Short bowel mucosal morphology, proliferation and inflammation at first and repeat STEP procedures.

BACKGROUND: Although serial transverse enteroplasty (STEP) improves function of dilated short bowel, a significant proportion of patients require repeat surgery. To address underlying reasons for unsuccessful STEP, we compared small intestinal mucosal characteristics between initial and repeat STEP procedures in children with short bowel syndrome (SBS). METHODS: Fifteen SBS children, who underwent 13 first and 7 repeat STEP procedures with full thickness small bowel samples at median age 1.5 years (IQR 0.7-3.7) were included. The specimens were analyzed histologically for mucosal morphology, inflammation and muscular thickness. Mucosal proliferation and apoptosis was analyzed with MIB1 and Tunel immunohistochemistry. RESULTS: Median small bowel length increased 42% by initial STEP and 13% by repeat STEP (p=0.05), while enteral caloric intake increased from 6% to 36% (p=0.07) during 14 (12-42) months between the procedures. Abnormal mucosal inflammation was frequently observed both at initial (69%) and additional STEP (86%, p=0.52) surgery. Villus height, crypt depth, enterocyte proliferation and apoptosis as well as muscular thickness were comparable at first and repeat STEP (p>0.05 for all). Patients, who required repeat STEP tended to be younger (p=0.057) with less apoptotic crypt cells (p=0.031) at first STEP. Absence of ileocecal valve associated with increased intraepithelial leukocyte count and reduced crypt cell proliferation index (p<0.05 for both). CONCLUSIONS: No adaptive mucosal hyperplasia or muscular alterations occurred between first and repeat STEP. Persistent inflammation and lacking mucosal growth may contribute to continuing bowel dysfunction in SBS children, who require repeat STEP procedure, especially after removal of the ileocecal valve. LEVEL OF EVIDENCE: Level IV, retrospective study.

Critical evaluation of the Hirschsprung-associated enterocolitis (HAEC) score: A multicenter study of 116 children with Hirschsprung disease.

OBJECTIVE: To identify the optimal clinical criteria to diagnose Hirschsprung-associated enterocolitis (HAEC) in children with Hirschsprung disease (HSCR). BACKGROUND: HAEC is the most common life-threatening complication in HSCR patients, yet the diagnostic criteria for HAEC remain unclear. The consensus-based HAEC scoring system was not validated using patient data, thereby making its diagnostic accuracy uncertain. METHODS: From 2009 to 2015, consecutive children with HSCR underwent retrospective evaluation of their medical records, and questionnaire-directed parent interviews to identify treatment of suspected HAEC episodes and the 16 clinical criteria in the HAEC score. Logistic regression modeling was employed to identify criteria predicting suspected HAEC episodes. RESULTS: One hundred sixteen HSCR patients met inclusion criteria, 43 patients (37.1%) were treated for at least one suspected HAEC episode. An HAEC score of 4 maximized the sum of sensitivity (83.7%) and specificity (98.6%) while the previously established cut-off score of 10 showed lower sensitivity (41.9%) with perfect specificity. Multivariable analysis identified four criteria utilized to create a new HAEC Risk score with performance characteristics similar to the HAEC score cutoff of 4. CONCLUSION: When using the HAEC score, a cutoff of 4 should be used rather than 10, which under-diagnosed patients with HAEC. Alternatively, the new HAEC Risk score could be employed. LEVEL OF EVIDENCE: Diagnostic Study, Level 3.

Reduced paraspinous muscle area is associated with post-colectomy complications in children with ulcerative colitis.

