Single Anastomosis Duodenal Switch




Single Anastomosis Duodeno-Ileal Bypass

What Is A SADI-S (Single Anastomosis Duodeno-Ileal Bypass)?

The Single Anastomosis Duodenal Switch or Single Anastomosis Duodeno-Ileal Bypass (SADI-S) is a weight loss procedure that was recently changed by the ASMBS from investigational to an approved weight loss surgery.  The procedure is a sleeve gastrectomy with a very aggressive bypass of a large portion of the small intestine.

The procedure has shown in recent studies a significant weight loss and dramatic resolution of weight-related comorbidities.

Patients after a SADI-S can achieve between 90-100% EWL (excess weight loss) between 12-18 months. Compare that with 60-80% EWL for a sleeve gastrectomy and/or a Roux en Y gastric bypass and you can see how patients can benefit from this type of procedure.

The loop duodenal switch or SADI-S just like the Roux en Y gastric bypass has a restrictive component and a malabsorption component. The restrictive component comes from a sleeve gastrectomy and the malabsorption component comes from bypassing most of the small bowel except the last 300-350 cm.

The patient will not only consume less food but also the absorption of the nutrients is highly limited.  This is good for weight loss and resolution of multiple weight-related comorbidities but it also increases the risk of nutrients, vitamins, and protein deficiencies in the future.  For this reason, SADI-S is not an operation for everyone. The patient needs to be highly compliant with vitamin monitoring and replacement for the rest of their life. 

In the Spotlight

Advantages & Disadvantages


  • Short hospital stay
  • Fantastic weight loss
  • Low risk of marginal ulcers
  • Short surgery time
  • Resolution of comorbidities


  • Irreversible
  • Potential for leak
  • Potential for narrowing
  • Potential for reflux
  • Potential for dumping syndrome

Surgical Technique

How Is A Single Anastomosis Duodenal Switch Done?

The single incision duodenal switch is done laparoscopically, Robotic or with five small incisions in the upper part of your abdomen. The largest incision is approximately 15 mm, this is usually the incision where the cut portion of the stomach is removed from the abdomen.

Using a high definition camera, monitor and long special instruments a large portion of the stomach is removed. The stomach is divided with a special mechanical stapler that is designed to cut and sew the stomach. This part of the surgery is identical to a sleeve gastrectomy.

The second portion of the surgery is to divide the duodenum past the pylorus. This is also done with a stapler. The junction between the small bowel and the colon is identified and the small bowel is run proximally to 300-350 cm. This part of the small bowel is then reconnected to the duodenum/stomach stapled line.

An endoscopy is performed to evaluate the staple line and to make sure that no leaks are present.

The surgery takes approximately 1.5 to 2 hours. The patient is then awakened from general anesthesia and is transported to the recovery room.

Long Term

Life After A SADI-S or Loop DS

Most patients after surgery will be admitted to the hospital for two days. The day after surgery you will be started on sips of water. The second day you will be advanced to sips of protein drinks. After discharge, you will strictly follow the diet that was given to you prior to surgery during the preop class given by the bariatric coordinator. The diet progresses from liquids, to puree, soft food and eventually to regular food in a period of 6-8 weeks.

After discharge, you should stay away from any heavy lifting or any excessive physical activities for 4-6 weeks.  Most patients will return to work 2-4 weeks after surgery. The routine follow up with Dr. Angel Caban is 2 weeks after surgery followed by visits every 3 months for the first year.

Weight loss after a SADI-S or Loop DS tents to be very rapid. You should expect to lose between 80-100% of your unhealthy or excess weight. As mentioned above the maximum weight loss is usually seen at 12-18 months. 

The first 3 months after surgery are crucial for your success. You will lose the majority of the weight in this period. It is imperative that you put great effort during the first quarter to lose as much weight as possible. Weight loss starts to taper down after the first 3 months.

Vitamin replacement needs to be a daily routine. The patient should focus on eating healthy and more natural foods to maintain normal vitamin, minerals, and protein levels.  The patient should also get labs done routinely to verify that adequate levels of vitamins and minerals are been maintained. 


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