What are the Complications of Weight Loss Surgery?

Bariatric surgery is effective treatment for obesity and its related disorders. Yet as increasing numbers of patients undergo this procedure, gastroenterologists encounter a growing number of complications. A Perspective article in the April issue of Clinical Gastroenterology and Hepatology discusses common complications of bariatric surgery and ways to manage them.

Bariatric surgeries include Roux-en-Y gastric bypass (RYGB), laparoscopic adjustable gastric band (LAGB), vertical banded gastroplasty (VBG), sleeve gastrectomy (SG), biliopancreatic diversion, and duodenal switch procedures. RYGB is performed more frequently and leads to an average percent excess weight loss of 56.7%–66.5% in the first 24 months after surgery. Diabetes resolves or improves in 86% of patients, hypertension in 68%, obstructive sleep apnea in 81%, and hyperlipidemia in 97%.

The digestive pathway following RYGB.

However, bariatric surgery can cause complications such as nausea, vomiting, and abdominal pain. According to Nitin Kumar and Christopher Thompson, to help patients with these side effects, gastroenterologists must be aware of which surgery the patient received and when it was performed, whether subsequent revisions were performed, and whether certain habits or risk factors could cause the complications. Endoscopic procedures are frequently required to evaluate and treat patients with these complications.

For example, gastrointestinal bleeding occurs more commonly after RYGB (1.9% of cases) than LAGB, SG, or VBG. Bleeding can develop at multiple sites, including the pouch, anastomoses, staple lines, the contiguous small intestine, the excluded stomach, or the bypassed small intestine. Kumar and Thompson explain that if endoscopy is performed, air insufflation should be minimized, and carbon dioxide insufflation should be used. Endoclips can be used to stop the bleeding, in conjunction with epinephrine injection. Electrocautery should be avoided at fresh staple lines.

About 20% of patients who undergo RYGB develop ulcers at the gastrojejunal anastomosis—most frequently in the first 3 months after surgery, but ulcers can develop at any time. Signs of ulcers include epigastric pain, nausea, vomiting, food intolerance, and bleeding.

Kumar and Thompson say that following bariatric surgery, endoscopy can be safely performed to investigate the gastric pouch, gastrojejunal anastomosis, and proximal Roux limb. For patients who have undergone RYGB, anastomotic ulcers should be treated with soluble proton pump inhibitors. Bile reflux can be treated with bile acid binders such as cholestyramine or colestipol. Patients should stop taking non-steroidal anti-inflammatory drugs, if possible, or combine them with proton pump inhibitors.

Endoscopy can be used to identify and treat other complications, such as removing foreign materials and repairing stenosis, leaks, and fistulas. Pancreatic and biliary disorder can be treated with endoscopic ultrasound and endoscopic retrograde cholangiopancreatography.

One of the biggest complications after bariatric surgery is weight regain—approximately 20% of patients have not lost 50% of their excess weight within 1 year of surgery. Furthermore, 30% of patients gain the weight back by 2 years after surgery, and 63.6% within 4 years.

Kumar and Thompson explain that weight regain be caused by neuroendocrine changes in regulation of metabolism that lead to a starvation response, followed by increases in appetite and energy conservation. Decreased satiety can result from loss of restriction; larger pouch size and gastrojejunal anastomosis diameter have been associated with weight regain. Gastrogastric fistula is another possible etiology. Treatment approaches for these problems include endoluminal therapy and endoscopic sutured revision of the dilated gastrojejunal anastomosis and gastric pouch.

As bariatric surgeries increase, Kumar and Thompson emphasize that it is important for gastroenterologists to become familiar with their complications and learn effective methods to address them.

Read the article online.
Kumar N, Thompson CC. Endoscopic management of complications after gastrointestinal weight loss surgery. Clin Gastroenterol Hepatol 2013;11:343–353.