Obesity Academy

The duodenal switch is a type of weight loss surgery that alters both your stomach and small intestine. This procedure involves removing a portion of your stomach, which is known as a gastrectomy, and rerouting your intestines to create a shorter pathway for food. This results in limiting the amount of food your stomach can accommodate, as well as reducing the quantity of nutrients that your small intestine can absorb from the food, classifying it as a "malabsorptive" procedure. Additionally, the surgery diminishes the production of hunger hormones that are typically produced by your stomach and small intestine.
Currently, there are two distinct types of duodenal switch procedures that are being performed. The first version is referred to as the biliopancreatic diversion with a duodenal switch, or sometimes the gastric reduction duodenal switch, and it has a more extensive history and research backing. On the other hand, the loop duodenal switch is a newer variation that was devised to streamline the procedure and decrease the likelihood of complications.

Why is it done?

If you have severe obesity (class III), which puts you at risk of or already experiencing obesity-related diseases such as high blood pressure, high cholesterol, and high blood sugar, your healthcare provider may recommend bariatric surgery. A BMI of 40 or higher, or a BMI of 35 with related diseases, could lead to a diagnosis of class III obesity. If your obesity and related conditions are more severe, with a BMI of 50 or higher or a severe form of obesity-related disease, your healthcare provider may recommend duodenal switch surgery. This procedure has the most profound weight loss effects among all bariatric surgeries and greatly improves metabolic syndromes like Type 2 diabetes. However, it also has a higher complication rate. Nevertheless, for people with severe conditions, the benefits of the duodenal switch outweigh the risks.

How does the duodenal switch compare with other common weight-loss surgeries?

Compared to other bariatric surgeries, the duodenal switch is performed less frequently because it is more complex and radical. It involves a greater amount of cutting and suturing in your digestive system and removes or bypasses more of your gastrointestinal tract than other procedures. This makes it somewhat more dangerous for complications, both during and after the procedure. However, the duodenal switch is also the most successful method for weight loss surgery, with the most significant and enduring outcomes.

What is the difference between duodenal switch vs. gastric bypass surgery?

The duodenal switch and the Roux-en-Y gastric bypass are similar weight loss procedures. Both involve decreasing the size of your stomach to limit the amount of food you can eat and bypassing a portion of your small intestine to reduce the number of nutrients and calories absorbed (weight loss through malabsorption). However, the duodenal switch places more emphasis on malabsorption, while the Roux-en-Y gastric bypass leans more towards restriction. The duodenal switch reduces stomach size by approximately 60% to 70% (compared to 70% to 80% with the Roux-en-Y), but it bypasses around 75% of the small intestine (versus approximately 30% with the Roux-en-Y).

What is the difference between the duodenal switch vs. the gastric sleeve?

The duodenal switch is a two-part surgery that begins with a gastric sleeve. In fact, the sleeve gastrectomy was initially created as the first step in the duodenal switch procedure. The gastric sleeve surgery reduces the stomach to a small, tubular “sleeve,” which is roughly 75% of its original size. The second part of the procedure, which bypasses a significant portion of the small intestine, results in greater weight loss than the gastrectomy alone but also increases the likelihood of adverse effects.

How much weight can you lose with a duodenal switch?

On average, individuals who undergo the duodenal switch procedure experience a weight loss of 80% of their excess weight within two years after surgery. This amount of weight loss is significantly higher than the average weight loss achieved with other bariatric surgeries, which usually ranges from 50% to 60%. Furthermore, people who have the duodenal switch procedure tend to maintain their weight loss for a longer period of time. Studies have demonstrated that, on average, they maintain a weight loss of 70% of their excess weight over a period of ten years. This implies that if you were 200 lbs. overweight, you could lose an average of 140 lbs and maintain that weight loss.

How effective is the duodenal switch?

