Duodenal Switch vs. Gastric Bypass: Which is Right for You?

There are often many comparisons between Roux-en-Y Gastric Bypass (RYGB) and Duodenal Switch w/ BilioPancreatic Diversion (DS/BPD) – a much newer surgical procedure. Both have similar methods of inducing weight loss, but slight differences that make it unique for each individual.

What is Duodenal Switch and Gastric Bypass Surgery?

The Roux-en-Y Gastric Bypass (often called “gastric bypass”) is one of the most commonly performed weight loss surgeries in the U.S. and Canada. This procedure reduces stomach size and reroutes a portion of the digestive tract, limiting calorie absorption. While effective in the short term, weight regain can occur over time, and patients may need to follow long-term dietary guidelines.

In comparison, the Duodenal Switch with Biliopancreatic Diversion (BPD-DS) offers one of the most effective outcomes for both significant weight loss and control of metabolic conditions like diabetes. This surgery involves reducing the stomach size and rerouting food away from most of the small intestine, minimizing calorie and nutrient absorption. Although this leads to sustained weight loss and metabolic benefits, BPD-DS carries higher risks, including nutritional deficiencies, due to its complexity.

Currently, duodenal switch surgery is more common in Europe, but its popularity is growing in the U.S. due to its long-term benefits in weight management and metabolic health.

Similarities Between Duodenal Switch and Gastric Bypass

Both gastric bypass and duodenal switch surgeries combine two key approaches:

• Reducing stomach size to limit food intake and help patients feel full more quickly.
• Rerouting food away from parts of the digestive tract to reduce calorie absorption.
• Hormonal Changes: Both surgeries alter gut hormones, which can help reduce hunger, improve satiety, and regulate blood sugar levels, making both procedures effective for managing type 2 diabetes.
• Permanent Procedures: Both duodenal switch and gastric bypass are generally irreversible surgeries. They involve permanent changes to the stomach and digestive system structure.
• Surgical Techniques: Both are typically performed laparoscopically (minimally invasive), which usually results in shorter recovery times and reduced risk of complications compared to open surgery.
• Long-Term Dietary and Lifestyle Changes: Both require patients to make lasting changes in their diet, physical activity, and lifestyle habits to achieve and maintain weight loss and prevent nutrient deficiencies.
• Nutritional Supplements: Due to the malabsorption in both procedures, patients often need to take vitamin and mineral supplements long-term to prevent deficiencies in nutrients like vitamin B12, iron, calcium, and vitamin D.
• Follow-Up Care: Both surgeries require ongoing medical follow-up to monitor weight loss progress, nutritional status, and potential complications. Regular check-ins help ensure patients maintain their health and meet their weight loss goals.

Despite these similarities, the duodenal switch bypasses a larger portion of the small intestine, leading to significantly less calorie and nutrient absorption compared to gastric bypass. While the small stomach pouch created in gastric bypass can stretch over time, leading to potential weight regain, the stomach configuration in the duodenal switch tends to maintain its size more consistently, reducing the likelihood of pouch stretching. This makes the duodenal switch especially effective for long-term weight maintenance and metabolic control.

Comparing Duodenal Switch and Gastric Bypass in Key Areas

1. Method of Weight Loss

• Gastric Bypass: gastric bypass surgery features a reduction in stomach size and alteration of the digestive process. Gastric bypass surgery involves the construction of a small pouch in the proximal part of the stomach that is then connected to your small intestine (the jejunum) with a section of small bowel of varying lengths; the pouch is separated from the remaining part of the stomach with staples.
• Duodenal Switch: Duodenal switch surgery combats weight loss in three different ways.
  – Initially, a sleeve gastrectomy is done. This features the removal of a large portion of the stomach with a stapling device, leaving behind a narrow tube, or sleeve, from the top to near the bottom of the stomach. With the reduction in stomach size, you will eat less and feel full faster.
  – In the second part of the procedure, food is routed away from the duodenum. The duodenum is the first portion of the small intestine and is the natural path of digestion. With the routing away of food from the duodenum, the amount of nutrients and calories absorbed by the body is drastically reduced.
  – The final part of the duodenal switch procedure involves a change in the normal way that bile and digestive juices break down food. This reduces the number of calories absorbed resulting in further weight loss. One end of the small intestine is linked to the duodenum (the first part of the small intestine), close to the end of the stomach.

