Issues for the Bariatric & Metabolic Professional
Procedure Is Growing in Popularity, But Long-term Efficacy Remains Unknown
By Monica Smith
San Diego—Sleeve gastrectomy, a procedure rarely performed a few years ago, seems to be emerging as the favored bariatric surgery in adolescents, and although it will be some time before researchers accrue enough long-term data to endorse the sleeve as the gold standard in young patients, mounting evidence in favor of the procedure suggests the trend will continue.
Surgeons debated the evidence in favor of and against performing pediatric bariatric operations in teens, as well as the rise in popularity of the sleeve, at the annual meeting of the Society of American Gastrointestinal and Endoscopic Surgeons (SAGES).
Aayed R. Alqahtani, MD, director, King Saud University Obesity Chair, and associate professor, College of Medicine, King Saud University, Riyadh, Saudi Arabia.|
Mary Brandt, MD, professor of surgery, Baylor College of Medicine, and surgical director, Adolescent Bariatric Surgery Program, Texas Children’s Hospital, Houston.
Thomas H. Inge, MD, PhD, professor of pediatrics and surgery, University of Cincinnati.
Marc P. Michalsky, MD, associate professor of clinical surgery, Ohio State University College of Medicine, and surgical director, Center for Healthy Weight and Nutrition, Nationwide Children’s Hospital, Columbus.
“It used to be that every once in a while we would do a sleeve; now every once in a while we do a Roux-en-Y gastric bypass [RYGB],” said Marc P. Michalsky, MD, associate professor of clinical surgery, Ohio State University College of Medicine, and surgical director, Center for Healthy Weight and Nutrition, Nationwide Children’s Hospital, Columbus.
Since 2008, bariatric surgeons at the Cincinnati Children’s Hospital Medical Center, also have witnessed a spike in interest in sleeve gastrectomy in the adolescent population. “There is a clear three-to-one preference if you allow families to hear pros and cons of both surgeries and make a partnership in deciding what operation to use,” said Thomas H. Inge, MD, PhD, professor of pediatrics and surgery, University of Cincinnati, during the debate at SAGES.
Pradeep Pallati, MD, University of Nebraska Medical Center, Omaha, and colleagues evaluated all pediatric bariatric cases in the University Health System Consortium database between October 2008 and September 2011 and witnessed a similar trend, which he described during a plenary session at SAGES that was recently published (session S054; Surg Endosc 2012 May 12 [Epub ahead of print]).
“We noticed that initially, just three years ago, only eight [adolescent] patients had sleeve gastrectomy. Last year, 24 had sleeve gastrectomy,” Dr. Pallati told General Surgery News. “At the same time, we saw that laparoscopic gastric banding has gone down. Our theory is that since the band has been around for many years and more researchers and surgeons are looking at complications related to the band, they are using the band less and picking up sleeve gastrectomy as a primary procedure.”
Dr. Pallati and colleagues found complications related to sleeve gastrectomy in the pediatric population were low, with no major morbidity. Although others have reported serious perioperative complications with the procedure, this series found no readmissions in the first month. “But as far as long-term weight loss and other outcomes, we don’t know yet,” Dr. Pallati said.
This unknown was a common refrain in presentations and discussions at the SAGES meeting regarding adopting sleeve gastrectomy in teenagers and children. Is sleeve gastrectomy the best surgery for young people? How young is too young? Awaiting long-term outcomes, we simply don’t know yet.
Bariatric Surgery in Adolescents
There are many persuasive arguments in favor of early intervention for obesity. Notably, there is the predictive value of knowing what lies ahead for obese children. “A large percentage of obese children go on to become obese as adults, particularly if they have a body mass index [BMI] over 40 kg/m2,” said Mary Brandt, MD, professor of surgery, Baylor College of Medicine, and surgical director, Adolescent Bariatric Surgery Program, Texas Children’s Hospital, Houston.
Second, children tend to experience worse and/or different comorbidities than adults. Obese children suffer worse asthma and sleep apnea than adults, and can develop Blount’s syndrome and
slipped capital femoral epiphysis, which adults do not experience. Furthermore, hypertension and cardiac disease early in life tend to shorten life.
Then there is quality of life. “Health-related quality of life in obese children is similar to that of children with cancer,” Dr. Brandt said. “Because we think the consequences of obesity are greater over time, the morbidity and mortality of adult obesity is worse when it begins in childhood.”
With behavioral changes and drug therapies unlikely to result in satisfactory long-term weight loss, many consider surgery the preferred treatment for management of obesity in adults. Questions remain, however, about the role of bariatric surgery in younger people due to concerns about nutritional deficiencies, perioperative complications, compliance and long-term outcomes.
