The duodenal switch (DS) is a popular surgery because patients are able to eat a near-normal meal (in much smaller quantities) while still experiencing significant long-term weight loss. With this operation, the majority of the most stretchable portion of the stomach is permanently removed, but basic stomach structure remains the same. In addition, the surgeon will also bypass roughly two-thirds to three-fourths of the upper small intestines, resulting in a significant decrease in calorie absorption. Weight loss is achieved both through restriction of food consumption as well as malabsorption.
How It Works
With this operation, the surgeon permanently removes the stretchy outer and upper 85 percent of the stomach, leaving a small, vertically-oriented tubular stomach. Stomach capacity is reduced from about a quart (1,000 ml) to roughly 5-6 ounces (150 ml). Depending on the size of the tube that is created, patients generally report feeling full after eating 4-6 ounces of solid food.
Because all of the important structural elements of the stomach and intestines are preserved, such as the antrum, the pylorus and the nerves that control stomach function, the result is a much smaller stomach that functions very similar to normal. This allows patients the ability to enjoy a relatively normal diet (in smaller quantities) without experiencing “dumping” syndrome.
The surgeon will also re-route the intestines so that calorie absorption is significantly reduced. The duodenum (the first section of the small intestine) is divided and connected to the last 8.5-10 feet (250-350 cm) of intestine. The top half of the intestine carries just digestive juices (bile and pancreatic juices) and is called the bilio-pancreatic limb (BPL). This section is reconnected to the food stream 3.5-7 feet (40-80 inches) from the colon (large intestine). The last segment of the intestine where the food and digestive juices mix is referred to as the common channel (CC). Absorption of nutrients and calories is determined by the length of the common channel, so a short channel helps decrease the chance of weight regain by decreasing calorie absorption.
One reason that good long-term weight loss has been reported with the duodenal switch is likely due to a dramatic decrease in the appetite-producing hormone known as ghrelin. The tissue that produces the hormone is almost completely removed with the stretchy outer portion of the stomach. Patients typically report a significant decrease in hunger and food consumption after this operation. In addition, rerouting the intestines helps bring food to the lowest portion of the small intestines earlier than usual which releases important appetite-suppressing hormones such as polypeptideYY (PYY) and glucagon-like peptide 1 (GLP1). This may explain the superior weight loss, weight maintenance and diabetes resolution associated with this surgery.
- Approximately 75-80% excess weight loss (EWL) has been reported. (4, 5). (Excess weight is the amount of weight over what is considered the “ideal body weight” for a person’s height [Current Weight – Ideal Weight = Excess Weight]. The percentage of excess weight loss (%EWL) is the percentage of weight loss from this excess weight.)
- Improvement/resolution in all major co-morbidities has been documented, including type 2 diabetes, sleep apnea, hypertension, high cholesterol and depression. A very high cure rate for diabetes has been reported with this surgery. (6)
- There is very little risk of “dumping” syndrome—which occurs when a patient consumes sugar or carbohydrates, or eats too quickly, causing nausea, cramping, diarrhea, sweating, vomiting and heart palpitations. Preservation of the pyloric valve provides for a more physiologic emptying of solid foods from the stomach enabling people to tolerate normal foods and reducing dumping syndrome.
- This is a pill-friendly operation. NSAIDS and Aspirin are well tolerated.
- Because weight loss is achieved through stomach restriction as well as malabsorption, this surgery is a great option for patients with a high BMI.
Dan, Dueodenal Switch