Navigating a Carotico-Clinoid Foramen and an Interclinoidal Bridge in the Endonasal Endoscopic Approach: An Anatomical and Technical Note.

Objective  The carotico-clinoid foramen and interclinoid bridge are two anatomical variants of the sellar region. If these anatomical variants go unrecognized and are not managed safely by the surgeon during expanded endoscopic endonasal surgery for a posterior clinoidectomy, a carotid artery injury may occur. We summarize a method to safely navigate in the presence of the carotico-clinoid foramen and interclinoid bridge in an endoscopic endonasal approach. Study Design  The study involves cadaveric dissection and management of the anatomical variants. Setting  The study took place in a cadaveric dissection laboratory. Participants  The object of study is one cadaveric head. Main Outcome Measures  After discovering the two variants in both cavernous sinuses of a cadaveric head, we established a stepwise coping strategy to avoid carotid artery injury while performing an endoscopic endonasal bilateral interdural pituitary transposition, and we report the final view after endoscopic management. Results  Debulking of the middle clinoid process can decrease the obstacle effect, and the pituitary transposition can be performed medial to the ossified carotico-clinoid ligament. Disconnection of the interclinoid bridge is the prerequisite to an effective posterior clinoidectomy, and distinguishing the transition between the sellar diaphragm and the interclinoid bridge is essential. Conclusion  In the presence of both the carotico-clinoid foramen and the interclinoid bridge, a bilateral interdural pituitary transposition can still be performed, although preoperative strategic preparation, full inspection, and stepwise disconnections are of paramount importance in such a scenario to avoid cavernous carotid artery injury. Thieme. All rights reserved.