At Johns Hopkins Bayview Medical Center’s quarterly breakfast with pediatricians, former Johns Hopkins bariatric surgeon Kimberly Steele begins her presentation with some startling statistics: obesity has more than doubled in children and quadrupled in adolescents in the past 30 years, according to the Centers for Disease Control and Prevention (CDC). The percentage of obese 6-to-11 year-olds increased from 7 percent in 1980 to 18 percent in 2012. The number of obese teens jumped from 5 to 21 percent over the same period. By 2012, more than one-third of children and adolescents were overweight or obese in the United States.
Citing obesity-related conditions like diabetes, heart disease and hypertension, along with estimates that by 2025 some 40 percent of Americans will be obese, Steele repeated Yale pediatrician David Katz’s dire prediction that “Today’s kids may become the first generation in the history of man to have a life expectancy projected to be less than that of their parents.”
While diet, exercise and behavior modification have helped patients lose weight, Steele cited studies showing many tend to regain the weight and then some (Ann Intern Med 1993;119:688-693). “It’s yoyo dieting that actually makes it worse,” she said.
So, is bariatric surgery a viable option for adolescent patients? And if so, when is it appropriate, what procedures are offered for youngsters, and what are their outcomes?
The evidence is still scarce because bariatric surgery has only recently been offered to adolescents, Steele noted, and most long-term studies have focused on obese adults. Generally those patients have fared well, with around 80 percent losing and keeping weight off. The 20 percent of patients who regain weight tend to have poor follow up (Obesity Surgery 2006 Aug;16(8):1032-1040).
“The nice thing about surgery is the weight loss is maintained and sustained,” said Steele. “Patients who stick with it, see their primary care physician and follow nutritional guidelines following surgery do great. Patients who disappear after their operation and don’t come back for resources have problems.”
The criteria for bariatric surgery for pediatric patients are not clearly defined, Steele noted, with recommendations based on adult guidelines. Groups like the American Society for Metabolic and Bariatric Surgery stipulate that adult surgical patients must have a BMI of over 40 with minor medical comorbidities or a BMI over 35 with significant comorbidities like arthritis, diabetes and sleep apnea. Also, they must have failed to achieve and retain weight loss through diet and exercise programs.
Bariatric surgeons like Thomas Inge have established guidelines for pediatric patients that include 6 months of weight management, physiologic maturity (13 years old for females and 15 years old for males), BMI of 40 with serious obesity-related comorbidities, or BMI of 50 with less severe comorbidities. Also, patients must be committed to comprehensive medical and psychological evaluations before and after surgery (Pediatrics 2004;114:217-223).
Steele noted that The Johns Hopkins Center for Bariatric Surgery, in partnership with the Mt. Washington Pediatric Hospital, now has an IRB-approved protocol for patients ages 16 to young adults. Criteria include a BMI over 40 with severe medical comorbidities, BMI over 50 with less severe obesity related conditions, and a failed supervised 6-month diet and exercise program. Pediatric patients, she added, go through rigorous educational, nutritional and psychiatric evaluations, as well as anesthesia, medical and surgical consultations to help determine whether they are candidates for surgery. A strong supportive family environment is also required. The need for surgery, Steele added, is another decisive factor.
“In cases where there’s no other alternative, yes, bariatric surgery can help,” Steele said. “Surgery does result in a meaningful and sustained weight loss. That’s what we can offer teens who are really struggling.”
The Center offers such pediatric patients three surgical options, all laparoscopic—adjustable gastric band, sleeve gastrectomy, and gastric bypass. The band and sleeve are so-called “restrictive” weight loss procedures in that they limit the amount of food patients can eat at any one time. The band approach, in which a saline-filled plastic band is wrapped around the top part of the stomach like a belt to reduce food intake, is the least invasive procedure. No incisions or resections are made in the stomach and small bowel, allowing for full digestion and absorption.
“I try to teach the parents and the kids that eating a hamburger would be really rough,” Steele said. “Also, ice cream, sugary drinks and pretty much anything that can melt in your mouth get through, so for those sweet eaters the band tends not to work. It’s important to recognize that when you’re discussing the best procedure for an adolescent.”
In the vertical sleeve, three-quarters of the stomach is removed, reducing its typical watermelon size to that of a banana. Also, because there’s no cutting or rerouting of the small bowel, bile and pancreatic fluid allow food to be completely digested and absorbed in the bowel.
Malabsorption, however, does occur in the gastric bypass procedure, in which a small stomach pouch the size of an egg is created to restrict the amount of food that can be eaten before feeling full. The lower portion of the small intestine is attached to this newly created pouch, allowing food to be digested but bypassing the upper part of the small intestine where minerals and vitamins are easily absorbed. Because gastric bypass, along with the band and sleeve are restrictive approaches, patients must comply with post-operative nutritional guidelines to adjust their intake to its significantly smaller size.
So, what’s the best procedure for adolescents? That’s still being determined by studies, Steele said, but all three approaches have shown good results echoing adult outcomes with sustained weight loss in about 80 percent of patients and significant improvement in comorbid conditions. In a 2005 multicenter outcomes study of adolescent gastric bypass patients, one year after surgery average fasting insulin declined 70 percent, fasting glucose 13 percent, and triglycerides 30 percent. There was a total resolution of sleep apnea, as well as a decrease in ventricular wall thickness and left ventricular mass index. Also, patients experienced a significant improvement in quality of life and symptoms of depression (J Pediatric Surg 2006;41:137-143).
In a one-year follow-up of 45 adolescents who had the band procedure, patients lost on average 45 percent of excess body weight. Also, 55 percent of patients had complete resolution—and 29 percent improvement—of comorbid conditions (J Am Coll Surg November 2009). In a band-gastric bypass comparison study of 590 teens, there were 4.7 percent band revisions/removals vs 2.90 percent bypass revisions (Pediatrics 2010 Oct;126(4)e746-53). Steele attributes the band’s higher complication rate, in part, to the need for adjustments to the band and lack of follow-up by patients.
Despite favorable outcomes following gastric bypass, Steele feels the surgery is “too extreme” for adolescents. Concerns include diarrhea and nausea related to dumping syndrome, caused by bypassed food emptying into the small intestine too quickly. Another issue is anemia resulting from decreased iron absorption. The recommendation for many gastric bypass patients is 3,000 units of vitamin D daily and calcium supplements for life.
So is the sleeve, which requires no adjustments and presents no malabsorption issue, the answer for adolescents? There is little long-term data on the sleeve gastrectomy, though a retrospective study from 2008 to 2011 of 108 adolescents showed weight loss similar to that in adults who have undergone the procedure (Surgery 2012 Aug;152:212-217).
“It has the lowest complication rate, it’s less invasive, there’s less risk of or vitamin deficiencies, and it gives patients the ability to convert to gastric bypass as adults,” Steele said. “Nowadays, the sleeve is very much in favor.”
Steele concluded that patients and families considering weight loss surgery should consult with their pediatrician and a comprehensive bariatric center like Hopkins’ that offers multidisciplinary pediatric services. For more information, contact the Johns Hopkins Center for Bariatric Surgery at 410-550-0409.