Single-anastomosis duodenal switch or loop duodenal switch (SADI) is an emerging surgical procedure for treating morbid obesity. It is a derivation of the double-anastomosis duodenal switch with comparable weight reduction and remission of obesity-related metabolic comorbidities. Single-anastomosis duodenal switch has reduced side effects and is a less complex operation.
SADI-S is a safe and effective standalone procedure for patients with a higher Body Mass Index (BMI) and/or severe metabolic syndrome. It is also a viable option as a secondary revisional procedure to save the primary one.
An expert bariatric surgeon begins the operation by cutting and redacting 80% of the stomach. The remnant stomach (100-150 mL) bypasses a sizable portion of the bowel (60-75%) by connecting the sleeve-shaped gastric pouch to the small intestine loop.
Single-anastomosis duodenal switch promotes greater weight loss and superior control of type 2 diabetes, hypertension, non-alcoholic fatty liver disease, and sleep apnea than gastric sleeve surgery and RNY gastric bypass.
This comprehensive guide covers the necessary information for those considering SADi-S bariatric surgery.
How SADi-S/SIPS Came About
Most bariatric surgeons avoided the traditional biliopancreatic diversion/duodenal switch (BPD-DS) due to the difficulty associated with the surgery and the magnified risks involved. The Single Anastomosis Duodeno-Ilean Bypass with Sleeve Gastrectomy (SADi-S) is a simplified version of the conventional biliopancreatic diversion with a duodenal switch.
The one connection duodenal switch was invented in 2007 as a more accessible alternative for doctors to negate these downsides of the mainstream BPD-DS. It trims the greater curvature of the stomach and shortens the intestinal absorption of food traveling from the stomach to the common channel.
The International Federation for the Surgery of Obesity and Metabolic Disorders (IFSO) and the American Society for Metabolic and Bariatric Surgery (ASMBS) have endorsed this new innovative operation for obesity cure and metabolic improvement.
SADI is becoming widely accepted as a first procedure as well as a re-operation option for failed sleeve gastrectomy.
What is SADi-S/SIPS Procedure?
Single Anastomosis Duodeno-Ileal bypass with Sleeve Gastrectomy (SADi-S) or Stomach Intestinal Pylorus-Sparing (SIPS) is a promising and moderately-aggressive laparoscopic surgery for severe obesity treatment. It has two mechanisms to help morbidly obese patients get a durable weight loss and eliminate underlying medical conditions.
- Restrictive Component – A large portion of the stomach (70%) is cut and stapled to reduce its size to create restrictions.
- Hypoabsorptive Component – The lengthy small intestine is divided into two by connecting it to the stomach (end-to-side anastomosis). Therefore, it reduces the time food is spent in the intestinal loop where nutrients are absorbed.
- Shorter Digestive Loop – The food intake from the stomach to the distal bowel has very little time to ingest before reaching the common channel.
- Longer Biliopancreatic Loop – Takes the bile from the liver to the common channel, where food gets exposed to digestive juices.
Expected Weight Loss Results
The SADI-S is a powerful procedure for losing body fat and overall comorbidity remission. Patients experience reduced appetite, small meal restrictions, and hormonal changes with less absorption of the intake of calories for a quick and durable weight loss. SADI-S patients can lose 40% of their total body weight within two years.
- 20% EWL in 3 months
- 41% EWL in 6 months
- 72% EWL & 37% TWL in 1 year
- 89% EWL in 18 months
- ~100% EWL & 40% TWL in 2 years
- 38% TWL in 5 years
* Excess Weight Loss (%EWL) & Total Weight Loss (%TWL)
→ Click here to try out our bariatric surgery weight loss calculator.
Although this type of duodenal switch is safer than its counterpart, it still has higher risks than other bariatric procedures. Operative complexities can be more dangerous due to the intestinal diversion caused by cutting and sewing the small intestine to other organs. This malabsorptive element escalates the possibility for bile, acid, and other stomach contents to spill into the peritoneum (abdominal cavity).
Although complications are unlikely, here are the more prominent hazards to be mindful of:
- Detrimental reaction to anesthesia (long operating time)
- Intestinal or duodenal leak
- Gastric leak
- Excessive blood loss
- Gastrointestinal blockage or bowel obstruction
- Anastomotic site stricture
- Blood clots
The main objective of the single-loop duodenal switch (SADI-S) is to reduce this danger by having only one “Y” connection. The risk of leakage and discharge of intestinal acids and other harmful juices into the peritoneum is significantly increased with every anastomosis.
Finding highly skilled loop duodenal switch surgeons with vast education, training, and experience can mean the difference between long-term success, failure, and even mortality.
Adverse Side Effects
As a newer alternative method to gastric sleeve and roux-en-y bypass, not all adverse events are known. Limited research and few studies make it difficult to predict the outcomes, post-op risks, and weight loss for patients.
- Malnutrition of minerals, vitamins, and other micronutrients
- 2 to 3 bowel movements daily
- Dumping syndrome, diarrhea
- Increased gas and bloating after eating
- Higher rate of intestinal obstruction
- Potentially difficult bowel movements
- Metabolic disorders
Advantages vs. Disadvantages
The loop duodenal switch has many advantages compared to alternative weight loss surgeries. Cormobidy resolution and high excess body fat loss are two cornerstones attracting super obese patients to the SADI-S procedure.
