A Case Report of Bilateral Carotico‐clinoid Foramina and a Unilateral Accessory Optic Canal: Implications for Anterior Clinoidectomy

Abstract

The lesser wing of the sphenoid has important anatomical relationships with both the ophthalmic artery (OphA) and internal carotid artery (ICA). Irregularly, the carotico‐clinoid ligament, a ligament connecting the anterior and middle clinoid processes, ossifies to create the carotico‐clinoid foramen (CCF) through which the ICA travels. The presence of the CCF has been reported to occur at a frequency ranging from 4.25% to 35.67%. Likewise, another variant, the accessory optic canal (AOC) will transmit the OphA instead of the optic canal. The AOC is present in approximately 1% of individuals. This study documents a bilateral CCF and a unilateral AOC occurring simultaneously. During anterior clinoidectomy procedures, both the CCF and AOC can create surgical complications. Knowledge of the unique combination of anatomical variants presented in this report may prevent adverse surgical events during anterior clinoidectomy procedures including hemorrhage of the ophthalmic artery or internal carotid artery and subsequent vision loss or death. Research was supported by funding from the WV Research Challenge Fund [HEPC.dsr.14.13].