Normal sinonasal endoscopic surgical anatomy

Endoscopic sinus surgery (ESS) is indicated for the treatment of chronic rhinosinusitis refractory to medical management, as well as selected sinonasal pathology. The normal endoscopic anatomy is crucial to understanding safe and effective ways of opening the natural sinus drainage patterns and resecting benign and malignant neoplasms. This section focuses on the normal anatomical landmarks used to identify the maxillary, ethmoid, sphenoid, and frontal sinuses, as well as their natural drainage patterns. The figures used clearly demonstrate the “safe” zones of entry into each sinus cavity. Many of the landmarks described here are also effective in revision ESS, which is discussed in a later section. The key to efficacious ESS is a thorough understanding of the triplanar preoperative computed tomography imaging and correlating this with the endoscopic 2-dimensional view.