Variations of the course of the internal carotid artery in the parapharyngeal space and their frequency were
studied in order to determine possible risks for acute haemorrhage during pharyngeal surgery and traumatic
events, as well as their possible relevance to cerebrovascular disease. The course of the internal carotid
artery showed no curvature in 191 cases, but in 74 cases it had a medial, lateral or ventrocaudal curve, and
17 preparations showed kinking (12) or coiling (5) out of a total of 265 dissected carotid sheaths and 17
corrosion vascular casts. In 6 cases of kinking and 2 of coiling, the internal carotid artery was located in
direct contact with the tonsillar fossa. No significant sex differences were found. Variations of the internal
carotid artery leading to direct contact with the pharyngeal wall are likely to be of great clinical relevance in
view of the large number of routine procedures performed. Whereas coiling is ascribed to embryological
causes, curving is related to ageing and kinking is thought to be exacerbated by arteriosclerosis or
fibromuscular dysplasia with advancing age and may therefore be of significance in relation to the
occurrence of cerebrovascular symptoms.