Intraoperative uses of near-infrared fluorescence spectroscopy in pediatric surgery: A systematic review

BACKGROUND

The application of near infrared spectroscopy (NIRS) imaging in surgery is growing. This study aimed to systematically review the literature to summarize the intraoperative uses of NIRS in pediatric surgery.

METHODS

A PRISMA-compliant literature search was conducted in PubMed, Embase, Scopus, and Web of Science from inception to February 2020. Title/abstract and then full-text screening were performed. The Oxford centre for Evidence Based Medicine tool (OCEBM) was used to evaluate the level of evidence of included studies.

RESULTS

Reviewers identified 53 articles. Of which, 34 studies (64.2%) were case-series and 11 (20.8%) were case reports. Most of the studies (n = 45, 84.9%) were level 4 on the OCEBM tool. The most common uses of NIRS were to visualize the biliary tree and to identify primary and metastatic malignant tissues. Other applications include assessment of perfusion of tissues including bowel anastomoses, and lymphatic surgery. Several advantages of the introduction of NIRS in pediatric surgery exist including having the potential to reduce operative time and intra/post-operative complications. Moreover, NIRS helps in detecting malignant tissues that can be missed by conventional imaging. However, NIRS has important limitations such as difficulty in identification of the biliary tree in obese patients or inflamed gallbladder, detection of small deeply localized malignant tissues, as well as the high cost.

CONCLUSIONS

NIRS is a promising modality that can be used intraoperatively to augment different pediatric surgical procedures. NIRS has important advantages and limitations compared to conventional surgery, however, more studies are required to evaluate its outcomes and cost-effectiveness.

LEVEL OF EVIDENCE

IV.

High prevalence of subnormal testosterone in obese adolescent males: reversal with bariatric surgery

OBJECTIVE

Obesity in adolescent males is associated with the lowering of total and free testosterone concentrations. Weight loss may increase testosterone concentrations.

DESIGN AND METHODS

We evaluated the changes in sex hormones following bariatric surgery in 34 males (age range: 14.6-19.8 years) with obesity. These participants were part of a prospective multicenter study, Teen-Longitudinal Assessment of Bariatric Surgery. The participants were followed up for 5 years after surgery. Total testosterone, total estradiol, luteinizing hormone, follicle-stimulating hormone, sex hormone-binding globulin, C-reactive protein, insulin and glucose were measured at baseline, 6 months and annually thereafter. Free testosterone, free estradiol and HOMA2-IR were calculated.

RESULTS

Study participants lost one-third of their body weight after bariatric surgery, with maximum weight loss achieved at 24 months for most participants. Free testosterone increased from 0.17 (95% CI: 0.13 to 0.20) at baseline to 0.34 (95% CI: 0.30 to 0.38) and 0.27 nmol/L (95% CI: 0.23 to 0.32) at 2 and 5 years (P < 0.001 for both), respectively. Total testosterone increased from 6.7 (95% CI: 4.7 to 8.8) at baseline to 17.6 (95% CI: 15.3 to 19.9) and 13.8 (95% CI: 11.0 to 16.5) nmol/L at 2 and 5 years (P < 0.001), respectively. Prior to surgery, 73% of the participants had subnormal free testosterone (<0.23 nmol/L). After 2 and 5 years, only 20 and 33%, respectively, had subnormal free testosterone concentrations. Weight regain was related to a fall in free testosterone concentrations.

CONCLUSIONS

Bariatric surgery led to a robust increase in testosterone concentrations in adolescent males with severe obesity. Participants who regained weight had a decline in their testosterone concentrations.

Initial Laparotomy Versus Peritoneal Drainage in Extremely Low Birthweight Infants With Surgical Necrotizing Enterocolitis or Isolated Intestinal Perforation: A Multicenter Randomized Clinical Trial

OBJECTIVE

The aim of this study was to determine which initial surgical treatment results in the lowest rate of death or neurodevelopmental impairment (NDI) in premature infants with necrotizing enterocolitis (NEC) or isolated intestinal perforation (IP).

SUMMARY BACKGROUND DATA

The impact of initial laparotomy versus peritoneal drainage for NEC or IP on the rate of death or NDI in extremely low birth weight infants is unknown.

METHODS

We conducted the largest feasible randomized trial in 20 US centers, comparing initial laparotomy versus peritoneal drainage. The primary outcome was a composite of death or NDI at 18 to 22 months corrected age, analyzed using prespecified frequentist and Bayesian approaches.

RESULTS

Of 992 eligible infants, 310 were randomized and 96% had primary outcome assessed. Death or NDI occurred in 69% of infants in the laparotomy group versus 70% with drainage [adjusted relative risk (aRR) 1.0; 95% confidence interval (CI): 0.87-1.14]. A preplanned analysis identified an interaction between preoperative diagnosis and treatment group (P = 0.03). With a preoperative diagnosis of NEC, death or NDI occurred in 69% after laparotomy versus 85% with drainage (aRR 0.81; 95% CI: 0.64-1.04). The Bayesian posterior probability that laparotomy was beneficial (risk difference <0) for a preoperative diagnosis of NEC was 97%. For preoperative diagnosis of IP, death or NDI occurred in 69% after laparotomy versus 63% with drainage (aRR, 1.11; 95% CI: 0.95-1.31); Bayesian probability of benefit with laparotomy = 18%.

CONCLUSIONS

There was no overall difference in death or NDI rates at 18 to 22 months corrected age between initial laparotomy versus drainage. However, the preoperative diagnosis of NEC or IP modified the impact of initial treatment.

Fluorescent Cholangiography in Laparoscopic Cholecystectomy and the Use in Pediatric Patients

Background: Common bile duct (CBD) injury is one of the most serious complications of laparoscopic cholecystectomy and carries an incidence of 0.3%-0.7%. Recently indocyanine green (ICG) fluorescent cholangiography (FC) has been used as an adjunct to identify the biliary tract during adult laparoscopic cholecystectomy, allowing intraoperative identification of biliary anatomy. The objective of this article is to show its successful use in pediatric laparoscopic cholecystectomies. Method: From July 1, 2017, to November 30, 2018, surgeons at John R. Oishei Children's Hospital and Women and Children's Hospital of Buffalo have been utilizing ICG-FC as an adjunct in patients undergoing laparoscopic cholecystectomy. Thirty-one patients undergoing laparoscopic cholecystectomy had 1 mL of dilute ICG (2.5 mg) injected intravenously in the operating room (OR) before trocar placement. Demographics, intraoperative details, and subjective surgeon data were recorded for elective laparoscopic cholecystectomy cases involving ICG. We hypothesize that use of ICG-FC in the pediatric and adolescent patient population is a safe, reliable, and reproducible adjunct for identification of the biliary tree. Secondary outcomes were to identify rate of biliary anatomy identification, utilization ease, and operative times while using ICG technology in pediatric patients. Results: ICG-FC was used in 31 pediatric laparoscopic cholecystectomies performed by 5 surgeons at our institution. Ages ranged from 6 to 18 years. In all cases, the cystic duct-CBD junction was visualized while performing dissection of the triangle of Calot. No intraoperative complications occurred. Conclusions: ICG-FC provides a noninvasive real-time visualization of the extrahepatic biliary tree in children and adolescents. We demonstrate that ICG-FC can successfully be used as an adjunct in pediatric patients and has the potential to facilitate with the dissection and minimize risk of bile duct injuries during pediatric laparoscopic cholecystectomies.

Molecular determinants of ACTH receptor for ligand selectivity

The adrenocorticotropic hormone (ACTH) receptor, known as the melanocortin-2 receptor (MC2R), plays a key role in regulating adrenocortical function. ACTH receptor is a subtype of the melanocortin receptor family which is a member of the G-protein coupled receptor (GPCR) superfamily. ACTH receptor has unique characteristics among MCRs. α-MSH, β-MSH, γ-MSH and ACTH are agonists for MCRs but only ACTH is the agonist for ACTH receptor. In addition, the melanocortin receptor accessory protein (MRAP) is required for ACTH receptor expression at cell surface and function. In this review, we summarized the information available on the relationship between ACTH and ACTH receptor and provide the latest understanding of the molecular basis of the ACTH receptor responsible for ligand selectivity and function.