BACKGROUND AND OBJECTIVES: Sarcopenia, defined as reduced muscle mass, is typically assessed by CT scans, which are infrequently performed in children. Using MRI to measure sarcopenia, we determined the association with postoperative complications after colectomy for ulcerative colitis (UC). METHODS: Clinical and preoperative MRI data for 13-18-year-old UC patients who underwent colectomy were retrospectively reviewed. Bilateral paraspinous muscle area (PSMA) and psoas muscle area (PMA) at L3 vertebra were measured and averaged. Composite complications were infection, wound dehiscence, postoperative leak/abscess, prolonged ileus, pulmonary embolism, venous thromboembolism, or readmission. RESULTS: Twenty-nine patients with average age 15.9±1.36years and weight 61.5±19.8kg had a preoperative MRI. The 18/29(62%) with complications had significantly reduced PSMA (4.71±1.44 vs 5.64±1.38cm2, p=0.04) and PMA (7.16±2.60 vs 8.93±2.44, p=0.04). When stratified and compared to highest PSMA, patients with lowest PSMA had increased complication rates (88% vs 29%, p=0.04). There were no differences in age, BMI, albumin, CRP, ESR, or preoperative steroid or anti-TNFα use. Odds of complication in the lowest tertile were 25.0-fold higher than the highest tertile (p=0.04, 95% CI=1.2-520.73). CONCLUSION: This is the first study to show low PSMA on MRI is associated with complications and increased hospital stay after colectomy in children with UC. LEVELS OF EVIDENCE: Level III retrospective comparative study.

Interdependency of EGF and GLP-2 Signaling in Attenuating Mucosal Atrophy in a Mouse Model of Parenteral Nutrition.

BACKGROUND & AIMS: Total parenteral nutrition (TPN), a crucial treatment for patients who cannot receive enteral nutrition, is associated with mucosal atrophy, barrier dysfunction, and infectious complications. Glucagon-like peptide-2 (GLP-2) and epidermal growth factor (EGF) improve intestinal epithelial cell (IEC) responses and attenuate mucosal atrophy in several TPN models. However, it remains unclear whether these 2 factors use distinct or overlapping signaling pathways to improve IEC responses. We investigated the interaction of GLP-2 and EGF signaling in a mouse TPN model and in patients deprived of enteral nutrition. METHODS: Adult C57BL/6J, IEC-Egfrknock out (KO) and IEC-pik3r1KO mice receiving TPN or enteral nutrition were treated with EGF or GLP-2 alone or in combination with reciprocal receptor inhibitors, GLP-2(3-33) or gefitinib. Jejunum was collected and mucosal atrophy and IEC responses were assessed by histologic, gene, and protein expression analyses. In patients undergoing planned looped ileostomies, fed and unfed ileum was analyzed. RESULTS: Enteral nutrient deprivation reduced endogenous EGF and GLP-2 signaling in mice and human beings. In the mouse TPN model, exogenous EGF or GLP-2 attenuated mucosal atrophy and restored IEC proliferation. The beneficial effects of EGF and GLP-2 were decreased upon Gefitinib treatment and in TPN-treated IEC-EgfrKO mice, showing epidermal growth factor-receptor dependency for these IEC responses. By contrast, in TPN-treated IEC-pi3kr1KO mice, the beneficial actions of EGF were lost, although GLP-2 still attenuated mucosal atrophy. CONCLUSIONS: Upon enteral nutrient deprivation, exogenous GLP-2 and EGF show strong interdependency for improving IEC responses. Understanding the differential requirements for phosphatidylinositol 3-kinase/phosphoAKT (Ser473) signaling may help improve future therapies to prevent mucosal atrophy.

Antegrade continence enemas improve quality of life in patients with medically-refractory encopresis.

PURPOSE: Fecal incontinence is a socially debilitating problem for many children. We hypothesized that in selected patients with medically-refractory encopresis, placement of an appendicostomy or cecostomy tube for administration of antegrade continence enemas (ACE) would improve quality of life (QOL). METHODS: We reviewed all patients with encopresis who underwent appendicostomy or cecostomy placement from 2003 to 2014 at our institution. We contacted subjects' parents by phone and administered 3 surveys: a survey reflecting current stooling habits, a disease-specific QOL survey, and the PedsQL™ QOL survey. QOL surveys were completed twice by parents, once reflecting pre-operative QOL, then again reflecting current QOL. Pre-procedure and post-procedure scores were compared by paired t-test. RESULTS: Ten patients underwent appendicostomy/cecostomy for encopresis. Eight completed phone surveys. All procedures were performed laparoscopically. All patients experienced fecal soiling pre-operatively, whereas 5/8 surveyed patients (63%) noted complete resolution of soiling post-procedure (p<0.01). General and disease-specific QOL improved from pre-procedure to post-procedure in the following domains: social habits, physical activity, ability to spend the night elsewhere, feeling, and overall QOL (p<0.05). PedsQL™ scores improved significantly in physical functioning, social functioning, and overall functioning (p<0.05). CONCLUSIONS: Antegrade continence enemas significantly improve quality of life in patients with medically-refractory encopresis, likely related to resolution of soiling. LEVEL OF EVIDENCE: 4.

