Paranasal Sinuses Anatomy and Anatomical Variations

Anatomical variations of the sinuses are common and may lead to obstruction to the ventilation and drainage of the sinuses. This may lead to osteomeatal complex disease refractory to medications. A preoperative CT of the paranasal sinuses acts as road map guide to identify vital anatomical variations and its relationship to the orbit, skull base, neurological and vascular structures, to prevent iatrogenic injuries. To control intraoperative bleeding, it is critical to identify the anterior and posterior ethmoidal artery indentations and sphenopalatine artery in the anterior and lateral nasal walls. It is essential for the surgeon to familiarize with the anatomy of the ethmoid region, lateral nasal wall, sphenoid sinus, sella and parasellar region and pterygopalatine/infratemporal fossa before embarking on these approaches. The advent of CT scans and state-of-the-art FESS instrumentation has made surgery of the paranasal sinuses less of a mystery for the surgeon. Therefore, identifying and addressing these anatomical variations during FESS is crucial in restoring ventilation and drainage