Establishing Reference Values for Lean Muscle Mass in the Pediatric Patient.

OBJECTIVES: Adults with decreased muscle mass experience worse outcomes and more frequent complications. The effects of sarcopenia on pediatric outcomes are unknown. Our objective was to define reference values for lean muscle mass in a healthy pediatric population to facilitate future studies on the impact of lean muscle mass on pediatric outcomes. PATIENTS AND METHODS: Bilateral psoas muscle surface area was measured by computed tomography in a healthy pediatric population undergoing evaluation after trauma. Pearson correlation coefficients (PCCs) were calculated for age, weight, height, body mass index (BMI), total psoas muscle area, and psoas muscle index (PMI; defined as psoas muscle area divided by height squared). Quantile regression was used to determine age- and sex-specific percentiles of psoas muscle area and PMI. RESULTS: Analysis of 494 male and 288 female patients with available imaging (median age: 9.3 years, interquartile range: 5.4-13.4; 63.1% male) was performed. For males, age correlated strongly with total psoas volume (PCC = 0.87), height (0.95), and weight (0.88) and poorly with BMI (0.45). In females, age correlated strongly with total psoas volume (0.88), height (0.92), weight (0.88) and poorly with BMI (0.19). Gender-specific curves and charts were created using output from the quantile regression from reference values of the total psoas muscle area corresponding to the 25th, 50th, and 75th percentiles across all ages. CONCLUSIONS: We created gender-specific reference charts for total and height-normalized psoas muscle area in healthy children based on age. These results can be used in future studies to establish the effects of sarcopenia in pediatric patients.

Orientation in Perpetuity: An Online Clinical Decision Support System for Surgical Residents.

BACKGROUND: Limiting variability is an essential element to improving quality of care. Frequent resident turnover represents a significant barrier to clinical standardization. Trainees joining new surgical services must familiarize themselves with the guidelines and protocols that direct patient care as well as their learning objectives and expectations. A clinical decision support system (CDSS) is a dynamic, searchable electronic resource intended for use at the point of care. The CDSS can provide convenient and timely access to relevant information for residents, allowing them to incorporate the most up-to-date protocols and guidelines in their daily care of patients. The objective of this quality improvement intervention was to determine the objective rate of CDSS utilization and its subjective value to residents. MATERIALS AND METHODS: An internally developed, web-based CDSS including essential, clinically useful documents was created for use by trainees on a busy pediatric surgery service. A standardized orientation was provided to each resident and fellow on joining the service, complemented by a summary card to be attached to the trainee's ID badge. CDSS usage was monitored using web analytics. Trainees who rotated before and after the CDSS launch were surveyed regarding attitudes toward clinical resources and confidence in patient management. RESULTS: Documents published to the CDSS included 33 clinical guideline documents and 207 additional educational and support files including reference materials from service orientation were made available to trainees and staff. Goals for resident usage were established by evaluation and adaptation of early traffic patterns. Analysis of web traffic collected over 14 consecutive months revealed utilization above target levels, with 4.0 average weekly page views per trainee (IQR: 1.6-5.6). A total of 60 survey responses were received (54% of trainees invited); majorities of rotating trainees and survey respondents were trainees in general surgery and most were interns. Mean composite scores reflected a trend toward improved satisfaction when seeking CDSM (before intervention 3.18 [SD 0.73], after intervention 3.92 [SD 0.70], range 1-5) which was statistically significant (P = 0.005). Mean scores also improved across five of six components of the composite score (mean improvement 0.75, range: 0.53-0.92), four of which were statistically significant (P = 0.001-0.038). Most (59%) respondents reported that they used the CDSS frequently. CONCLUSIONS: Convenient access to a CDSS resulted in greater than expected utilization as well as higher resident satisfaction with and confidence in materials provided. A CDSS is a promising tool offering quick access to high-quality information in challenging trainee environments.

Paget-Schroetter syndrome in 21 children: outcomes after multidisciplinary care.