Redo pullthrough for Hirschsprung disease.

Pullthrough procedures for Hirschsprung diseases typically have favorable results. However, some children experience long-term postoperative complications comprising stooling disorders, such as intermittent enterocolitis, severe stool retention, intestinal obstruction, as well as incontinence. Reoperative Hirschsprung Disease surgery is complex. This begins with the workup after the initial presentation following primary pullthrough, continues with the definitive surgical correction with redo pullthrough, and ends with long-term follow-up of individuals. The decision tree can be varied with each patient. The operating pediatric surgeon must be able to utilize different operations and treatment options available. While lesser procedures may provide relief in a select population, those with residual aganglionosis or transition zone pathology or mechanical problems will likely require a redo pullthrough. Thus, the diagnostic workup, treatment plan, and definitive surgical care should be coordinated, and executed by an experienced, specialized team at a pediatric referral center.

Magnetic resonance imaging (MRI)-assisted laparoscopic anorectoplasty for imperforate anus: a single center experience.

PURPOSE: Surgical procedures for high imperforate anus have ranged from the posterior sagittal anorectoplasty (PSARP) to laparoscopic-assisted anorectoplasty (LAARP). PSARP bisects the sphincter muscle complex, introducing muscle injury and scarring. LAARP uses a straight trocar to traverse an often non-linear sphincter muscle complex. MRI-assisted LAARP (MRI-LAARP) guides the neorectum precisely through the middle of the entire sphincter complex along its trajectory. We present our experience utilizing MRI intraoperatively during LAARP. METHODS/PROCEDURE: Ten children underwent MRI-LAARP procedures. Intraoperative MRI was performed to delineate the sphincter complex, and to guide the advancement of an MRI-compatible needle through the center of the complex from skin to the peritoneal cavity. The remainder of the procedure was completed using the standard LAARP technique. RESULTS: All had successful MRI needle placement through the sphincter complex. Nine patients had successful laparoscopic pull-through procedures; one was converted to open due to severe intraperitoneal adhesions. Postoperative stay averaged 5.4 ± 4.4 days. Out of the ten patients, one child had mild dehiscence of the anal anastomosis requiring revision 11 days postoperatively. CONCLUSION: The theoretical advantage of the MRI-LAARP is placing the neorectum through the entire sphincter complex without transecting the muscle. Follow-up of these patients shows good short-term results; however, long-term follow-up will be needed to best assess sphincter and bowel function.

Ultrasound-guided intrasphincteric botulinum toxin injection relieves obstructive defecation due to Hirschsprung's disease and internal anal sphincter achalasia.

PURPOSE: Chronic obstructive defecation can occur in patients with Hirschsprung Disease (HD) and internal anal sphincter (IAS) achalasia. Injection of Botulinum Toxin (BoTox) into the IAS can temporarily relieve obstructive defecation, but can be challenging when performed by tactile sense alone. We compared results of BoTox injections with and without ultrasound (US) guidance. METHODS: We retrospectively reviewed BoTox injections into the IAS for obstructive defecation over 5years. Analyzed outcomes included short-term improvement, defined as resolution of enterocolitis, new ability to spontaneously defecate, and/or normalization of bowel movement frequency 2weeks post-operatively, as well as requirement of more definitive surgical therapy (myotomy/myomectomy, colectomy, colostomy, cecostomy/appendicostomy, and/or sacral nerve stimulator implantation). Outcomes were compared using t-test and Fisher's Exact test, with significance defined as p<0.05. RESULTS: Twelve patients who underwent BoTox injection were included, including 5 patients who underwent injections both with and without ultrasound. Ten underwent an ultrasound-guided injection (13 injection procedures), 5 of whom had HD. Seven underwent an injection without ultrasound guidance (17 injection procedures), 5 of whom had HD. Procedures performed with US resulted in greater short-term improvement (76% versus 65% without ultrasound) and less requirement of a definitive procedure for obstructive defecation (p<0.05). CONCLUSIONS: US-guided BoTox injection is safe and effective for obstructive defecation, and may decrease the need for a definitive operation. LEVEL OF EVIDENCE: III.

