More than 4.4 million U.S. children and adolescents are deemed severely obese, a condition that puts them on a lifelong path to a range of cardio-metabolic diseases, drives up their cancer risk and shortens their life spans.
And while bariatric surgery has become a mainstay in the medical toolbox for the treatment of morbid obesity in adults, when it comes to treating adolescents, the procedure remains somewhat misunderstood.
Pediatric surgeon Ann O’Connor, MD, director of the Adolescent Bariatric Surgery Program at Ann & Robert H. Lurie Children’s Hospital of Chicago untangles truth from fiction and discusses best practices in treating severely obese teens.
The belief that surgical intervention should be postponed until adulthood is well-intended but largely misguided, O’Connor says. Waiting too long to stem the toxic cascade fueled by obesity can have grave long-term consequences, as hypertension, diabetes and sleep apnea persist year after year.
“As physicians our first duty is to do no harm, but in this case, failure to intervene may pose a greater risk,” O’Connor says.
Some of the most convincing evidence for earlier intervention comes from a recent multi-center study published in the New England Journal of Medicine showing that nearly all adolescents with type 2 diabetes were in remission three years post-surgery. The same study found that 86 percent of those with abnormal kidney function before surgery experienced normalization of kidney function three years thereafter. Seventy-four percent of those with hypertension were normotensive at that endpoint, while 66 percent of those with abnormal cholesterol experienced improvements in their dyslipidemia.
Obese patients also have a higher lifetime risk of several cancers, including malignancies of the endometrium, gallbladder, pancreas and esophagus.
“Cancer risk is cumulative and proportionate to years of exposure, so the longer we wait, the higher the risk,” O’Connor says.
That was true, O’Connor says. Twenty years ago. Since then, an influx of data has clarified efficacy, success rates and complications of bariatric surgery, while also informing best surgical approach depending on individual patient factors.
“Our understanding of technique, patient selection, complications and outcomes have all evolved over the past few decades,” O’Connor says. “But when it comes adolescents, attitudes toward the procedure have not caught up with that reality.”
O’Connor cautions that much of the success and safety of the procedure is predicated on a highly selective screening process, careful pre-op assessment and rigorous post-op follow-up.
The belief that a child’s obesity is somehow the family’s fault and a result of cavalier parenting remains more pervasive among clinicians than it should be, O’Connor says, especially, in light of all the science pointing to the contrary.
“We now have studies in twins showing that both genetic and epigenetic factors can fuel morbid obesity,” O’Connor says. “Lifestyle and family dynamic can be catalysts but underlying biologic mechanisms are the true drivers of this pathology.”
Launched in October of 2014, the Lurie Children’s bariatric surgery program remains the only program in Illinois dedicated specifically to the treatment of teens. So far, it has “graduated” 10 patients. Another 10 are undergoing evaluation. There have been no complications and all patients are losing weight at the expected rate – 60 percent of excess pounds are typically shed within the first two years.
Careful patient selection
Bariatric surgery should be considered in teens with a BMI over 40, or for those with BMI between 35 and 40 and co-morbidities, such as sleep apnea, diabetes, hypertension, nonalcoholic steatohepatitis or pseudotumor cerebri.
Teens must be 13 years or older and mature enough to understand the implications of surgery. They must be able to commit to a lifestyle of diet, exercise and long-term medical follow-up after the procedure. Such commitment, O’Connor says, is the greatest predictor of success. Lack thereof, she says, is the most compelling reason to postpone or avoid surgery altogether.
“We never operate on kids who cannot assent or who appear not ready or mature enough to do so,” O’Connor says.
To rule out any underlying psychiatric or emotional problems, patients undergo screening sessions with a clinical psychologist. Any eating disorders or other mental issues must be addressed and treated before surgery.
“Our philosophy on operating is conservative: When in doubt, don’t.”
Pre-op testing to thwart post-op complications
Nutritional screens. To avert or correct nutritional deficiencies, O’Connor’s team checks baseline levels for vitamin D, vitamin B, calcium and iron. Even subtle insufficiencies warrant proactive correction with supplements to avert full-blown deficiency post-surgery. O’Connor believes that pre-emptive treatment may also boost healing and reduce infection risk.