OBJECTIVE: To review the presentation, management, and outcomes of Paget-Schroetter syndrome (PSS) in children and propose a multidisciplinary treatment algorithm involving pediatric and vascular surgery, interventional radiology, and hematology. STUDY DESIGN: Patients with PSS presenting between 2003 and 2013 were reviewed. Demographics, symptoms, therapies, and functional outcomes were noted. Data from early patients informed the development of a multidisciplinary treatment algorithm applied to later patients. RESULTS: Of 21 patients, mean ± SD age was 16 ± 1.6 years and 11 (52%) were male. Of patients with complete presentation data, common symptoms were edema (84%), discoloration (58%), and pain (58%). Thrombophilia workup revealed one heterozygote for factor V Leiden, 2 patients with factor VIII elevation and 1 patient with mildly low antithrombin. The most recent 8 patients were treated according to an algorithm developed by a multidisciplinary working group through experience with the first 13 cases. All patients underwent a venogram, endovascular intervention (including 15 receiving catheter-directed thrombolysis), and operative ipsilateral thoracic outlet decompression (first rib resection, anterior scalenectomy, and venolysis). Postoperative complications included hemothorax (2), pneumothorax (1), and recurrent thrombosis (2). Follow up duration was 12 ± 9.5 months. Symptoms recurred transiently in 1 patient. CONCLUSION: Pediatric patients with PSS can be treated successfully using a multidisciplinary treatment algorithm including anticoagulation, catheter-directed thrombolysis, and operative decompression of the thoracic outlet. Early outcomes are promising.

Predictors of Enteral Autonomy in Children with Intestinal Failure: A Multicenter Cohort Study.

OBJECTIVES: In a large cohort of children with intestinal failure (IF), we sought to determine the cumulative incidence of achieving enteral autonomy and identify patient and institutional characteristics associated with enteral autonomy. STUDY DESIGN: A multicenter, retrospective cohort analysis from the Pediatric Intestinal Failure Consortium was performed. IF was defined as severe congenital or acquired gastrointestinal diseases during infancy with dependence on parenteral nutrition (PN) >60 days. Enteral autonomy was defined as PN discontinuation >3 months. RESULTS: A total of 272 infants were followed for a median (IQR) of 33.5 (16.2-51.5) months. Enteral autonomy was achieved in 118 (43%); 36 (13%) remained PN dependent and 118 (43%) patients died or underwent transplantation. Multivariable analysis identified necrotizing enterocolitis (NEC; OR 2.42, 95% CI 1.33-4.47), care at an IF site without an associated intestinal transplantation program (OR 2.73, 95% CI 1.56-4.78), and an intact ileocecal valve (OR 2.80, 95% CI 1.63-4.83) as independent risk factors for enteral autonomy. A second model (n = 144) that included only patients with intraoperatively measured residual small bowel length found NEC (OR 3.44, 95% CI 1.36-8.71), care at a nonintestinal transplantation center (OR 6.56, 95% CI 2.53-16.98), and residual small bowel length (OR 1.04 cm, 95% CI 1.02-1.06 cm) to be independently associated with enteral autonomy. CONCLUSIONS: A substantial proportion of infants with IF can achieve enteral autonomy. Underlying NEC, preserved ileocecal valve, and longer bowel length are associated with achieving enteral autonomy. It is likely that variations in institutional practices and referral patterns also affect outcomes in children with IF.

Preservation of biochemical liver function with low-dose soy-based lipids in children with intestinal failure-associated liver disease.

OBJECTIVES: Intestinal failure-associated liver disease (IFALD) contributes to significant morbidity in pediatric patients with intestinal failure (IF); however, the use of parenteral nutrition (PN) with a fish oil-based intravenous (IV) emulsion (FO) has been associated with biochemical reversal of cholestasis and improved outcomes. Unfortunately, FO increases the complexity of care: because it can be administered only under Food and Drug Administration compassionate use protocols requiring special monitoring, it is not available as a 3-in-1 solution and is more expensive than comparable soy-based IV lipid emulsion (SO). Because of these pragmatic constraints, a series of patient families were switched to low-dose (1 g kg(-1) day(-1)) SO following biochemical resolution of cholestasis. The present study examines whether reversal of cholestasis and somatic growth are maintained following this transition. METHODS: The present study is a chart review of all children with IFALD who switched from FO to SO following resolution of cholestasis. Variables are presented as medians (interquartile ranges). Comparisons were performed using the Wilcoxon signed-rank test. RESULTS: Seven patients ages 25.9 (16.2-43.2) months were transitioned to SO following reversal of cholestasis using FO. At a median follow-up of 13.9 (4.3-50.1) months, there were no significant differences between pretransition and post-transition serum alanine and aspartate aminotransferases, direct bilirubin, and weight-for-age z scores. Because of recurrence of cholestasis, 1 patient was restarted on FO after 4 months on SO. CONCLUSIONS: Biochemical reversal of IFALD and growth were preserved after transition from FO to SO in 6 of 7 (86%) patients. Given the challenges associated with the use of FO, SO may be a viable alternative in select patients with home PN.