Complications of bariatric surgery in adolescents

Over the past decade, outcomes data have demonstrated the benefit of bariatric surgery in achieving both sustained weight loss and reversal of co-morbidities. Comparing these data to contemporary known risks of adolescent bariatric surgery informs the patients and providers considering bariatric procedures and provides insight into potential ways to reduce and manage complications. The goal of this article is to review the common surgical and postoperative complications following bariatric procedures and discuss approaches to improve their safety. A systematic review identifying bariatric surgery complications in adolescents was conducted. The review focused on the data relevant to adolescent bariatric surgery. However, when necessary, adult studies were used to address the gaps in available pediatric information. The data pertaining to the intraoperative, short term, and long term surgically related and nutritional related complications show that complication are declining with increasing experience. Specific recommendations and strategies to avoid major complications of bariatric surgery in adolescents are offered.

Musculoskeletal Pain, Physical Function, and Quality of Life After Bariatric Surgery

OBJECTIVES

To evaluate the longitudinal effects of metabolic and bariatric surgery (MBS) on the prevalence of musculoskeletal and lower extremity (LE) pain, physical function, and health-related quality of life.

METHODS

The Teen Longitudinal Assessment of Bariatric Surgery study (NCT00474318) prospectively collected data on 242 adolescents undergoing MBS at 5 centers over a 3-year follow-up. Joint pain and physical function outcomes were assessed by using the Health Assessment Questionnaire Disability Index, Impact of Weight on Quality of Life - Kids, and the Short Form 36 Health Survey. Adolescents with Blount disease (n = 9) were excluded.

RESULTS

Prevalent musculoskeletal and LE pain were reduced by 40% within 12 months and persisted over 3 years. Adjusted models revealed a 6% lower odds of having musculoskeletal pain (odds ratio = 0.94, 95% confidence interval: 0.92-0.99) and a 10% lower odds of having LE pain (odds ratio = 0.90, 95% confidence interval: 0.86-0.95) per 10% reduction of BMI. The prevalence of poor physical function (Health Assessment Questionnaire Disability Index score >0) declined from 49% to <20% at 6 months (P < .05), Physical comfort and the physical component scores, measured by the Impact of Weight on Quality of Life - Kids and the Short Form 36 Health Survey, improved at 6 months postsurgery and beyond (P < .01). Poor physical function predicted persistent joint pain after MBS.

CONCLUSIONS

Joint pain, impaired physical function, and impaired health-related quality of life significantly improve after MBS. These benefits in patient-reported outcomes support the use of MBS in adolescents with severe obesity and musculoskeletal pain and suggest that MBS in adolescence may reverse and reduce multiple risk factors for future joint disease.

Down Syndrome and Postoperative Complications in Children Undergoing Intestinal Operations

OBJECTIVE

This paper intends to evaluate the association between Down Syndrome (DS) and postoperative medical and surgical complications and inpatient postoperative mortality in pediatric patients undergoing intestinal operations.

METHODS

The 2012 Kids' Inpatient Database was queried to compare short-term postoperative medical and surgical complications and in-patient mortality among patients with DS undergoing intestinal operations to a cohort without DS using inverse probability weighting. Subset analysis was performed for patients undergoing intestinal operations exclusive of gastrostomy placement. Adverse treatment effects were calculated for the outcomes of interest.

RESULTS

Of 17,026 pediatric patients undergoing intestinal operations, 444 had DS. In unadjusted analysis, medical complications (urinary tract infection, deep venous thrombosis, sepsis, pneumonia) occurred in 7.9% of patients with DS, compared to 14.1% of those without (p < 0.001). Surgical complications (wound disruption, hemorrhage, superficial or deep wound infection) occurred in 3.5% of patients with DS, compared to 4.6% of those without (p = 0.34), and in-patient mortality occurred in 0.3% of patients with DS, compared to 2.7% of those without (p = 0.009). Adverse treatment effects (ATE) calculated after inverse probability weighting demonstrated no difference for medical or surgical complications but a significantly decreased mortality with DS.

CONCLUSIONS

Contrary to common perception and data extrapolated from the adult literature, pediatric patients with DS have neither higher medical nor surgical complication rates after intestinal operations. Similar to patients undergoing congenital heart surgery, pediatric patients with DS have a lower postoperative inpatient mortality after these general operations compared to those without DS. Mechanisms influencing risks in DS patient remain unknown.

LEVEL OF EVIDENCE

Level III, retrospective comparative study.

Multi-disciplinary weight management compared to routine care in youth with obesity: what else should be monitored?

PURPOSE

Efficacy of multi-disciplinary weight management (MDM) in youth has not been compared to their routine care.

OBJECTIVES

To compare body mass index z-score (zBMI) and blood test (lab) changes (Δ) in youth before and after MDM and to correlate bio-impedance analysis (BIA) and lab measurements.

METHODS

We compared zBMI Δ (from referring providers' records), within 3 months prior to MDM, to monthly zBMI Δ after MDM, in a retrospective cohort of youth at a tertiary MDM center. BIA and lab measurements after 6 months, MDM were compared to baseline.

RESULTS

We reviewed 316 records (12.9 ± 3.5 years, 49% males, 104.8 ± 35.1 kgs). The pre-MDM zBMI Δ (0.02 ± 0.1) was reversed after MDM (-0.03 ± 0.09, visit 2, P < 0.001). The zBMI Δ progressed on follow-up (-0.14 ± 0.05, visit 6). Baseline BIA components correlated with Homeostatic Model Assessment of Insulin resistance (HOMA-IR), triglycerides, and systolic blood pressure. HbA1c, HOMA-IR, and liver functions significantly improved on follow-up. MDM participation showed progressive attrition and dropped to 11.6% at visit 6.

CONCLUSION

MDM in youth resulted in zBMI and lab improvements compared to their pre-MDM measurements. BIA provided additional outcome measures that correlated with metabolic markers. MDM follow-up was limited by the progressive participant drop-out. Behavioral economic strategies are needed to improve adherence.

It Is a Wrap! Or Is It?: The Role of Fundoplication in Infant Feeding Intolerance

Purpose: Fundoplication is one of the most common procedures performed by pediatric surgeons, frequently for gastroesophageal reflux with feeding intolerance. No consensus exists in its management, with multiple institutions opting for medical therapy over surgical intervention. Methods: A case-based survey was administered at a national pediatric surgery conference. Clinical vignettes described former-premature infants with reflux and feeding intolerance with or without failure to thrive (FTT), neurological impairment, complex cardiopathy, and respiratory symptoms. Odds ratios (ORs) for fundoplication were calculated from participants' responses. Results: Surgeons elected to perform fundoplication in 14%-74% of cases. The OR for performing fundoplication in the presence of FTT was 1.84 (confidence interval [CI] 1.34-2.54, P = .0002) overall, achieving significance in subgroup analysis for cardiopathy (OR 3.56, CI 1.88-6.71, P = .0001) and neurological impairment (OR 1.79, CI 1.04-3.07, P = .04), but not in the absence of these comorbidities (OR 1.05, CI 0.61-1.83, P = .86). The OR for fundoplication in the presence of neurological impairment was 1.97 (CI 1.34-2.90, P = .0005) and that for cardiopathy was 1.70 (CI 1.20-2.40, P = .003), independent of FTT status. In subgroup analysis, the greatest predictors for fundoplication were neurological impairment with FTT (OR 2.63, CI 1.55-4.48, P = .0004) and complex cardiopathy with FTT and cough/syncope (OR 7.14, CI 4.05-12.58, P < .0001). Presence of cardiopathy without FTT had the overall lowest odds of fundoplication (OR 0.40, CI 0.21-0.78, P = .006). Conclusion: Surgeons tend to perform fundoplication in the presence of FTT and other comorbidities, particularly when these are concurrent. Respiratory symptoms are a strong predictor for fundoplication in patients with complex cardiopathies.

Five-Year Outcomes of Gastric Bypass in Adolescents as Compared with Adults

BACKGROUND

Bariatric surgery results in weight loss and health improvements in adults and adolescents. However, whether outcomes differ according to the age of the patient at the time of surgery is unclear.

METHODS

We evaluated the health effects of Roux-en-Y gastric bypass in a cohort of adolescents (161 patients enrolled from 2006 through 2012) and a cohort of adults (396 patients enrolled from 2006 through 2009). The two cohorts were participants in two related but independent studies. Linear mixed and Poisson mixed models were used to compare outcomes with regard to weight and coexisting conditions between the cohorts 5 years after surgery. The rates of death and subsequent abdominal operations and selected micronutrient levels (up to 2 years after surgery) were also compared between the cohorts.