Duodenal switch surgery has a 90% success rate for weight loss, meaning that 90% of people lose at least half of their excess weight, with many losing more. The success rate for remission of related health conditions is also high, with as many as 90% of people with Type 2 diabetes able to stop taking their medications after the surgery. Due to its higher success rate, some people who do not lose enough weight with other bariatric surgeries may opt for revision surgery with the duodenal switch.

What obesity-related conditions can duodenal switch surgery help treat?

Obesity raises the risk of disease in nearly every body system. Duodenal switch surgery helps reduce the risk and the effects of developing these diseases, including:

• Cardiovascular disease: hypertension, arterial disease, vascular disease, heart attack, stroke.
• Respiratory diseases: asthma, obstructive sleep apnea, obesity hypoventilation syndrome.
• Metabolic diseases: hyperlipidemia, insulin resistance and diabetes.
• Gastrointestinal diseases: nonalcoholic fatty liver disease, nonalcoholic steatohepatitis.
• Reproductive diseases: polycystic ovary syndrome, infertility.
• Musculoskeletal pain: back strain, weight-bearing osteoarthritis.
• Cancer: especially colorectal cancer and liver cancer.

What happens before duodenal switch surgery?

If your healthcare provider believes you are a good candidate for surgery, you will enter a screening process. This will likely involve:

• Standard medical testing to make sure you are in good condition for surgery.
• Screening for alcohol, tobacco and drug use and therapy to help you quit if necessary.
• Psychological screening or counseling to make sure you are mentally and emotionally prepared for the big life changes ahead and the discipline that your new digestive system will require.
• Demonstrating that you have tried and failed to lose weight by other means.
• Enrolling in a seminar on bariatric surgery to make sure you understand what’s involved.

Once you’ve met these benchmarks and scheduled your surgery, your healthcare provider will put you on a preoperative diet for a couple of weeks. Losing a little weight before your procedure will make it safer.

How is a duodenal switch done?

• Open vs. Laparoscopic: Duodenal switch surgery can be done as a traditional open surgery or laparoscopic surgery. The laparoscopic method is less invasive, using narrow tools through small “keyhole” incisions instead of opening your abdominal cavity. Surgeons and patients often prefer to use minimally invasive surgery techniques, when possible, but some people may require open surgery to manage their conditions. Sometimes a surgery that begins as laparoscopically may need to convert to open surgery.
• Two steps: The duodenal switch is a two-step surgery that begins with a sleeve gastrectomy. Some people have the sleeve gastrectomy as a standalone procedure, but if you have it as part of a duodenal switch, your surgeon will remove slightly less of your stomach — about 65%. The next step in the process, the intestinal bypass, can be done in the same surgery or as a second surgery sometime later. Your surgeon may advise two separate surgeries if they believe this would be safer for you based on your conditions.
• Two methods: There are two methods to the duodenal switch: the original (biliopancreatic diversion) and the modified (loop) duodenal switch. The differences are in the second part of the surgery — the intestinal bypass. Both versions begin the bypass by dividing your small intestine near the top, in the section called the duodenum. Then they bring a lower section of your small intestine up to attach to the top, bypassing the middle. In this way, the duodenum is “switched” with a lower part of your small intestine.

The original duodenal switch bypasses most of your small intestine — about 80-90%. This drastically reduces how much nutrition your small intestine can absorb from your food, leading to significant weight loss but also a high risk of malnutrition. The modified (loop) version bypasses only about 50-60% to reduce this risk. The other difference is that the original duodenal switch divides and reconnects your small intestine in two different places. The modified duodenal switch is simpler, with only one division and reconnection.

What happens after duodenal switch surgery?

Your healthcare provider will schedule regular follow-up appointments with you for the first one to two years after your duodenal switch surgery, and periodic appointments thereafter for the rest of your life. The initial two-year period will be the time of most significant weight loss, and your provider will monitor your progress and health closely during this time. You will need to have regular blood tests to check for any nutritional deficiencies and take nutritional supplements every day for the rest of your life to prevent malnutrition.