Outcomes from a 12-Week, Open-Label, Multicenter Clinical Trial of Teduglutide in Pediatric Short Bowel Syndrome.

OBJECTIVE: To determine safety and pharmacodynamics/efficacy of teduglutide in children with intestinal failure associated with short bowel syndrome (SBS-IF). STUDY DESIGN: This 12-week, open-label study enrolled patients aged 1-17 years with SBS-IF who required parenteral nutrition (PN) and showed minimal or no advance in enteral nutrition (EN) feeds. Patients enrolled sequentially into 3 teduglutide cohorts (0.0125 mg/kg/d [n = 8], 0.025 mg/kg/d [n = 14], 0.05 mg/kg/d [n = 15]) or received standard of care (SOC, n = 5). Descriptive summary statistics were used. RESULTS: All patients experienced ≥1 treatment-emergent adverse event; most were mild or moderate. No serious teduglutide-related treatment-emergent adverse events occurred. Between baseline and week 12, prescribed PN volume and calories (kcal/kg/d) changed by a median of -41% and -45%, respectively, with 0.025 mg/kg/d teduglutide and by -25% and -52% with 0.05 mg/kg/d teduglutide. In contrast, PN volume and calories changed by 0% and -6%, respectively, with 0.0125 mg/kg/d teduglutide and by 0% and -1% with SOC. Per patient diary data, EN volume increased by a median of 22%, 32%, and 40% in the 0.0125, 0.025, and 0.05 mg/kg/d cohorts, respectively, and by 11% with SOC. Four patients achieved independence from PN, 3 in the 0.05 mg/kg/d cohort and 1 in the 0.025 mg/kg/d cohort. Study limitations included its short-term, open-label design, and small sample size. CONCLUSIONS: Teduglutide was well tolerated in pediatric patients with SBS-IF. Teduglutide 0.025 or 0.05 mg/kg/d was associated with trends toward reductions in PN requirements and advancements in EN feeding in children with SBS-IF. TRIAL REGISTRATION: ClinicalTrials.gov:NCT01952080; EudraCT: 2013-004588-30.

Taking a STEP back: Assessing the outcomes of multiple STEP procedures.

PURPOSE: Short bowel syndrome (SBS) is a highly morbid condition primarily because of parenteral nutrition (PN)-associated complications. Bowel lengthening via serial transverse enteroplasty (STEP) has become standard of care. While initial STEPs have resulted in weaning from PN, outcomes of repeated STEPs (ReSTEPs) are not well described. We investigated outcomes of initial STEP compared to ReSTEP procedures. METHODS: This retrospective review of STEPs included 17 children and a total of 24 procedures. Demographics, complications, hospital readmission rates, postoperative costs, and PN weaning were analyzed. RESULTS: Neither patient-specific data nor the etiology of SBS was predictive of requiring a ReSTEP. PN weaning was more likely in the year following a first STEP (18% wean rate vs. 0% for ReSTEP, p>.05). No ReSTEP patients reached enteral autonomy. Enteral nutrition (%EN) increases were greater after first STEP compared to ReSTEP (26.0% vs. 4.7%, p=0.03). This trend was true for bowel length as well, where first STEPs resulted in a 51% increase in bowel length compared to a 20% increase after in ReSTEP (p=0.02). CONCLUSIONS: ReSTEPs failed to result in significant PN weaning, with no ReSTEP patients achieving enteral autonomy during follow-up. Given its higher costs, smaller bowel length gains, and limited ability to produce enteral autonomy, surgeons should carefully consider performing ReSTEP procedures. LEVEL OF EVIDENCE: Level III.

Bacterial nutrient foraging in a mouse model of enteral nutrient deprivation: insight into the gut origin of sepsis.