RESULTS

There was no significant difference in percent weight change between adolescents (-26%; 95% confidence interval [CI], -29 to -23) and adults (-29%; 95% CI, -31 to -27) 5 years after surgery (P = 0.08). After surgery, adolescents were significantly more likely than adults to have remission of type 2 diabetes (86% vs. 53%; risk ratio, 1.27; 95% CI, 1.03 to 1.57) and of hypertension (68% vs. 41%; risk ratio, 1.51; 95% CI, 1.21 to 1.88). Three adolescents (1.9%) and seven adults (1.8%) died in the 5 years after surgery. The rate of abdominal reoperations was significantly higher among adolescents than among adults (19 vs. 10 reoperations per 500 person-years, P = 0.003). More adolescents than adults had low ferritin levels (72 of 132 patients [48%] vs. 54 of 179 patients [29%], P = 0.004).

CONCLUSIONS

Adolescents and adults who underwent gastric bypass had marked weight loss that was similar in magnitude 5 years after surgery. Adolescents had remission of diabetes and hypertension more often than adults. (Funded by the National Institute of Diabetes and Digestive and Kidney Diseases; ClinicalTrials.gov number, NCT00474318.).

Amino acid residue L112 in the ACTH receptor plays a key role in ACTH or α-MSH selectivity

The adrenocorticotropic hormone (ACTH) receptor, known as the melanocortin-2 receptor (MC2R), plays a key role in regulating adrenocortical function. MC2R is a subtype of the melanocortin receptor family and ACTH is only agonist for MC2R. Our previous result indicates that ACTH1-17 is the minimal peptide required for MC2R activation but DPhe7-ACTH1-17 has no activity at MC2R. In this study, we examined the molecular basis of the MC2R responsible for ligand selectivity using ACTH analogues and MC2R mutagenesis. Our results indicate that substitution of the 3TM of the MC2R with the corresponding region of the MC3R switches DPhe-ACTH1-17 from no activity to agonist. Further experiment indicates that substitution of the amino acid residue leucine to isoleucine in 112 (L112I) of the 3TM of the MC2R changes both DPhe-ACTH1-17 and ACTH1-15 from no activity to agonists. Surprisingly, mutation L112I switches α-MSH from no activity to agonist, suggesting that this residue plays a key role at MC2R for ligand ACTH or α-MSH selectivity.

Minimally invasive surgical exposure among US and Canadian pediatric surgery trainees, 2004-2016

BACKGROUND

Minimally invasive pediatric surgery has increased in breadth and complexity over the past several decades, with little data on minimally invasive surgery (MIS) training in US and Canadian pediatric surgery fellowship programs.

METHODS

We performed a time series analysis of Accreditation Council for Graduate Medical Education pediatric surgery fellow case logs from 2003 to 2016. Proportions of cases performed in an MIS fashion as well as per-fellow MIS case averages were recorded over time.

RESULTS

There was a 30.9% increase in average number of MIS cases per fellow over the study time period. Twenty-three recorded procedures included MIS and open options (17 abdominal, three thoracic, and three genitourinary). The proportion of cases performed using a minimally invasive approach increased by an average of 29.0%, 14.6%, and 47.0% for each of these categories, respectively. Significant variability was observed in specific cases such as laparoscopic and open inguinal hernias, ranging from 0 to 85 and nine to 152 per trainee, respectively, in the final year of data collection. When examining pyloromyotomy, a high-volume procedure with a known increase in the MIS approach, the proportion of cases performed MIS increased by 83.3%. The minimum and maximum number of cases per fellow recorded ranged from 0 to 114 during the eight years in which MIS pyloromyotomy was recorded.

CONCLUSIONS

MIS case exposure among graduating US and Canadian pediatric survey fellows increased substantially during the study period. More granular data, however, are needed to better define the current operative experience and criteria for determination of competency in advanced MIS.

Changes in Dietary Intake and Eating Behavior in Adolescents After Bariatric Surgery: an Ancillary Study to the Teen-LABS Consortium

BACKGROUND

A growing number of studies suggest that bariatric surgery is safe and effective for adolescents with severe obesity. However, surprisingly little is known about changes in dietary intake and eating behavior of adolescents who undergo bariatric surgery.

OBJECTIVE

Investigate changes in dietary intake and eating behavior of adolescents with obesity who underwent bariatric surgery (n = 119) or lifestyle modification (LM) (n = 169).

SETTING

University-based health systems METHODS: A prospective investigation of 288 participants (219 female and 69 male) prior to bariatric surgery or LM and again 6, 12, and 24 months (surgery patients only) after treatment. Measures included changes in weight, macronutrient intake, eating behavior, and relevant demographic and physiological variables.

RESULTS

Adolescents who underwent bariatric surgery experienced significantly greater weight loss than those who received LM. The two groups differed in self-reported intake of a number of macronutrients at 6 and 12 months from baseline, but not total caloric intake. Patients treated with surgery, compared to those treated with LM, also reported significantly greater reductions in a number of disordered eating symptoms. After bariatric surgery, greater weight loss from postoperative month 6 to 12 was associated with self-reported weight consciousness, craving for sweets, and consumption of zinc.

CONCLUSIONS

Adolescents who underwent bariatric surgery, compared to those who received LM, reported significantly greater reductions in weight after 1 year. They also reported greater reductions in disordered eating symptoms. These findings provide new information on changes in dietary intake and eating behavior among adolescents who undergo bariatric surgery.

Cardiovascular Risk Factors After Adolescent Bariatric Surgery

BACKGROUND AND OBJECTIVES

Severely obese adolescents harbor numerous cardiovascular disease risk factors (CVD-RFs), which improve after metabolic and bariatric surgery (MBS). However, predictors of change in CVD-RFs among adolescents have not yet been reported.

METHODS

The Teen-Longitudinal Assessment of Bariatric Surgery study (NCT00474318) prospectively collected anthropometric and health status data on 242 adolescents undergoing MBS at 5 centers. Predictors of change in CVD-RFs (blood pressure, lipids, glucose homeostasis, and inflammation) 3 years after Roux-en-Y gastric bypass and vertical sleeve gastrectomy were examined.

RESULTS

The mean (±SD) age of participants at baseline was 17 ± 1.6 years; 76% were girls, and 72% were white, with a median BMI of 51. Participants underwent Roux-en-Y gastric bypass (n = 161), vertical sleeve gastrectomy (n = 67), or adjustable gastric banding (n = 14). Increasing weight loss was an independent predictor of normalization in dyslipidemia, elevated blood pressure (EBP), hyperinsulinemia, diabetes, and elevated high-sensitivity C-reactive protein. Older participants at time of surgery were less likely to resolve dyslipidemia compared with younger participants, whereas girls were more likely than boys to demonstrate improvements in EBP. Even those participants without frank dyslipidemia or EBP at baseline showed significant improvements in lipid and blood pressure values over time.

CONCLUSIONS

Numerous CVD-RFs improve among adolescents undergoing MBS. Increased weight loss, female sex, and younger age predict a higher probability of resolution of specific CVD-RFs. The elucidation of predictors of change in CVD-RFs may lead to refinements in patient selection and optimal timing of adolescent bariatric surgery designed to improve clinical outcomes.

The impact of obesity on 30-day complications in pediatric surgery

PURPOSE

To examine the effects of obesity on specialty-specific surgical outcomes in children.

MATERIALS AND METHODS

Retrospective cohort study using the National Surgical Quality Improvement Program, Pediatric, 2012-2014. Patients included those aged 2-17 years who underwent a surgical procedure in one of six specialties. Obesity was the primary patient variable of interest. Outcomes of interest were postoperative complications and operative times. Odds ratios for development of postoperative complications were calculated using stepwise multivariate regression analysis.

RESULTS

Obesity was associated with a significantly greater risk of wound complications (OR 1.24, 95% CI 1.13-1.36), but decreased risk of non-wound complications (OR 0.68, 95% CI 0.63-0.73) and morbidity (OR 0.79, 95% CI 0.75-0.84). Obesity was not a significant factor in predicting postoperative complications in patients undergoing otolaryngology or plastic surgery procedures. Anesthesia times and operative times were significantly longer for obese patients undergoing most types of pediatric surgical procedures.

CONCLUSION

Obesity confers an increased risk of wound complications in some pediatric surgical specialties and is associated with overall decreased non-wound complications and morbidity. These findings suggest that the relationship between obesity and postoperative complications is complex and may be more dependent on underlying procedure- or specialty-related factors than previously suspected.

