Duodenal Switch Surgery for Weight Loss

The duodenal switch (DS) or biliopancreatic diversion with duodenal switch is a tried-and-true metabolic surgery with a few decades of history. However, the DS has only recently regained popularity as a surgical option for patients with severe morbid obesity – those with a BMI over 45 or 50. When it was first performed in the late 1980s, we knew far less about abdominal anatomy than we do today. As such, patients undergoing the DS often had significant gastrointestinal issues, including flatulence, foul-smelling stool, and diarrhea.

The DS soon brought about a new standalone procedure. In 2012, the first part of the DS, known as the gastric sleeve or sleeve gastrectomy, was approved by CMS as a covered standalone procedure. Before then, extremely obese patients would undergo the DS as a two-stage procedure, the first of which was a gastric sleeve, followed by the intestinal bypass. However, many patients with relatively lower BMI – those between 35 and 45 – did well with the sleeve alone.

Today, with standardization in technique and technology, the DS has become a more prevalent surgery because of its exceptional effectiveness and the fact that we’ve reduced many of the symptoms and side effects associated with it.

How the duodenal switch works

As mentioned above, the first part of a duodenal switch is a gastric sleeve. During this portion of the procedure, we cut away and remove a portion of the stomach pouch so that only 25% or so remains. This provides excellent restriction and removes the stomach’s fundus, the primary production center of the hunger hormone known as ghrelin. Removing this section of the stomach offers a twofold mechanical and hormonal benefit.

During the second part of the procedure, the small intestine is cut on the top end just below the stomach valve (pylorus) and on the bottom end near the large intestine. The ileum or lower small intestine is brought up to connect to the stomach pouch, bypassing more than half of the organ (and the entire jejunum) and reducing the number of calories absorbed. The lower side of the ileum is reconnected to itself near the large intestine, allowing pancreatic juices to enter the common channel for more normal digestion.

The procedure requires just over an hour of operative time. Patients are typically kept in the hospital for one night for observation unless certain health risk factors require a longer stay.

Benefits and expectations of the duodenal switch

• As mentioned above, the DS offers the most significant excess weight loss potential of any available bariatric surgery. Its combination of mechanical, hormonal, and malabsorptive weight loss mechanisms makes it an excellent option for patients with very high BMIs.
• Modern technique means that patients experience fewer adverse gastrointestinal effects but will have to remain on a multivitamin and other supplements (D, B12, Calcium, etc.) as necessary because of the malabsorption.
• Because a gastric sleeve is performed, patients tend to have fewer hunger pangs, especially during the first year and a half to two years after surgery, making initial weight loss easier and faster. However, it is essential to remember that ghrelin will start to be produced, albeit at lower quantities, by the small intestine, making improved diet and exercise a must to maintain weight loss in the long term.
• Any metabolic surgery, including the DS, aims to improve or resolve many of the diseases associated with morbid obesity. To that end, the DS is an excellent option. The most significant consideration, however, is that while most obesity-related diseases are improved, some patients may experience worsened gastroesophageal reflux disease (GERD) due to the increased pressure within the sleeve. This occurs in fewer than 10% of patients.
• Of course, everybody wants to know how much weight they should expect to lose. As with any procedure, the willingness and ability of the patient to follow their postoperative instructions make their weight loss success truly up to them. That said, on average, patients lose between 70% and 90% of their excess body weight after a switch.

DS as a Revisional Procedure

The DS can be an excellent revisional procedure and get patients back on track towards their goals. If revising a band, the band is simply cut away, and a DS is performed as if it were a primary surgery. If revising a gastric sleeve and there are no issues with the sleeved stomach, your surgeon will add the appropriate dual anastomosis intestinal bypass.

Is the DS right for me?

The best way to know if the DS is your best option is by consulting a knowledgeable and qualified bariatric surgeon like Dr. Tsuda. 

There are a few possible alternatives to consider. For patients with poorly controlled diabetes or acid reflux, a gastric bypass may be more suitable, though average excess body weight loss is somewhat lower. For some patients, especially those who have favorable bariatric surgery insurance coverage, a single anastomosis version of the DS, known as the Single Anastomosis Duodeno-Ileostomy or SADI, may be an excellent option that achieves about 90% of the excess body weight loss potential of a DS with fewer risks. 

The bottom line

The Duodenal Switch or DS is a major bariatric procedure with exceptional excess body weight loss results that is growing in popularity, especially for patients with severe obesity – those with a body mass index over 45-50. While the DS isn’t right for everyone, it can be a life-changing option for those who qualify. Speak to a qualified Bariatric Surgeon to learn whether the DS is right for you.