The Sleeve Gastrectomy or Tube Gastrectomy involves removing the lateral 2/3rds of the stomach with a stapling device. It can be done laparoscopically (keyhole surgery) but is not reversible. It basically leaves a stomach tube instead of a stomach sack.
The residual stomach capacity is about 200mls or less.
Issues with Tube gastrectomy
Stomach tube may stretch up over time leading to late weight regain.
The amount of weight reduction is in the region of 60% - 70% of excess weight lost over the first 1-2 years.
It is a good option for people living in remote areas because it is a "set and forget" operation which requires less post op follow up.