This procedure involves removing 2/3rds to 3/4ths of the stomach. The remaining portion is basically a narrow sleeve that connects to the intestines. Often times this procedure is followed by a gastric bypass. Sometimes this surgery will be sufficient on its’ own.
This procedure is an easier way to start the process for very overweight people. After the surgery they can monitor weight loss and then take the next step if necessary. However this process is not reversible and there are typical surgery risks involved.