Total parenteral nutrition (TPN) leads to a shift in small intestinal microbiota with a characteristic dominance of Proteobacteria This study examined how metabolomic changes within the small bowel support an altered microbial community in enterally deprived mice. C57BL/6 mice were given TPN or enteral chow. Metabolomic analysis of jejunal contents was performed by liquid chromatography/mass spectrometry (LC/MS). In some experiments, leucine in TPN was partly substituted with [13C]leucine. Additionally, jejunal contents from TPN-dependent and enterally fed mice were gavaged into germ-free mice to reveal whether the TPN phenotype was transferrable. Small bowel contents of TPN mice maintained an amino acid composition similar to that of the TPN solution. Mass spectrometry analysis of small bowel contents of TPN-dependent mice showed increased concentration of 13C compared with fed mice receiving saline enriched with [13C]leucine. [13C]leucine added to the serosal side of Ussing chambers showed rapid permeation across TPN-dependent jejunum, suggesting increased transmucosal passage. Single-cell analysis by fluorescence in situ hybridization (FISH)-NanoSIMS demonstrated uptake of [13C]leucine by TPN-associated bacteria, with preferential uptake by Enterobacteriaceae Gavage of small bowel effluent from TPN mice into germ-free, fed mice resulted in a trend toward the proinflammatory TPN phenotype with loss of epithelial barrier function. TPN dependence leads to increased permeation of TPN-derived nutrients into the small intestinal lumen, where they are predominately utilized by Enterobacteriaceae The altered metabolomic composition of the intestinal lumen during TPN promotes dysbiosis.

Small Bowel Diameter in Short Bowel Syndrome as a Predictive Factor for Achieving Enteral Autonomy.

Children with short bowel syndrome commonly have dilated small bowel. We found that the extent of dilation was associated with bowel length and that both were related to achieving enteral autonomy.

Blockade of the renin-angiotensin system prevents acute and immunologically relevant colitis in murine models.

BACKGROUND: Blockade of the renin-angiotensin system (RAS) has been shown to alleviate inflammatory processes in the gastrointestinal tract. The aim of this study was to determine if blockade of the RAS would be effective in an immunologically relevant colitis model, and to compare outcome with an acute colitis model. METHODS: A losartan analog, CCG-203025 (C23H26ClN3O5S) containing a highly polar sulfonic acid moiety that we expected would allow localized mucosal antagonism with minimal systemic absorption was selected as an angiotensin II type 1a receptor antagonist (AT1aR-A). Two colitis models were studied: (1) Acute colitis was induced in 8- to 10-week-old C57BL/6J mice by 2.5 % dextran sodium sulfate (DSS, in drinking water) for 7 days. (2) IL10-/-colitis Piroxicam (200 ppm) was administered orally in feed to 5-week-old IL-10-/-mice (C57BL/6J background) for 14 days followed by enalaprilat (ACE-I), CCG-203025 or PBS administered transanally for 14 days. RESULTS: In the DSS model, weight loss and histologic score for CCG-203025 were better than with placebo. In the IL10-/-model, ACE-I suppressed histologic damage better than CCG-203025. Both ACE-I and CCG-203025 reduced pro-inflammatory cytokines and chemokines. CONCLUSIONS: This study demonstrated the therapeutic efficacy of both ACE-I and AT1aR-A for preventing the development of both acute and immunologically relevant colitis.

Diet-dependent, microbiota-independent regulation of IL-10-producing lamina propria macrophages in the small intestine.

Intestinal resident macrophages (Mϕs) regulate gastrointestinal homeostasis via production of an anti-inflammatory cytokine interleukin (IL)-10. Although a constant replenishment by circulating monocytes is required to maintain the pool of resident Mϕs in the colonic mucosa, the homeostatic regulation of Mϕ in the small intestine (SI) remains unclear. Here, we demonstrate that direct stimulation by dietary amino acids regulates the homeostasis of intestinal Mϕs in the SI. Mice that received total parenteral nutrition (TPN), which deprives the animals of enteral nutrients, displayed a significant decrease of IL-10-producing Mϕs in the SI, whereas the IL-10-producing CD4(+) T cells remained intact. Likewise, enteral nutrient deprivation selectively affected the monocyte-derived F4/80(+) Mϕ population, but not non-monocytic precursor-derived CD103(+) dendritic cells. Notably, in contrast to colonic Mϕs, the replenishment of SI Mϕs and their IL-10 production were not regulated by the gut microbiota. Rather, SI Mϕs were directly regulated by dietary amino acids. Collectively, our study highlights the diet-dependent, microbiota-independent regulation of IL-10-producing resident Mϕs in the SI.

