Evaluation of the ethmoid skull-base height prior to endoscopic sinus surgery: A preoperative computed tomography evaluation technique

Introduction: Iatrogenic ethmoid skull base (ESB) injury during endoscopic sinus surgery (ESS) is a potentially devastating complication. The height of the ESB can vary substantially and should be assessed during preoperative evaluation of the sinus computed tomography (CT) scan. Methods: The objective of this study is to describe an objective preoperative CT evaluation technique to assist the surgeon in defining the height of the ESB prior to performing ESS. Results: We propose a technique which measures the height of the ESB from a single horizontal mid-orbital line located on a standardized coronal sinus CT image at the level of the anterior ethmoid artery canal. Conclusions: Utilization of an objective preoperative CT measurement technique may quantify identification of a low ESB and optimize surgical awareness of this potentially dangerous anatomic skull base variation.