In 1991, when the National Institutes of Health (NIH) published its stance on surgical treatment for obesity, it could not conclude for or against bariatric surgery in adolescents (NIH Consensus Statement 1991;9:1-20). Today, however, the Academy of Pediatrics recommends bariatric surgery for patients with a BMI of 50 kg/m2 or greater, or a BMI of at least 40 kg/m2 plus severe comorbidities (Pediatrics 2007;120:S254-S288).
But attitudes toward bariatric surgery in adolescents vary by specialty. Although surgeons have shown increasing acceptance of surgical intervention in young patients and interest in developing surgical programs for adolescents, primary care physicians remain less than eager to refer adolescents to surgery for obesity (Obes Surg 2005;15:1192-1195; Obes Surg 2011;20:937-942).
At this point, even among those who agree that surgery should be an option, no one really knows which is the best procedure for young people. Gastric banding, RYGB and sleeve gastrectomy all have their strengths and weaknesses, pitting weight loss and resolution of comorbidities against complications and long-term nutritional deficiencies. But the surging popularity of the gastric sleeve suggests surgeons and informed patients and their families think it offers the best tradeoff.
“The gastric sleeve offers excellent treatment of obesity with very few complications,” said Dr. Inge, arguing in favor of sleeve gastrectomy during
SAGES’s debate session on pediatric bariatric surgery.
“There is no foreign body left to erode or require removal, no adjustments are needed, and malabsorption should be less. There is a great reduction in ghrelin, so hunger satiety signals are quite dramatically affected after sleeve gastrectomy. Bowel obstruction later in life is unlikely, the pylorus is preserved and the biliary tract is not excluded.”
He pointed to a randomized controlled trial that found weight loss at three years to be about the same in adult patients who underwent either RYGB or sleeve gastrectomy, with the latter being associated with reduced nutritional deficiencies (Obes Surg 2011;21:1650-1656).
“But people are always concerned with long-term outcomes,” Dr. Inge said. “If you look at three and six years, you see a weight loss curve almost identical to what happens with the bypass [RYGB], where you see initial dramatic weight loss, and then the system resets itself a few years out at about 50% excess weight loss” (Ann Surg 2010;252:319-324).
Hard data on the gastric sleeve in adolescents was unavailable until recently, but results from the largest study to date look promising. Aayed R. Alqahtani, MD, director, King Saud University Obesity Chair, and associate professor, College of Medicine, King Saud University, Riyadh, Saudi Arabia, and his colleagues reported an average excess weight loss of 62% at two years in 108 obese adolescents who underwent the procedure (Ann Surg 2012;00:1-8).
“That parallels what we might see with gastric bypass, and it’s certainly greater than the average results we might see with the band procedure,” Dr. Inge said. “There is also a 90% reduction in sleep apnea symptoms, a 94% resolution of diabetes, prehypertension, hypertension and dyslipidemia,” 83%, 75% and 70%, respectively. “So the data are very striking and similar to what we’ve come to expect from gastric bypass,” Dr. Inge said.
Dr. Inge hopes to contribute to accumulating evidence about the efficacy and safety of several procedures through the NIH-sponsored Teen Longitudinal Assessment of Bariatric Surgery, which has completed enrollment and includes a sizeable number of adolescents undergoing sleeve gastrectomy.
“We are collecting hundreds of variables prospectively, so we should be able to add numbers as well as rigorous research methodology to questions of ultimate outcome of sleeves in teenagers,” Dr. Inge said. “From adult data, we are worried about reflux, so we are monitoring reflux very carefully in teens who have undergone this procedure.”
Dr. Brandt, taking the role in the debate against sleeve gastrectomy, argued that there is not long-term data to make this the procedure of choice in children.
“My only concern is that we really don’t have good 10-year data yet,” Dr. Brandt said. “For instance, the lap band was hugely popular, but now that long-term data is being reported, it is being proven to be not such a good choice.”
Although she does not expect the sleeve to be a failure 15 or 20 years from now, the possibility of poor long-term outcomes is an unsettling proposition.
“Physiologically, there is certainly the potential that the sleeve will dilate, and the procedure could cause damage to the esophagus. Also, there is a possibility that the ghrelin cells could repopulate,” which might nullify effect on satiety. “So it’s like any new procedure. The data we have now suggest the sleeve is the best procedure [for adolescents]. But this is why we do research and why we follow patients long term.”