2. Stomach Alterations

• Gastric Bypass: There is the creation of a new stomach known as the stoma. The main stomach is bypassed, allowing the creation of a new stomach known as the stoma. The stoma is made from the intestines.
• Duodenal Switch: Instead of the creation of a new stomach, duodenal switch features a reduction in the size of the original stomach. More than 80% of the stomach is removed – this is similar to gastric sleeve surgery.

3. Changes in the Intestine

• Gastric Bypass: The intestine is literally “cut and bypassed.” There are a reconnection and rerouting of the stoma to bypass a large portion of the intestines. This causes a reduction in the absorption of nutrients and calories.
• Duodenal Switch: Here, the intestines are not “cut and bypassed.” They are “switched!” What this implies is that the new stomach created is switched to the lower end of the small intestines. This is done to alter the digestion process and reduce food absorption.

4. Time Required for Surgery

• Gastric Bypass: gastric bypass requires just two hours operating time. In extreme cases, it could be up to three hours.
• Duodenal switch: Duodenal switch is a more complex and risky procedure. It takes a minimum of four hours to complete.

5. Average hospital stay

• Gastric Bypass: 2 to 3 days
• Duodenal Switch: 3 days

6. Recovery Time

• Gastric Bypass: 2 – 3 weeks
• Duodenal Switch: 3 – 4 weeks

7. Advantages

• Gastric Bypass: gastric bypass has been performed hundreds of thousands of times. Hence, it is popular sort of, and its effects are well known.
• Duodenal switch: Weight loss is 70% – 80%.Weight loss is experienced within a year of surgery. The duodenal switch procedure has a great advantage in that it can drastically reduce weight gain by about 150 pounds. This is because it restricts the quantity of food you can consume at a time and also how much calories you can absorb at a time. The advantage it has over gastric bypass is that the weight loss is sustained over many years.

8. Disadvantages

• Gastric Bypass: Major and complicated surgery with associated risks. Bleeding, vomiting, and leakage may occur. There is also need for daily supplements and vitamins.
• Duodenal Switch: The surgical process is non-reversible. It comes with attendant surgical complications. A major disadvantage of duodenal switch surgery is that it carries with it greater health risks. Patients with duodenal surgery spent more time in the operating theatre compared to gastric bypass beneficiaries. They also experienced more blood loss than the gastric bypass group. Post-surgery hospital stay was twice as long as that of the gastric bypass beneficiaries. The risk of death and development of nutritional deficiency was also higher compared to gastric bypass. Despite the risks involved, it comes with the best potential for reward.

9. Description of Surgery

• Gastric Bypass: Gastric bypass surgery involves the construction of a small pouch in the proximal part of the stomach that is then connected to your small intestine (the jejunum) with a section of small bowel of varying lengths; the pouch is separated from the remaining part of the stomach with staples.
• Duodenal Switch: Long vertical sleeve-like pouch (about 4-5 oz or 120-150cc). The first portion of the small intestine, duodenum, is attached to the last 6 feet of small intestine, where food and digestive juices are remixed after 12 feet. Moderate restriction of the volume of food that can eat. Provides moderate malabsorption of fat, which can cause bloating and diarrhea.

10. Post-surgery Dietary Information

• Gastric Bypass: Patients are required to eat thrice daily. The meals must be of small portions; Sugar and fats must be avoided to prevent dumping syndrome; there is a need for intake of protein and vitamin supplements to avoid deficiency. Menstruating women must include the following as part of their supplements – iron, multivitamin, calcium, and vitamin B12.
• Duodenal Switch: Patients must eat thrice daily; just like in gastric bypass, patients must strictly take their protein and vitamin supplements. Menstruating women should include calcium, multivitamin, iron, and ADEK vitamins in their supplements.

