During the vertical sleeve gastrectomy, approximately 85% of the stomach is removed, leaving a tube or sleeve-shaped stomach with a much smaller volume. The outlet valve and the nerves to the stomach remain intact with this procedure, making it unlike the other bariatric surgery techniques. The stomach is drastically reduced in size, and its function is changed from a food storage tank to a food channel. The sleeve gastrectomy is not reversible.
The fact that it does not involve any bypass of the intestinal tract may well be the strongest reason to consider the vertical sleeve. Because of this fact, patients don’t suffer the complications that come with intestinal bypass. This makes the vertical sleeve a good choice for patients who are already suffering from anemia, Crohn's disease, or other conditions that make surgery involving intestinal bypass undesirable.
Most patients can expect to lose 40 - 50% of excess body weight over six to twelve months.
During vertical sleeve surgery, the main part of the stomach, which produces the hormones that stimulate hunger, is removed. This means that, while the stomach is reduced in size and the volume of food eaten is limited, the stomach still functions normally.
The gastric sleeve reduces the likelihood of ulcers. It also comes without the problems associated with bypass forms of weight loss surgery including anemia, intestinal obstruction or blockage, osteoporosis, protein shortage and vitamin deficiency. The sleeve gastrectomy is a laparoscopic treatment that is beneficial to patients with a particularly high body mass index (BMI).
The risks of problems with the vertical sleeve are low but include blockages in the sleeve or post-operative leaks along the staple line. Because this surgery doesn’t provide any component of gastric bypass, some patients may experience a disappointing level of weight loss or weight regain over time. The laparoscopic sleeve gastrectomy could be converted to a gastric bypass if necessary, but it is unlikely. The gastric sleeve procedure is not reversible because part of the stomach is permanently removed.