As with any surgical procedure, complications can occur. These complications may occur during or after surgery. Some of these risks and complications are inherent in any surgical procedure, especially when general anesthesia is used. You should consult your doctor about these risks. In addition, possible complications, especially after FESS, include
The risk of this complication is less than 1 percent. The brain is separated from the sinuses by a thin layer of bone. This layer of bone can be punctured, for example by a severely infected sinus, especially if the surgeon does not have a clear view. Such a tear can cause some of the fluid surrounding the brain to leak out. Additional surgery may be needed to repair the tear.