Is duodenal switch surgery safe?

The risks of duodenal switch surgery are similar to those of any other abdominal surgery. They include:

• Wound infection
• Excessive bleeding
• Reactions to anesthesia
• Blood clots

Complications more specific to gastric bypass surgery can include:

• Hernias. Hernias occur when one of your organs pushes through a gap in your muscle wall.
• Small bowel obstruction. Scar tissue can cause narrowing or obstruction of your small intestine.
• Anastomotic leaks. The intestinal bypass involves surgically severing and reconnecting your small intestine (anastomosis). If the connection point leaks, it can lead to serious infection inside your abdominal cavity.

These are rare. Minimally invasive techniques reduce these risks, and so does the modified version of the duodenal switch. The risk of death from duodenal switch surgery is a little over 1%.

What are the advantages of the duodenal switch?

• Highest success rate of all bariatric surgeries with greatest overall weight loss.
• Improves hunger, metabolism, blood lipid and blood sugar levels long-term.
• Total remission of Type 2 diabetes.
• Slightly larger gastric sleeve than other procedures, allowing for slightly larger meals.
• Rarely causes dumping syndrome, so you don’t have to completely avoid sugar or fats.
• Longer life with significantly reduced risk of death by any cause.

What are the possible long-term complications or side effects of duodenal switch surgery?

• Malnutrition. This is the most important risk of duodenal switch surgery. However, it is preventable and treatable as long as you and your healthcare provider stay attentive to the risk. Now that your small intestine will not be able to absorb as much nutrition from your food, you’ll have to take nutritional supplements daily. Your healthcare provider will also continue to test you periodically for nutritional deficiencies for the rest of your life. Deficiencies are possible even when you do take supplements, but as long as your healthcare provider catches them, they can treat them.
• Diarrhea. This is another side effect of malabsorption in your small intestine. Your small intestine won’t be able to digest your food as thoroughly as before or extract as much water. This can make for loose, smelly stools and gas. It can also make stools more frequent. Some people find that these side effects level out after their digestive systems adjust to the surgery.
• Bile reflux. Surgery that affects the pyloric valve, the opening between your stomach and your small intestine, can cause it to malfunction. If the pyloric valve doesn’t close properly, one possible result is bile reflux. That means the bile that your gallbladder sends to your small intestine to help digest food can backwash into your stomach. Bile reflux can erode your stomach lining, leading to gastritis and stomach ulcers. Bile reflux is more of a risk with the modified duodenal switch (although a low risk). The original is designed to prevent it.
• Gallstones. Rapid weight loss sends a large load of cholesterol to your liver to process. When your liver sends bile to your gallbladder, it carries extra cholesterol with it. This extra cholesterol can build up in your gallbladder, forming cholesterol gallstones. Gallstones don’t always cause problems, but they can be dangerous if they travel and get stuck in your bile ducts. Your healthcare provider may give you a prescription medication to prevent gallstones after surgery.

What is the weight-loss timeline following duodenal switch surgery?

Weight loss will vary from person to person, but there are some general trends. The initial three months after the surgery will have the most rapid weight loss, where you can expect to lose approximately 30% of your excess weight. The rate of weight loss will slow down over the following three months. By the end of the first year, you may lose around 50% to 75% of your excess weight. Typically, weight loss peaks between 12 to 18 months after the surgery, where it can reach 75% to 85% of your excess weight.

What is the recovery time from duodenal switch surgery?

After the surgery, you will probably need to stay in the hospital for a few days, followed by a few weeks of recovery at home before you can resume work. During the recovery period, your body will undergo significant changes, including rapid weight loss. You will also have to adhere to strict dietary instructions for what and how you eat during your recovery period. This is to allow your digestive system to recover and adapt to the new changes. It may take one to two weeks to progress through each stage on your way back to a normal diet, including:

• Clear liquid diet
• Full liquid diet
• Pureed foods
• Soft diet