Tight Glycemic Control With Insulin Does Not Affect Skeletal Muscle Degradation During the Early Postoperative Period Following Pediatric Cardiac Surgery.

OBJECTIVE: Critical illness is associated with significant catabolism, and persistent protein loss correlates with increased morbidity and mortality. Insulin is a potent anticatabolic hormone; high-dose insulin decreases skeletal muscle protein breakdown in critically ill pediatric surgical patients. However, insulin's effect on protein catabolism when given at clinically utilized doses has not been studied. The objective was to evaluate the effect of postoperative tight glycemic control and clinically dosed insulin on skeletal muscle degradation in children after cardiac surgery with cardiopulmonary bypass. DESIGN: Secondary analysis of a two-center, prospective randomized trial comparing tight glycemic control with standard care. Randomization was stratified by study center. PATIENTS: Children 0-36 months who were admitted to the ICU after cardiac surgery requiring cardiopulmonary bypass. INTERVENTIONS: In the tight glycemic control arm, insulin was titrated to maintain blood glucose between 80 and 110 mg/dL. Patients in the control arm received standard care. Skeletal muscle breakdown was quantified by a ratio of urinary 3-methylhistidine to urinary creatinine. MEASUREMENTS AND MAIN RESULTS: A total of 561 patients were included: 281 in the tight glycemic control arm and 280 receiving standard care. There was no difference in 3-methylhistidine to creatinine between groups (tight glycemic control, 249 ± 127 vs standard care, 253 ± 112, mean ± SD in µmol/g; p = 0.72). In analyses restricted to the patients in tight glycemic control arm, higher 3-methylhistidine to creatinine correlated with younger age, as well as lower weight, weight-for-age z score, length, and body surface area (p < 0.005 for each) and lower postoperative day 3 serum creatinine (r = -0.17; p = 0.02). Sex, prealbumin, and albumin were not associated with 3-methylhistidine to creatinine. During urine collection, 245 patients (87%) received insulin. However, any insulin exposure did not impact 3-methylhistidine to creatinine (t test, p = 0.45), and there was no dose-dependent effect of insulin on 3-methylhistidine to creatinine (r = -0.03; p = 0.60). CONCLUSION: Although high-dose insulin has an anabolic effect in experimental conditions, at doses necessary to achieve normoglycemia, insulin appears to have no discernible impact on skeletal muscle degradation in critically ill pediatric cardiac surgical patients.

Laparoscopic-Assisted Pancreatic Necrosectomy: Technique and Initial Outcomes.

BACKGROUND: Necrotizing pancreatitis (NP) may result de novo or following procedures such as ERCP or partial pancreatectomy (post-procedural), and may require surgical debridement. Video-assisted retroperitoneal debridement (VARD) is a standard approach for NP that employs a 5 cm incision with varying degrees of blind and open debridement. We describe our technique and outcomes of a modified VARD called laparoscopic-assisted pancreatic necrosectomy (LAPN) performed through a single 12 mm incision that uses direct laparoscopic visualization during debridement. METHODS: At one medical center, all LAPN patients (2012-2020) were assessed for demographics, disease factors, and outcomes. Bivariate logistic regression analyses were performed to identify factors independently associated with recovery after LAPN for patients with de novo vs post-procedural necrosum. RESULTS: Over 9 years, 60 patients underwent LAPN for NP. Median age was 57 years (IQR: 47-66) and 43 (69%) were men. Pancreas necrosum was de novo in 39 (63%) patients and post-procedural in 23 (37%). NP resolved with a median of 1 LAPN procedure and median hospitalization was 33 days. The LAPN major morbidity rate and in-hospital mortality rate were 47% and 5%. No significant differences were seen between NP etiology cohorts, although post-procedure NP patients trended towards a faster clinical recovery to baseline compared to de novo patients (193 vs 394 days; p-value = .07). CONCLUSIONS: LAPN offers a smaller incision with excellent visualization and non-inferior outcomes, regardless of etiology, with likely faster recovery for patients with post-procedural vs de novo necrotizing pancreatitis.

Suction Rectal Biopsy is Accurate in Late Preterm Infants with Suspected Hirschsprung Disease.

