This operation is performed using an endoscope, a rigid tube with a light on one end. The tube is threaded into your nose and up into the sinus openings. Using this technique, your sinuses can be drained and the sinus openings can be enlarged, allowing better drainage in the future. If polyps (benign growths) are discovered, they can be removed. This type of sinus surgery has a high rate of success and a low rate of complications. However, if complications occur, they may be serious.