Where your sinus surgery is performed depends on the specifics of your surgery, as well as your general health and medical status. Most sinus surgery in the United States is typically performed at an Ambulatory Surgery Center (ASC). In some cases, sinus procedures are performed in the office setting. In more complex cases, or in patients with health conditions (cardiac disease, pulmonary disease, patients on blood thinners, etc) where it is preferable that they be observed and/or monitored in a hospital setting overnight, surgery may be performed in a standard hospital operating room.