BACKGROUND: Few data are available to substantiate the dogma commonly held by pediatric surgeons and pediatric pathologists that rectal biopsies may be inaccurate or risky in preterm neonates. We aimed to address these concerns. METHODS: We performed a single-institution retrospective review of patients who underwent suction rectal biopsies at <37 weeks corrected age from 2009 to 2018. The primary outcomes were accuracy of biopsy results and procedural complications. RESULTS: Forty-nine patients underwent suction rectal biopsy at <37 weeks corrected age. Mean gestational age at biopsy was 35.2 weeks (range 32.1-36.9) and mean weight was 2126 g (range 1590-3100). Five (10%) infants had biopsies positive for Hirschsprung Disease. All 5 later underwent pull-through operations and had pathologic confirmation of an aganglionic segment. The remaining 44 (90%) had biopsies showing ganglion cells. None were later found to have HD during the follow up period. Those who underwent biopsy at <2000 g (16/44) had 100% sensitivity [95% CI 48, 100] and specificity [95% CI 92, 100] (2 true positives, 14 true negatives). There were no complications identified. CONCLUSION: Suction rectal biopsy can be performed safely in preterm infants as small as 1590-2000 g with high accuracy. Clinicians should not hesitate to perform a biopsy for a premature infant when clinically appropriate. TYPE OF STUDY: Study of a diagnostic test. LEVEL OF EVIDENCE: Level IV.

The pediatric surgery match by the numbers: Defining the successful application.

BACKGROUND: Pediatric surgery remains the most competitive general surgery subspecialty. The authors suspected significant inflation in academic metrics since the last published paper. This study aimed to identify factors associated with applicant success in the match. METHODS: After IRB approval, all applications to a single accredited pediatric surgery fellowship program were reviewed for match years 2014-2018. Matched and unmatched applicants were compared in an unadjusted and adjusted analysis. RESULTS: This training program received 414 of 425 total applications (97%). Match results were available for 388 (94%). Matched applicants were more likely to train in programs with pediatric surgery fellowships (64% vs. 28%) and to have dedicated research time (55% vs. 21%; all p < 0.01). Matched applicants had more total publications (median: 12 vs. 7, p < 0.01) and higher ABSITE scores (median: 64th vs. 59th percentile, p < 0.01). Training in multiple programs negatively impacted the chance to match (p < 0.01). The median number of publications per applicant increased over the study time period from 7 to 11 (p < 0.01). CONCLUSIONS: The likelihood of matching into a pediatric surgery fellowship was related to the type of residency attended, dedicated research time, ABSITE scores, and number of publications. Overall, the total number of publications reported by all applicants increased. TYPE OF STUDY: Retrospective Comparative Study. LEVEL OF EVIDENCE: Level III.

Complications after proctocolectomy and ileal pouch-anal anastomosis in pediatric patients: A systematic review.

BACKGROUND/PURPOSE: Colectomy with ileal pouch-anal anastomosis (IPAA) is the standard of care for patients with familial adenomatous polyposis (FAP) and refractory ulcerative colitis (UC). The rates of postoperative complications are not well established in children. The objective of this systematic review is to establish benchmark data for morbidity after pediatric IPAA. METHODS: PubMed, Embase, and The Cochrane Library were searched for studies of colectomy with IPAA in patients ≤21 years old. UC studies were limited to the anti-tumor necrosis factor-α agents era (1998-present). All postoperative complications were extracted. RESULTS: Thirteen studies met the inclusion criteria (763 patients). Compared to patients with FAP, UC patients had a higher prevalence of pouch loss (10.6% vs. 1.5%). Other major complications such as anastomotic leak, abscess, and fistula were uncommon (mean prevalence 4.9%, 4.2%, and 5.0%, respectively, for patients with UC; 8.7%, 4.2%, and 4.3% for FAP). The most frequent complication was pouchitis (36.4% of UC patients). CONCLUSIONS: Devastating complications from colectomy and IPAA are rare, but patients with UC have poorer outcomes than those with FAP. Much of the morbidity may therefore stem from patient or disease factors. Multicenter, prospective studies are needed to identify modifiable risks in patients with UC undergoing IPAA. LEVEL OF EVIDENCE: Prognostic, level II.

Whole Body Protein Turnover and Net Protein Balance After Pediatric Thoracic Surgery: A Noninvasive Single-Dose 15 N Glycine Stable Isotope Protocol With End-Product Enrichment.

