The SADI procedure, formally known as Single Anastomosis Duodeno-Ileal bypass with sleeve gastrectomy (SADI-S), is a bariatric surgery designed for significant weight loss and improvement of obesity-related health conditions. A modification of traditional duodenal switch surgery, it streamlines the process while aiming for comparable outcomes. This procedure alters both food consumption and nutrient absorption. Endorsed by the American Society for Metabolic and Bariatric Surgery, SADI-S provides an effective option for severe obesity.
Defining the SADI Procedure
The SADI procedure involves two primary anatomical changes within the digestive system. The first step creates a gastric sleeve, where approximately 80% of the stomach is removed, leaving a smaller, tube-shaped stomach. This reduction in stomach size limits the amount of food a person can eat at one time, promoting earlier feelings of fullness.
Following the sleeve gastrectomy, the surgeon performs a duodenal-ileal bypass, which is the “single anastomosis” aspect of the procedure. The small intestine is divided just beyond the stomach. The new gastric sleeve is then connected to a segment of the lower small intestine (ileum), effectively bypassing a significant portion of the upper small intestine. This rerouting of the small intestine reduces the length over which food mixes with digestive enzymes, leading to decreased absorption of calories and nutrients, particularly fats and carbohydrates. This combination achieves substantial weight loss and can also lead to beneficial hormonal changes that help control blood sugar and appetite.
Who Qualifies for SADI
Patient selection for the SADI procedure involves specific criteria. Candidates for SADI-S are individuals with a Body Mass Index (BMI) of 40 or greater, classifying them as having severe obesity. Patients with a BMI between 35 and 39.9 may also be considered if they have obesity-related health conditions, such as type 2 diabetes, high blood pressure, or obstructive sleep apnea, which can significantly improve with weight loss.
A history of failed non-surgical weight loss attempts, including structured diets and exercise programs, is a prerequisite. Before surgery, a comprehensive medical and psychological evaluation is conducted. This assessment helps determine if the patient is physically and mentally prepared for the surgery and understands the long-term lifestyle changes and commitment required for success.
The SADI Surgical Process
The SADI procedure is performed laparoscopically, a minimally invasive approach that involves small incisions in the abdomen. This technique utilizes a laparoscope, a thin tube with a camera, to guide the surgeon. This minimally invasive method results in shorter recovery times, less pain, and smaller scars compared to open surgery.
Before the operation, patients follow a pre-operative diet for about two weeks, which is high in protein and low in carbohydrates, calories, and fat. This diet helps reduce liver size and abdominal fat, making the procedure safer and quicker. During the surgery, the first stage involves creating the gastric sleeve by removing a large portion of the stomach. The second stage connects the newly formed stomach sleeve to the lower part of the small intestine, bypassing the upper sections. Patients stay in the hospital for two to three days after the procedure for initial recovery and monitoring.
Life After SADI Surgery
Following SADI surgery, patients embark on a structured dietary progression for healing and adaptation. Initially, a clear liquid diet is followed for a few days, transitioning to full liquids and then pureed foods over the first few weeks. This gradual reintroduction of food helps prevent discomfort and ensures proper healing of the surgical sites.
Long-term dietary adjustments include consuming smaller portions, prioritizing lean proteins, and incorporating a balanced intake of vegetables and whole grains. Due to the malabsorptive component of the SADI procedure, lifelong vitamin and mineral supplementation is necessary to prevent nutritional deficiencies. Regular follow-up appointments with a bariatric team, including dietitians and surgeons, are important to monitor progress, address any concerns, and adjust dietary and supplement regimens as needed. Patients can expect significant weight loss, with studies reporting 70% to 85% excess weight loss at 5 to 10 years post-surgery, along with improvements or remission of obesity-related conditions like type 2 diabetes, high blood pressure, and sleep apnea.
SADI in Context of Bariatric Surgery
The SADI procedure offers a combination of restrictive and malabsorptive effects among common bariatric surgeries. Unlike a standalone Gastric Sleeve, which primarily restricts food intake by reducing stomach size, SADI-S adds an intestinal bypass for enhanced weight loss and metabolic improvements. The SADI procedure results in more significant weight loss and higher rates of type 2 diabetes remission compared to gastric sleeve alone, especially for individuals with higher initial BMIs.
Compared to the traditional Roux-en-Y Gastric Bypass (RNY), SADI-S involves only one intestinal connection (anastomosis) instead of RNY’s two, which may reduce surgical time and the risk of certain complications like internal hernias. While both RNY and SADI-S offer restrictive and malabsorptive benefits, SADI-S provides a greater degree of malabsorption, leading to more substantial weight loss for individuals with very high BMIs. However, RNY may be preferred for patients with pre-existing acid reflux, as SADI-S can worsen it.