Key amino acid residue in Melanocortin-1 receptor (melanocyte α-MSH receptor) for ligand selectivity

The melanocortin-1 receptor (MC1R) is a subtype of the melanocortin receptor family and NDP-α-MSH is a non-selective agonist for MC1R. The core sequence of NDP-α-MSH, His-Phe-Arg-Trp, is important for ligand binding and biological activities at the melanocortin receptor subtypes (MCRs). A recent study indicates that Trp⁹ in NDP-α-MSH plays an important role in ligand selectivity. Deletion of Trp⁹ in NDP-α-MSH (des-Trp⁹-NDP-α-MSH) resulted in loss of agonist activity at MC4R, although remains agonist activity at MC1R. The molecular basis for this receptor ligand selectivity is unknown. In this study we examined what region of the MC1R is responsible for des-NDP-α-MSH selectivity. Our results indicate that (1) substitution of TM3 of MC4R with the corresponding region of MC1R switches des-Trp⁹-NDP-α-MSH from no activity to agonist; (2) des-Trp⁹-NDP-α-MSH exhibits agonistic activity at the L133M mutation of the MC4R; and (3) substitution of non-conserved amino acid residue M128 in TM3 of MC1R significantly reduced des-Trp⁹-NDP-α-MSH agonist activity. Our results demonstrate that amino acid residue 128 in TM3 of MC1R, or amino acid residue L133 in TM3 of the MC4R, play crucial roles in ligand des-Trp⁹-NDP-α-MSH selectivity at MC1R or MC4R.

Novel use of porcine extracellular matrix in recurrent stricture following repair of tracheoesophageal fistula

Anastomotic stricture is a common complication following repair of esophageal atresia (EA). Many factors are thought to contribute to stricture formation and a variety of management techniques have been developed. In this case report, we describe the treatment of a recurrent anastomotic stricture following repair of long-gap esophageal atresia. Porcine bladder extracellular matrix (ECM) was mounted on a stent and delivered endoscopically to the site of recurrent stricture. An appropriate positioning was confirmed using direct endoscopic visualization and intra-operative fluoroscopy. The patient recovered well with persistent radiographic and functional improvements in previous stricture.

The molecular impact of omega 3 fatty acids on hepatic pro-inflammatory cytokine signaling

PURPOSE

Parenteral nutrition associated liver disease (PNALD) develops in a subset of children receiving parenteral nutrition for intestinal failure. Omegaven™ is an omega-3 fatty acid (Ω3FA) lipid emulsion high in docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) that can lessen PNALD. Inflammatory cytokines (IL-1, TNF-α, TGF-β) are elevated in PNALD and can decrease paraoxonase 1 protein expression (PON1). We sought to determine the effect of Omegaven™, EPA, and DHA on inflammatory cytokines TNF-α, IL-1, and TGF-β via ERK1/2 and p-Smad2/3 signaling pathways as well as the changes in intracellular PON1 protein expression as a potential mechanism explaining the protective effects of Omegaven™ and Ω3FA.

METHODS

HepG2 cells were cultured with each cytokine and Omegaven™, or EPA and DHA, or Intralipid™. P-Smad2/3 and PON1 protein levels were measured by Western blotting. ERK1/2 signaling was studied using homogenous time resolved fluorescence.

RESULTS

Omegaven™ decreased TGF-β mediated Smad2/3 signaling by 30% (70% of control ±12, p<0.03). Omegaven™ decreased IL-1 and TNF-α mediated ERK1/2 signaling (0.49 fold ±0.09, p<0.05 and 0.22±0.05, p<0.05) compared to control.

CONCLUSION

Our results describe potential mechanisms by which Omegaven™ and Ω3FA can be hepatoprotective in the setting of PNALD by abating inflammatory cytokine signaling.

Molecular signatures of human melanocortin receptors for ligand binding and signaling

Human melanocortin receptors (hMCRs) belong to the seven-transmembrane (TM) domain proteins. There are five hMCR subtypes and each of these receptor subtypes has different patterns of tissue expression and physiological function. The endogenous agonists for hMCRs are α-, β-, and γ-MSH and ACTH and endogenous antagonists are Agouti and AGRP which are the only known naturally occurring antagonists for the receptors. These peptides have their own profiles regarding the relative potency for specific hMCR subtype. Extensive studies have been performed to examine the molecular basis of the hMCRs for different ligand binding affinity and potency. Studies indicate that natural ligand α-MSH utilizes conserved amino acid residues for MCR specific binding (orthosteric binding) while synthetic ligands utilize non-conserved amino acid residues for receptor subtype specific binding (allosteric binding). ACTH is the only endogenous agonist for hMC2R and more amino acid residues at hMC2R are required for ACTH binding and signaling. HMCR computer modeling provides the detailed information of ligand and MCR interaction. This review provides the latest understanding of the molecular basis of the hMCRs for ligand binding and signaling. This article is part of a Special Issue entitled: Melanocortin Receptors - edited by Ya-Xiong Tao.

Changes in Functional Mobility and Musculoskeletal Pain After Bariatric Surgery in Teens With Severe Obesity: Teen-Longitudinal Assessment of Bariatric Surgery (LABS) Study

IMPORTANCE

Severe obesity is associated with mobility limitations and higher incidence of multijoint musculoskeletal pain. It is unknown whether substantial weight loss improves these important outcomes in adolescents with severe obesity.

OBJECTIVE

To examine the association of bariatric surgery with functional mobility and musculoskeletal pain in adolescents with severe obesity up to 2 years after surgery.

DESIGN, SETTING, AND PARTICIPANTS

The Teen-Longitudinal Assessment of Bariatric Surgery Study is a prospective, multicenter, observational study, which enrolled 242 adolescents (≤19 years of age) who were undergoing bariatric surgery from March 2007 through February 2012 at 5 US adolescent bariatric surgery centers. This analysis was conducted in November 2015.

INTERVENTIONS

Roux-en-Y gastric bypass (n = 161), sleeve gastrectomy (n = 67), or laparoscopic adjustable gastric band (n = 14).

MAIN OUTCOMES AND MEASURES

Participants completed a 400-m walk test prior to bariatric surgery (n = 206) and at 6 months (n = 195), 12 months (n = 176), and 24 months (n = 149) after surgery. Time to completion, resting heart rate (HR), immediate posttest HR, and HR difference (resting HR minus posttest HR) were measured and musculoskeletal pain concerns, during and after the test, were documented. Data were adjusted for age, sex, race/ethnicity, baseline body mass index (calculated as weight in kilograms divided by height in meters squared), and surgical center (posttest HR and HR difference were further adjusted for changes in time to completion).

RESULTS

Of the 206 adolescents with severe obesity included in the study, 156 were female (75.7%), the mean (SD) age was 17.1 (1.6) years, and the mean (SD) body mass index was 51.7 (8.5). Compared with baseline, significant improvements were observed at 6 months for the walk test time to completion (mean, 376 seconds; 95% CI, 365-388 to 347 seconds; 95% CI, 340-358; P < .01), resting HR (mean, 84 beats per minute [bpm]; 95% CI, 82-86 to 74 bpm; 95% CI, 72-76), posttest HR (mean, 128 bpm; 95% CI, 125-131 to 113 bpm; 95% CI, 110-116), and HR difference (mean, 40 bpm; 95% CI, 36-42 to 34 bpm; 95% CI, 31-37). These changes in time to completion, resting HR, and HR difference persisted at 12 months and 24 months. Posttest HR further improved from 6 months to 12 months (mean, 113 bpm; 95% CI, 110-116 to 108 bpm; 95% CI, 105-111). There were statistically significant reductions in musculoskeletal pain concerns at all points.

CONCLUSIONS AND RELEVANCE

These data provide evidence that bariatric surgery in adolescents with severe obesity is associated with significant improvement in functional mobility and in the reduction of walking-related musculoskeletal pain up to 2 years after surgery.

Gallbladder disease in children

Biliary disease in children has changed over the past few decades, with a marked rise in incidence-perhaps most related to the parallel rise in pediatric obesity-as well as a rise in cholecystectomy rates. In addition to stone disease (cholelithiasis), acalculous causes of gallbladder pain such as biliary dyskinesia, also appear to be on the rise and present diagnostic and treatment conundrums to surgeons.

Advances in Pediatric Surgical Education: A Critical Appraisal of Two Consecutive Minimally Invasive Pediatric Surgery Training Courses

BACKGROUND

Mandates for improved patient safety and increasing work hour restrictions have resulted in changes in surgical education. Educational courses increasingly must meet those needs. We sought to determine the experience, skill level, and the impact of simulation-based education (SBE) on two cohorts of pediatric surgery trainees.

MATERIALS AND METHODS

After Institutional Review Board (IRB) exempt determination, a retrospective review was performed of evaluations for an annual advanced minimally invasive surgery (MIS) course over 2 consecutive years. The courses included didactic content and hands-on skills training. Simulation included neonatal/infant models for rigid bronchoscopy-airway foreign body retrieval, laparoscopic common bile duct exploration, and real tissue diaphragmatic hernia (DH), duodenal atresia (DA), pulmonary lobectomy, and tracheoesophageal fistula models. Categorical data were analyzed with chi-squared analyses with t-tests for continuous data.