BACKGROUND: We used the 15 N glycine urinary end-product enrichment technique to quantify whole body protein turnover following thoracic surgery. MATERIALS AND METHODS: A single dose of 15 N glycine (2 mg/kg) was administered orally on postoperative day 1 to children (1-18 years) following thoracic surgery. 15 N enrichment of ammonia and urea was measured in mixed urine after 12 and 24 hours, respectively, and protein synthesis, breakdown, and net balance determined. Nitrogen balance (dietary intake minus urinary excretion) was calculated. Urinary 3-methylhistidine:creatinine ratio was measured as a marker of skeletal muscle protein breakdown. RESULTS: We enrolled 19 subjects-median (interquartile range): age, 13.8 years (12.2-15.1); weight, 49.2 kg (38.4-60.8)-who underwent thoracotomy (n = 12) or thoracoscopic (n = 7) surgery. Protein synthesis and breakdown by 15 N enrichment were 7.1 (5.5-9) and 7.1 (5.6-9) g·kg-1 ·d-1 with ammonia (12 hours) as the end product, and 5.8 (3.8-6.7) and 6.7 (4.5-7.6) with urea (24 hours), respectively. Net protein balance by the 15 N glycine and urinary urea nitrogen methods were -0.34 (-0.47, -0.3) and -0.48 (-0.65, -0.28) g·kg-1 ·d-1 , respectively (rs = 0.828, P < .001). Postoperative change in 3-methylhistidine:creatinine ratio did not correlate significantly with protein breakdown or balance. CONCLUSION: The single-dose oral administration of 15 N glycine stable isotope with measurement of urinary end-product enrichment is a feasible and noninvasive method to investigate whole body protein turnover in children. After major surgery, children manifest increased protein turnover and net negative balance due to increased protein breakdown.

Ileostomy Prolapse in Children with Intestinal Dysmotility.

BACKGROUND: A relationship between intestinal motility and ileostomy prolapse has been suggested but not demonstrated objectively. AIMS: This study evaluated the association between ileostomy prolapse and intestinal dysmotility in children. METHODS: IRB-approved retrospective review of 163 patients with ileostomies (1998-2014) at a single institution. Patients were categorized as having clinical dysmotility as a primary diagnosis (n = 33), clinically suspected dysmotility based on underlying diagnosis (n = 60), or intestinal dysmotility unlikely (n = 70) at the time of ileostomy present. Intestinal manometry was categorized as normal (n = 13) or abnormal (n = 10). Primary outcome was pathologic stoma prolapse. Multivariate analysis using a logistic regression model and log-rank test to compare stoma prolapse rates over time between motility groups were used. RESULTS: Clinical diagnosis of dysmotility (p ≤ 0.001) and manometric findings of dysmotility (p = 0.024) were independently associated with stoma prolapse. Clinical dysmotility correlated with manometric findings (κ = 0.53). Prolapse occurred in 42% of patients with dysmotility, 34% of patients with suspected dysmotility, and 24% of patients with normal motility. One-year prolapse-free stoma "survival" was 45% for dysmotility, 72% for suspected dysmotility, and 85% for intestinal dysmotility unlikely groups (p = 0.006). CONCLUSIONS: Children with intestinal dysmotility are at great risk for stoma prolapse. Intestinal manometry could help identify these patients preoperatively.

Cost comparison of initial lobectomy versus fine-needle aspiration for diagnostic workup of thyroid nodules in children.

BACKGROUND: Though uncommon in children, pediatric thyroid nodules carry a higher risk of malignancy than adult nodules. While fine-needle aspiration (FNA) has been well established as the initial diagnostic test in adults, it has been more slowly adopted in children. The purpose of this study was to examine the comparative cost of FNA versus initial diagnostic lobectomy (DL) in the pediatric patient with an ultrasound-confirmed thyroid nodule. METHODS: A decision tree model was created using an adolescent with an asymptomatic thyroid nodule as the reference case. Probabilities were defined based on review of the pediatric and adult literature. Costs were determined from previous literature and the publicly available Medicare physician fee schedule. Tornado plot and sensitivity analyses were performed to assess sources of cost variation. RESULTS: Using decision analysis, FNA was less costly than DL with an estimated cost of $2529 vs. $5680. Tornado analysis demonstrated that the probability of an initial indeterminate FNA result contributed most to cost variation. On sensitivity analysis, when probability of an indeterminate FNA result was increased to 35%, the maximum value found in the literature, FNA remained less costly. In Monte Carlo simulation set to 10,000 iterations, FNA was superior to DL in 74% of cases. CONCLUSIONS: In this theoretical model based on available literature and costs, FNA is less costly than DL for initial diagnostic workup of thyroid nodules in children. Securing resources to offer FNA in the work-up of thyroid nodules may be financially beneficial to hospitals and patients. LEVEL OF EVIDENCE: Level 1 cost effectiveness study - using reasonable costs and alternatives used in study with values obtained from many studies, study used multi-way sensitivity analysis.

