Obesity describes the excess accumulation of body fat and is currently endemic in the United States, afflicting over 35% of the adult population. Although the percentage of body fat (>25% in men and >32% in women) is commonly used to describe obesity, these measurements are not readily available to most clinicians. Therefore, obesity is more commonly assessed by calculating the patient’s body mass index (BMI) or weight (kg) divided by their height in square meters (m2).1 Using these criteria, obesity is defined as having a BMI greater than 30, and clinically severe or morbid obesity is described as a having a BMI greater than 40 or a BMI greater than 35 with severe medical comorbidities.2 Using BMI criteria, more than 50% of adult Americans are overweight or obese, and approximately 5% are morbidly obese.3
Although these definitions are helpful in identifying individuals who are “at risk” for obesity-related complications, neither BMI nor percentage body fat describes the regional distribution of body fat. This is important because medical consequences of obesity are related in part to the distribution of body fat. Visceral or android obesity is more common in men and associated with insulin resistance, gastroesophageal reflux, hyperlipidemia, hypertension, obstructive sleep apnea (OSA), and metabolic syndrome.2,4,5 Gynecoid or subcutaneous obesity describes an excess accumulation of subcutaneous fat in the gluteal or buttock area and is more commonly seen in women. Degenerative joint disease, impaired mobility, dyspnea on exertion, asthma, urinary stress incontinence, and dysfunctional uterine bleeding are common medical consequences of obesity as well. Although the metabolic consequences of subcutaneous adiposity are less than for visceral adiposity, complications related to wound healing and surgical site infections are more common with subcutaneous adiposity.6,7,8
INDICATIONS AND WORKUP FOR BARIATRIC SURGERY
In 1991, the National Institutes of Health published a consensus statement, entitled “Gastrointestinal Surgery for Severe Obesity.”9 In this publication, they described the generally accepted criteria for surgical weight loss or “bariatric surgery.” Evaluation by a comprehensive, multidisciplinary team comprising experienced surgeons and individuals with medical, psychiatric, and nutritional expertise is recommended. The generally accepted criteria for surgical weight loss include BMI greater than 35 with severe medical comorbidities (typically type 2 diabetes or OSA) or BMI greater than 40, failure of medical weight loss, and no psychological contraindications to surgery.9 At this time, the most commonly performed surgical procedures were vertical banded gastroplasty (VBG) and the Roux-en-Y gastric bypass (RYGB).
Although weight loss operations have changed since 1991, the process of evaluating potential candidates for bariatric surgery remains similar. Most bariatric surgery programs offer a general information session that allows potential surgical candidates a chance to learn about the different surgical procedures; the preoperative evaluation process (nutrition counseling, psychological evaluation, medical workup); and the risks and benefits of different procedures and to ask questions ...