Duodenal Switch vs Gastric Bypass

Before deciding on a weight loss surgery, it’s important to understand the difference between the different options that are available to you. The Duodenal Switch (DS) and Roux en-Y Gastric Bypass (RNY) are two¬† popular weight loss surgeries. Both procedures combine restrictive and malabsorptive weight loss techniques to produce significant weight loss in people battling obesity. However, the anatomy of these techniques is very different and, as a result, the possible outcomes and side effects will be different.

Learn more about the differences between the Duodenal Switch and the Gastric Bypass.

Restrictive Component

During the Gastric Bypass, a very small pouch is made at the top part of the stomach using staples or sutures. The bottom part of the stomach is bypassed completely and becomes a “blind” stomach. Food moves from the stomach into the intestines through a new connection made in the top pouch, instead of through the pylorus that is located at the bottom of the stomach.

During the Duodenal Switch, the outer curvature of the stomach is removed completely. What remains is a narrow sleeve-shaped stomach. Food continues to enter and leave the stomach in the same manner as before the surgery since the pylorus is left in tact and unchanged.

As a result of these differences:

  • Duodenal Switch patients can eat larger portions.
  • Gastric Bypass patients may feel more hunger because the “blind” stomach still produces hunger hormones.
  • Gastric Bypass patients may suffer “dumping” when eating certain foods that move directly into the small intestine without passing through the pylorus.

Malabsorptive Component

Calories are absorbed by the body when food mixes with bile and digestive juices in different parts of the small intestine. Both Gastric Bypass and Duodenal Switch bypass certain sections of the small intestine in order to reduce the amount of calories that are absorbed by the body when food is eaten, which results in significant weight loss and long-term weight maintenance.

The Gastric Bypass surgery reroutes the small intestine to remove the duodenum (top portion) and part of the jejunum (middle portion) from the digestive process.

The Duodenal Switch procedure rearranges the small intestine so that the food and bile travel down separate paths through the digestive system. Food, bile and digestive juices come together in a very short common channel where nutrients can be absorbed just before remaining food and waste is moved into the large intestine.

As a result:

  • DS patients only absorb about 20% of fat, 60% of protein and 60% of the complex carbohydrates they consume.
  • Patients of both DS and RNY surgeries require vitamin supplements and routine blood work to maintain optimum health.

Weight Loss Results

Although Duodenal Switch does incorporate restrictive weight loss methods, weight maintenance is largely achieved through malabsorption. This malabsorption rate is believed to contribute to the high percentage of weight loss typically experienced by DS patients as well as the long-term success rates.

Weight loss surgery success is measured by the percentage of excess weight loss, or EWL. Average EWL results for RNY and DS surgeries are as follow:

RNY

  • EWL% at 1-2 years – 48%-85%
  • EWL% at 3-6 years – 53%-77%
  • EWL% at 7-10 years – 25%-68%

DS

  • EWL% at 1-2 years – 65%-83%
  • EWL% at 3-6 years – 62%-81%
  • EWL% at 7-10 years – 60%-80%

In addition to having a higher percentage of excess weight loss, Duodenal Switch also offers the highest success rate for curing type 2 diabetes after surgery. This is attributed to the metabolic effect caused by the rerouting of the small intestine.

Talk to your doctor about which weight loss surgery is the best option for you.