Cadaver-Based Simulation Increases Resident Confidence, Initial Exposure to Fundamental Techniques, and May Augment Operative Autonomy.

OBJECTIVE: Surgical simulation is an important adjunct in surgical education. The majority of operative procedures can be simplified to core components. This study aimed to quantify a cadaver-based simulation course utility in improving exposure to fundamental maneuvers, resident and attending confidence in trainee capability, and if this led to earlier operative independence. DESIGN: A list of fundamental surgical procedures was established by a faculty panel. Residents were assigned to a group led by a chief resident. Residents performed skills on cadavers appropriate for PGY level. A video-recorded examination where they narrated and demonstrated a task independently was then graded by attendings using standardized rubrics. Participants completed surveys regarding improvements in knowledge and confidence. SETTING: The course was conducted at the Emory University School of Medicine and the T3 Laboratories in Atlanta, GA. PARTICIPANTS: A total of 133 residents and 41 attendings participated in the course. 133 (100%) participating residents and 32 (78%) attendings completed surveys. RESULTS: Resident confidence in completing the assigned skill independently increased from 3 (2-3) to 4 (3-4), p < 0.01. Residents stated that a median of 40% (interquartile range: 20%-60%) of procedures were performed for the first time in the course, and the same number had been performed only in the course. The percentage of skills attendings believed residents could perform independently increased from 40% (40%-60%) to 60% (60%->80%), p < 0.04. Attendings were more likely to grant autonomy in the operating room after this exercise (4 [3-5]). CONCLUSIONS: A cadaveric skills course focused on fundamental maneuvers with objective confirmation of success is a viable adjunct to clinical operative experience. Residents were formally exposed to fundamental surgical maneuvers earlier as a result of this course. This activity improved both resident and attending confidence in trainee operative skill, resulting in increased attending willingness to grant a higher level of autonomy in the operating room.

Necrotizing enterocolitis is associated with earlier achievement of enteral autonomy in children with short bowel syndrome.

PURPOSE: Necrotizing enterocolitis (NEC) remains one of the most common underlying diagnoses of short bowel syndrome (SBS) in children. The relationship between the etiology of SBS and ultimate enteral autonomy has not been well studied. This investigation sought to evaluate the rate of achievement of enteral autonomy in SBS patients with and without NEC. METHODS: Following IRB approval, 109 patients (2002-2014) at a multidisciplinary intestinal rehabilitation program were reviewed. The primary outcome evaluated was achievement of enteral autonomy (i.e. fully weaning from parenteral nutrition). Patient demographics, primary diagnosis, residual small bowel length, percent expected small bowel length, median serum citrulline level, number of abdominal operations, status of the ileocecal valve (ICV), presence of ileostomy, liver function tests, and treatment for bacterial overgrowth were recorded for each patient. RESULTS: Median age at PN onset was 0 weeks [IQR 0-0]. Median residual small bowel length was 33.5 cm [IQR 20-70]. NEC was present in 37 of 109 (33.9%) of patients. 45 patients (41%) achieved enteral autonomy after a median PN duration of 15.3 [IQR 7.2-38.4]months. Overall, 64.9% of patients with NEC achieved enteral autonomy compared to 29.2% of patients with a different primary diagnosis (p=0.001, Fig. 1). Patients with NEC remained more likely than those without NEC to achieve enteral autonomy after two (45.5% vs. 12.0%) and four (35.7% vs. 6.3%) years on PN (Fig. 1). Logistic regression analysis demonstrated the following parameters as independent predictors of enteral autonomy: diagnosis of NEC (p<0.002), median serum citrulline level (p<0.02), absence of a jejunostomy or ileostomy (p=0.013), and percent expected small bowel length (p=0.005). CONCLUSIONS: Children with SBS because of NEC have a significantly higher likelihood of fully weaning from parenteral nutrition compared to children with other causes of SBS. Additionally, patients with NEC may attain enteral autonomy even after long durations of parenteral support.

