The Primitive Arterial Connections within the Central Nervous System and their Neurological Implications in Everyday Medical Practice

Abstract

IntroductionThe primitive trigeminal artery (PTA) is an anastomosis between the internal carotid artery (ICA) and the basilar artery (BA), that runs close to the trigeminal ganglion (hence its name). Conversely, the primitive trigeminal artery variants (PTAV) connect the ICA with cerebellar arteries. The trigeminal artery is said to regress following the development of the posterior communicating artery during the foetal life. However, when it persists, it might cause neuralgia and nerve palsies due to its proximity and compression of the III, IV, V and VIth cranial nerves.AimThe following study aimed to find the pooled prevalence estimate (PPE) of the presence of the PTA and the PTAVs, their types, as well as probe for sources of heterogeneity.Materials and methodsThe authors conducted a thorough search of major medical online databases. The references of the primarily identified studies were screened for any other potentially eligible articles. Data from the studies that met the inclusion criteria was extracted and pooled into the Meta‐analysis. The quality of the included studies was evaluated by the AQUA tool.ResultsThe authors deemed eligible 39 studies (110 866 patients). The overall PPE of the PTA and PTAVs was found to be 0.39% (95% CI: 0.31–0.49), slightly more prevalent in females (0.7%, 95% CI: 0.5–0.8) than males (0.4%, 95% CI:0.3–0.6). The PTA was solely found in 0.3% (95% CI: 0.2–0.4), whereas the PTAV only was noted in 0.2% (95% CI: 0.1–0.3). The PTA and the PTAVs originated most commonly from the C4 of the ICA (97.6%, 95% CI:93.7–100.0), had the lateral (parasellar) course in 89.0% (95% CI: 84.2–93.1) and the medial (intrasellar) in 11.0% (95% CI: 6.9–15.8). The anastomosis between the ICA and the anterior inferior cerebellar artery predominated amongst the PTAVs (72.1%, 95% CI: 50.0–95.7). Hypoplasia of the BA was noted in 42.5% (95% CI: 23.0–63.1)of patients with the PTA or the PTAV.ConclusionsAlthough this study showed that both the PTA and PTAV are rare variants (0.3% and 0.2% respectively), a neurosurgeon should be vigilant of their presence especially during the transspehnoidal approach to the pituitary neoplasms. The medial (intrasellar) type might pose a higher risk of iatrogenic complications due to its proximity to the pituitary gland. Similarly, the lateral (parasellar) type might complicate the percutaneous gasserian ganglion procedure.Support or Funding InformationThis study was supported by “The Best of the Best! 3.0 (Najlepszy z Najlepszych! 3.0)” Grant of the Polish Ministry of Science and Higher Education.This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.