Single Anastomosis Duodenal Interposition (SADI)

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Single Anastomosis Duodenal Interposition (SADI) in Houston

Single anastomosis duodenal interposition (SADI), also referred to as one anastomosis duodenal switch or Loop DS, is an adaptation of the standard duodenal switch procedure.  It is most beneficial for patients in the morbidly obese and super morbidly obese weight range with or without associated diabetes and lipedemia.

This operation has been thoroughly evaluated by the American Society for Metabolic and Bariatric Surgery (ASMBS) and recently introduced as an important option for both primary and revisional operations (2). SADI can be a primary weight loss surgery or a revisional operation to an existing sleeve. This procedure may be the most effective next step in achieving  long-term weight loss. 

For a personal consultation to discuss a SADI procedure, call Texas Endosurgery Associates. Ricardo Bonnor M.D., FACS, FASMBS is an experienced surgeon in primary and revisional bariatric surgery in Houston, Texas. Call (281) 579-5638 to arrange your appointment.

Excess Weight: What are the Risks?

Obesity is a leading cause of poor health in the United States. A BMI over 40, or exceeding 100 lbs over ideal body weight, significantly increases your chance of developing  health problems. 

Over time, excess weight can cause or will exacerbate numerous health conditions, many of which can become life-threatening without effective treatment. 

These include the following:

  • Type 2 Diabetes
  • Hypertension
  • Dyslipidemia (Elevated Cholesterol)
  • Cardiovascular Disease
  • Liver Dysfunction
  • Respiratory Disorders
  • Musculoskeletal Disorders
  • Subfertility
  • Some Cancers (2)

When is a SADI operation indicated?

A SADI operation is for patients with a body mass index over 40. Weight-loss surgery is typically categorized into two types: 

  • Restriction: Limits the amount of food that can be ingested. 
  • Restriction and Malabsorption: Limits the amount of food and also the absorption of calories and potentially nutrients.

Examples of purely restrictive surgeries include the placement of a gastric band, or “lap” band, or a sleeve gastrectomy. Combination procedures that restrict food intake and reduce absorption include the Roux-en-Y gastric bypass, duodenal switch, and SADI. Dr. Bonnor also routinely performs revision bariatric procedures which may be purely restrictive or a combination.

Are you a good candidate for weight-loss surgery? Find out here.

About SADI

In surgery, anastomosis means the creation of a connection between two tubular structures in the body such as arteries, veins, and with weight loss surgery, parts of the digestive tract. And, in the case of SADI, it refers to the alterations made to the small intestine during surgery. First described in the mid-2000s, and now performed worldwide, the SADI procedure is a two part operation. The first part of a SADI procedure involves the creation of a sleeve, while the second part reroutes the small intestine in a way similar to a gastric bypass. Note the use of the word similar because the intestinal configuration for a bypass is a Y configuration and the intestinal configuration of the SADI is a loop or omega.  

Part 1: Sleeve

Simply described, a sleeve gastrectomy involves removing a large portion of the stomach leaving the remaining stomach as a long, vertical tube. This tube continues directly to the small intestine to help patients feel fuller faster and restrict the amount of food consumed. There is no anastomosis or connection in this procedure.   

Part 2: Duodenal Interposition

The duodenum is the first part of the small intestine. In the second part of the SADI procedure, the duodenum is divided just below the stomach. This preserves the opening at the bottom of the stomach, the pylorus important for decreasing the chances of dumping syndrome. A portion of the small intestine is connected to the duodenum, bypassing a large portion of the small intestine where calories and nutrients are normally absorbed.

SADI vs. Duodenal Switch

The duodenal switch, also known as a Bilio-pancreatic diversion with duodenal switch (BPD-DS), involves the removal of a portion of the stomach and creates two connection points in the small intestine. It creates an alimentary limb through which food flows and and a biliary limb of the small intestine that supplies bile and pancreatic fluid for digestion.

The SADI procedure differs from the duodenal switch in how the small intestine is reconstructed. As its name suggests, the SADI procedure involves one connection, whereas the duodenal switch involves two. The duodenal switch has a separate alimentary limb and biliary limb, whereas in the SADI involves one connection. As a result, the SADI means less potential complications such as bowel obstruction and potentially fewer nutritional deficiencies.(3)  Both procedures have similar recovery times.


