 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%.The most common complication of FESS is cerebrospinal fluid leak (CSFL), which has been observed in about 0.2% of patients.