Duodenal switch or biliopancreatic diversion with duodenal switch (BPD-DS) is a useful but complicated weight loss surgery that is preferred for morbidly obese/super-obese individuals. It is also the bariatric surgery of last resort following the failure of other weight loss surgeries. Today, duodenal switch success rate is the highest among the common bariatric surgeries. This is not unconnected to the combination of both restrictive as well as malabsorptive mechanisms. The degree of malabsorption in the duodenal switch is higher than that of gastric bypass due to a longer length of small intestine that is rendered non-functional in the former.
The stomach capacity reduction is achieved via a gastric sleeve surgery. This is then followed simultaneously by the malabsorptive component that involves an alteration in the anatomy of the small intestine in such a way that contact between food particles and pancreatic enzymes and bile do not occur until the last 50cm of the small intestine. This means that only 50cm length of the small intestine is involved in digestion and absorption. An adjunct to this procedure is cholecystectomy (gallbladder removal) to prevent post-operative gallstone formation.
Success rates of the duodenal switch can be measured by looking at the expected weight loss and resolution of comorbid conditions at different times after surgery. These two parameters will translate to a higher quality of life as well as a reduction in premature death.
Sucandy et al. reported a higher percentage excess weight loss at 18months after duodenal switch (79.6%) over gastric sleeve surgery (64%).1In another study, a review of 566 patients who had duodenal switch revealed no mortality after 90days, percentage excess weight loss averages 81% at 12months, 88% at 24months and 83% at 36months. Also, Hemoglobin A1c (HbA1c) dropped from 7.1% to 4.7% in patients who had diabetes before surgery.2
Over a period of 15 years, Marceau et al. reported the outcome of the duodenal switch in 1423 patients. Survival rate was found to be 92% with the risk of death <1.2(similar what obtains in the general population). Diabetes was completely cured in 92% of patients while CPAP machine was discontinued in 90% of patients. Those who were asthmatic also recorded significant improvement with reduction in the need for medication in more than 88% of asthmatics.3
Mingrone et al. reported remission of type 2 diabetes mellitus in 95% of patients after 2years of duodenal switch. This was higher than 75% remission rate in patients who had gastric bypass.4
Gastric bypass surgery is another weight loss procedure that combines both malabsorptive and restrictive mechanisms. However, the duodenal switch has been shown to be superior in weight loss outcome as well as the resolution of comorbid conditions. Prachand et al. reviewed the result of 350 super-obese patients 198 of whom had duodenal switch while the remaining 152 had gastric bypass. The average percentage excess weight loss at 12 months after the duodenal switch was 64.1% as against 55.9% after gastric bypass surgery. These figures rose to 71.6% and 60.1% at 24months respectively.5
In summary, the duodenal switch is one of the involved weight loss surgeries if not the most complex. Combining restrictive and malabsorptive mechanisms makes it the best option for super-obese individuals who requires more weight loss. Although it appears to have the highest complication rates, overall, the mortality rate is less than staying obese.