Gastric band gastroplasty (or "gastric band") is a surgical procedure consisting of placing a ring around the junction between the esophagus and the stomach. This ring is connected to a chamber positioned under the skin and its pressure is adjusted by injection or withdrawal of water by puncture of this chamber, thus playing on the degree of necking. The procedure is one of the types of gastroplasty, the other being the "vertical gastroplasty bandaged by stapling". It is part of bariatric surgery or "obesity surgery" and can lead to significant weight loss in some cases.