Duodenal Switch

Duodenal Switch (DS) 

According to the American Society for Bariatric Surgery and the National Institutes of Health, The Duodenal Switch (DS) is the most effective procedure for weight loss and most effective in the treatment of Diabetes Mellitus.This procedure is considered a “malabsorptive” operation and is performed with the intent of decreasing caloric intake by increasing the nutrition to move rapidly through the intestine and not completely absorb. The DS represents less than 2% of all weight loss currently being performed in the USA. This procedure is less commonly performed due to the higher resulting malabsorption, the technical difficulty of the procedure and need for increased vitamin and mineral supplementation by the patients on a daily basis. 

In this malabsorptive procedure, stapling creates a larger sleeved stomach with approximately 60% of the lateral stomach permanently removed. The outlet from this newly created sleeved stomach and duodenum is then separated just below the pylorus. A long roux limb with a short (150cm) common channel is then created. The duodenum is then reconnected to the alimentary limb of the ileum. Food enters the stomach and then is diverted to this “roux” limb before coming into contact with digestive enzymes from the “biliopancreatic” limb roughly 150 cms from the cecum (the common limb). The food and digestive enzymes are in contact for only a short common portion before entering the colon. This results in many of the ingested calories not being absorbed and they are subsequently disposed of by the colon, particularly fat soluble material and minerals. Because of the larger size of the stomach DS patients will not have the restriction that sleeve and gastric bypass patients experience. Due to the increased malabsorption these patients will need a substantially greater need for supplements on a daily basis to avoid malnutrition than other surgical patients. Undigested food (Carbohydrates, Proteins, and Fats) entering the colon may cause increased flatulence and loose bowel movements. Many patients move their bowels ½ hour after eating and may move their bowels 4 – 6 times per day. Medications may also not be fully absorbed prior to entering the colon and might need more frequent dosing regimens to be as effective after this procedure. This procedure can be utilized for any BMI that qualifies, however, because of the nutritional deficiencies that can develop it is better reserved for the patient who is massively obese with BMI above 50, those patients with severe diabetes mellitus, and those patients that require a second operation to achieve weight loss goals.

Advantages:

• May be able to consume larger meal portions with less restriction of food intake 
• Less Dumping syndrome due to pylorus preservation 
• The average excess weight loss after the DS procedure is generally higher in a compliant patient than with any other procedure. 
• 6 months after surgery, weight loss can average >80% of excess body weight. 
• Less recidivism – Studies show that after 10 to 14 years, >60% of excess body weight loss has been maintained by most patients. 
• A 2000 study of 500 patients showed that 96% of certain associated health conditions studied (back pain, sleep apnea, high blood pressure, diabetes and depression) were improved or resolved.

Risks and Considerations: 

• Because the duodenum is bypassed, poor absorption of iron and calcium can result in the lowering of total body iron and a predisposition to iron deficiency anemia. 
• Multiple vitamin and mineral deficiencies can develop (mostly fat soluble)
• May require multiple vitamin and mineral supplementation on a daily or regular basis to correct deficiencies.
• Augments poor eating habits as it is often necessary to eat more often and consume larger portions of food
• Sallow or yellow appearance, brittle hair, thin skin, and foul breath are common
• In some cases, poor eating behavior (large portions of “greasy” food intake will result in foul smelling flatulence and numerous “urgent” loose stools. 
•  Considered by many patients to have a “high maintenance” supplemental need. 
•  Patients who lose too much weight may need revisional surgery to allow better absorption.