Gastrointestinal Surgery for Obesity: A Question of Life and Death and Expertise

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The first surgical operation for treating obesity was a jejunal-ileal (JI) bypass procedure, performed in the early 1950s. Although this procedure resulted in considerable weight loss, it also caused many serious medical complications, including those involving the gastrointestinal tract (eg, steatohepatitis, cirrhosis, gallstones, severe malabsorption, diarrhea, and colonic pseudo-obstruction) and other organ systems (eg, arthritis, osteoporosis/osteomalacia, and renal disease). The frequency and severity of postoperative complications led to the abandonment of the JI bypass as a therapeutic option for obesity.

The field of weight loss surgery has advanced considerably since the early days of the JI bypass, and several different surgical approaches are now routinely performed. The majority of bariatric surgical procedures currently performed in the United States and in the world involves 1 of 3 types of operations: gastric bypass procedure, laparoscopic adjustable gastric banding, and biliopancreatic diversion with duodenal switch. Each of these procedures can be performed laparoscopically. The gastric bypass procedure is most commonly performed, but the use of laparoscopic gastric banding is rapidly increasing.

Fifteen years ago, the indications for bariatric surgery (ie, gastric bypass procedure and vertical banded gastroplasty) were reported in a “National Institutes of Health (NIH) Consensus Conference Statement on Gastrointestinal Surgery for Severe Obesity.” The panel concluded that eligible patients were those who had “morbid obesity,” defined as a body mass index (BMI) ≥40 kg/m² or a BMI of 35.0–39.9 kg/m² plus one or more severe obesity-related medical complications (eg, hypertension, type 2 diabetes, heart failure, or sleep apnea).

The number of people with morbid obesity is increasing. In the last 20 years, the prevalence of adults in the United States with a BMI ≥40 kg/m² increased more than 4-fold and those with a BMI ≥50 kg/m² increased more than 5-fold. Morbid obesity is a deadly disease and has adverse effects on almost every organ system in the body. Gastrointestinal surgery is the most effective approach for achieving long-term weight loss in extremely obese patients. For example, obese patients who undergo gastric bypass surgery lose about two thirds of their excess weight (or about 30% of their initial weight) in the first 1–2 years after surgery, with a slight weight regain thereafter.

Recently, a series of articles appeared in JAMA (October 2005), which underscored the dark side of bariatric surgery, perioperative mortality, and postoperative re-hospitalization, and resulted in considerable media attention. Data from one study found that 30-day postoperative mortality among Medicare beneficiaries undergoing open bariatric surgery (2%) was much higher than that reported previously in large case series (∼0.5%). However, there is an important bariatric surgery learning curve, and surgical and institutional experience is important predictors of postoperative survival. Data from a previous study conducted in Washington State found that the 30-day postoperative patient mortality rate was 15 times higher for surgeons who performed fewer than 20 bariatric procedures than for those who performed more than 86 lifetime bariatric procedures. In addition, institutions where fewer than 50 procedures were performed per year have the highest rates of in-hospital mortality.

The results from these studies suggest that standards should be established for performing bariatric surgery, and that surgical outcomes will be better if procedures are performed by experienced surgeons within established programs. Therefore, the American Society for Bariatric Surgery is developing a Bariatric Centers of Excellence program. Recognition as a Center involves a site inspection, and requires that the institution performs ≥125 cases/year with surgeons who perform ≥50 cases/year, has standardized procedures and clinical care pathways, facilities for optimal bariatric patient care, and provides long-term patient follow-up. At present, more than 125 hospitals have applied for full approval. Data from 106 hospitals, which perform an average of ∼300 cases/year, found that 90-day postoperative mortality was 0.14% (W. Pories presentation at the 2005 annual meeting of the North American Association for the Study of Obesity). These results compare well with postoperative mortality rates for other surgical procedures, such as hip replacement (0.3%), coronary artery bypass graft (3.5%), aortic aneurysm repair (3.9%), and esophageal resection (9.1%).

This information is important for gastroenterologists. An increasing number of patients who are morbidly obese will be seen by gastroenterologists because of the relationship between obesity and gastrointestinal disease. In addition, the use of bariatric surgery to treat morbid obesity will likely increase. Approximately 170,000 bariatric surgical procedures were performed in 2005, which is <1% of those who meet the eligibility criteria for bariatric surgery, outlined by the NIH Consensus Conference. Therefore, gastroenterologists need to know when to refer patients for bariatric surgery, who are the skilled surgeons, and where are the experienced centers.

The intersection between obesity, bariatric surgery, and gastroenterology suggests that gastroenterologists should develop stronger clinical and research partnerships with bariatric surgeons. This relationship will improve clinical outcomes and provide insights into the gastrointestinal mechanisms responsible for the beneficial effects of surgery.