What is bariatric surgery?

Indications and Procedures

Candidates for bariatric surgery are the severely obese, with a body mass index (BMI) of 40 or more, or a BMI of 35 to 39 with serious medical conditions, such as diabetes mellitus, heart
disease, hypertension, and sleep
apnea. Typically, to qualify for surgery patients must first have tried other methods of weight loss (dietary modification, exercise, and/or drug therapy) and must be seriously impaired in their ability to perform routine activities. In addition, patients should undergo extensive psychiatric evaluation to ensure that they understand the risks of the procedure and are motivated enough to cope with its dramatic effects and permanent lifestyle changes.

There are two types of procedures. Restrictive surgery—including vertical banded gastroplasty,
gastric banding, or laparoscopic gastric banding (lap band)—uses bands or staples near the top of the stomach to create a small pouch that restricts food intake to no more than one-half to one cup. The stoma, a tiny gap in the pouch that opens into the lower stomach, slows the emptying of the pouch to prolong fullness, thus reducing hunger.

Malabsorptive surgery involves surgical rearrangement of the digestive system to bypass parts of the stomach and small intestine, where most nutrients are absorbed. Roux-en-Y gastric bypass
is the most commonly performed operation, derived from a procedure developed in 1966 by Edward E. Mason and named after the Y-shaped connection it creates. Roux-en-Y combines restriction with malabsorption, bypassing the lower stomach and the duodenum to connect the stomach pouch directly to the jejunum, or (less frequently) the iliem. In biliopancreatic diversion, sometimes performed on patients with a BMI of 50 or more, a portion of the stomach is actually removed, with the remaining section attached directly to the ileum, thus shortening the small intestine drastically to produce greater weight loss.

Uses and Complications

To lose weight and keep it off, surgery alone is not enough; strict diet and exercise regimens must be maintained. On average, bypass patients lose 66 percent of their excess weight after two years but gain some back as a result of stretching of the pouch over time. At five years, the loss of excess weight typically stabilizes at 33 to 50 percent. Restrictive procedures tend to result in comparatively less weight loss because there is no malabsorption. Diabetes, hypertension, and high cholesterol may improve significantly after surgery, often before marked weight loss occurs. Arthritis, sleep apnea, and other obesity-related conditions may gradually improve as weight is lost. In addition, patients often experience improved mobility and stamina and may report enhanced self-esteem and social acceptance.

Patients with very severe obesity, heart disease, diabetes, or sleep apnea and those who have inexperienced surgeons are at greater risk of developing complications. Gastric bypass patients face a 0.5 to 1.0 percent fatality rate; restrictive surgery patients fare better at 0.1 percent. Follow-up operations are required in 10 to 20 percent of patients. Most lap band patients experience at least one side effect, including abdominal pain, heartburn, nausea, vomiting, and band slippage to the extent that up to 25 percent may have the bands removed. If staples are used, then the risk of developing a leak or rupture is around 1.5 percent, leading to serious infection and often requiring further surgeries; laparoscopic patients appear to be at higher risk. Because 30 percent of patients develop gallstones after surgery as a result of rapid weight loss, the gallbladder is often removed as well. In 2 percent of cases, the spleen may be injured, necessitating its removal.

Other complications include blood clots, gaseous distention, infection, bowel or esophageal perforation, bowel strangulation, hernias, strictures, ulcers, late staple breakdown, menstrual irregularities, and hair loss. Patients undergoing malabsorptive procedures by definition will suffer from nutritional deficiencies, including anemia and metabolic bone disease resulting in osteoporosis, unless supplements are taken daily; regular vitamin B12 shots are necessary for some patients. Many patients will require further cosmetic surgery to remove large, sagging folds of skin.

All patients may experience vomiting from eating too much or too quickly. Pain behind the breastbone can result from insufficient chewing, causing large food particles to lodge in the stoma. Between 70 and 80 percent of gastric bypass patients will develop dumping syndrome, a condition caused by eating too much fat or sugar, which can result in severe dizziness or weakness, abdominal cramps, nausea, vomiting, and diarrhea. Biliopancreatic bypass is further associated with chronic diarrhea and other long-term complications such as liver disease.

Perspective and Prospects

Surgical treatment for obesity began in the early 1950s with dangerous intestinal bypass procedures. As techniques have improved, the number of surgeries performed has mushroomed. The American Society for Bariatric Surgery reports that its member surgeons performed 28,800 operations in 1999, 63,100 in 2002, and 80,000 in 2007; by 2010, the number had plateaued at 113,000. During the same period, however, many more of the lucrative surgeries were performed by nonmembers. Evolving surgical practices and long-term outcomes remain difficult to evaluate as clinical trial data are lacking, and proof of overall improvements in health and longevity is scanty. According to the American Medical Association, the long-term consequences of weight-loss surgery remain uncertain. To establish the overall safety and efficacy of such surgery, more research and stringent clinical trials are needed.

Bibliography

American Society for Bariatric Surgery. http://www .asbs.org.

Davis, Garth, and Laura Tucker. The Expert's Guide to Weight-Loss Surgery. New York: Hudson Street Press, 2009.

Flancbaum, Louis, Erica Manfred, and Deborah Flancbaum. The Doctor’s Guide to Weight Loss Surgery: How to Make the Decision That Could Save Your Life. New York: Bantam Books, 2004.

Hart, Dani. I Want to Live: Gastric Bypass Reversal. Fort Collins, Colo.: Mountain Stars, 2002.

Inabnet, William B., Eric J. DeMaria, and Sayeed Ikramuddin, eds. Laparoscopic Bariatric Surgery. Philadelphia: Lippincott Williams & Wilkins, 2005.

Kothari, Shanu N. Bariatric and Metabolic Surgery. Philadelphia: Saunders, 2011.

Mitchell, James E., and Martina de Zwaan, eds. Bariatric Surgery: A Guide for Mental Health Professionals. New York: Routledge, 2005.

Nussbaum, Michael S. Gastric Surgery. Philadelphia: Lippincott Williams and Wilkins, 2013.

Rogers, Jennifer T. Gastric Bypass: Surgical Procedures, Health Effects, and Common Complications. New York: Nova Science, 2010.

U.S. Department of Health and Human Services. Public Health Service. National Institutes of Health. Office of Medical Applications of Research. Gastrointestinal Surgery for Severe Obesity: A Consensus Development Conference. Bethesda, Md.: Author, 1991.