Bilateral pentafurcation of the common carotid arteries: a cadaveric case study

Arterial variations in branching patterns off the external carotid artery are of clinical significance, especially in surgical operations and procedures of the head and neck. Variations of the eight typical branches off the carotid artery and their branching patterns have been documented in the literature and several classification systems have been proposed. The common carotid artery typically bifurcates at the upper border of the thyroid cartilage into the external carotid and internal carotid arteries. This case report details the rare occurrence of a bilateral common carotid artery pentafurcation, with the external and internal carotid artery and three additional branches that typically branch off of the external carotid artery. Limited documentation of pentafurcation of the carotid artery exists, and bilateral pentafurcation has not been previously documented in the literature.

A bilateral pentafurcation of the common carotid artery was found during routine cadaveric anatomy dissection by first year medical students at Kansas City University College of Osteopathic Medicine. Detailed dissection of the carotid system branches was then performed to verify findings and identify the atypical branching patterns. Measurements were taken and characteristics of all branches were documented.

In addition to the typical internal and external carotid branches, the right and left common carotid artery produced the superior thyroid, ascending pharyngeal, and occipital arteries, resulting in bilateral carotid artery pentafurcation.

This case presents a rare finding of bilateral carotid artery pentafurcation. Documentation and reporting of the variability in carotid vasculature benefits both radiologic and surgical specialties and assists in predicting the impact of carotid artery anomalies on the pathophysiology of carotid atherosclerosis.