articles were also evaluated. Data regarding prevalence, laterality, origin, course patterns, and associated anomalies were extracted and pooled into a meta-analysis.


RESULTS
A total of 39 studies (110,866 patients) were included in the meta-analysis. The total pooled prevalence estimate of PTA and PTAVs combined was 0.4% (95% confidence interval [CI], 0.3-0.5). Individually, PTA was present in 0.3% of patients and PTAV in 0.2%. Both arteries most often originated from the C4 internal carotid artery and took a course lateral to the dorsum sellae. The anterior inferior cerebellar artery type was the predominant PTAV (72.1%). Basilar artery hypoplasia was found in 42.5% of patients with a PTA.


CONCLUSIONS
PTA and PTAVs are rare vessels, but they are clinically important because they can contribute to trigeminal neuralgia. Knowledge of the potential course of these arteries is essential in neuroradiology and neurosurgery, especially in minimally invasive procedures such as the endoscopic endonasal transsphenoidal approach to the pituitary gland and the percutaneous gasserian ganglion procedure.
['Brzegowy|Karolina|K|', 'Pękala|Przemysław A|PA|', 'Zarzecki|Michał P|MP|', 'Pękala|Jakub R|JR|', 'Roy|Joyeeta|J|', 'Aziz|Hasina M|HM|', 'Tubbs|R Shane|RS|', 'Walocha|Jerzy A|JA|', 'Tomaszewski|Krzysztof A|KA|', 'Mikos|Marcin|M|']
D001488:Basilar Artery D000076103:Biological Variation, Individual D002343:Carotid Artery, Internal D020785:Central Nervous System Vascular Malformations D002531:Cerebellum D002536:Cerebral Arteries D006801:Humans D002532:Intracranial Aneurysm D015995:Prevalence
Primitive trigeminal artery Carotid-basilar anastomosis Internal carotid artery Fetal intracranial artery Vascular anatomy