Surgery in which the operative procedure is hazardous. Major surgery is irregularly distinguished from minor surgery according to whether or not it requires a general anesthetic, involves an amputation above the ankle or wrist, or includes entering one of the body cavities (abdomen, chest or head).
Surgical operations involving important organs in the body.
Any surgical procedure that requires general anesthesia or assistance in respiration.
An operation risking a potential hazard and disruption of physiological function (e.g., entering a body cavity, excision of large tumors, amputation of a large body part, insertion of a prosthesis, open heart procedures). All surgeries are potentially dangerous and may involve a risk to life.
Surgery that poses a potential threat to life.