RESULTS

Participants had limited prior advanced neonatal MIS experience, with 1.95 ± 2.84 and 1.16 ± 1.54 prior cases in the 2014 and 2015 cohorts, respectively. The 2015 cohort had significantly less previous experience in lobectomy (P = .04) and overall advanced MIS (P = .007). Before both courses, a significant percentage of participants were not comfortable with DH repair (39%-42%), DA repair (50%-74%), lobectomy (34%-43%), and tracheoesophageal fistula repair (54%-81%). After course completion, > 60% of participants reported improvement in comfort with procedures and over 90% reported that the course significantly improved their perceived ability to perform each operation safely.

CONCLUSION

Pediatric surgery trainees continue to have limited exposure to advanced MIS during clinical training. SBE results in significant improvement in both cognitive knowledge and trainee comfort with safe operative techniques for advanced MIS.

Molecular impact of omega 3 fatty acids on lipopolysaccharide-mediated liver damage

BACKGROUND

Growing evidence suggests that omega 3 fatty acid containing lipid emulsions have a beneficial effect on parenteral nutrition associated liver disease (PNALD). However, the cellular and molecular mechanisms responsible for this effect are unclear. In this study, we investigated whether Omegaven™ fish oil emulsion could inhibit lipopolysaccharidase (LPS) mediated liver damage.

METHODS

We examined the effects of Omegaven™ and LPS alone and synergistically on hepatic paraoxonase 1 (PON1), a potent antioxidant protein, ERK1/2 activity, and TLR4 regulation.

RESULTS

LPS did not alter PON1 release from HepG2 cells but did significantly decrease PON1 protein synthesis (44%, P<0.05). Omegaven™ alone had no direct effect on PON1 release. However, it did significantly reverse LPS-mediated decrease in PON1 protein levels (control: 100%; LPS alone: 56+/4%; LPS+Omegaven™: 87+/6%, P<0.05). Furthermore, molecular analysis indicated that Omegaven™ blocked LPS-mediated increase in ERK1/2 activity (35% increase), an important LPS signal transduction pathway. TLR4, the receptor for LPS, was down-regulated in the presence of Omegaven™.

CONCLUSION

Omegaven™ may be beneficial in patients with PNAC because of its ability to reverse LPS-mediated inhibition of antioxidant promoting PON1 expression, and this activity may be in part mediated by the ERK1/2 pathway.

Weight Loss and Health Status 3 Years after Bariatric Surgery in Adolescents

BACKGROUND

Bariatric surgery is increasingly considered for the treatment of adolescents with severe obesity, but few prospective adolescent-specific studies examining the efficacy and safety of weight-loss surgery are available to support clinical decision making.

METHODS

We prospectively enrolled 242 adolescents undergoing weight-loss surgery at five U.S. centers. Patients undergoing Roux-en-Y gastric bypass (161 participants) or sleeve gastrectomy (67) were included in the analysis. Changes in body weight, coexisting conditions, cardiometabolic risk factors, and weight-related quality of life and postoperative complications were evaluated through 3 years after the procedure.

RESULTS

The mean (±SD) baseline age of the participants was 17±1.6 years, and the mean body-mass index (the weight in kilograms divided by the square of the height in meters) was 53; 75% of the participants were female, and 72% were white. At 3 years after the procedure, the mean weight had decreased by 27% (95% confidence interval [CI], 25 to 29) in the total cohort, by 28% (95% CI, 25 to 30) among participants who underwent gastric bypass, and by 26% (95% CI, 22 to 30) among those who underwent sleeve gastrectomy. By 3 years after the procedure, remission of type 2 diabetes occurred in 95% (95% CI, 85 to 100) of participants who had had the condition at baseline, remission of abnormal kidney function occurred in 86% (95% CI, 72 to 100), remission of prediabetes in 76% (95% CI, 56 to 97), remission of elevated blood pressure in 74% (95% CI, 64 to 84), and remission of dyslipidemia in 66% (95% CI, 57 to 74). Weight-related quality of life also improved significantly. However, at 3 years after the bariatric procedure, hypoferritinemia was found in 57% (95% CI, 50 to 65) of the participants, and 13% (95% CI, 9 to 18) of the participants had undergone one or more additional intraabdominal procedures.

CONCLUSIONS

In this multicenter, prospective study of bariatric surgery in adolescents, we found significant improvements in weight, cardiometabolic health, and weight-related quality of life at 3 years after the procedure. Risks associated with surgery included specific micronutrient deficiencies and the need for additional abdominal procedures. (Funded by the National Institute of Diabetes and Digestive and Kidney Diseases and others; Teen-LABS ClinicalTrials.gov number, NCT00474318.).

High Prevalence of Nonalcoholic Fatty Liver Disease in Adolescents Undergoing Bariatric Surgery

BACKGROUND & AIMS

Little is known about the prevalence of nonalcoholic fatty liver disease (NAFLD) among severely obese adolescents or factors that determine its development. We investigated the prevalence of NAFLD in a multicenter cohort of adolescents undergoing bariatric surgery and the factors associated with it.

METHODS

We enrolled 242 adolescents undergoing bariatric surgery between March 2007 and February 2012 at 5 tertiary care centers into a multicenter, prospective observational cohort study. Intraoperative core liver biopsies were collected from 165 subjects; 17 were excluded because of insufficient liver tissue or use of hepatotoxic medications, so 148 remained in the study (mean age, 16.8 ± 1.6 years; median body mass index = 52 kg/m(2)). Liver tissues were analyzed by histology using validated criteria. Hepatic gene expression was analyzed in 67 samples.

RESULTS

NAFLD was present in 59% of this predominantly female (72%), white (68%), non-Hispanic (91%) cohort. Of subjects with NAFLD, 24% had borderline and 10% had definite nonalcoholic steatohepatitis (NASH). Mild fibrosis (stage 2 or lower) was observed in 18% of liver biopsies and stage 3 was observed in 0.7%, but cirrhosis was not detected. Dyslipidemia was present in 78% of subjects, hypertension in 44%, and diabetes in 14%. More severe NAFLD was associated with increasing levels of alanine aminotransferase, fasting glucose level, hypertension (each P < .01), and white blood cell count (P = .04). Only diabetes was associated with detection of fibrosis (odds ratio = 3.56; 95% confidence interval: 1.93-6.56). Microarray analysis associated presence of NASH with altered expression of genes that regulate macrophage chemotaxis, cholesterol absorption, and fatty acid binding.

CONCLUSIONS

More than half of adolescents undergoing bariatric surgery in this cohort had NAFLD, yet the prevalence of severe or fibrotic NASH was low. Increasing severity of NAFLD was associated with level of alanine aminotransferase and cardiometabolic risk factors, but not body mass index. Based on gene expression analysis, borderline and definite NASH were associated with abnormal immune function, intestinal cholesterol absorption, and lipid metabolism.

DIABETES AND PREDIABETES ARE SIGNIFICANTLY HIGHER IN MORBIDLY OBESE CHILDREN COMPARED WITH OBESE CHILDREN

OBJECTIVE

The objective of this study was to examine the prevalence and characteristics of comorbidities in obese and morbidly obese children with a comparison between the 2 sets of children.

METHODS

This was a retrospective electronic chart review of obese and morbidly obese children and adolescents as defined by body mass index. We evaluated medical history of comorbid conditions, medication use, and cardiovascular risk markers, including blood pressure, lipid profile, and glycosylated hemoglobin.

RESULTS

There were 1,111 subjects (African American = 635; non-Hispanic white = 364; Hispanic = 36; others = 86), of which 274 were obese and 837 were morbidly obese children with a mean age of 12.7 ± 3.37 years. Morbidly obese children had a higher prevalence of prediabetes (19.5% of obese versus 27.3% of morbidly obese; P<.0001) and type 2 diabetes (39.8% of obese versus 52.4% of morbidly obese; P<.0001). Use of medications for treatment of asthma was significantly higher in the morbidly obese group compared with the obese group (21% versus 14%; P = .01).

CONCLUSION

Morbidly obese children have a higher prevalence of diabetes, prediabetes, and use of asthma medications compared with obese children.

Musculoskeletal Pain, Self-reported Physical Function, and Quality of Life in the Teen-Longitudinal Assessment of Bariatric Surgery (Teen-LABS) Cohort

IMPORTANCE

Obesity is associated with chronic musculoskeletal pain and is a risk factor for disability and osteoarthritis.

