 Functional Endoscopic Sinus Surgery is considered a success if most of the symptoms, including nasal obstruction, sleep quality, olfaction and facial pain, are resolved after a 1-2 month postoperative healing period.Reviews of FESS as a method for treating chronic rhinosinusitis have shown that a majority of patients report increased quality of life after undergoing surgery.The success rate of FESS in treating adults with CRS has been reported as 80-90%, and the success rate in treating children with CRS has been reported as 86-97%.