Roux-en-Y Gastric Bypass Procedure: A Bariatric Surgical Procedure for Gastric Resectioning in Murine Model

Begin the Roux-en-Y procedure — a gastric resection surgery — by placing an anesthetized mouse in the supine position. Dissect the abdomen and externalize the small intestine to locate the jejunum — the middle part of the intestine.

Perform two nearby ligations on the jejunum and make an excision between them. This process generates two intestinal limbs — the biliary limb is proximal to the stomach and the alimentary limb is distal to the stomach. Place the biliary limb near the existing intestinal loop. Make equal-sized longitudinal incisions on their antimesenteric surface.

Perform side-to-side anastomosis by suturing incised regions of the biliary limb and the intestinal loop, allowing the gastric juices to enter intestines directly. Locate the stomach and ligate the pylorus — the portion of the stomach that opens into the intestine, which prevents the food from entering the intestine.

Make a new longitudinal incision near the pylorus and the pulled end of the alimentary limb and perform the second side-to-side anastomosis. This new path is called the Roux limb, and the intestine now resembles ‘Y’ shape. Return the ligated organs to the abdominal cavity and suture the incision site.

Post-surgery, the food directly enters from the stomach to the Roux limb, bypassing the normal gastric route. The smaller intestinal length decreases nutrient absorption, causing a reduction in the mouse’s weight.