Bariatric Surgery in the Pediatric Patient

Pediatric Surgery
An interactive discussion between Dr. Ponsky, Dr. Harmon and Dr. Inge about the role of bariatric surgery in pediatric patients.

Dr. Inge is Chief of Pediatric Surgery, Akers Endowed Chair in Pediatric Surgery, and Director of Adolescent Bariatric Surgery at Children’s Hospital of Colorado.

Dr. Harmon is professor of Surgery at University of Buffalo and Surgeon-in-Chief at Oishei Children’s Hospital.

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Need for bariatric surgery in the current era:
  • The need for obesity surgery in the current era is mostly driven by the hard to control obesity related co-morbidities in children and the increasing incidence of obesity in teenagers. These co-morbidities include type 2 diabetes and obstructive sleep apnea. Bariatric surgery effectiveness in adults has also led more pediatric surgeons to adopt the same in the pediatric population.
Non-operative techniques for weight loss:
  • Non-operative weight loss techniques are more effective for younger children and for lower BMI categories. Lifestyle modifications can lead to about 5-10% of weight loss which is much less effective compared to bariatric surgery.
  • Calorie restriction is superior to exercise for weight loss. Weight loss maintenance is best achieved by exercise therapy and caloric restriction.
Pharmacotherapy for weight loss:
  • Drugs like orlistat, phentermine and topiramate are useful in adolescents but the overall weight loss resulted from them is not impressive (around 2% for orlistat for example).
  • These drugs are also not without significant side effects – for example orlistat can cause diarrhea.
Timing of bariatric surgery and patient referral:
  • Bariatric surgery is usually delayed until adolescence although surgeons worldwide have performed surgery in younger children in with good results. Also, comorbidities are an important factor in deciding to perform surgery rather than just need for weight loss.
  • Surgery is performed at lower BMIs as surgery initially results in 30% weight loss and lower weights can be achieved at lower BMIs.
  • Some patients are self-referred as their parents have undergone bariatric surgery. Some patients are referred by endocrinologists.
Multidisciplinary pre-operative management:
  • Preoperative and postoperative multidisciplinary management consists of a team of pediatric endocrinologists, gastroenterologists and psychologists. Surgeons can get to know patients when patients are referred to these medical specialists for weight loss – this also covers the 6-month mandatory period of medical trial of weight loss required by insurance carriers. Multidisciplinary management is also pivotal in preparing patients and families for surgery. These teams can also help deal with medically difficult patients such as those with monogenic obesity.
  • Unfortunately, appropriate insurance coverage is an important factor in considering surgery. Surgeons are an important advocate for patients in this process.
Surgical options:
  • Sleeve gastrectomy (LSG) has replaced Roux-en-Y gastric bypass (RYGB) as the first-choice procedure in adolescents in the current era. Gastric banding (LAGB) has not resulted in satisfactory outcomes in adults and is not generally preferred in children.
  • RYGB is a high potency operation that is usually chosen for difficult to treat monogenic forms of obesity. Otherwise LSG and RYGB are equally efficacious for exogenous obesity with LSG having a  slightly lower risk profile.
Steps of sleeve gastrectomy:
  • Most are performed laparoscopically.
  • Dissection starts with an energy device to take the greater omentum off the greater curvature of the stomach 5-6 cm proximal to the pylorus and continued all way up to the cardia and the short gastric vessels.
  • A bougie is then passed and laid along the lesser curvature. Some also use a clamp.
  • Serial stapling is then performed to take off the stomach along the greater curvature using the bougie as a guide to the size of the remnant stomach.
  • One needs to be careful while placing the final staples at the cardia so as not to include the esophagus while at the same time not leaving too much fundus as the latter can lead to significant reflux.
  • Staple line is then inspected and any bleeding is oversewn with figure of 8 stitches.
  • The specimen is extracted through one of the port sites which may need to be enlarged.
Steps of Roux-en-Y gastric bypass:
  • Most surgeries are completed laparoscopically.
  • As in sleeve gastrectomy, a Nathanson liver retractor can be used to retract the left lobe of the liver.
  • A lesser curvature based pouch is created by firing a stapler about 5 cm from the GE junction across the stomach and then firing vertically towards the cardia to complete the pouch.
  • The small intestine is then measured 50 cm from the ligament of Trietz and stapled at that point to separate the small bowel at that point. The small bowel then measured from that point to about 100 cm to create a Roux limb. This is then brought either in an antecolic or retrocolic fashion to create the gastrojejunostomy with the pouch.
  • The GJ is created either with a vertical stapler or with a 2.5cm circular stapler.
  • The jejuno-jejunostomy is then completed with linear staplers. The defect caused by stapler insertion can be closed either with hand sewn sutures or with staples.
  • The defects where internal hernias occur (Eg: Peterson defect) need to be closed.
Post-operative protocol:
  • Postoperatively clear liquids are started – usually 4 ounces an hour on the first day and 6 ounces the following day. Patients are usually discharged when they are able to consume 64-96 ounces a day of clear liquids.
  • Postoperatively diet is slowly advanced to soft mechanical diet rich in proteins in order to preserve the lean body mass. Usually small meals amounting to about 500 kcal in a day is consumed by the end of the first month. Proteins should amount to 60-80g per day.
Complications:
  • Sleeve gastrectomy patients can have a leak. Some surgeons routinely do an upper GI contrast study before starting liquids. Bleeding from the staple line can result in a GI bleed and may require endoscopic intervention. Reflux can be an issue on the long term but is likely less of a problem in teenagers compared to adults. All patients are put on PPIs postoperatively by some surgeons. The lack of a viable surgical option to reflux after a LSG should be discussed preoperatively with patients. Incidence of trocar site hernias can be reduced by suture closing large defects especially at the site of specimen removal.
  • Nutritional complications are lesser with LSG compared to RYGB and these including anemias and vitamin deficiencies.
  • RYGB has a greater risk of complications including internal hernias, strictures and marginal ulcers.
Outcomes of bariatric surgery:
  • Ideal weight loss expectation for the first year is usually 25-30%.
  • Obstructive sleep apnea resolves in most patients within weeks of surgery. The same with type 2 diabetes and glucose intolerance. This is not related to weight loss and could be related to neurohumoral mechanisms mediated by GI hormones. This is even more apparent with RYGB compared to LSG.
Long-term outcomes:
  • On the long-term weight loss is maintained, although there is usually some minor weight regain. Comorbidities which are resolved usually do not recur. This is not observed with medical weight loss where patients usually tend to develop more frequent and severe comorbidities with time. The TEEN-LABS is an NIH sponsored multi-center prospective study which has been instrumental in elucidating pediatric bariatric surgery outcomes.
Future research:
  • Research areas include less minimally invasive modalities like the gastric balloon and endoluminal stapling device which have shown some promise especially in the adult population. The other research area is to utilize the role of gut hormones to augment the effects of bariatric surgery.

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