Minor arteries from the intrapetrosal internal carotid artery: Possible clinical implications. An anatomical study

Abstract

The microvascular anatomy of the petrosal and suprapetrosal segments of the internal carotid artery (ICA) was studied in a consecutive autopsy material consisting of 58 ICA's from 29 individuals and in an additional 11 decalcified tissue blocks of the pars petrosa. The level above the external orifice of the carotid canal and the lumen width were registered for every artery debranching from the ICA. Special attention was paid to topographical close relationships between carotid branches and sympathetic nerves indicating a possible nutritional significance for the small arteries. The petrosal ICA had one or more branches in 64% of the specimens. 90% of the individuals had at least one branch from either ICA. The branches showed a mean lumen width of 187 μm for the petrosal and 290 μm for the suprapetrosal segment of the ICA. A considerable number of the petrosal carotid branches probably represent vasa nervorum for the sympathetic nerves and have a specific histological appearance. These vessels may have clinical implications, i.e., the evolvement of a Horner's syndrome during attacks of cluster headache or disease of the ICA.

Key Words:

• Carotid canal
• internal carotid artery
• carotid sympathetic plexus
• vasa nervorum
• Horner's syndrome
• cluster headache
• carotid artery disease