New Techniques and Guidelines Point Way to Bariatric Surgery

Question: How do I select patients for bariatric surgery?

Answer: The increasing acceptance of bariatric surgery for the treatment of obesity by providers and insurance carriers reflects our improved understanding of the pathophysiology of weight regulation.

In the initial evaluation of the obese patient, it is important to screen and treat secondary causes of unwanted weight gain and to diagnose and treat comorbid conditions. Before considering medical or surgical management, allow 4–6 months for efforts to improve poor lifestyle habits, such as inactivity and a diet high in calorie-dense foods, to determine if the resulting weight loss is sufficient to achieve a healthy weight.

Many practitioners will suggest that a severely obese patient undergo a 4–6-month pharmacological trial using an agent such as phentermine, sibutramine (Meridia, Abbott), or orlistat (Xenical, Roche) before surgery is considered. Even if the patient experiences a typical 5–10% weight loss on medication, however, many extremely obese subjects still meet criteria for surgical management, where average weight loss is 20–30%.

Within the past 5 years, several events helped vault bariatric surgery ahead of lifestyle or medical therapy for the treatment of severely obese patients. These include widespread adoption of laparoscopic techniques resulting in reduced morbidity rates,¹ recognition of the importance of the foregut in the feedback control of weight regulation,² and publication of long-term outcomes studies demonstrating improvements in diabetes, sleep apnea, and blood pressure control.^3,4

In 2000, the National Heart, Lung, and Blood Institute and the North American Association for the Study of Obesity (now NAASO, The Obesity Society) published guidelines to help practitioners determine if their patients qualify for consideration of bariatric surgery.⁵ Patients with a body mass index (BMI) >40 are considered at high enough risk for long-term complications to warrant surgical management even in the absence of concomitant diseases. Surgery also can be considered for patients with a BMI 35–40 and a comorbid condition, including diabetes, hyperlipidemia, hypertension, sleep apnea, arthritis, gastroesophageal reflux disease, cardiovascular disease, and other pulmonary diseases.

Although safety and efficacy for subjects with a BMI <35 were not established when these recommendations were written, newer techniques and improved outcomes data leave open the possibility that patients with BMIs of 30–35 and multiple or severe comorbid diseases might best be treated by the surgeon.

A recent paper suggests that patients >65 years are at higher risk from bariatric surgery.⁶ But the data supporting this conclusion included Medicare patients, who usually are at higher risk for worse outcomes, and patients who had the higher-risk open procedures.⁷ Children with severe obesity and obesity-related diseases, typically orthopedic problems and severe sleep apnea, should be evaluated and managed by specialized pediatric obesity centers.

Finally, a recommendation for surgery depends on whether a bariatric surgical center of excellence is available locally. If such a center is not nearby, finding a surgeon with experience of at least 50–100 cases is one of the best predictors for low 30-day mortality.⁸ ▪