Branches of the petrous and cavernous segments of the internal carotid artery.

Microsurgical approaches to the skull base require a thorough knowledge of the microvasculature of this region. Interestingly, most standard texts of anatomy do not mention the branches of the internal carotid artery as it travels through the temporal bone and cavernous sinus. Although small and with often conflicting descriptions, these arterial branches may be of significance when contributing to the vascular supply of such pathological entities as meningiomas and vascular malformations. Furthermore, multiple anastomoses exist between these branches and branches of the external carotid artery, thus providing a potentially important collateral circulation between these two systems and thus retrograde flow needed to maintain the patency of the distal internal carotid artery (ICA) when this vessel is obstructed proximally. We review the literature regarding these branches of the internal carotid artery and their clinical significance.