In a sleeve gastrectomy, also referred to as a vertical sleeve gastrectomy or gastric sleeve procedure, the outer margin of the stomach is removed to limit food intake, leaving a sleeve of stomach, roughly the dimensions and shape of a banana, and therefore the pylorus, the muscle that controls emptying of food from the stomach into the intestine. A sleeve gastrectomy may be a purely restrictive procedure. The sleeve gastrectomy, by reducing the dimensions of the stomach, allows the patient to feel full after eating less and taking in fewer calories. The surgery removes that portion of the stomach that produces a hormone which will makes a patient feel hungry. Sleeve gastrectomy may be a simpler operation than the gastric bypass procedure because it doesn't involve rerouting of or reconnection of the intestines. The sleeve gastrectomy, unlike the Lap band, doesn't require the utilization of a banding device to be implanted around some of the stomach.