  • Effective long-term weight-loss method
  • Lower risk of gastrointestinal side-effects
  • Helps to reduce or resolve obesity-related disease
  • Particularly effective in patients with type-2 diabetes

Several studies show that SADI is an effective way to not only lose weight, but to also address weight-related comorbidities. Evidence from multiple studies shows that SADI can resolve type 2 diabetes, abnormal lipid levels, high blood pressure, and sleep apnea. (1)(4)

SADI: A Solution to Type-2 Diabetes?

Type-2 diabetes is a chronic condition that causes insulin resistance, meaning the amount of blood sugar (glucose) is too high. As the body cannot process energy from food efficiently in type-2 diabetes, the condition can: 

  • Increase thirst
  • Cause fatigue 
  • Increase thirst and urination 
  • Lead to frequent infections 
  • Cause wounds to heal slower

After SADI, a majority of patients attain rapid type-2 diabetes remission, with greater than 90 percent achieving remission in the first year after surgery. (5)

Candidates for SADI

SADI is an effective way for patients with a BMI over 40 to achieve significant weight loss. It is well-suited to patients looking for a long-term solution to excess weight and obesity-related comorbidities like type-2 diabetes. It is also effective for patients who already have a sleeve and need a revision to address weight regain or complications from a previous sleeve.

Other Bariatric Procedures 


The sleeve is the first step in a SADI procedure. Many patients find that they can attain dramatic weight loss through this surgery alone. By removing 75-80% of the stomach, a sleeve gastrectomy restricts food intake. Patients also achieve satiety (fullness) at a much faster rate. In suitable candidates, success rates one year after sleeve surgery approaches 96%. (6)

Gastric Bypass

In a gastric bypass, a small stomach pouch is created and attached to a divided portion of the small intestine in a Y-shaped alteration to the digestive tract. Gastric bypass is a more complex surgery compared to the sleeve. This operation is best suited for diabetes and acid reflux.

Duodenal Switch

The SADI technique is a variation of the standard duodenal switch procedure. Where the SADI technique has one connection point, the standard or double anastomosis DS has two connections and creates a common channel for food and digestive enzymes. As with the sleeve and SADI procedure, a significant portion of the stomach is removed. Duodenal switch surgery works best in patients with a BMI over 40.

SADI Weight-Loss Surgery in Houston, TX

If you are considering weight loss surgery, we are here to help you and provide valuable information, please call (281) 579-5638  and consult with us at Texas Endosurgery Associates. 


  1. Kallies K, Rogers AM. American Society for Metabolic and Bariatric Surgery updated statement on single-anastomosis duodenal switch. Surgery for Obesity and Related Diseases. 2020;16(7):825-830. doi:10.1016/j.soard.2020.03.020 
  2. Ioannis Kyrou, Randeva HS, Constantine Tsigos, Grigorios Kaltsas, Weickert MO. Clinical Problems Caused by Obesity. Published January 11, 2018. 
  3. ASMBS. Bariatric Surgery Procedures | ASMBS. American Society for Metabolic and Bariatric Surgery. Published 2019. 
  4. Surve A, Cottam D, Medlin W, et al. Long-term outcomes of primary single-anastomosis duodeno-ileal bypass with sleeve gastrectomy (SADI-S). Surgery for Obesity and Related Diseases. 2020;16(11):1638-1646. doi:10.1016/j.soard.2020.07.019 
  5. Liagre A, Martini F, Anduze Y, et al. Efficacy and Drawbacks of Single-Anastomosis Duodeno-Ileal Bypass After Sleeve Gastrectomy in a Tertiary Referral Bariatric Center. Obesity Surgery. 2021;31(6):2691-2700. doi:10.1007/s11695-021-05323-y 
  6. Hoyuela, C. (2017). Five-year outcomes of laparoscopic sleeve gastrectomy as a primary procedure for morbid obesity: A prospective study. World Journal of Gastrointestinal Surgery, 9(4), 109–117.