Restriction (Vertical Gastrectomy): The stomach is restricted by dividing it vertically and removing more than 85% of it. This part of the procedure is not reversible. The stomach that remains is shaped like a banana and measures from 4-7 ounces (120-250cc) depending on the surgeon performing the procedure. The nerves to the stomach and the outlet valve (pylorus) remain intact with the idea of preserving the functions of the stomach while reduing the volume. By comparison, in a Roux-en-Y gastric bypass, the stomach is divided, not removed, and the pylorus is excluded. The Roux-en-Y gastric bypass stomach can be reconnected(reversed) if necessary.

Duodenal Switch: What is Malabsorption?

Malabsorption (Duodenal Switch):

The intestines are divided and rearranged to separate food from the digestive juices, thereby creating malabsorption. The food limb is attached to the duodenum and receives food from the stomach. This limb is 150 cm long. The digestive juices are now separated from the food and travel for over 500 cm in the bypassed small intestine. Both food and digestive juices mix together and travel together for 100 cm in the common limb. Thus, food and digestive juices are separated for most of the length of the intestines. This prevents you from absorbing all of the calories that you eat. By comparison, the intestinal bypass in a Roux-en-Y gastric bypass is much less extensive, and the common limb for digestive juices and food to mix is approximately 5 times longer. Therefore, the Roux-en-Y gastric bypass has minimal malabsorption compared to the Duodenal Switch procedure.

The Advantages of the Duodenal Switch Weight Loss Surgery Procedure

The more normal stomach allows for better eating quality but may possibly result in more      diarrhea and foul smelling bowel movements and gas
No dumping syndrome because the pylorus is preserved
Minimizes the chance of an ulcer occurring
Very effective for high BMI patients (BMI>55 kg/m2)
The intestinal bypass is partially reversible for those having malabsorptive complications
Laparoscopic approach is offered by some surgeons

The Disadvantages of the Duodenal Switch Weight Loss Surgery Procedure

Greater chance of chronic diarrhea
Significant malabsorption leads to anemia, protein deficiency and metabolic bone disease in up      to 5% of patients
More foul smelling stools and gas
Carbohydrates can be well absorbed and lead to inadequate weight loss
This procedure is the most complex surgical weight loss procedure and may yield an       unacceptable level of complications in high risk patients(heart failure, sleep apnea)

Duodenal Switch: Risks and Complications

As with any surgery, there can be complications. This list can include:

Deep vein thrombophlebitis 0.7%
Non-fatal pulmonary embolus 0.5%
Pneumonia 0.5%
Acute respiratory distress syndrome 0.25%
Splenectomy 0.9%
Gastric leak and fistula 2.0%
Duodenal leak 1.5%
Distal Roux-en-Y leak 0.25%
Postoperative bleeding 0.5%
Duodenal stomal obstruction 0.75%
Small bowel obstruction 2.0%
Death 1.0%