Malabsorption occurs as a result of the incomplete uptake of calories and nutrients that you ingest. The food you ingest travels through the narrow stomach tube, and then enters into a 150cm segment of bypassed intestine. At the same time, your digestive enzymes (from the liver, gallbladder, and pancreas) will be diverted so that they only mix with this ingested food for the last 100cm of intestines. The final result is predominately fat calorie malabsorption. Although the weight loss is significant, oftentimes, these undigested fats cause gas and loose, foul-smelling bowel movements, called steatorrhea. (see disadvantages and risks).
The biliopancreatic diversion with duodenal switch operation can be performed either using the laparoscopic technique or by using the open technique. Advantages to the laparoscopic technique may include a faster recovery, lower risk of hernia, lower risk of wound infection, improved cosmesis, and less pulmonary complications. Discuss with your surgeon which technique is right for you.
The biliopancreatic diversion with duodenal switch provides durable weight loss that can approach 80-90% of your excess weight, but these results can vary significantly. Variables that can influence your outcome include the duration of time after the operation that you check your weight, the quality of your follow-up visits, your surgeon’s experience, your motivation and compliance, and your initial body mass index. In most patients (but not all) however, the weight loss is superior to both the Lap Band and to the Roux-en-Y gastric bypass. Associated with a BPDDS is a marked improvement (and in some cases complete resolution) of certain obesity-related comorbidities. Conditions that are known to resolve or improve dramatically include diabetes, sleep apnea, osteoarthritis, high blood pressure, reflux disease, and high cholesterol.
Disadvantages and Risks
Complications after the biliopancreatic diversion with duodenal switch are divided into those that happen early and those that happen later. Like after a Roux-en-Y, early complications can include (but are not limited to) anastomotic leak, acute and chronic wound infection, blood clots in the leg, pulmonary embolism, bleeding at the staple line, respiratory failure or pneumonia, and bowel obstruction. Late complications can include incisional hernia, bowel obstruction, internal hernia, stoma stenosis, marginal ulcers (though less so than after a Roux-en-Y), and gallstone formation.
A very important complication related to the malabsorptive component of the BPDDS is the potential for fat, mineral, and nutrient deficiencies. Vitamin A deficiency can lead to night blindness and vitamin D deficiency can lead to osteoporosis. Being a malabsorptive operation, the BPDDS requires life-long medical and nutritional follow-up and failure to comply with follow-up recommendations can lead to significant complications. Other complications specifically related to the BPDDS include foul smelling gas as a result of the fat malabsorption and chronic diarrhea.
Compared to having a Roux-en-Y gastric bypass, patients do not experience the “dumping syndrome” as often. The BPDDS is considered a permanent operation (as a significant portion of your stomach is removed from your body). However, in certain situations (severe protein-calorie malnutrition), the intestinal limb lengths can be revised or the bypassed segments of intestine reversed with a second major operation that carries its own additional risks (see revisional surgery). In addition, rapid weight loss can be associated with hair loss, which will usually resolve itself over time.
The risk of dying following a biliopancreatic diversion with duodenal switch is between 0.6% - 6%. The true mortality rates may vary between institutions and may depend both on your surgeon's experience as well as on your medical status and comorbidities. In certain situations, your surgeon may feel it is safer to perform this operation in two stages (two separate operations), which has been shown to decrease the overall mortality and morbidity rates, though longer-term studies are still needed. (see two-stage operations).
Make sure to review all of the risks and mortality rates with your surgeon carefully.