Surgical anatomy of the paranasal sinuses

Understanding the anatomy of the paranasal sinuses is probably the most important prerequisite for endoscopic sinus surgery (ESS). As a matter of fact, most feared complications of ESS are the result of an uncontrolled maneuvering beyond the boundaries of the sinuses, mainly into the orbit or through the base of the skull. Even with the most experienced surgeons, these complications are still encountered, facilitated by some preexisting anatomical variants or pathological modifi cations caused by the underlying disease. Many constant landmarks have been described by diff erent authors since ESS was fi rst introduced in the late 1970s. These anatomical landmarks let beginners achieve a good spatial orientation when navigating within the sinuses, and help them perform the most complete sinus surgery while minimizing the risk to the patient. However, there is a defi-nite learning curve that can make one divide ESS into increasing levels of diffi culty in surgical skills, starting with the simple nasal endoscopy and ending with the most advanced frontal sinus procedures. In addition to the understanding of the anatomy, a thorough knowledge of the embryology, pathology and imaging of the sinuses is also very important for a comprehensive management of sinuses problems, but these topics are beyond the scope of this chapter.