Endoscopic sinus surgery, an endoscope is inserted into the nose, providing the doctor with an inside view of the sinuses. Surgical instruments are inserted alongside the endoscope. This allows the doctor to remove small amounts of bone or other material blocking the sinus openings and remove growths (polyps) of the mucous membrane. In some cases a laser is used to burn away tissue blocking the sinus opening. A small rotating burr that scrapes away tissue may also be used. The surgery may be done in a hospital or in a doctor’s office. Either local or general anesthesia may be used. The procedure takes 30 to 90 minutes.