Obesity Surgery in Pediatrics

No one in the health care field can avoid noting that there is an epidemic of obesity in the United States today. In 1980, 47% of American adults were overweight with body mass indices greater than 25. At present, the prevalence of overweight has increased to more than 65% using this same standard. The percent of individuals with a body mass index (BMI) between 25 and 30 has remained around 33% or essentially the same since 1980. The frightening statistic is that all of the increase in patients with elevated BMI is a result of an increase in the number of individuals with a BMI greater than 30. In 1980, the figure was 15%, but it is now 31% of the total (1). In other words, the fat are getting fatter. Super-obesity (BMI greater than 50) was unusual 20 years ago. Now it is common. Unfortunately, children are no different. In some areas of the United States, the prevalence of pediatric overweight is around 40% and pediatric obesity around 22% (2). The super-obese child is becoming a common sight. Because as many as 83% of obese children will become obese adults (3–6) (Inge T. In Press.), the epidemic of obesity in children is driving the epidemic in adults. How and when this epidemic will end can only be speculated. But end it must. Obesity in the child can lead to numerous co-morbidities. Co-morbid conditions are often silent in the obese child but have the potential to be life threatening or life altering. Cardiac risk factors such as hypertension, hyperlipidemia, hyperinsulinemia, and sleep apnea are common in obese children. Eighty percent of overweight adolescents have one risk factor for cardiac disease and 20% have two (3,4). Glucose metabolism is altered in as many as 25% of obese children (8), resulting in a dramatic increase in the prevalence of type 2 diabetes in the pediatric population (9,10). Twenty-six percent to 37% of obese children have an abnormal polysomnograph (11,12), and 7% have true sleep apnea (13). Obese children account for 66% to 80% of patients with tibia vara or Blount's disease (6,13) and 50% to 70% of children with slipped capital femoral epiphysis (6). More than 15% of obese children have evidence of steatohepatitis, and most of these children are already experiencing the development of fibrosis of the liver (14). Polycystic ovarian syndrome, pseudotumor cerebri, biliary disease, depression, and lack of self-esteem resulting in under-performance in school and society are all associated with obesity in children and adolescents. Medical treatment of obesity is difficult and frequently unsuccessful. Behavior modification, diet, and exercise are the keys, but only one of five children succeeds (Klish WJ, Personal experience.). Sibutramine and orlistat have been used in children but generally produce very modest weight loss and significant side effects (15). The obese child with life-threatening co-morbidities who is noncompliant with weight loss therapy has frustrated many of us. Despite their failures with medical therapy, these children deserve a chance for a better life. It is for this reason that we are beginning to explore bariatric surgery for the treatment of obese children with life-threatening or life-altering co-morbidities. In the United States, surgery has been used for the treatment of morbid obesity in adults for almost 50 years. Some of these surgeries, referred to collectively as “bariatric,” from the Greek word “baros” or weight, have proven effective in decreasing morbidity and mortality in obese adults (16–19). A consensus panel of the National Institutes of Health (NIH) established indications for bariatric surgery in adults in 1991 (20). At that time, obese adults with a BMI ≥40 and no co-morbidities or a BMI ≥35 and co-morbidities who had multiple failed attempts at medical management were considered candidates for bariatric surgery. Adolescents were not included as potential candidates for bariatric surgery by the NIH consensus panel because they were considered unique. There were no data on the safety and efficacy of this kind of surgery in the adolescent, and the panel recognized that there were issues unique to adolescence that might make the guidelines for bariatric surgery in adolescents more conservative than in adults. Significant weight loss in the younger adolescent might interfere with linear growth. There are ethical concerns regarding obtaining assent from adolescents for bariatric procedures in light of their uniquely vulnerable psychology. There are insufficient data to assess the effect of these procedures on reproductive ability and pregnancy outcome. Because the adolescent is still growing, there may be greater nutritional impact of the decreased absorption of essential nutrients, such as calcium, iron, zinc, and specific vitamins. However, if the co-morbidities associated with adolescent obesity respond well to bariatric surgery, there may be a desirable long-term improvement in quality and length of life. For this reason, we think bariatric surgery can and should be performed if the adolescent patient is carefully selected and carefully monitored after surgery. The guidelines for patient selection for bariatric surgery in adolescents have been outlined by the American Pediatric Surgical Association Clinical Task Force on Bariatric Surgery (7). They include patients with: failure to lose weight after at least 6 months of organized attempts; near-mature physiologic status of Tanner Stage III or above; BMI ≥40 with major life-threatening co-morbidities or ≥50 with minor but life-altering co-morbidities; commitment to medical and psychological evaluation before and after surgery; commitment to avoid pregnancy for at least 1 year after surgery; ability and intent to adhere to postoperative nutritional guidelines; supportive family environment; and ability to provide informed assent (patient) and consent (family). The preoperative evaluation should include a careful history and family history. The complete physical examination should include a carefully obtained blood pressure reading and evaluation of gait. Serum studies should include, but not be restricted to, an alanine transaminase (ALT), aspartate transaminase (AST), gamma-glutamyl-transpeptidase (GGT), lipid profile, complete blood count, thyroid function tests, tests for active infection with Helicobacter pylori, a pregnancy test for females, screening for micronutrient deficiencies, and a fasting insulin, glucose, and hemoglobin A1C (HbA1C). If the glucose or HbA1C