Gastric Sleeve
In gastric sleeve surgery, also called vertical sleeve gastrectomy, a surgeon removes most of your stomach, leaving only a banana-shaped section that is closed with staples. Like gastric band surgery, this surgery reduces the amount of food that can fit in your stomach, making you feel full sooner. Taking out part of your stomach may also affect gut hormones or other factors such as gut bacteria that may affect appetite and metabolism. This type of surgery cannot be reversed because some of the stomach is permanently removed.
Source https://www.niddk.nih.gov/health-information/weight-management/bariatric-surgery/types