11. Surgery Results

• Gastric Bypass: patients can expect to lose up to 70% of excess weight; people with a body mass index of 33-55 are the best candidates for gastric bypass.
• Duodenal Switch: It is most suited for those with a body mass index of 50 kg/m² and above. Patients with a body mass index lesser than 45 kg/m2 may lose excess weight if they partake of duodenal switch surgery. Also, the duodenal switch is riskier than any other form of weight loss surgery.

Research Studies

The long-term effects of bariatric surgical procedures on overall health and mortality are still uncertain, hence more research studies are necessary. The findings of these studies are important considering the rapid increase in the number of bariatric surgery operations performed in the United States and worldwide, and may have significant repercussions for the estimated 31 million U.S. individuals meeting criteria for bariatric surgery.

Journal of the American Medical Association

A recent study investigating the long-term benefits of obesity-related surgeries has found that the procedure encourages sustained weight loss as compared to other means of combating obesity. The study published in the Journal of the American Medical Association looked closely at the case of 1,156 participants between the ages of 18 and 72 with morbid obesity cases. Study samples were divided into three groups:

1. A control group of 417 participants who were denied surgery, though they wanted it.
2. Another group of 418 participants who underwent surgery.
3. A second control group of 321 participants who expressed no desire for surgery.

After six years, it was discovered that the group that underwent the gastric bypass surgery recorded significant improvements in cardiovascular health and weight loss compared to those who opted for no surgery. There was also an improvement in heart disease and metabolic risk factors in those who underwent the surgery. They had a lower chance of having high cholesterol or high blood pressure when compared to those who did not.

Archives of Surgery

A recent research published in the Archives of Surgery and conducted by researchers at the Fort Lewis Madigan Army Medical Center has discovered that there may be a rival for gastric bypass surgery which has held sway as the gold standard surgical procedure for obesity. This new rival is none other than Duodenal Switch Surgery. Duodenal switch surgery is less common but more complex than gastric bypass surgery.

Studies have shown that duodenal switch and gastric bypass surgeries are effective in the treatment of morbidly obese patients. Duodenal switch surgery is usually reserved for individuals with a BMI greater than or equal to 50 kg/m². It is also used where other weight loss surgeries have failed.

Duodenal switch surgery reduces the ability of the patient to absorb calories. This implies that with the duodenal switch, the patient can lose more weight when compared to other forms of surgery. However, there is the risk of being nutrient deficient afterward. Some of these nutritional deficiencies can be life-threatening if left untreated.

Researchers at Fort Lewis compared 1,545 patients with an average Body Mass Index of 52 who underwent a duodenal switch procedure and 77,406 beneficiaries of gastric bypass surgery (having an average BMI of 48). This was done between 2007 and 2010. The former were considered as super obese while the latter were classified as morbidly obese. At the two-year follow-up, it was observed that beneficiaries of the duodenal switch surgery had lost their body weight in excess of 79% compared to the beneficiaries of gastric bypass, who maintained a 67% loss. It was also observed that about 20% of gastric bypass beneficiaries still retained 50% of their excess weight by both the first and second-year follow-ups – constituting a failure of the gastric bypass weight loss surgery when compared to the duodenal switch surgery, which had only 6% to 9% failure rates at 1 and 2 years respectively.

It was also observed that duodenal switch patients had a much better chance of controlling obesity-related conditions like diabetes, sleep apnea, and high blood pressure after surgery.

A major disadvantage of duodenal switch surgery is that it carries with it greater health risks. Patients with duodenal surgery spent more time in the operating room compared to gastric bypass beneficiaries. They also experienced more blood loss than the gastric bypass group. Post-surgery hospital stay was twice as long as that of the gastric bypass beneficiaries. The risk of death and development of nutritional deficiency was also higher compared to gastric bypass. Despite the risks involved, it comes with the best potential for reward.

References:

• Researchers Take a Closer Look at Weight Loss Surgeries
• Gastric Bypass vs Duodenal Switch Surgery Comparison