Endoscopic sinus surgery under the navigation system for a frontal sinus cyst: a case report

Draf's drainage surgery, an endonasal micro-endoscopic approach to establish one of three types of frontal sinus drainage, is becoming the standard operative procedure in Europe and America especially for recurrent cases. We reported a recurrent frontal sinus cyst that we treated in accordance with Draf's drainage surgery under the navigation system. The patient was an 81-year-old male, who complained of diplopia when gazing upward. His left eyeball was displaced downward, and there was a disorder of sursumduction. Emergency computed tomography (CT) showed that there was soft shadow in the left frontal sinus that had infiltrated into the left orbita. We performed an external incision with Killian's operation opening the lesion. The patient visited our hospital again with the same complaints 3 months later. Emergency CT showed findings that were similar to the previous time. We performed endonasal frontal sinus opening surgery in accordance with Draf's drainage surgery type III with the navigation system. Postoperative nasal fiberscopy 4 months later showed that the frontal duct penetrating to the frontal sinus remained open above the base of the middle nasal turbinate. Although there is a trend that Killian's operation causes mucoceles, endoscopic sinus surgery is unlikely to cause mucoceles. Moreover, we can perform this operation safely with the navigation system.