Anatomical variability in termination of basilar artery in human cadaveric brain

Abstract

AIm:The basilar artery (BA) is the prominent median vessel of the vertebrobasilar circulation and usually terminates into two posterior cerebral arteries forming the posterior angle of the Circle of Willis (CW). To tackle different variations of CW, basilar artery acts as a guideline for neuroradiologists and neurosurgeons. Basilar termination is the most frequent site of aneurysm. Abnormalities at the site of termination may compress the oculomotor nerve. Variations at the termination may complicate surgeries at the base of brain. The present study aims to add to the knowledge regarding the termination pattern of the BA. mATeRIAL and meTHods: 170 BA terminations were studied. Morphological variations in the termination pattern were noted. Frequency of variations in termination patterns was recorded. Dimensions of BA were measured. Data were analyzed.ResuLTs: Morphological variations in termination were seen in 17.64%. Bifurcation, Trifurcation, Quadrifurcation, Pentafurcation and Nonfurcation of BA was seen in 82.35%, 5.29%, 5.88%, 3.52% and 2.94% respectively. BA associated with aneurysm and Fenestration was seen in 3.52% and 1.17% respectively. Mean length and diameter of BA was 30.27 mm and 4.8 mm respectively.

Vascular variations associated with intracranial aneurysms

“…High Willis asymmetry rates in bleeding aneurysms confirm the relationship between hemodynamic disturbance due to asymmetric configuration and aneurysm formation and rupture (3,4,7,12,13,15,23,26,29,33). In bleeding ACoA aneurysms, Stojanovic et al (33) reported that the asymmetry presence accounted for 72.7%; morphological changes were present in the A1 segment (44%) and mainly on the right side (60%).…”

“…Krayenbuhl and Yaşargil (15) reported vertebral artery fenestration or anomalous termination. Gunnal et al (7) found morphological variations in termination in 17.64% of the cases. The prevalence of fenestrations of the intracranial VB system was reported to be between 1.17% and 2.77% (7,13,37).…”

“…arteriovenous malformation or cerebrovascular occlusive disease by changing the blood-flow pattern and increasing hemodynamic stress (3,4,7,12,13,15,23,26,29). There are some reports that have investigated the relationship between variations and aneurysm localization in cadaveric (12,20,28) and clinical studies (14,18,22,31).…”

Terminal end Variations and Common Pathological Abnormalities of the Basilar Artery among the Ugandan Population: a Human Autopsy Study

“…Similar studies have reported the same variations though with a varying prevalence rates. 10,11 Ogeng'o et al 11 reported 82.1% normal bifurcation in a black Kenyan population and Gunnal et al 10 82.5% in a turkish population. These two studies reported a significantly higher prevalence of bifurcations as compared with our study.…”

“…Several morphological studies have documented the terminal end variations of the basilar artery among various populations including bifurcations, trifurcations, quadrifurcations and pentafurcations. [9][10][11][12] These multiple branching patterns are believed to be lodging points for thromboembolic phenomena and pathologies like atherosclerosis and aneurysms. Aneurysms with multiple branching patterns at such points would lead to nerve compressions resulting into optical abnormalities.…”