"" Hexafurcation of Basilar Artery in a Black Kenyan Population

Research Article

Austin J Anat. 2016; 3(1): 1046.

Hexafurcation of Basilar Artery in a Black Kenyan Population

Ogeng’o JA, Mwachaka PM*, Olabu BO, Ogeng’o NM and Gimongo J

Department of Human Anatomy, University of Nairobi- Kenya, Kenya

*Corresponding author: Mwachaka PM, Department of Human Anatomy, University of Nairobi, P.O. BOX 00100 – 30197 Nairobi, Kenya

Received: October 24, 2015; Accepted: January 18, 2015; Published: January 22, 2016

Abstract

Pattern of terminal branching of the basilar artery may influence predisposition to atherosclerosis and aneurysms. Knowledge of unusual patterns is also important in interpretation of extent of stroke and during neuroradiological and neurosurgical procedures at basilar artery termination. Two hundred brains of black Africans were studied for pattern of variant termination. We observed two cases of unusual termination: two hexafurcations. All these cases were associated with variant origin of superior cerebellar and thalamoperforator arteries. This suggests that variant termination of basilar artery may include hexafurcation consequent to unusual origin of superior cerebellar and thalamoperforator arteries. Neurosurgeons, neurophysicians, neuroradiologists should be aware of such strange terminal branching pattern if they are to avoid inadvertent vascular injury. We recommend preoperative evaluation of the region before surgery.

Keywords: Basilar artery; Hexafurcation; Africans; Atherosclerosis

Introduction

The Basilar Artery (BA), usually terminates by dividing into two posterior cerebral arteries [1,2]. Variant terminations described include double posterior cerebral arteries and common trunks for Posterior Cerebral Arteries (PCA) and Superior Cerebellar Arteries (SCA) trifurcation, quadrifurcation and pentafurcation [3- 5]. Such variant branching patterns of arteries predisposes them to atherosclerosis and aneurysms [6,7], and may complicate surgery at basilar bifurcation angle and clivus [8]. The abnormalities may also alter the relationships with and compress occulomotor nerve [9]. There are, however, few reports on variant termination of the basilar artery. We recently reported up to 5 branches. In all cases of trifurcation, qudrifurcation and pentafurcation, the variation was due to duplication and rostral shift of superior cerebellar artery [4]. Potentially, more than five branches is possible but hitherto unreported in spite its importance. This study, therefore investigated the pattern of termination of the basilar artery in a black Kenyan population, for cases where there were more than five terminal branches.

Materials and Methods

Two hundred brains were examined. The arachnoids matter was gently peeled off to expose the basilar artery in its entire length. Pia matter, veins and small perforating arteries were sacrificed to clarify the pattern of termination. The termination was examined further for unusual terminal branching pattern. The arteries given off just before terminal bifurcation, which coursed laterally to ramify over the superior surface of cerebellar hemispheres, were identified as Superior Cerebellar Artery (SCA). The terminal branches which were joined to internal carotid by posterior communicating were identified as Posterior Cerebral Artery (PCA). Images of these patterns were taken with a high resolution digital camera.

Results

Unusual terminal branching of basilar artery, hexafurcation, whereby the basilar artery gave rise to six unequivocal branches was noted in two cases. In one, there were two superior cerebellar arteries arising from the same point as PCA bilaterally (Figure 1A). In the second one, the unusual rostral superior cerebellar artery was duplicated unilaterally, and one enlarged thalamoperforator arose from basilar bifurcation (Figure 1B).

Citation: Ogeng’o JA, Mwachaka PM, Olabu BO, Ogeng’o NM and Gimongo J. Hexafurcation of Basilar Artery in a Black Kenyan Population. Austin J Anat. 2016; 3(1): 1046. ISSN : 2381-8921