Due to changing activity patterns and increased calorie intake in many societies, obesity has become a global problem. In 2010, nearly 36 percent of American adults were obese, according to the National Center for Health Statistics. One consequence of this obesity epidemic is a sharp upturn in the number of surgical procedures being performed to help people lose weight. Among the variety of available bariatric techniques, Roux-en-Y gastric bypass is considered the “gold standard.” As with all surgical procedures, complications can arise during and after a gastric bypass.
Any surgical procedure that involves anesthesia and inserting instruments into a body cavity can lead to complications. Unanticipated blood loss, abnormal heart rhythms, respiratory problems, inadvertent organ injury or death may occur during surgery. In the immediate postoperative period, blood clots, heart attack, pneumonia and surgical wound infections are additional dangers. These complications are unusual and can be reduced by choosing a surgeon who has extensive experiencing performing gastric bypasses.
According to a 2012 review in the “Canadian Journal of Surgery,” problems that arise during the first 2 weeks after surgery are considered early complications. One of the dreaded early complications of gastric bypass is a leak around one of the sites where your stomach or intestine was cut and reattached. Such “anastamotic” leaks occur in only 0.5 to 5 percent of gastric bypass surgeries, but they are fatal in nearly 50 percent of cases when they do occur.
Postoperative bleeding, an early complication that follows 2 to 4 percent of Roux-en-Y procedures, can occur within the abdominal cavity, where it may not be easily detectable, or within the bowel, which usually leads to bloody or tarry stools. Small bowel obstruction, usually the result of twisting or entrapment of a loop of small intestine within the abdominal cavity, is another potential early complication of gastric bypass. Blood transfusions or more abdominal surgery may be needed to address these issues.
After the first 2 postoperative weeks, small bowel obstruction remains high on the list of potential complications of gastric bypass procedures. Anastomotic strictures, which are constrictions at the sites where your intestine was divided and reattached, develop in up to 23 percent of people undergoing gastric bypass. Vomiting or swallowing difficulties may be the only sign of a stricture, which could require another surgery to repair. In up to 16 percent of people, ulcers occur at the site where the stomach pouch is joined to the small intestine. And 1 to 6 percent of people develop fistulas, or abnormal communications, between their stomach pouch and nearby organs.
Because your stomach is bypassed during a Roux-en-Y procedure, several nutrients that depend on acid for their absorption may not be as readily absorbed after your surgery. A study published in the May 2008 issue of “The American Journal of Clinical Nutrition” demonstrated that nearly all people who undergo gastric bypass develop nutritional deficiencies within 2 years of their surgery and require specific supplements to correct them. Iron, calcium, vitamin B12 and folate are most commonly affected, but deficiencies of magnesium, vitamin D, beta-carotene, zinc, and thiamine have also been noted.
Although it is not necessarily a complication of a gastric bypass, weight gain occurs in approximately 10 percent of people during the 5 years following their surgery. While this may be caused by the formation of an abnormal communication between your stomach pouch and the bypassed stomach, most people gain weight due to failure to control their eating behaviors. Re-evaluation and behavioral modification is recommended for these people before another surgery is considered.