The cervical internal carotid artery normally runs straight to the skull base without branching.(1) However, aberrant courses of the extracranial internal carotid artery are not rare and may place the vessel in close relationship with the pharyngeal wall.(2, 3) We present this clinical observation to draw the readers’ attention on a probably underappreciated anatomic variation.
A 77-year-old woman had long-standing moderate dysphagia and right-sided foreign body sensations in the throat. She had no history of alcohol or tobacco abuse. On examination, smooth irritation-free mucous membranes were found, but a funicular pulsatile mass was detected on the posterior pharyngeal wall on the right. Endoscopy displayed that the mass continued down to the hypopharynx. It was finally attributed to an aberrant course of the internal carotid artery. The patient was instructed to advise every treating physician of this anatomic variation and to abstain from sharp-edged food such as chicken bones and fish.
Pronounced extracranial aberrations of the internal carotid artery have a calculated incidence of 5% in the general population and can often be found bilaterally. They result from embryologic maldevelopment and age-related loss of elasticity in the vessel wall. These anatomic variations remain asymptomatic in the majority of cases but can also become apparent with dysphagia, pharyngeal foreign body sensations, intraoral pulsations, or signs of cerebrovascular insufficiency in case of sharp vessel bends.1, 2, 3 If placed in close opposition with the pharyngeal wall (Figure 1A and B), an aberrant internal carotid artery is at risk of injury during intubation, endoscopy, and routine pharyngeal or dental procedures. It may also be misdiagnosed as a parapharyngeal tumor.(2, 3) Therefore, the awareness of extracranial aberrations of the internal carotid artery is essential for every clinician.
References
1. Paulsen F, Tillmann B, Christofides C, et al. Curving and looping of the internal carotid artery in relation to the pharynx: frequency, embryology and clinical implications. J Anat. 2000;197:373–381.
2. Hertzanu Y, Tovi F. Radiology case of the month (Aberrant internal carotid artery manifesting as a pharyngeal mass). J Otolaryngol. 1992;21:294–296.MEDLINE
3. Ricciardelli E, Hillel AD, Schwartz AN. Aberrant carotid artery (Presentation in the near midline pharynx). Arch Otolaryngol Head Neck Surg.1989;115:519–522. MEDLINE
— Jens Pfeiffer, MD, Gerd J. Ridder, MD
This article was originally published in the March 2009 issue of The American Journal of Medicine.
