Ileal Interposition with Sleeve Gastrectomy

Ileum is the end part of the small intestine. Ileal interposition therefore, is a sort of the exchange of the initial and final portions of the intestine. The upper (duodenum & jejunum) & lower parts of small intestine (ileum), secrete different hormones. The initial part secretes those hormones that are insulin resistant. These include ghrelin, GIP and glucagon. The final part of the ileum, on the other hand excretes those hormones that are sensitive to insulin. An example for this kind of hormone is GLP-1. The main objective of this surgery is to increase the amount of insulin sensitive hormones and to reduce the amount of insulin resistant hormones.

In Ileal interposition, a part of the ileum is displaced surgically. In addition to this, the upper portion of the stomach is also removed. This is done so that the effect of the interposition is very well pronounced. By the removal of upper stomach portion, the amount of ghrelin is decreased. This hormone has 2 primary functions:

  • The hormone sends impulses to the brain so as to create the sensation of hunger.

  • The hormone is also associated with intra-cellular insulin resistance.

There is also yet another reason having the stomach portion removed. If it is not done, gastric dilatation shall happen. Accompanying this, other conditions like vomiting, nausea etc shall also result.

By this surgery, the amount of ghrelin that is excreted is significantly reduced. Thus, the excessive secretion of this hormone during type 2 diabetes is compensated. Also, the patient shall feel only less sensation of hunger even after very little consumption.

It can be concluded that the purpose of this surgery is not entirely to minimize the stomach area.

Bariatric surgeries have become advantageous in not only controlling obesity, but also in controlling other conditions like hypertension, diabetes etc. Ileal interposition combining sleeve gastrectomy is a metabolic surgery that can also lead to weight loss.

This is a very prominent surgical method for the management of diabetes mellitus type 2. In this laparoscopic procedure, the area that produces ghrelin is excised. Since ghrelin acts against insulin, any decrease in the amount of ghrelin can lead to increase in the amount of insulin. By this procedure, a portion of ileum is surgically cut and the remaining position is placed very close to the stomach. GLP-1, the substance secreted by the ileum, increases the insulin secretion. Therefore, the dependency of insulin injections can be significantly reduced through this surgery and in most patients can be completely stopped.

In addition, the food can reach the ileum in a very short span of time. Therefore, the undigested food enters the ileum fast and this action accelerates the production of GLP-1. GLP-1 further stimulates the insulin producing beta cells of the pancreas.

Procedure: General anesthesia is administered for the operation. At first an ileal segment of 170cm is created beginning at a distance of 30cm from the ileo-cecal junction. Interposition of this segment with jejunum is then performed. For performing this, the jejunum is divided from the ligament of Trietz. The 3 anastomoses (communication between blood vessels) are also performed using staplers. In order to prevent internal herniation, the mesenteric gaps are closed using polypropylene sutures.

Jejunal Ileal Interposition

In this surgery, the jejunum is sectioned almost 50 cm distal to the duodenojejunal junction by employing a linear cutter stapler. The jejunal ends are interposed with the proximal and distal ends of the ileal segment. This is performed at the site of jejuna division. Closure of the mesenteric gaps is then performed. As the fundus of the stomach is also removed, the secretion of ghrelin is significantly reduced. Although the entire surgical procedure is complex and time consuming, the result obtained is long lasting.

Duodenal Ileal Interposition

The surgical procedure is similar to the jejunoileal interposition. Analogous to the former surgery, here the duodenum is divided and then this portion is then interpositioned with the distal and proximal ends of the ileal segment. This is performed in the duodenojejunal junction.

Advantage of Ileal interposition surgery.

There are a number of advantages for this procedure. Some of the advantages are as follows:

  • The onset of diabetes is delayed by 120 days (tolerance of 40 days) through this surgery compared to other conventional surgeries.

  • The surgery does not cause any malabsorption.

  • The surgery can reduce the intake of calories.

  • Loss of ghrelin can be brought out by this surgery.

  • The surgery also leads to lower plasma glucose excursions.

In addition, the surgery also has the advantages of bariatric surgeries. These include:

  • Reduction in the level of cholesterol, high blood pressure, sleep apnea, liver problems etc.

  • Reduction in the cardiovascular problems.