Persistent hypoglossal artery

Abstract

It is well known that the internal carotid artery has no branches in the neck during postfetal life (von Lanz & Wachsmuth, 1955), but during embryonic development there are anastomotic connections between the internal carotid and basilar artery that rarely persist after intrauterine life (Hassen-Khodja et al. 1992; Widmann & Sumpio, 1992; De Caro et al. 1995). The most common anomaly found incidentally on angiography is a persisting trigeminal artery, but persistent hypoglossal, otic and proatlantal arteries can also be found (Reynolds et al. 1980; Ouriel et al. 1988; Salas et al. 1998). We report a rare example of a persistent hypoglossal artery in a 64 y old female cadaver, cause of death unknown, embalmed by standard mortuary procedures for dissection during the routine anatomy course. The persistent hypoglossal artery originated from the anteromedial wall of the left internal carotid artery 2.5 cm above the bifurcation (Fig.). It extended towards the hypoglossal canal. The diameter of its lumen was 1.5 mm. During its course in the neck, it was positioned anterior to the internal carotid artery and medial to the facial and lingual arteries, the posterior belly of the digastric muscle and the convexity of the hypoglossal nerve in the neck. At 1 cm above the convexity of the hypoglossal nerve in the neck, the artery gave rise to a branch that entered the skull through the carotid canal anteromedial to the internal carotid artery (Fig. 1) and joined the basilar artery. The medial branch of the hypoglossal artery crossed the internal carotid artery on its medial side and entered the skull together with the hypoglossal nerve and joined the basilar artery. We found no other anomalies in the cerebral arterial system.