Indications and endonasal treatment of petrous apex cholesterol granulomasKohanski, Michael A.; Palmer, James N.; Adappa, Nithin D.Current Opinion in Otolaryngology & Head and Neck Surgery: February 2019 - Volume 27 - Issue 1 - p 54–58 doi: 10.1097/MOO.0000000000000511 NOSE AND PARANASAL SINUSES: Edited by Samuel S. Becker and Nithin D. Adappa Buy Abstract Author InformationAuthors Article MetricsMetrics Purpose of review Lesions of the petrous apex of the temporal bone can be challenging to access and approaches laterally through the mastoid as well as medially through an endonasal approach are utilized to access this region while preserving function of adjacent structures. Cholesterol granulomas of the petrous apex requiring surgery are marsupialized to prevent expansion of the inflamed cyst and relieve associated clinical symptoms. The endonasal approach to the petrous apex has in the past been limited to lesions medial to the internal carotid artery. Recent findings Endoscopic approaches have been developed to expand the range of petrous apex lesions that are accessible endonasally. These endonasal corridors include a nasopharyngeal/transclival corridor, lateralization of the internal carotid artery to create an expanded medial window, a pterygopalatine infrapetrosal approach, and a contralateral maxillary approach, which allow improved access to the inferior and lateral petrous apex. Nasoseptal flaps may reduce the risk of postoperative stenosis of the drainage tract. Summary Endoscopic endonasal approaches can be used safely to address both medial and lateral/inferior petrous apex lesions. Morbidity of these procedures is low and use of a nasoseptal flap may limit restenosis of the drainage pathway. Division of Rhinology, Department of Otorhinolaryngology-Head and Neck Surgery, University of Pennsylvania, Perelman School of Medicine, Philadelphia, Pennsylvania, USA Correspondence to Michael A. Kohanski, MD, PhD, Division of Rhinology, Department of Otorhinolaryngology-Head and Neck Surgery, University of Pennsylvania Medical Center, 5th Floor Ravdin Building, 3400 Spruce Street, Philadelphia, PA 19104, USA. Tel: +1 215 614 0491; e-mail: Michael.Kohanski@uphs.upenn.edu Copyright © 2019 Wolters Kluwer Health, Inc. All rights reserved.