J Neurol Surg B
DOI: 10.1055/s-0039-1691831
Original Article
Georg Thieme Verlag KG Stuttgart · New York

Preoperative Computed Tomography Imaging of the Sphenoid Sinus: Striving Towards Safe Transsphenoidal Surgery

John Raseman
1  Department of Diagnostic Radiology, Mallinckrodt Institute of Radiology, St. Louis, Missouri, United States
,
Melike Guryildirim
2  Department of Diagnostic Radiology, Rush University Medical Center, Chicago, Illinois, United States
,
André Beer-Furlan
3  Department of Neurological Surgery, Rush University Medical Center, Chicago, Illinois, United States
,
Miral Jhaveri
2  Department of Diagnostic Radiology, Rush University Medical Center, Chicago, Illinois, United States
,
Bobby A. Tajudeen
4  Department of Otorhinolaryngology–Head and Neck Surgery, Rush University Medical Center, Chicago, Illinois, United States
,
Richard W. Byrne
3  Department of Neurological Surgery, Rush University Medical Center, Chicago, Illinois, United States
,
Pete S. Batra
4  Department of Otorhinolaryngology–Head and Neck Surgery, Rush University Medical Center, Chicago, Illinois, United States
› Author Affiliations
Further Information

Publication History

24 October 2018

04 April 2019

Publication Date:
28 May 2019 (online)

Abstract

Introduction Preoperative high-resolution computed tomography (HRCT) is essential in patients undergoing transsphenoidal surgery to identify potential high-risk anatomic variations. There is no consensus in the literature, as to which grading system to use to describe these variants, leading to inconsistent terminology between studies. In addition, substantial variability exists in the reported incidence of anatomic variants. In this study, we performed an institutional imaging analysis and literature review with the objective of consolidating and clearly defining these sphenoid sinus anatomical variations. In addition, we highlighted their surgical implications and propose a checklist for a systematic assessment of the sphenoid sinus on preoperative CT.

Methods Review of the literature and retrospective analysis assessing several imaging parameters in 81 patients who underwent preoperative HRCT imaging for endoscopic transsphenoidal tumor resection from January 2008 through July 2015 at Rush University Medical Center.

Results The most common sphenoid pneumatization patterns were sellar (45%) and postsellar (49%) types. Anterior clinoid process (ACP) pneumatization was seen in 17% of patients with high concordance of ipsilateral optic nerve (ON) protrusion. ON protrusion and dehiscence was present in 17 and 6% of patients, respectively. Internal carotid artery (ICA) protrusion and dehiscence was present in 30 and 5% of patients, respectively. Dehiscence rates from local bone invasion overlying the ICA and ON occurred in 17 and 4% of cases, respectively.

Conclusions Our study highlights and reviews the key variants that have potential to impact surgical complications and outcomes in a heterogeneous patient population. The proposed preoperative CT checklist for patients, undergoing transsphenoidal surgery, consistently identifies these higher risk anatomical variants.