The single anastomosis duodenal switch (SADI-S), also known as loop duodenal switch, is a surgical procedure for individuals with severe obesity and associated health challenges. It is a modified version of the traditional duodenal switch, designed to achieve substantial and lasting weight loss.
What Single Anastomosis Duodenal Switch Entails
The SADI-S procedure combines two primary surgical modifications: a sleeve gastrectomy and an intestinal bypass. Initially, a significant portion of the stomach is removed, creating a smaller, tube-shaped stomach. This alteration significantly reduces the stomach’s capacity.
Following the sleeve gastrectomy, the first part of the small intestine, the duodenum, is divided just below the stomach’s natural valve. A segment of the lower small intestine, the ileum, is then connected directly to this divided duodenum. This creates a single connection, or anastomosis, a distinguishing feature of the SADI-S procedure compared to the two connections in a traditional duodenal switch.
The preservation of the pyloric valve is a key aspect, which helps regulate stomach emptying and may reduce the risk of complications.
How Single Anastomosis Duodenal Switch Promotes Weight Loss
SADI-S promotes weight loss through a dual mechanism involving both restriction and malabsorption. The sleeve gastrectomy component physically limits the amount of food an individual can consume at one time, as the newly created stomach sleeve holds significantly less volume. This restriction leads to reduced caloric intake.
The intestinal bypass component reroutes food directly into the latter part of the small intestine, bypassing a substantial length of the digestive tract. This bypass reduces the time and surface area available for the absorption of calories, fats, and other nutrients, leading to malabsorption. As a result, fewer calories are taken in by the body.
Beyond these physical changes, SADI-S also induces hormonal shifts that contribute to weight loss and improved metabolic health. The altered food pathway influences the release of gastrointestinal hormones that regulate hunger and satiety. These hormonal changes can decrease appetite, increase feelings of fullness, and improve the body’s ability to regulate blood sugar levels.
Eligibility for Single Anastomosis Duodenal Switch
Candidacy for SADI-S requires a comprehensive medical evaluation. Generally, individuals with severe obesity, defined as a Body Mass Index (BMI) of 40 or greater, are considered. Patients with a BMI between 35 and 39.9 may also be candidates if they have significant obesity-related health conditions, such as type 2 diabetes, high blood pressure, or obstructive sleep apnea.
A history of unsuccessful attempts at weight loss through non-surgical methods, like diet and exercise, is also an important criterion. Candidates must demonstrate a commitment to making long-term lifestyle changes and adhering to post-operative guidelines. A thorough medical and psychological assessment ensures preparedness for surgery and subsequent adjustments. Specific conditions like Barrett’s esophagus, severe gastro-esophageal reflux disease, or a major hiatal hernia might be contraindications.
Recovery and Long-Term Lifestyle Adjustments
Immediately following SADI-S surgery, patients typically have a hospital stay of about two to three days. During this time, light movement, such as walking, is encouraged within hours of the procedure. The diet begins with clear liquids, gradually progressing to full liquids over the first week or two.
Over the subsequent weeks, the diet transitions to pureed or semi-solid foods, then to solid foods. Patients learn to consume small, frequent meals and focus on nutrient-dense choices while avoiding high-calorie and high-fat foods. Most individuals can resume light activities within one to two weeks, with a full return to normal activities occurring within four to six weeks.
Beyond the initial recovery, long-term lifestyle adjustments are necessary for sustained outcomes. Regular physical activity becomes a consistent part of daily life, with a general recommendation of around 250-300 minutes weekly, including strength training. Adherence to follow-up appointments with the bariatric team is also important for monitoring progress and addressing any concerns.
Managing Nutrition and Health After Single Anastomosis Duodenal Switch
Due to the malabsorptive component of SADI-S, lifelong nutritional management is a significant aspect of post-surgical care. Patients are at a higher risk of developing deficiencies in various vitamins and minerals because less of the small intestine is available for absorption. These include fat-soluble vitamins (A, D, E, K), vitamin B12, iron, and calcium.
To prevent these deficiencies, consistent daily supplementation with a bariatric-specific multivitamin and mineral blend is required. Higher doses of specific vitamins and minerals, such as vitamin D3 and iron, are also commonly prescribed based on individual needs.
Regular blood tests are conducted to monitor nutritional status, usually at 3, 6, and 12 months in the first year, and annually thereafter. Significant weight loss is a common outcome, often improving or resolving conditions like type 2 diabetes, high blood pressure, and sleep apnea. However, diligent nutritional management remains the primary focus for long-term health after SADI-S to prevent complications.