Abdominal MRI without Enteral Contrast Accurately Detects Intestinal Fibrostenosis in Patients with Inflammatory Bowel Disease.

Patients with inflammatory bowel disease (IBD) presenting for surgical evaluation require thorough small bowel surveillance as it improves accuracy of diagnosis (ulcerative colitis versus Crohn's) and differentiates those who may respond to nonoperative therapy, preserving bowel length. MRI has not been validated conclusively against histopathology in IBD. Most protocols require enteral contrast. This study aimed to 1) evaluate the accuracy of MRI for inflammation, fibrosis, and extraluminal complications and 2) compare MRI without enteral contrast to standard magnetic resonance enterography. Adults with Crohn's disease or ulcerative colitis who underwent abdominal MRI and surgery were retrospectively reviewed. Of 65 patients evaluated, 55 met inclusion criteria. Overall sensitivity and specificity of MRI for disease involvement localized by segment were 93 per cent (95% confidence interval = 89.4-95.0) and 95 per cent (95% confidence interval = 92.3-97.0), respectively (positive predictive value was 86%, negative predictive value was 98%). Sensitivity and specificity between MRI with and without oral and rectal contrast were similar (96% vs 91% and 99% vs 94%, P > 0.10). As were positive predictive value and negative predictive value (85% vs 96%, P = 0.16; 97% vs 99%, P = 0.42). Magnetic resonance is highly sensitive and specific for localized disease involvement and extraluminal abdominal sequelae of IBD. It accurately differentiates patients who have chronic transmural (fibrotic) disease and thus may require an operation from those with acute inflammation, whose symptoms may improve with aggressive medical therapy alone. MRI without contrast had comparable diagnostic yield to standard magnetic resonance enterography.

Extraluminal distraction enterogenesis using shape-memory polymer.

PURPOSE: Although a few techniques for lengthening intestine by mechanical stretch have been described, they are relatively complex, and the majority involve placement of an intraluminal device. Ideally, techniques applicable to humans would be easy to perform and extraluminal to avoid the potential for mucosal injury. This study of distraction enterogenesis used an extraluminal, radially self-expanding shape-memory polymer cylinder and a simple operative approach to both elongate intestine and grow new tissue. METHODS: Young Sprague Dawley rats (250-350 g) underwent Roux-en-Y isolation of a small intestinal limb and were divided in three groups: no further manipulation (Control 1, C1); placement of a nonexpanding device (Control 2, C2); or placement of a radially expanding device by the limb (Experimental, Exp). For C2 and Exp animals, the blind end of the limb was wrapped around the radially expanding cylindrical device with the limb-end sutured back to the limb-side. Bowel length was measured at operation and at necropsy (14 days) both in-situ and ex-vivo under standard tension (6g weight). Change in length is shown as mean ± standard deviation. A blinded gastrointestinal pathologist reviewed histology and recorded multiple measures of intestinal adaptation. The DNA to protein ratio was quantified as a surrogate for cellular proliferation. Changes in length, histologic measures, and DNA:protein were compared using analysis of variance, with significance set at P<0.05. RESULTS: The length of the Roux limb in situ increased significantly in Exp animals (n=8, 29.0 ± 5.8mm) compared with C1 animals (n=5, -11.2 ± 9.0mm, P<0.01). The length of the Roux limb ex vivo under standard tension increased in the Exp group (25.8 ± 4.2mm) compared with the C2 group (n=6, -4.3 ± 6.0, P<0.01). There were no differences in histologic measures of bowel adaptation between the groups, namely villous height and width, crypt depth, crypt density, and crypt fission rate (all P ≥ 0.08). Muscularis mucosal thickness was also not different (P=0.25). There was no difference in DNA:protein between groups (P=0.47). CONCLUSION: An extraluminally placed, radially expanding shape-memory polymer cylinder successfully lengthened intestine, without damaging mucosa. Lack of difference in muscularis thickness and a constant DNA:protein ratio suggests that this process may be related to actual growth rather than mere stretch. This study demonstrated a simple approach that warrants further study aiming at potential clinical applicability.

Metabolic bone disease in pediatric intestinal failure patients: prevalence and risk factors.

