The clinical pathway described on this paper was employed in our institution beginning in March 2008. Patients who underwent LSG via this protocol until July 2014 were included. In order to study the effect of bariatric surgery on growth, the surgical group was matched for age, gender, and height with obese children and adolescents who are in the non-surgical WM program at the same period.
Weight Management Selection Criteria
The criteria for acceptance into the WM program include an age below 21 years and a body mass index at or greater than the 85th percentile for age. Patients are categorized based on BMI percentile and comorbidity burden and according to internationally accepted standards  (Fig. 1).
Weight Management Program Details
A multidisciplinary team (MDT) consisting of a pediatric endocrinologist, a bariatric surgeon, dieticians, nurses, psychologists, and health educators counsels each patient and monitors their progress. Once a month, a full-day workshop is held for new patients and their families, during which the pediatric endocrinologist, the senior dietician, the psychologist, and the health educator, all discuss how to have a healthy lifestyle with parents and children. The discussions include examples of poor choices, substitutions for common unhealthy choices, hands-on training on how to prepare healthy foods, and physical education lessons. Each patient is then regularly seen in the clinic according to their health category (Fig. 1). In the clinic, care is provided via a family-based approach focused on nutrition and behavior counseling. Additionally, patients are prescribed regular physical activity according to their age, and their parents are encouraged to monitor and calculate the duration of physical activity performed each day. Patients are seen monthly by the dietician, the nurse, the psychologist, and the health educator, and every 3 months by the pediatric endocrinologist.
Bariatric Surgery Selection Criteria
Under our care pathway, bariatric surgery is only recommended for children and adolescents who fail WM while their obesity is deemed to have a major impact on their lives. Additionally, it is ensured that the patients and their families are motivated, compliant, have a full understanding of the risks and benefits of the procedure, and are prepared for lifelong commitment.
The criteria include (1) a BMI of at least 40 kg/m2 (or having multiple comorbid conditions with a BMI higher than 35 kg/m2 or above the 99th percentile for age); (2) having undergone the family-based nutritional and behavioral therapy program with our institution’s multidisciplinary team for at least 6 months with failure to achieve weight reduction of at least 10 % from baseline body weight; (3) presence of a dedicated caregiver from the patient’s family; (4) supportive psychological evaluation in the form of behavioral (features of conduct disorder, impulsivity, and aggression), cognitive (psychiatric history, readiness to change, and commitment to instructions), emotional (depression and self-harm including suicide ideation or previous attempt, anxiety, and stress), and psychosocial assessment (activities and interests, friendships, bullying, and social isolation). All evaluations are performed through a one-to-one interview, and patients with significant findings in the interview are further evaluated with the concerned specialist; (5) motivation and realistic expectations by the patient and their family; (6) absence of contraindications for surgery; and (7) informed consent or parental consent with child assent based on patient age.
Upon fulfillment of all criteria for bariatric surgery, we evaluate all patients in the multidisciplinary obesity clinic with a specific perioperative protocol. The patients are interviewed 2 weeks prior to admission to assess their readiness and complete understanding of risks and benefits of the surgery. Their investigational workup is reviewed and any questions the patient or their family might have are answered (Tables 1). On this visit, they are provided with an instructions manual regarding the surgery, perioperative care, and postoperative commitments. At the time of the patient’s admission for surgery, nurses are provided with a detailed set of pre-typed preoperative orders for each patient (Table 2). Depending on the hospital’s policies, patients can be admitted to the ward on the day of the surgery or the night before. (See Tables 3 and 4).
Patients are positioned in the reverse Trendelenburg French position and a five-trocar approach is used. The abdominal cavity is insufflated with carbon-dioxide to a pressure of 15 mmHg using a 10 mm optic port placed at or within a variable distance above the umbilicus, based on the patient’s age. This port serves as the camera trocar. Four additional trocars (one 12 mm and three 5 mm) are placed under laparoscopic view. The greater curvature is then freed close to the stomach wall, beginning from approximately 2 cm proximal to the pylorus to the angle of His using a Ligasure™ device (Valleylab, USA). The left crus is then dissected and the angle of His is delineated. Posterior adhesions to the pancreas are lysed. A 36-Fr calibrating tube (34-Fr for patients below the age of 12 years) is placed transorally and carefully advanced through the pylorus to the duodenum. At 2–3 cm from the pylorus, the stomach is divided using a linear stapler (Echelon 60 Disposable, Ethicon, Endo-Surgery, Inc., Cincinnati, OH). A green load (4.1 mm) followed by a gold (3.8 mm) and a blue load (3.5 mm) is used for all patients except for those younger than 12 years with thinner stomachs, where only gold and blue loads were used. There is no routine staple line reinforcement or routine testing for leak or drain placement. The resected stomach is then extracted through the 12 mm port site, and the port sites are closed using the Endo Close device (US Surgical TM).
As part of the clinical pathway, the attending nurses are provided with a set of pre-typed orders for each patient (Table 2). Scheduled medical visits are performed by the multidisciplinary team over the next one to two postoperative days, providing the patients and their families with specific instructions and guidance as per protocol. The clinical nutritionist provides postoperative diet summary and nutrient supplements to each patient (Tables 3 and 4). Based on preoperative evaluation including clinical and polysomnography results, patients with severe obstructive sleep apnea (OSA) are admitted to the intensive care unit (ICU) overnight. Otherwise, all patients are sent back to a ward staffed with nurses experienced in caring for severely obese patients. On the second postoperative day and upon tolerance of oral intake, patients are discharged with home instructions and long-term follow-up schedule (Table 5).
All outcomes of interest are prospectively collected in a custom-developed database. It includes clinical research forms (CRF) that capture medical assessment, anthropometric measurements, investigations, and medications prescribed. The CRFs capture data on each of the following stages: (1) Each visit during the non-surgical WM period, (2) preoperative assessment, (3) operative details, (4) in-hospital stay, (5) discharge notes, and (6) postoperative follow-up points (3, 6, and 12 postoperative months and annually thereafter).
Safety of bariatric surgery is comprehensively assessed by documenting all intraoperative and postoperative complications. Additionally, growth after surgery is compared with growth of the non-surgical WM control group through assessing height z-score, which was calculated using the LMS method developed by Cole . This method is a standard technique for constructing age-related growth references and summarizes the distribution of an anthropometric variable at each value of a covariate (age) in terms of three parameters: Box–Cox power (L), median (M), and coefficient of variation (S). After calculating the three parameters at each age from the reference population, these values can be used to calculate z-scores for the respective anthropometric variable. The LMS parameters used in this study were calculated by the Centers for Disease Control and Prevention (CDC) from their growth charts . Growth velocity, which was assessed via measuring height change, was also measured.
Efficacy of bariatric surgery is assessed by measuring adiposity change and resolution of comorbidities. Excess weight lost and BMI change are calculated as previously described .
The comorbidities monitored are diabetes, prediabetes, hypertension, prehypertension, dyslipidemia, and sleep apnea, and they are all assessed using internationally accepted definitions that are specific to pediatric age groups [19–22]. Remission and improvement in comorbidities was assessed based on clinical and biochemical parameters with specific cut-off ranges that have been described previously .