For the record, Dr. Brandt performs RYGB in her adolescent patients, although her group has done sleeve gastrectomies when they thought the risks associated with RYGB were high enough to warrant the simpler procedure. “I really think Roux-en-Y gastric bypass is the gold standard, and that until we have all the data we need, in this vulnerable population we are obligated to do what is proven,” she said.
How Young Is Too Young?
Many pediatric surgeons, concerned about developmental issues in children who are still physiologically and psychologically immature, are hesitant to extend bariatric surgery to children below the age of 13 or 14 years. Others, troubled by the potential effect of a lifetime of obesity when intervention is delayed, feel that reserving bariatric surgery for teens is too restrictive.
“Bariatric surgery is a solution, and yes, there are some concerns … about safety,” said Dr. Alqahtani, arguing for bariatric surgery at any age during the debate session. “But sleeve gastrectomy in children is not a new idea.” A survey conducted since 1965 of sleeve gastrectomy for various indications in children under the age of 12 years has found consistent normal growth, he said.
Dr. Alqahtani’s review of 108 young patients undergoing sleeve gastrectomy included many patients who do not meet current recommendations for bariatric surgery in adolescents; 21 had a BMI less than 40 kg/m2, and five had a BMI less than 35 kg/m2. Furthermore, the patients’ ages ranged from 5 to 21 years, with 47 patients under the age of 14 years.
Comorbidities did not discriminate by age, and were seen in about 83% of all patients. Younger children, in fact, had a higher prevalence of sleep apnea, which was seen in 49%, compared with 21% of the older children. Type 2 diabetes was seen in about 20% of both groups, and nearly 50% of all children had dyslipidemia.
In addition to the sleep apnea, diabetes and hypertension, 40% of the younger children had nonalcoholic fatty liver disease activity scores greater than 5, and 12% had bridging fibrosis.
“Do we want to leave these patients suffering and living with their problems? Should we leave these patients to die of cirrhosis in the future? It is not an option,” Dr. Alqahtani said.
Over the 24 months of follow-up, 90% of the patients experienced successful weight loss, and resolution of comorbidities ranged from 70% to 100%.
“Excess weight loss is no different in [children] less than 14 or more than 14 years of age,” Dr. Alqahtani said. “Regardless of age, and based on comorbidities, we should not deny [surgical] treatment.”
He did caution that bariatric surgery for very young people should be performed only by qualified bariatric surgeons in institutions with a committed program; that the program adhere to a clear, clinical pathway; that the program assure long-term follow-up with a goal of 75% at five years; and that surgery is justified by valid, clearly documented indications on a case-by-case basis.
Many surgeons, however, feel that bariatric surgery in children who have not completed puberty is unproven, and probably not indicated. Dr. Michalsky argued against the idea of bariatric surgery at any age.
“If you look at severely obese 4-year-olds, the probability of developing adult obesity is about 20%; by the teens, that concordance is up to 80%. We don’t know the probability of an 8- or 9-year-old developing severe obesity.”
It comes down to a risk-ratio analysis in determining the appropriate time to operate. What is the risk associated with allowing patients to continue in their trajectory until they reach a more traditional time frame for adolescent bariatric surgery, compared with the risk of performing such dramatic procedures in the very young?
“Although I think these operations can be done at any age, and you can document effective weight loss as Dr. Alqahtani has shown, my concern is that we really have no long-term data looking at the nutritional consequence of doing so,” Dr. Michalsky said.
Physiology and metabolism differ between children and adolescents, particularly in bariatric patients, where adolescents tend to be physiologically similar to adults. “Most of these patients have completed their growth potential, so the concept of stunted growth in these patients is more theoretical,” Dr. Michalsky said. “But nutritional deficiencies are still a concern. There is evidence across all the different operations that nutritional and vitamin deficiencies need to be attended to.”
One of the first studies to examine nutritional status in adolescents undergoing bariatric surgery (RYGB in this case) found that although the proportion of protein, fat and carbohydrates went unchanged from baseline intake, protein, calcium and fiber intakes fell below the recommended daily intake (Surg Obes Relat Dis 2012;8:331-336). “That’s a big problem for a bunch of 8- or 9-year-olds,” Dr. Michalsky said.
The main objection to performing bariatric surgery in preteens is that there simply is not enough data available to support the safety of this approach. “Until there is evidence that we can perform operations of this nature on children that young with our current armamentarium of operations, they are not going to be widely accepted in that population,” Dr. Michalsky said. “But the current age range may need to be revisited in the future in the event that technologies and/or procedures that would provide significant weight reduction without micro- and macro-nutrient deficiencies become available.”