Analysis of risk factors contributing to morbidity from gastrojejunostomy feeding tubes in children.

PURPOSE: The purpose of this study was to define morbidity from gastrojejunostomy tube (GJT) placement in children. METHODS: A retrospective single-center 5-year review of GJT placement in children was performed. Age, weight, prior surgery, indication, type of GJT, and complications (GJT replacement, wound complications, and perforation) were recorded. Logistic regression for morbidity was performed. RESULTS: 142 children underwent 394 GJT placements at a median age of 2.7years (range 5 weeks-18years). The most common indications were failure to thrive (62%) and reflux (25%). Among the 296 GJT replacements, the most common reason was tube dislodgement (30%). Risk factors for replacement, which occurred at a median interval of 12 weeks (range 2days-2.4years), were peristomal complaint (OR=5.4, p=0.02) and prior GJT replacement (OR=1.8, p=0.03). In all, 7 (5%) jejunal perforations occurred at a median of 3 days (range 0-21 days) from GJT placement. Patients with perforation had a median weight of 4.6kg (range 3-11.2kg) and age of 3.9months (range 8 weeks-2.1years). Lower weight (p<0.01) and younger age (p=0.02) predicted perforation, with those weighing less than 6kg (OR=51.9, p<0.001) or younger than 6months (OR=28.6, p<0.01) at highest risk. CONCLUSIONS: GJT placement has a significant risk of recurrent dislodgement and the highest risk of perforation in children weighing less than 6kg or younger than 6months. Alternate feeding options should be strongly considered in this vulnerable population.

Impact of the Nationwide Intravenous Selenium Product Shortage on the Development of Selenium Deficiency in Infants Dependent on Long-Term Parenteral Nutrition.

BACKGROUND: For patients dependent on parenteral nutrition (PN), selenium must be supplemented intravenously. A nationwide intravenous selenium shortage began in April 2011. The impact of this shortage on PN-dependent infants was evaluated by examining the provision of selenium, development of biochemical deficiency, and costs associated with the shortage. MATERIALS AND METHODS: This single-center, retrospective study included PN-dependent infants aged ≤1 year who weighed ≤30 kg, received PN for ≥1 month, and had ≥1 serum selenium measurement. The primary outcome was the incidence of biochemical selenium deficiency. Secondary outcomes included severity of biochemical deficiency, clinical manifestations, costs, and relationship between serum selenium levels and selenium dose. RESULTS: The average selenium dose decreased 2-fold during the shortage (2.1 ± 1.2 µg/kg/d; range, 0.2-4.6 µg/kg/d) versus the nonshortage period (3.8 ± 1 µg/kg/d; range, 2.4-6 µg/kg/d; P < .001). A linear relationship between serum selenium concentration and selenium dose was observed (r(2) = 0.42), with a dose of 6 µg/kg/d expected to result in normal serum levels in most cases. Similar proportions of patients developed biochemical deficiency in both groups: shortage period, 59.1%; nonshortage, 66.7%; P = .13. The severity of biochemical deficiency was similar between groups. A significant increase in incremental cost during the shortage was observed. CONCLUSION: This is the first study examining the impact of the intravenous selenium shortage on PN-dependent infants. Both groups exhibited similarly high incidences of biochemical selenium deficiency, suggesting higher empiric doses may benefit this population. However, ongoing shortages limit the ability to provide supplementation.

Altered fecal short chain fatty acid composition in children with a history of Hirschsprung-associated enterocolitis.