PURPOSE: Patients with intestinal failure (IF) are known to have impaired absorption of nutrients required for maintenance of skeletal mass. Rates and risk factors of low bone mineral density (BMD) are unknown in pediatric IF patients. METHODS: Following IRB approval, patients with IF having undergone DXA scans were identified and laboratory, clinical, and nutritional intake variables were recorded. Low BMD was defined by a z-score of less than or equal to -2.0. Univariate followed by multivariable regression analysis was performed. RESULTS: Sixty-five patients underwent a total of 99 routine DXA scans. Twenty-seven (41%) had vitamin D deficiency, 22 (34%) had low BMD, and nineteen (29%) had a history of fractures. Variables noted to be associated with low BMD (p<0.1) on univariate analysis were considered for multivariable regression. Multivariable regression identified WAZ and serum calcium levels (p<0.05) as independent predictors of low BMD z-score. None of the other evaluated factors were associated with the risk of low BMD. Low BMD was not associated with risk of fractures. CONCLUSION: There is a significant incidence of low BMD in children with IF. WAZ and lower serum calcium levels are associated with risk of low BMD. Additional long term prospective studies are needed to further characterize the risk factors associated with low BMD.

Factors Affecting Spontaneous Closure of Gastrocutaneous Fistulae After Removal of Gastrostomy Tubes in Children With Intestinal Failure.

BACKGROUND: Children with intestinal failure (IF) frequently require gastrostomy tubes (GTs) for long-term nutrition support. Risk factors for persistent gastrocutaneous fistulae (GCFs) in pediatric patients with IF are largely unknown but may include underlying nutrition status and duration of indwelling GT. MATERIALS AND METHODS: Records of patients with IF having undergone GT removal and allowed a trial at spontaneous closure were reviewed. Nonparametric continuous variables were analyzed using the Wilcoxon rank sum test. Post hoc analysis was performed to identify the optimal threshold of GT duration predicting probability of spontaneous closure identified using receiver operating characteristic curve analysis. RESULTS: Fifty-nine children with IF undergoing GT removal were identified. Spontaneous closure occurred in 36 (61%) sites, while 23 (39%) underwent operative closure at a median 67 days after GT removal. The duration of indwelling GT was significantly shorter in the spontaneous closure group (11.5 vs 21 months, P = .002). Of 33 GT indwelling for ≤ 18 months, 28 (85%) closed spontaneously, compared with only 9 of 26 (35%) with duration >18 months (P < .001). With GCF persisting beyond 7 days, only 21% (6/28) of sites closed spontaneously, but this dropped to 6% (1/18) of cases with concurrent GT duration >18 months. CONCLUSIONS: Of the risk factors evaluated, only prolonged GT duration was associated with an increased likelihood of failure to close spontaneously. It is significantly less likely in pediatric patients with IF in whom GCF persists >7 days, particularly if the duration of GT is >18 months. Relatively earlier operative closure should be considered in this group.

Serious congenital heart disease and necrotizing enterocolitis in very low birth weight neonates.

BACKGROUND: Infants with serious congenital heart disease (CHD) appear to be at increased risk for necrotizing enterocolitis (NEC). This study aimed to quantify the incidence and mortality of NEC among very low birth weight (VLBW) neonates with serious CHD, and identify specific CHD diagnoses at the highest risk for developing NEC. STUDY DESIGN: Data were prospectively collected on 257,794 VLBW (401 to 1,500 g) neonates born from 2006 to 2011 and admitted to 674 Vermont Oxford Network US centers. Entries were coded for specific CHD diagnoses and reviewed for completeness and consistency. Survival was defined as alive in-hospital at 1 year or discharge. RESULTS: Of eligible neonates, 1,931 had serious CHD. Of these, 253 (13%) developed NEC (vs 9% in infants without CHD, adjusted odds ratio [AOR] 1.80, p<0.0001). Mortality for neonates with CHD and no NEC was 34%, vs 55% for those with CHD and NEC (p<0.0001). Both groups of CHD patients had higher mortality than infants with NEC without CHD (28%, p<0.0001). Although NEC mortality overall decreases with higher birth weight, mortality for NEC and CHD together does not. CONCLUSIONS: The incidence of NEC is significantly higher in VLBW neonates when CHD is present. The mortality of CHD and NEC together is substantially higher than that with each disease alone. Infants with atrioventricular canal appear to have higher risk for developing NEC than other CHD diagnoses. In addition to providing benchmark incidence and mortality data, these findings may have utility in the further study of the pathophysiology of NEC.