2026 Poster Presentations
P325: STEPWISE TECHNIQUE FOR SAFE EXPOSURE OF THE PARACLINOID, PARASELLAR AND PARACLIVAL ICA FOR ENDOSCOPIC ENDONASAL APPROACH: TECHNICAL NUANCES
Thibault Passeri, MD1; Rakhmon Egamberdiev, MD1; Gianluca Fabozzi, MD1; Ivo Peto, MD1; Hussam Abou Al Shaar, MD1; Ali Allatar, MD1; Eric Wang, MD2; Carl Snyderman, MD2; Paul Gardner, MD1; Garret Choby, MD2; Georgios A. Zenonos, MD1; 1Department of Neurological Surgery, University of Pittsburgh Medical School (UPMC), Pittsburgh, USA; 2Department of Otolaryngology, University of Pittsburgh Medical School (UPMC), Pittsburgh, USA
Introduction: Over the past decade, endoscopic endonasal surgery (EES) has become a cornerstone in the treatment of skull base pathologies. Expanded lateral corridors in EES often require exposure of the internal carotid artery (ICA), increasing the risk of a rare but potentially devastating complication. We describe a stepwise strategy to optimize safe ICA exposure and review our institutional experience with injuries during bone removal.
Methods: Anatomical dissections were performed on silicone-injected cadaveric heads to define safe techniques for exposing the paraclinoid (PClin), parasellar (PS), and paraclival (PCliv) ICA segments. In addition, a retrospective review of all patients who underwent EEA at our institution between June 1998 and January 2025 was conducted to identify cases of intraoperative ICA injury specifically occurring during the exposure phase. Surgical videos are included to illustrated the proposed stewise technique.
Results: Our approach emphasizes stepwise “eggshell” drilling, controlled fracture, and circumferential removal of bony protuberances to ensure safe ICA exposure (Figure 1). For the PClin /PS segments, key steps included: (1) opening the sella to the medial opticocarotid recess (MOCR), (2) sellar floor drilling, (3) unroofing the anterior cavernous sinus wall, (4) inferior-to-superior ICA skeletonization to the distal dural ring, (5) en bloc removal of the middle clinoid process, (6) tuberculum margin drilling, (7) optic canal unroofing, and (8) MOCR removal. For the PCliv segment : (1) anterior ICA skeletonization, (2) drilling of the middle/lower clivus, and (3) en bloc resection of the medial wall and posterior bone behind the ICA. Among 4,924 EES procedures with ICA exposure, ICA injury during bone removal occurred in 5 cases (0.1%): 3 at the PS segment and 2 at the PCliv segment
Conclusions: Safe ICA exposure during EES requires a combination of comprehensive anatomical knowledge, careful preoperative imaging assessment, and adherence to a stepwise, meticulous surgical technique. This structured approach is critical to minimize the risk of ICA injury during bone removal and to improve patient safety in complex skull base procedures.
Figure 1: Endoscopic endonasal view of key anatomical landmarks for safe exposure of the paraclinoid (PClin) / parasellar (PS) and paraclival (PCliv) segments of internal carotid artery (ICA). The colored area correspond to the following structures removed step-by-step : A) Paraclinoid and parasellar ICA : 1 (blue) : sella turcica ; 2 (yellow) : floor of the sella ; 3 (light blue) : anterior wall of the cavernous sinus ; 4 (red) PS and PClin segments of the ICA ; 5 (dark blue outline) : middle clinoid process ; 6 (yellow) inferior aspect of the optic canal ; 7 (green) : inferolateral aspect of the tuberculum ; 8 (dark blue outline) : medial optico-carotid recess. B) Paraclival ICA : 1 (blue) : sella turcica ; 2 (yellow) : floor of the sella ; 3 (light blue) : anterior wall of the cavernous sinus ; 4 (red) paraclival segment of the ICA ; 5 (green) : clival recess ; 6 (dark blue outline) : medial wall of PCliv ICA.