Duodenal Switch - Procedure, Indication, and Complications

Introduction

It was in 1987 that the duodenal switch procedure was described by DeMeester and his colleagues. Later the same year, Dr. Douglas Hess adapted this procedure to the treatment of severe obesity. It is a procedure that shows the greatest overall weight loss. It also offers the best control of systemic conditions like diabetes. Duodenal switch is less common because it is more complex, and patients are required to commit to lifelong vitamin supplements and a protein-rich diet.

What Is Duodenal Switch?

Duodenal switch is a weight-loss procedure that involves modifying the stomach and small intestine. This surgical procedure combines gastrectomy with an intestinal bypass. A gastrectomy is a surgical procedure that involves the removal of a part of the stomach. Intestinal bypass makes the path that the food takes through the intestine shorter. The duodenal switch restricts how much food the stomach can hold, and how much nutrition the small intestine can absorb from the food. This makes the procedure a malabsorptive one. Duodenal switch can also reduce the hunger hormones that the stomach and the small intestine normally produce. There are two types of duodenal switch:

1. The biliopancreatic diversion with a duodenal switch or the gastric reduction duodenal switch.

2. The loop duodenal switch.

Why Is Duodenal Switch Surgery Performed?

The duodenal switch is recommended for those who have clinically severe obesity (class III), which makes the person more prone to obesity-related problems. The obesity-related diseases include systemic syndromes such as high blood pressure, high sugar, and high cholesterol, which are precursors to kidney diseases, heart diseases, and diabetes. People are diagnosed with class III obesity if they have a body mass index (BMI) of 40 or higher, or they have a BMI of 35 and one of the related diseases. The duodenal switch surgery is recommended if the person has a BMI of 50 or higher, or a severe form of obesity-related disease. The duodenal switch, in comparison to other bariatric procedures, has more profound results, and it improves metabolic diseases such as type 2 diabetes. Duodenal switch has a higher rate of complications but in severe cases, the benefits outweigh the risks.

How Is the Duodenal Switch Surgery Done?

Before the Procedure - The person who is found eligible for the surgery will undergo the screening process. This involves standard medical testing to check whether the person is in good condition for surgery, screening for alcohol, drug, and tobacco use, and therapy to help him quit if required. Psychological screening or counseling to check for emotional and mental preparedness for the big life changes ahead and the discipline that the new digestive system will require. The person is enrolled in a seminar on bariatric surgery to ensure that they understand the procedure. After the person has met the benchmarks and scheduled the surgery, he will be put on a preoperative diet for a couple of weeks. Losing some weight before the surgery will make it safe.

During the Procedure -

• Duodenal switch surgery can be performed either as open or laparoscopic surgery. The laparoscopic surgical method is minimally invasive and is done using narrow tools through small incisions instead of opening the abdominal cavity. Patients and doctors prefer to use less invasive surgery techniques when possible, but some patients require open surgery to manage their condition. At times a surgery that begins laparoscopically may need to be converted to open surgery.

• Duodenal switch surgery is a two-step surgical procedure that begins as a sleeve gastrectomy. Some patients may have this sleeve gastrectomy as a standalone procedure, but if they have it as a part of the duodenal switch, the doctor will remove slightly less of their stomach, about 65 %. The next step is the intestinal bypass, which can be done in the same surgery or as a second surgery, sometimes later. Two separate surgeries are advised if the doctor believes this would be safer for the patient based on the conditions.

• There are two methods for the duodenal switch, namely, the biliopancreatic diversion (original) and the modified loop duodenal switch. The difference is in the second part of the surgery, the intestinal bypass procedure. Both methods start by dividing the small intestine near the top, in the section called the duodenum, then the lower section of the small intestine is brought up to get it attached to the top, bypassing the middle. This is how the duodenum is switched with a lower part of the small intestine.

• The original duodenal switch bypasses most of the small intestine, about 80 to 90 %. This acutely reduces how much nutrition the small intestine can absorb from the food leading to significant weight loss but also a high risk of malnutrition. The modified loop method bypasses about 50 to 60 % to reduce the risk of malnutrition. Another difference is that the original method divides and reconnects the small intestine in two different places. The loop duodenal switch is simpler and has only one division and reconnection.

After the Procedure - The patient will have frequent follow-up appointments with their regular doctor for up to two years and periodic appointments for the rest of their life. The first two years will witness dramatic weight loss. During this time, the doctor will continuously monitor the progress and health. Patients will go through regular blood tests for nutritional deficiencies for the rest of their life. Patients will be advised to take daily nutritional supplements for life as it is essential to prevent malnutrition.

What Are the Complications of Duodenal Switch?

The risks of duodenal switch surgery are the same as those of any other abdominal surgery. They include:

• Excessive bleeding.

• Blood clots.

• Reaction to anesthesia.

• Wound infection.

Complications specific to duodenal switch surgery are:

• Small Bowel Obstruction - Scar tissue causes obstruction or narrowing of the small intestine.

• Hernias - It occurs when one of the organs pushes through a gap in the muscle wall.

• Anastomotic Leaks - Anastomosis involves surgically severing and reconnecting the small intestine. Serious infection can occur inside the abdominal cavity if the connection point leaks.

• Malnutrition - It is preventable and treatable as long as the concerned doctor is attentive to the risk.

• Diarrhea - It is a side effect of malabsorption in the small intestine. The small intestine won’t be able to digest food as properly as before or extract as much water.

• Bile Reflux - It is more of a risk with the modified duodenal switch. The original method is designed to prevent it.

• Gallstones - Rapid weight loss sends a huge load of cholesterol to the liver to process.

Conclusion

Duodenal switch surgery is a surgical procedure for weight loss. The duodenal switch surgery shows an average weight loss of 80 % of excess weight over a two-year period. The duodenal switch surgery is expected to have a 90 % of success rate for weight loss. Since it is a complicated and extreme surgical procedure, it is less commonly performed.