Specifically, health benefits include;
- Type II diabetes control
- Regulates and stabilizes a patient’s daily blood sugar
Patients must take bariatric multivitamins and minerals for the rest of their life. They may also experience foul-smelling stools, flatulence, and diarrhea if they eat fatty food.
|Nutritional Deficiency||Medium High||High||Low||Medium|
|Excess Weight Loss||85%||90%||70%||75%|
|Recovery||3 to 6 weeks||3 to 6 weeks||1 to 2 weeks||2 to 4 weeks|
|Surgery Duration||2.5 hrs||3 hrs.||1 hr.||2 hrs.|
SADI vs. BPD-DS
In novel SADIS surgery, the Roux-en-Y construction (BPD-DS) is replaced with a single duodeno-ileal anastomosis. SADIS has a lower risk of diarrhea, flatulence, nutritional deficiencies, and intestinal obstruction, frequently experienced with a standard duodenal switch. It is most suitable for patients with class III obesity (BMI > 40). Patients do not have reflux.
SADI vs. Sleeve
SADI is a more powerful procedure as it consists of a restrictive component like sleeve gastrectomy as well as a malabsorptive component like RNY gastric bypass.
- Higher excess body weight lost
- Less discipline is needed for permanent success
- Higher remission rates for diabetes, cardiovascular disease, and hypertension
- Re-sleeve revision is significantly less effective and has low rates of success
- Higher risk operation
- Reduced risk of acid reflux/GERD
- Strict long-term dietary restrictions
- Lifetime vitamin supplements are mandatory
SADI vs. Gastric Bypass
The pouch is tiny in the RNY bypass procedure, and the pyloric valve is detoured.
- Higher excess weight loss (%EWL)
- One anastomosis instead of two
- Higher remission rates for comorbidities
- Higher complications
- Large stomach size
- Newer procedure than bypass
- Lower risk of dumping syndrome
Patients must follow a strict pre-operative diet before surgery and a post-operative diet after.
The pre-operative diet duration is based on your Body Mass Index (BMI), ranging from 2 days up to 8 weeks long. The purpose is to shrink your liver to make it easier for the surgeon to operate safely and without interruption from internal organs. Any tobacco products, including vapes and cigarettes, should be avoided at least 1 month before surgery. Alcohol is not allowed at least two weeks before.
The diet consists of;
- Lean meats, low carbs, reduced sugar, and
- 2 days clear liquid diet: Stop consuming solid foods entirely and only intake fluids 48 hours before surgery. Includes protein shakes, clear broths (chicken, vegetable, beef, or bone), vegetable juice, sugar-free drinks, or other clear juice without pulp or carbonation, etc.
Learn more duodenal switch pre-operative diet guide.
Everyone transitions along the duodenal switch post-operative diet phases at a different rate as everyone’s body is different. Thus you should refrain from comparing your progress with other BPD/DS patients. You want to be in each phase for a minimum of 5 days with good toleration – no nausea, vomiting, abdominal pain, bloating, or diarrhea.
The post-op diet consists of;
- Phase one: clear liquids (starting day of surgery to day 5)
- Phase two: thick liquids (starts on day 5 thru day 10)
- Phase three: soft solids (starts on day 10 thru day 21)
- Phase four: solid foods (between 15 to 21 days)
Learn more about the duodenal switch post-operative diet stages here.
- Some patients have an intolerance to foods/drinks that contain:
- Spicy or greasy food
- Popcorn, milk/dairy (lactose)
- Red meats
- Teriyaki sauce
- Some patients experience difficulty in digesting foods, including:
- Pork chops
- Gummy candies
- Raw veggies
- Anastomotic leaks in SADi-S can be more problematic. Although rare, leaks are also prevalent in Sleeve Gastrectomy, Duodenal Stump (Anastomotic), or Duodenoileostomy.
- Patients have a higher chance of bile reflux than regular biliopancreatic diversion (BPD/DS).
- Sweet eaters feel dumping syndrome similar to RNY gastric bypass.
- Risk of low anemia, protein, and nutrients but less than DS.
- Patients must take life-long vitamin/mineral supplements and follow-up visits with their primary care physician.
Compared with the classical duodenal switch surgery (BPD/DS), SADi-S uses restrictive and hypoabsorptive techniques to drastically lower a patient’s BMI with a less complex operation.
The two-anastomosis biliopancreatic diversion with duodenal switch (DS-BPD) was invented in 1986 and modeled after the RNY gastric bypass. The core difference was a longer portion of the Y-shaped intestine rerouted while maintaining a larger stomach pouch. The most distal segment of the small bowel was reattached to the stomach. DS had a majority of intestines bypassed to reduce calories, vitamins, and minerals absorption.
The word “anastomosis” means a “surgical connection” – for example, cutting and end of the small intestine and attaching it to the surface of the skin to form a temporary stoma, or when pieces of the intestine and a piece of the stomach are brought together to form a continuous tube.
Medical Tourism for SADI
Most bariatric doctors, especially in the United States, are not educated or trained in performing the Duodenal Switch (DS) or any variations of it. Due to the rising prices and scarcity in the U.S. or Canada, North American patients swarm to countries like Mexico to undergo DS and its off-spring SADI-s.
The price for the duodenal switch in Mexico ranges from $7,000 to $10,000, dwarfing the average price in the U.S. – starting at $30,000 USD without insurance.
Advanced and specialized destination surgery outfits, like Mexico Bariatric Center, offer Duodenal Switch and SADi-S with experienced bariatric surgeons for a fraction of the cost.