test result is abnormal, an oral glucose tolerance test should be obtained. A polysomnogram is indicated in patients with symptoms of obstructive sleep apnea. Bone age assessment can be considered in younger patients to evaluate skeletal maturity. Formal psychological testing should be done to assess personality traits, cognitive maturity, depression, eating behavior, and quality of life that may have a bearing on candidacy for surgery. A variety of surgical techniques have been used for weight control in the last 50 years, but currently the two most common bariatric surgical procedures are the Roux-en-Y gastric bypass and the adjustable gastric band. Both procedures can be done laparoscopically. The adjustable gastric band is purely restrictive in nature. It creates a small proximal gastric pouch that induces early satiety and decreased oral intake. The advantage of this procedure is that the gastric band is connected to a subcutaneous reservoir, which can be accessed through the skin. Increasing or decreasing the amount of saline in the band system can adjust the pouch size. Removing all the saline from the reservoir can at least partially reverse the procedure. The adjustable gastric band, although attractive, is not yet approved by the United States Food and Drug Administration (FDA) for use in patients younger than 18 years. The Roux-en-Y gastric bypass is both restrictive and malabsorptive. A small gastric pouch is created, but the distal stomach is separated from the pouch and the jejunum is brought up and attached to the pouch. The stomach, duodenum, and a small portion of the proximal jejunum are then attached to the jejunum at a variable distance downstream from the pouch. Because gastric, hepatic, and pancreatic secretions bypass a segment of jejunum before entering the small bowel, digestion is less efficient, and some malabsorption results. Currently the most common bariatric procedure, gastric bypass is considered by many to be the best surgical treatment of morbid obesity (18). The two most common early postoperative complications of gastric bypass are acute gastric distension and anastomotic leak (16,21). The most common late postoperative complications are anastomotic stricture (16,22), internal hernia, and thiamin deficiency. Patients are at a unique risk for the development of beriberi or thiamin deficiency with cardiac and neurologic sequelae if the condition is not identified and treated early. In adolescents, the long-term risk of mineral (i.e., iron or calcium) or micronutrient (i.e., folate or B12) deficiency is not well defined but is a legitimate concern (21). Successful pregnancy is possible after bariatric surgery, but there is a potential risk to the fetus during the rapid weight loss phase in the first year after surgery. After gastric bypass, a very low calorie, low carbohydrate diet is enforced by the surgery itself. It is important to maintain protein intake (0.6 g/kg/day) adequate to maintain lean body mass. Vitamin and mineral supplementation is required. Multivitamins should be in a chewable or soluble form and given in two divided doses per day. Calcium citrate supplements are recommended (1200–1500 mg/day). Whether this supplement will be uniformly adequate to optimize bone growth in a growing adolescent still needs requires clarification. B complex vitamin supplementation usually is recommended to augment the thiamin contained in standard multivitamins. Iron should be supplemented, even though tolerance for this mineral is poor. The prothrombin time should be monitored as a measure of vitamin K sufficiency. Patients should receive proton pump inhibitors. Nonsteroidal anti-inflammatory medications are avoided to avoid ulceration of the Roux-en-Y limb. Ursodiol and ranitidine are given for at least 6 months after surgery to decrease the risk of cholelithiasis and marginal ulcer. Patients with symptomatic gallstones should have a cholecystectomy before the bariatric procedure. Outcomes of bariatric surgery have been extensively reported in adults (17–19,21,22). After Roux-en-Y gastric bypass, 84% to 90% of adults lose more than 50% of their excess weight and have a significant improvement of co-morbidities (16,21,23). Weight loss reaches a plateau after 12 to 18 months in most patients (16). As many as 30% of adult patients regain much, if not all, of the weight lost after surgery (24,25). Surgical mortality for Roux-en-Y gastric bypass is 0.5% to 1% (16,21). Early complications, such as pulmonary embolus, anastomotic leak, or wound infection, occur in 1% to 5% of adult patients (16,21). Late complications, including stricture, small bowel obstruction, marginal ulcer, and mineral or vitamin deficiency, occur in up to 30% of adult patients (21). Many of the complications can be prevented by careful follow-up. The adjustable gastric band has not been as successful as Roux-en-Y gastric bypass. Weight loss is less, averaging only 21% to 38% of the patient's excess weight (26). Although most reports consider weight loss as the indicator of success in obesity surgery, we think that the reversal of co-morbidities should be the primary outcome for adolescents undergoing this procedure. Mortality after gastric band operation is less than 1% (22). Complication rates as high as 40% have been reported, but in a recent report, the complication rate was lower (26). Complications include erosion of the band into the stomach, band slippage, gastric mucosal intussusception through the band, pouch dilatation, esophagitis, and malfunction of the subcutaneous port (22,26). The reoperation rate after gastric band may be as high as 41% (22,26). There are recent reports of reoperation rates less than 5%, implying that outcomes may be improving as experience increases (27). Bariatric surgery in adolescents has been reported in a number of studies since 1985 (16,23,28–37). These studies include 140 adolescent patients, of whom 113 had open procedures and 27 had laparoscopic surgery. The outcome data of these adolescents is similar to that reported in adults. However, the long-term results of bariatric surgery in adolescents are unknown. Therefore, we strongly recommend that these procedures be done only in centers with the required multidisciplinary patient support services and in centers able to participate in well-organized prospective investigations (Inge T. In Press.). Accurate, long-term outcome data are essential to determine the risk in relation to benefit of these procedures in the pediatric population.