OBJECTIVES

To describe the prevalence, sites, and intensity of musculoskeletal pain in adolescents with severe obesity; to evaluate associations between musculoskeletal pain and self-reported physical function as well as weight-related quality of life; and to evaluate the association between musculoskeletal pain and high-sensitivity C-reactive protein level.

DESIGN, SETTING, AND PARTICIPANTS

Teen-Longitudinal Assessment of Bariatric Surgery (Teen-LABS) is a prospective, observational study that collects standardized data on adolescents undergoing weight loss surgery at 5 US centers. We examined baseline data from this cohort between February 28, 2007, and December 30, 2011. We excluded adolescents with Blount disease and slipped capital femoral epiphyses. A total of 233 participants were included in these analyses.

MAIN OUTCOMES AND MEASURES

We assessed musculoskeletal pain and pain intensity of the lower back, hips, knees, and ankles/feet using the visual analog scale, categorizing musculoskeletal pain into lower back pain, lower extremity (hips, knees, and feet/ankles combined) pain, and no pain. We assessed self-reported physical function status with the Health Assessment Questionnaire Disability Index and assessed weight-related quality of life with the Impact of Weight on Quality of Life-Kids measure. We adjusted for sex, race, age at surgery, body mass index (BMI; calculated as weight in kilograms divided by height in meters squared), and clinical depressive symptoms in regression analyses.

RESULTS

Among the 233 participants, the mean (SD) age at surgery was 17.1 (1.56) years and the median BMI was 50.4. Participants were predominantly female (77%), white (73%), and non-Hispanic (93%). Among the participants, 49% had poor functional status and 76% had musculoskeletal pain. Lower back pain was prevalent (63%), followed by ankle/foot (53%), knee (49%), and hip (31%) pain; 26% had pain at all 4 sites. In adjusted analyses, compared with pain-free participants, those reporting lower extremity pain had greater odds of having poor physical function according to scores on the Health Assessment Questionnaire Disability Index (odds ratio = 2.82; 95% CI, 1.35 to 5.88; P < .01). Compared with pain-free participants, those reporting lower extremity pain had significantly lower Impact of Weight on Quality of Life-Kids total scores (β = -9.42; 95% CI, -14.15 to -4.69; P < .01) and physical comfort scores (β = -17.29; 95% CI, -23.32 to -11.25; P < .01). After adjustment, no significant relationship was observed between musculoskeletal pain and high-sensitivity C-reactive protein level.

CONCLUSIONS AND RELEVANCE

Adolescents with severe obesity have musculoskeletal pain that limits their physical function and quality of life. Longitudinal follow-up will reveal whether weight loss surgery reverses pain and physical functional limitations and improves quality of life.

Cardiovascular Risk Factors in Severely Obese Adolescents: The Teen Longitudinal Assessment of Bariatric Surgery (Teen-LABS) Study

IMPORTANCE

Severe obesity is increasingly common in the adolescent population but, as of yet, very little information exists regarding cardiovascular disease (CVD) risks in this group.

OBJECTIVE

To assess the baseline prevalence and predictors of CVD risks among severely obese adolescents undergoing weight-loss surgery.

DESIGN, SETTING, AND PARTICIPANTS

A prospective cohort study was conducted from February 28, 2007, to December 30, 2011, at the following 5 adolescent weight-loss surgery centers in the United States: Nationwide Children's Hospital in Columbus, Ohio; Cincinnati Children's Hospital Medical Center in Cincinnati, Ohio; Texas Children's Hospital in Houston; University of Pittsburgh Medical Center in Pittsburgh, Pennsylvania; and Children's Hospital of Alabama in Birmingham. Consecutive patients aged 19 years or younger were offered enrollment in a long-term outcome study; the final analysis cohort consisted of 242 participants.

MAIN OUTCOMES AND MEASURES

This report examined the preoperative prevalence of CVD risk factors (ie, fasting hyperinsulinemia, elevated high-sensitivity C-reactive protein levels, impaired fasting glucose levels, dyslipidemia, elevated blood pressure, and diabetes mellitus) and associations between risk factors and body mass index (calculated as weight in kilograms divided by height in meters squared), age, sex, and race/ethnicity. Preoperative data were collected within 30 days preceding bariatric surgery.

RESULTS

The mean (SD) age was 17 (1.6) years and median body mass index was 50.5. Cardiovascular disease risk factor prevalence was fasting hyperinsulinemia (74%), elevated high-sensitivity C-reactive protein levels (75%), dyslipidemia (50%), elevated blood pressure (49%), impaired fasting glucose levels (26%), and diabetes mellitus (14%). The risk of impaired fasting glucose levels, elevated blood pressure, and elevated high-sensitivity C-reactive protein levels increased by 15%, 10%, and 6%, respectively, per 5-unit increase in body mass index (P < .01). Dyslipidemia (adjusted relative risk = 1.60 [95% CI, 1.26-2.03]; P < .01) and elevated blood pressure (adjusted relative risk = 1.48 [95% CI, 1.16-1.89]; P < .01) were more likely in adolescent boys compared with adolescent girls. White individuals were at greater risk of having elevated triglyceride levels (adjusted relative risk = 1.76 [95% CI, 1.14-2.72]; P = .01) but were less likely to have impaired fasting glucose levels (adjusted relative risk = 0.58 [95% CI, 0.38-0.89]; P = .01).

CONCLUSIONS AND RELEVANCE

Numerous CVD risk factors are apparent in adolescents undergoing weight-loss surgery. Increasing body mass index and male sex increase the relative risk of specific CVD risk factors. These data suggest that even among severely obese adolescents, recognition and treatment of CVD risk factors is important to help limit further progression of disease.

Severe obesity and comorbid condition impact on the weight-related quality of life of the adolescent patient

OBJECTIVES

To assess links between comorbid health status, severe excess weight, and weight-related quality of life (WRQOL) in adolescents with severe obesity and undergoing weight-loss surgery (WLS) to inform clinical care.

STUDY DESIGN

Baseline (preoperative) data from Teen Longitudinal Assessment of Bariatric Surgery, a prospective multicenter observational study of 242 adolescents with severe obesity (MedianBMI = 50.5 kg/m(2); Meanage = 17.1; 75.6% female; 71.9% white) undergoing WLS, were used to examine the impact of demographics, body mass index (BMI), presence/absence of 16 comorbid conditions, and a cumulative comorbidity load (CLoad) index on WRQOL scores (Impact of Weight on Quality of Life-Kids).

RESULTS

WRQOL was significantly lower than reference samples of healthy weight, overweight, and obese samples. Of 16 comorbid conditions, the most prevalent were dyslipidemia (74.4%), chronic pain (58.3%), and obstructive sleep apnea (56.6%). Male subjects had a greater CLoad (P = .01) and BMI (P = .01), yet less impairment in total WRQOL (P < .01) than females. CLoad was a significant predictor of male WRQOL. For females, psychosocial (vs physical) comorbidities, BMI, and white race were significant predictors of WRQOL impairment. Less prevalent conditions (eg, stress urinary incontinence) also emerged as contributors to lower WRQOL.

CONCLUSIONS

WRQOL impairment is substantial for adolescents with severe obesity undergoing WLS, with predictors varying by sex. These patient-data highlight targets for education, support, and adjunctive care referrals before WLS. Furthermore, they provide a comprehensive empirical base for understanding heterogeneity in adolescent WRQOL outcomes after WLS, as weight and comorbidity profiles change over time.

Third transmembrane domain of the adrenocorticotropic receptor is critical for ligand selectivity and potency

The ACTH receptor, known as the melanocortin-2 receptor (MC2R), plays an important role in regulating and maintaining adrenocortical function. MC2R is a subtype of the melanocortin receptor (MCR) family and has unique characteristics among MCRs. Endogenous ACTH is the only endogenous agonist for MC2R, whereas the melanocortin peptides α-, β-, and γ-melanocyte-stimulating hormone and ACTH are full agonists for all other MCRs. In this study, we examined the molecular basis of MC2R responsible for ligand selectivity using ACTH analogs and MC2R mutagenesis. Our results indicate that substitution of Phe(7) with D-Phe or D-naphthylalanine (D-Nal(2')) in ACTH(1-24) caused a significant decrease in ligand binding affinity and potency. Substitution of Phe(7) with D-Nal(2') in ACTH(1-24) did not switch the ligand from agonist to antagonist at MC2R, which was observed in MC3R and MC4R. Substitution of Phe(7) with D-Phe(7) in ACTH(1-17) resulted in the loss of ligand binding and activity. Molecular analysis of MC2R indicated that only mutation of the third transmembrane domain of MC2R resulted in a decrease in D-Phe ACTH binding affinity and potency. Our results suggest that Phe(7) in ACTH plays an important role in ligand selectivity and that the third transmembrane domain of MC2R is crucial for ACTH selectivity and potency.

