Roux-en-Y Gastric Bypass procedure is considered the gold standard treatment for GERD in obese patients. The creation of a small gastric pouch diverts most of the acid produced by the stomach away from the distal esophagus. The Roux limb mechanism effectively prevents bile reflux into the esophagus and promotes esophago-gastric emptying by creating a negative pressure system. Studies in dogs have shown that the Roux limb must be at least 30 cm in length to prevent bile reflux. Measuring the small intestine intra-operatively is not an accurate process since the intestine is continuously contracting and relaxing. Furthermore, there are no studies in humans about the optimal Roux limb length that is associated with bile reflux prevention. Most bariatric surgeons have adopted a 75 cm Roux limb length for gastric bypasses performed for weight loss. The majority of obese patients are reflux free following gastric bypass surgery.
Once a year, a patient presents to my office with epigastric pain, heartburn and occasional bilious vomiting or nighttime bile liquid regurgitation years after gastric bypass surgery. The workup starts with upper endoscopy to evaluate the bypass anatomy, rule out gastritis, gastro-jejunostomy stricture, hiatal hernia and distal esophagitis. I try to approximate the length of the Roux limb especially when I am able to reach the jejuno-jejunostomy. I them perform an esophageal manometry and place a pH impedance catheter to check for reflux events.
The most common cause of GERD after Roux-en-Y gastric bypass surgery is a short Roux limb. The roux limb can be anatomically short requiring a lengthening procedure to fix the problem. It can also be functionally short in which case the treatment depends on the particular patient situation. In my practice, the most common cause of functionally short Roux limb is the presence of a hiatal hernia. When the gastric pouch herniates into the negative pressure system of the thoracic cavity above the diaphragm, reflux occurs. The negative chest pressure overcomes that of the alimentary limb favoring bile reflux into the gastric pouch and distal esophagus. All gastric bypass patients presenting to my office with GERD do not respond at all to proton pump inhibitor therapy. Most of these patients have evidence of Barrett’s esophagus on biopsies taken from the distal esophagus. Such findings are highly suggestive of bile reflux. The presence of gastric pouch mucosa inflammation or marginal ulcer as well bile pooling on upper endoscopy further indicate bile reflux. A cholescintigraphy may be performed in such cases but the yield of such a study is very poor. In my experience, a good hiatal hernia repair that restores the normal anatomy of 3 cm of tension free intra-abdominal esophagus results in GERD resolution. Obviously, if the Roux limb happens to be short intra-operatively, a lengthening procedure is added to the hiatal hernia repair.
In summary, GERD may occur following gastric bypass in the setting of a short Roux limb. Careful work-up and the proper treatment can safely and effectively resolve GERD.