for severe obesity in adults but has not been approved for use in adolescents under 18 years of age.
Surgical Procedures
RYGB, laparoscopic adjustable gastric band (LAGB), and laparoscopic sleeve gastrectomy (LSG) are the most commonly performed weight loss surgeries (Figures 3.1–3.3). Gastric band and sleeve gastrectomy are restrictive procedures (meaning that they cause limitation to food intake), while the RYGB has been described as a procedure whose effects are related to a combination of gastric restriction and intestinal malabsorption. Despite these classifications, it has become clear that all weight loss procedures have metabolic effects, which may contribute more significantly to postoperative weight loss than can be explained simply by gastric restriction and intestinal malabsorption alone.
Figure 3.1 Pencil drawing of RYGB.
Source: Penn Medicine
In the RYGB, a small stomach pouch is created and the jejunum is divided. The distal limb of the jejunum is then connected directly to the small gastric pouch, bypassing the rest of the stomach and the proximal intestine. The small bowel is then placed in continuity with itself more distally, thereby providing a route for biliopancreatic secretions to mix with food. The small size of the stomach limits the capacity of food intake, while calorie and fat absorption is limited as the majority of the stomach and duodenum are bypassed.
The LAGB is a laparoscopic procedure where an inflatable silicone band is placed around the upper part of the stomach, creating a tiny new stomach pouch that limits the capacity to take in large amounts of food. The band position results in a small stomach outlet that leads to slowing of upper gastric emptying and increases the sensation of satiety. The band is able to be inflated and deflated by injecting a needle through the skin into a port connected to the band to adjust the size of the opening from the gastric pouch. Gastric banding has the benefit of being relatively reversible and minimally invasive, as it requires no cutting or stapling of the stomach or bowel (Figure 3.4).
Figure 3.2 Pencil drawing of LAGB.
Source: Swedish Health Services
Figure 3.3 Pencil drawing of LSG.
Source: UNC Medical Center
Figure 3.4 Pencil drawing of how to deflate port on LAGB.
Source: Reproduced from Hamdan et al. (2011)
The LSG is performed by removing 75–80% of the stomach and leaving a long gastric tube or sleeve of the stomach, thereby restricting intake. This procedure was initially part of a staged approach to more complex weight ‐loss procedures but has been shown to offer significant weight loss and improvement of comorbid conditions such that it is currently offered as a stand‐alone procedure.
Indications
Bariatric surgery is available to patients with severe obesity who have a low probability of successful weight loss with nonoperative measures, and who demonstrate motivation to continue medical treatment and lifestyle changes after surgery. In adults, criteria for bariatric surgery include those with a BMI > 40 or those with a BMI > 35 with comorbid diseases. As the risks of bariatric surgery in adolescents are not yet completely understood, adolescents are typically offered bariatric surgery primarily if they have comorbidities. Adolescents with severe comorbidities such as type 2 DM, moderate to severe sleep apnea, or pseudotumor may be considered surgical candidates with a BMI as low as 35. Adolescents with mild comorbidities and a BMI of 40 or greater are also potential candidates for weight loss surgery. While degree of obesity and weight‐related medical problems are the most basic determinants of potential candidacy, adolescent patients should undergo a thorough workup to rule out medically reversible causes of obesity or contraindications to surgery. The workup typically involves evaluation by a multidisciplinary team, including a pediatric/adolescent medical weight loss specialist, a bariatric surgeon (or pediatric surgeon with expertise in performing bariatric procedures), a dietician, a mental health professional with experience in evaluating bariatric patients, an exercise specialist, and others. In addition, most patients undergo an intensive medical weight management program throughout the evaluation period prior to proceeding to weight loss surgery.
Complications
An estimated 5–25% of patients who undergo bariatric surgery will have complications. Most surgical complications will occur in the immediate postoperative period, perhaps while the patient is still in the hospital. These include anastamotic leak, pulmonary embolism, and bleeding. We will not discuss these complications in depth in this chapter.
Delayed complications occur in an estimated 10% of patients who undergo weight loss surgery. Patients may present to the emergency department (ED) with these delayed complications. Complications may be related to the device itself (if one is placed), to intermediate or late surgical complications (such as bowel obstruction), or they may relate to gastrointestinal (GI) symptoms that occur as a result of changing the GI tract anatomy (Table 3.1). Practitioners treating patients who have had bariatric surgery must be alert to the fact that these patients can have GI disorders that are not secondary to their weight loss surgeries as well. Any patient with significant abdominal symptoms who has had bariatric surgery in the past should be evaluated by a surgeon experienced with such patients. Such consultation may be helpful in directing the most appropriate workup and management, and early consultation is essential in those cases where a prompt return to the operating room is indicated. The main bariatric surgery complications with timing, symptoms, diagnostics and treatment are summarized in Table 3.2.
Table 3.1 GI symptoms and associated causes.
| DiarrheaMalabsorptionBile saltsDumping syndromeFood intoleranceLactose intoleranceIrritable bowel syndromeBacterial overgrowthInfectionVomitingOvereatingNoncompliance with bariatric surgery dietObstructionMarginal ulcersStomal stenosisGastric band slippage with gastric prolapseRoux stasis syndromeExcessively tight gastric bandGallstonesGastroesophageal refluxConstipationDehydration due to decreased fluid intakeIron supplementationMultivitamin supplementation |
All patients who present with abdominal pain, nausea, vomiting, or diarrhea after having weight loss surgery should have a full exam, with close attention to signs of dehydration and shock. Tachycardia is especially worrisome, as it may indicate dehydration, sepsis or infection (particularly in the setting of a postoperative leak), GI bleeding, pulmonary embolism, or even acute myocardial infarction. Intravenous access and full laboratory