Routine utilization of single-incision pediatric endosurgery (SIPES): a 5-year institutional experience

BACKGROUND

Single-incision pediatric endosurgery (SIPES) allows operation through one access site, eliminating the multiple sites traditionally used. There are few large series evaluating the versatility of SIPES. The purpose of this study is to review a 5-year single-institution experience with routine SIPES use.

PATIENTS AND METHODS

This is an Institutional Review Board-approved retrospective analysis of prospectively collected data. All SIPES cases from March 2009 to December 2013 were included. Our database contains demographics, procedure type, operative duration, estimated blood loss, instance of added ports or conversion to open, complications, and follow-up duration.

RESULTS

Of 1322 SIPES operations performed, most (82.1%) were appendectomies and cholecystectomies. Of 871 (66%) patients seen in follow-up, with a median duration of 26 days, 53 (6.1%) experienced postoperative complications. Forty-two cases (4.8%) were surgical-site infections, of which 4 required drainage. Less frequent complications that required operative intervention include recurrent inguinal hernia (n=4), umbilical hernia (n=3), intraabdominal abscess (n=1), bleeding (n=1), abdominal compartment syndrome (n=1), bowel obstruction (n=1), stitch granuloma (n=1), and persistent postoperative pain (n=1).

CONCLUSIONS

Operative times and complication rates are comparable to those in prior reported multiport laparoscopic series, allowing safe integration of SIPES into the routine of a surgical practice for most common procedures.

Access to care for adolescents seeking weight loss surgery

OBJECTIVE

Adolescents seeking weight loss surgery (WLS) frequently encounter obstacles obtaining treatment authorization from insurance carriers. This study identified factors influencing authorization for adolescents with clinical indications for WLS.

METHODS

A retrospective review was conducted for adolescents with clinical indications for WLS at five adolescent centers. This cohort represented a consecutive series of adolescents with insurance benefits for WLS for whom insurance authorization was sought between 2009 and 2011. Outcomes included number and timing of insurance authorizations for surgery, denials, and appeals.

RESULTS

Records from 57 adolescents (74% female; mean age 16 (range: 12-17) years; mean BMI 51.3 kg/m(2) ) were reviewed. Of these, only 47% were approved with the original request. Eighty percent of those denied were approved on appeal, while 11% never obtained authorization for surgery. Age less than 18 years and proposed procedure were the most common reasons for denial.

CONCLUSIONS

Less than half of adolescents with clinical indications for surgery received approval for the procedure on the first request. The appeal process typically resulted in overturning of denials, so that surgical care could be delivered.

Structural insight into the MC4R conformational changes via different agonist-mediated receptor signaling

The melanocortin-4 receptor (MC4R) plays a key role in the regulation of food intake and body weight. Previous studies indicate that α-melanocyte stimulating hormone (α-MSH) binds to MC4R and activates three signal pathways (cAMP, calcium, and mitogen-activated protein kinase pathways), whereas MC4R synthetic agonist THIQ can activate only the cAMP pathway. The molecular basis of the MC4R responsible for different ligand-mediated signaling is unknown. We hypothesize that different MC4R agonists can stabilize different MC4R conformations and result in ligand-mediated signal transduction. In this study, we examined the effect of the MC4R conformational change in cAMP signaling pathways mediated by different agonists by cross-linking two transmembrane helices (TM3 and TM6). We generated and tested 11 single and 8 double mutations that are located at the end of TM3 and beginning of TM6 in MC4R. Our results indicate that (1) single or double mutations of the MC4R did not significantly alter cAMP production induced by NDP-MSH compared to that of wild-type MC4R except single mutation 243H (the mutation 243H significantly decreased cAMP production mediated by NDP-MSH or THIQ due to a low level of receptor expression at the cell surface), (2) the mutation 247H significantly decreased THIQ-mediated cAMP production but not NDP-MSH, and (3) the receptor cAMP signaling pathway activation by THIQ is blocked in the presence of Zn(2+) with the double mutation I150/242H but activation by NDP-MSH is not, suggesting that the activated conformation of MC4R mediated by NDP-MSH and THIQ is different. This study provides insight into the molecular basis of MC4R responsible for receptor signaling mediated by different agonists.

Kidney function in severely obese adolescents undergoing bariatric surgery

OBJECTIVE

Determine objective measures of kidney function and analyze factors associated with kidney dysfunction in severely obese adolescents undergoing weight loss surgery were described.

METHODS

Cross-sectional data from 242 adolescent participants in the Teen-Longitudinal Assessment of Bariatric Surgery (Teen-LABS) study before weight loss surgery were analyzed. Kidney status was assessed by measuring urine albumin creatinine ratio to determine microalbuminuria and by calculating serum cystatin C-based estimated glomerular filtration rate (eGFR) to assess kidney function.

RESULTS

Mean age and median body mass index (BMI) were 17.1 years and 50.5 kg/m(2) , respectively; 76% were females and 65% were non-Hispanic white race. Fourteen percent of the cohort had microalbuminuria, and 3% had macroalbuminuria; 3% had eGFR < 60 ml/min/1.73 m(2) , and 7.1% had eGFR > 150 ml/min/1.73 m(2) . In adjusted analyses, female gender and increasing ferritin levels were significantly associated with the presence of microalbuminuria/macroalbuminuria. Increasing BMI and homeostasis model assessment of insulin resistance values were significantly associated with lower eGFR.

CONCLUSIONS

A significant number of severely obese adolescents undergoing weight loss surgery have evidence of early kidney dysfunction. Longitudinal studies following weight loss surgery in these individuals are needed to determine whether these kidney abnormalities are reversible following weight loss therapy.

The value of Pa(CO2) in relation to outcome in congenital diaphragmatic hernia

BACKGROUND

Postnatal assessment of disease severity is critical for analysis of mortality rates and development of future interventions in congenital diaphragmatic hernia (CDH).

OBJECTIVE

The objective of this study was to stratify the risk of mortality based on arterial Paco 2.

METHODS

Retrospective analysis of infants (n = 133) with CDH admitted to a regional extracorporeal membrane oxygenation (ECMO) center in two different periods: period I (1987-1996; n = 46) and period II (2002-2010; n = 87).

RESULTS

The mortality rate (37%) was similar in both periods (p = 0.98). Paco 2 < 60 mm Hg in the first arterial blood gas (ABG) was an independent predictor of survival in both periods (p = 0.03). The predicted survival rate was 84% if initial Paco 2 was < 55 mm Hg. For infants with initial Paco 2 > 55 mm Hg treated with ECMO (n = 83), the predicted survival rate was 11% if the Paco 2 was > 88 mm Hg before the initiation of ECMO.

CONCLUSION

Paco 2, a surrogate of lung hypoplasia, may be useful for risk stratification in CDH. Paco 2 < 60 mm Hg in the first ABG may indicate milder pulmonary hypoplasia. A Paco 2 > 80 mm Hg in the first ABG and/or before ECMO may indicate severe pulmonary hypoplasia.

Diabetes Status and Race are Associated with Cardiovascular Risk Markers in Obese Adolescents

OBJECTIVE

The objective of this study was to evaluate differences in cardiovascular disease (CVD) risk markers in obese adolescents based on diabetes status and race in order to improve risk-reduction intervention strategies.

METHODS

This was a retrospective, cross-sectional study of obese adolescents, age 10 to 21 years, who were evaluated at Children's of Alabama between 2000 and 2012. Subjects were classified by glycated hemoglobin (HbA1c) as having normoglycemia, prediabetes, or type 2 diabetes mellitus (T2DM).

RESULTS

There were a total of 491 African American (AA) or Caucasian American (CA) subjects. Body mass index was not different between HbA1c and racial groups. Compared to subjects with normoglycemia or prediabetes, subjects with T2DM had higher levels of total cholesterol (TC) (178.6 ± 43.8 mg/dL vs. 161.5 ± 32.5 mg/dL vs. 162.4 ± 30.6 mg/dL; P<.0001) and low-density-lipoprotein cholesterol (107.4 ± 39.2 mg/dL vs. 97.0 ± 31.0 mg/dL vs. 97.5 ± 26.9 mg/dL; P = .0073). Compared with AA subjects, CA subjects had lower high-density-lipoprotein cholesterol (HDL-C) levels (40.4 ± 10.4 mg/dL vs. 44.3 ± 11.9 mg/dL; P = .0005) and higher non-HDL-C levels (129.6 ± 36.2 mg/dL vs. 122.5 ± 37.5 mg/dL; P = .0490). Of the characteristics studied, HbA1c had the most significant positive association with dyslipidemia and was strongly correlated with both TC (β, 4.21; P<.0001) and non-HDL-C (β, 4.3; P<.0001).

