An Adjustable Gastric Band is a band that goes around the upper part of the stomach. It is inserted laparoscopically, and when fully inserted it creates a small “pouch” in the upper stomach, thereby reducing the stomach’s capacity (and the patient’s capacity for food).
Unlike stomach stapling, gastric banding can be adjusted in size by inflating or deflating the band.
Picture of gastric banding (WebMD)
Definitions from around the web:
“Gastric banding is another form of gastroplasty, in which a synthetic band is placed around the stomach just below the esophagogastric junction.” -Medscape.com
“Adjustable gastric banding is a form of restrictive weight loss surgery (bariatrics) designed for obesity patients … The band is inflated /adjusted via a small access port placed just under the skin…” -Answers.com
“A surgically implanted device used to help a person lose weight. In a surgical procedure, a band is placed around the upper part of the stomach, creating a small pouch that can hold only a small amount of food.” -MedicineNet.com