“Vitamin deficiencies — particularly in vitamin D — are known to exacerbate inflammation, delay wound healing and fuel infection risk,” O’Connor says. “Correcting them before surgery makes sense.”
Insulin instead of glucose. To capture those on the cusp of developing diabetes, O’Connor checks insulin levels instead of the more commonly recommended glucose levels.
“Kids with elevated insulin are likely to develop diabetes within two years,” she says. “Knowing who is at greatest risk can help inform decision-making for patients and physicians alike.”
Cardiac check-up. Echocardiograms to detect left ventricular hypertrophy can inform treatment decisions that include blood pressure medication in addition to surgery. Hypertension and obesity can each drive cardiac muscle thickening, so being both obese and hypertensive delivers a one-two punch to the cardiac muscle.
“There’s emerging evidence that high levels of fat can alter signaling in the cardiomyocytes and cause aberrations in heart muscle tectonics,” O’Connor says. “The good news is that left ventricular hypertrophy can be reversed with weight loss and normalizing of blood pressure, with or without medication.”
Post-op contraception. The reproductive implications of weight-loss surgery are vastly under-appreciated, O’Connor says. Many obese girls have irregular periods due to hormonal imbalances. As these imbalances get resolved by post-op weight loss, a girl’s pregnancy risk goes up dramatically. Contraception is a must-have conversation with any females undergoing the procedure, says O’Connor. She has informally teamed up with an adolescent gynecologist for consults, a collaboration she’s hoping to formalize as a regular part of the program. O’Connor advises her sexually active patients to consider an IUD, which can be placed during the surgery itself.
No Smoking. Because smoking can delay tissue healing and increase the risk for post-operative stomach leakage, O’Connor refuses to operate on teens who are active smokers. She conducts periodic pre-op and post-op drug testing, including cotinine levels.
In an ideal world, patients would be followed for five years post-surgery, but in reality many drop out sooner. The minimum follow-up O’Connor demands of her patients is one year. Follow-up is most critical for psychological issues, which can in turn influence lifestyle and weight loss. This is because, O’Connor says, many patients with pre-existing addictive behaviors may substitute binge eating with other addictions following surgery. It is also critical to ensure patients don’t starve themselves in a misguided attempt to accelerate weight loss.
“It’s important for them to understand that not eating enough can dampen their metabolism and they can plateau.”
The preferred surgery for most patients is sleeve gastrectomy, in which 80 percent of the stomach is removed. The approach has lower complication rates, compared to Roux-en-y gastric bypass, which has fallen out of favor.
However, O’Connor cautions, the gastric bypass remains a better choice for those with treatment-resistant GERD, so careful pre-op assessment for acid reflux is critical, O’Connor says. Patients who report recurrent symptoms despite medication should undergo endoscopy to assess the condition of their esophagus and rule out Barrett’s esophagus.
“The sleeve gastrectomy can create high pressure on the stomach and flare-up reflux, which can further damage the esophagus,” O’Connor says. “In this subpopulation, the gastric bypass makes more sense.”
Overall, post-operative complication risk varies widely, with reports ranging from 2 percent to 20 percent. A recent New England Journal of Medicine study found 13 percent of patients required a follow-up procedure within three years of treatment. Careful patient selection and surgical skill can minimize post-operative risk to 1-3 percent, O’Connor says. In experienced hands, the risk for post-operative complications is comparable to that of laparoscopic cholecystectomy, she says.
The most dreaded complication of bariatric surgery is stomach leakage, which usually develops within the first few months of operation. It is caused by high pressure along the surgical staple line. Smoking and uncontrolled diabetes both drive up that risk so getting diabetes under control and smoking cessation before operation can decrease the likelihood of stomach leaks.
O’Connor says the current medical approach to treating obesity in teens is a woeful exercise in extremes — nothing or surgery. As any multifactorial disease, however, obesity requires a cocktail of treatments ranging from diet and exercise to medication to surgery.
There is a subpopulation of obese children who would be good candidates for pharmacologic, rather than surgical, management of obesity.
“This is a spectrum disease and our toolbox needs to reflect that,” O’Connor says. “We really ought to bridge that gap and precision-target treatment to reflect each patient’s physiologic and metabolic profile.”
Dr. O’Connor sees patients at Lurie Children’s at Northwestern Medicine Central DuPage Hospital in Winfield, Il.