PURPOSE: Children with Hirschsprung disease (HD) who have a history of enterocolitis (HAEC) have a shift in colonic microbiota, many of which are necessary for short chain fatty acid (SCFA) production. As SCFAs play a critical role in colonic mucosal preservation, we hypothesized that fecal SCFA composition is altered in children with HAEC. METHODS: A multicenter study enrolled 18 HD children, abstracting for history of feeding, antibiotic/probiotic use, and enterocolitis symptoms. HAEC status was determined per Pastor et al. criteria (12). Fresh feces were collected for microbial community analysis via 16S sequencing as well as SCFA analysis by gas chromatography-mass spectrometry. RESULTS: Nine patients had a history of HAEC, and nine had never had HAEC. Fecal samples from HAEC children showed a 4-fold decline in total SCFA concentration vs. non-HAEC HD patients. We then compared the relative composition of individual SCFAs and found reduced acetate and increased butyrate in HAEC children. Finally, we measured relative abundance of SCFA-producing fecal microbiota. Interestingly, 10 of 12 butyrate-producing genera as well as 3 of 4 acetate-producing genera demonstrated multi-fold expansion. CONCLUSION: Children with HAEC history have reduced fecal SCFAs and altered SCFA profile. These findings suggest a complex interplay between the colonic metabolome and changes in microbiota, which may influence the pathogenesis of HAEC.

Tight Junction Ultrastructure Alterations in a Mouse Model of Enteral Nutrient Deprivation.

BACKGROUND: Total parenteral nutrition (TPN), a necessary treatment for patients who cannot receive enteral nutrition, is associated with infectious complications due in part to a loss of intestinal epithelial barrier function (EBF). Using a mouse model of TPN, with enteral nutrient deprivation, we previously demonstrated an increase in mucosal interferon-γ and tumor necrosis factor-α; these cytokine changes are a major mediator driving a reduction in epithelial tight junction (TJ) protein expression. However, the exact ultrastructural changes to the intestinal epithelial barrier have not been previously described. AIM: We hypothesized that TPN dependence results in ultrastructural changes in the intestinal epithelial TJ meshwork. METHODS: C57BL/6 mice underwent internal jugular venous cannulation and were given enteral nutrition or TPN with enteral nutrient deprivation for 7 days. Freeze-fracture electron microscopy was performed on ileal tissue to characterize changes in TJ ultrastructure. EBF was measured using transepithelial resistance and tracer permeability, while TJ expression was measured via Western immunoblotting and immunofluorescence staining. RESULTS: While strand density, linearity, and appearance were unchanged, TPN dependence led to a mean reduction in one horizontal strand out of the TJ compact meshwork to a more basal region, resulting in a reduction in meshwork depth. These findings were correlated with the loss of TJ localization of claudin-4 and tricellulin, reduced expression of claudin-5 and claudin-8, and reduced ex vivo EBF. CONCLUSION: Tight junction ultrastructural changes may contribute to reduced EBF in the setting of TPN dependence.

Development of an operative suspension system for the performance of MRI-OR-guided laparoscopic anoplasty.

BACKGROUND: MRI-guided laparoscopic assisted anorectoplasty (MRI-LAARP), a new approach for surgical correction of high imperforate anus, does not bisect the sphincter complex as in the PSARP and is able to pull the neorectum through the entire sphincter complex unlike the LAARP. There is no available MRI-compatible device to position and transport patients during this procedure. We report on the design of such a device here. METHODS AND DEVICE: The device was constructed from 1.0″ polyvinylchloride tubing and poly-methyl methacrylate (Plexiglass(®)) platform. The device has a stable, rigid base on which platform is secure. An adjustable and removable superstructure is secured to this base to suspend legs for lithotomy position. RESULTS: MRI-LAARP has been performed on 6 patients. The device has performed well and meets requirements set forth in development including construction with MRI-compatible materials, size fitting in the MRI bore, ability to hold patient in lithotomy position, ability to position and support MRI flex coils, and providing stability while transporting to a separate OR with needle in position. CONCLUSIONS: This device provides a stable structure to position and transport a patient with a needle in a tenuous position without dislodgement allowing this procedure, and potentially other procedures, to be done in hospitals without MROR capability.