CONCLUSION

Obese adolescents with T2DM have more abnormal lipoprotein profiles than those with normoglycemia or prediabetes. Obese CA adolescents have more abnormal lipids than obese AA adolescents. HbA1c was the characteristic most highly associated with abnormal lipoprotein profiles in our subjects. Our results show that CVD risk markers in obese adolescents vary by race and HbA1c concentration.

Minimal access laparoscopic surgery for treatment of ulcerative colitis and familial adenomatous polyposis coli in children and adolescents

BACKGROUND

Laparoscopic restorative proctocolectomy is standard surgical treatment for patients with ulcerative colitis (UC) and familial adenomatous polyposis coli (FAP). Scar burden can be minimized by reducing the number of laparoscopic ports. The aim of this study is to review the authors' experience with reduced-port laparoscopy in this setting and to compare it with conventional laparoscopy using multiple ports.

MATERIALS AND METHODS

Charts of pediatric patients undergoing colectomy for UC or FAP between 2009 and 2012 were retrospectively reviewed. Patients who had the operation performed through one or two multichannel ports were assigned to the minimal access (MA) study group. Patients who had four or five single-channel ports with or without an additional small laparotomy were assigned to the LAP group.

RESULTS

Twenty-two patients were identified. Ages at first operation were 2-18 years (median, 13.5 years). There were no conversions to laparotomy and no mortality. Mean operative times for the MA and LAP groups, respectively, were 250 and 284 minutes for abdominal colectomy with end ileostomy (P=.15), 198 and 301 minutes for completion proctectomy with diverting loop ileostomy (DLI) (P=.26), and 455 and 414 minutes for proctocolectomy with ileal pouch-anal anastomosis and DLI (P=.72). A major complication requiring laparotomy occurred in 1 patient (9%) in the MA group and in 2 patients (18%) in the LAP group.

CONCLUSIONS

Minimal access laparoscopic surgery for UC and FAP is safe and feasible. A slightly larger incision at the ostomy site facilitates extraction of the specimen and extracorporeal construction of a J-pouch. Operative times and hospital stay are comparable to those with multiport laparoscopy.

Utility of immature granulocyte percentage in pediatric appendicitis

BACKGROUND

Acute appendicitis is the most common cause of abdominal surgery in children. Adjuncts are used to help clinicians predict acute or perforated appendicitis, which may affect treatment decisions. Automated hematologic analyzers can perform more accurate automated differentials including immature granulocyte percentages (IG%). Elevated IG% has demonstrated improved accuracy for predicting sepsis in the neonatal population than traditional immature-to-total neutrophil count ratios. We intended to assess the additional discriminatory ability of IG% to traditionally assessed parameters in the differentiation between acute and perforated appendicitis.

MATERIALS AND METHODS

We identified all patients with appendicitis from July 2012-June 2013 by International Classification of Diseases-9 code. Charts were reviewed for relevant demographic, clinical, and outcome data, which were compared between acute and perforated appendicitis groups using Fisher exact and t-tests for categorical and continuous variables, respectively. We used an adjusted logistic regression model using clinical laboratory values to predict the odds of perforated appendicitis.

RESULTS

A total of 251 patients were included in the analysis. Those with perforated appendicitis had a higher white blood cell count (P=0.0063), C-reactive protein (CRP) (P<0.0001), and IG% (P=0.0299). In the adjusted model, only elevated CRP (odds ratio 3.46, 95% confidence interval 1.40-8.54) and presence of left shift (odds ratio 2.66, 95% confidence interval 1.09-6.46) were significant predictors of perforated appendicitis. The c-statistic of the final model was 0.70, suggesting fair discriminatory ability in predicting perforated appendicitis.

CONCLUSIONS

IG% did not provide any additional benefit to elevated CRP and presence of left shift in the differentiation between acute and perforated appendicitis.

Pediatric and adolescent obesity: management, options for surgery, and outcomes

The past four decades have witnessed a marked rise in the number of children and adolescents with obesity. Severe obesity has also become increasingly prevalent. More young patients who have obesity are being referred for weight management and weight loss surgery, thus posing new challenges to both the medical personnel who care for them as well as the institutions in which that care is provided. This manuscript is generated from the material presented at the Education Day symposium entitled "Surgical Care of the Obese Child" held at the 42nd Annual Meeting of the American Pediatric Surgical Association in Palm Desert, CA, on May 22, 2011. Herein the presenters at the symposium update the material addressing evaluation of a young person for weight loss surgery (including the team approach to patient evaluation and institutional infrastructure and responsibilities). The procedures most frequently available to young patients with obesity are identified, and current outcomes, trends, and future direction are also discussed.

Tales from previous times: important eponyms in pediatric surgery

The use of eponyms in medicine has a long and captivating tradition, which applies to pediatric surgery as well. Unfortunately, even though these eponyms are widely used, oftentimes the fascinating personalities and lives behind these names remain unrecognized or underappreciated, especially among residents, fellows and younger-generation pediatric surgeons. Therefore, in this article, we review 15 names that are frequently used as eponyms in modern pediatric surgery and hereby enlighten the personalities behind them. Given their particular frequency, we choose the following eponyms: Ramstedt pylorotomy, Nissen fundoplication, Murphy's sign and sequence, McBurney's sign and incision, Meckel's diverticulum, Kasai portoenterostomy, Ladd's procedure, Morgagni and Bochdalek hernia, Ravitch operation, Nuss procedure, Hirschsprung disease, Swenson pullthrough, Peña procedure and Wilms tumor. A detailed description of the historical importance of these personalities and their contribution to our field is given. Without the appropriate historical background, it is difficult for the current younger and next generation pediatric surgeons to grasp the full spectrum of the ongoing progress in our field. Therefore, our article conveys not only important insight into the past, but also provides young surgeons with an important historical perspective essential to understand the current and future developments in modern pediatric surgery.

Perioperative outcomes of adolescents undergoing bariatric surgery: the Teen-Longitudinal Assessment of Bariatric Surgery (Teen-LABS) study

IMPORTANCE

Severe obesity in childhood is a major health problem with few effective treatments. Weight-loss surgery (WLS) is being used to treat severely obese adolescents, although with very limited data regarding surgical safety for currently used, minimally invasive procedures.

OBJECTIVE

To assess the preoperative clinical characteristics and perioperative safety outcomes of severely obese adolescents undergoing WLS.

DESIGN, SETTING, AND PARTICIPANTS

This prospective, multisite observational study enrolled patients from February 28, 2007, through December 30, 2011. Consecutive patients aged 19 years or younger who were approved to undergo WLS (n = 277) were offered enrollment into the study at 5 academic referral centers in the United States; 13 declined participation and 22 did not undergo surgery after enrollment, thus the final analysis cohort consisted of 242 individuals. There were no withdrawals.

MAIN OUTCOMES AND MEASURES

This analysis examined preoperative anthropometrics, comorbid conditions, and major and minor complications occurring within 30 days of operation. All data were collected in a standardized fashion. Reoperations and hospital readmissions were adjudicated by independent reviewers to assess relatedness to the WLS procedure.

RESULTS

The mean (SD) age of participants was 17.1 (1.6) years and the median body mass index (calculated as weight in kilograms divided by height in meters squared) was 50.5. Fifty-one percent demonstrated 4 or more major comorbid conditions. Laparoscopic Roux-en-Y gastric bypass, vertical sleeve gastrectomy, and adjustable gastric banding were performed in 66%, 28%, and 6% of patients, respectively. There were no deaths during the initial hospitalization or within 30 days of operation; major complications (eg, reoperation) were seen in 19 patients (8%). Minor complications (eg, readmission for dehydration) were noted in 36 patients (15%). All reoperations and 85% of readmissions were related to WLS.

CONCLUSIONS AND RELEVANCE

In this series, adolescents with severe obesity presented with abundant comorbid conditions. We observed a favorable short-term complication profile, supporting the early postoperative safety of WLS in select adolescents. Further longitudinal study of this cohort will permit accurate assessment of long-term outcomes for adolescents undergoing bariatric surgery.

TRIAL REGISTRATION

clinicaltrials.gov Identifier: NCT00474318.