Three-Dimensional Imaging of the Enteric Nervous System in Human Pediatric Colon Reveals New Features of Hirschsprung's Disease.

BACKGROUND & AIMS: Hirschsprung's disease is defined by the absence of the enteric nervous system (ENS) from the distal bowel. Primary treatment is "pull-through" surgery to remove bowel that lacks ENS, with reanastomosis of "normal" bowel near the anal verge. Problems after pull-through are common, and some may be due to retained hypoganglionic bowel (ie, low ENS density). Testing this hypothesis has been difficult because counting enteric neurons in tissue sections is unreliable, even for experts. Tissue clearing and 3-dimensional imaging provide better data about ENS structure than sectioning. METHODS: Regions from 11 human colons and 1 ileal specimen resected during Hirschsprung's disease pull-through surgery were cleared, stained with antibodies to visualize the ENS, and imaged by confocal microscopy. Control distal colon from people with no known bowel problems were similarly cleared, stained, and imaged. RESULTS: Quantitative analyses of human colon, ranging from 3 days to 60 years old, suggest age-dependent changes in the myenteric plexus area, ENS ganglion area, percentage of myenteric plexus occupied by ganglia, neurons/mm2, and neuron Feret's diameter. Neuron counting using 3-dimensional images was highly reproducible. High ENS density in neonatal colon allowed reliable neuron counts using 500-µm2 × 500-µm2 regions (36-fold smaller than in adults). Hirschsprung's samples varied 8-fold in proximal margin enteric neuron density and had diverse ENS architecture in resected bowel. CONCLUSIONS: Tissue clearing and 3-dimensional imaging provide more reliable information about ENS structure than tissue sections. ENS structure changes during childhood. Three-dimensional ENS anatomy may provide new insight into human bowel motility disorders, including Hirschsprung's disease.

Pediatric retrograde cricopharyngeal dysfunction diagnosed by high-resolution impedance manometry.

OBJECTIVES: The inability to burp, known as retrograde cricopharyngeal dysfunction (R-CPD), was initially described in adults. The proposed clinical diagnostic criteria for R-CPD include belching inability, abdominal bloating and discomfort/nausea, postprandial chest pain, and involuntary noises. Botulinum toxin injection to the cricopharyngeal muscle has been reported to be beneficial. High-resolution esophageal impedance-manometry (HRIM) features in adolescent patients with R-CPD have not been described yet.  The aim of our study was to describe the clinical and HRIM findings of pediatric patients with R-CPD. METHODS: Clinical and manometric features of five pediatric patients diagnosed with R-CPD were reviewed. HRIM study protocol was modified to include the consumption of carbonated drink to provoke symptoms and distinctive manometric features. RESULTS: We report five female patients aged 15-20 years who presented with an inability to burp and involuntary throat sounds. HRIM revealed normal upper esophageal sphincter (UES) relaxation during swallowing, but abnormal UES relaxation with concurrent high esophageal impedance reflecting air entrapment and secondary peristalsis following the carbonated drink challenge. Four patients exhibited esophageal motility disorder. All patients reported improvement or resolution of symptoms after botulinum toxin injection to the cricopharyngeus muscle. CONCLUSIONS: Adolescents with an inability to burp, reflux-like symptoms, bloating, and involuntary throat noises should be assessed for R-CPD by pediatric gastroenterologists with HRIM. The relatively recent recognition of this novel condition is the likely reason for its under- and misdiagnosis in children.

A multicenter registry study on percutaneous electrical nerve field stimulation for pediatric disorders of gut-brain interaction.

OBJECTIVES: Percutaneous electrical nerve field stimulation (PENFS) has demonstrated promise in single-center trials for pediatric abdominal pain-related disorders of gut-brain interaction (DGBI). Our aim was to explore efficacy of PENFS as standard therapy for DGBI in a registry involving multiple pediatric gastroenterology referral centers. METHODS: This was a multicenter, prospective open-label registry of children (8-18 years) undergoing PENFS for DGBI at seven tertiary care gastroenterology clinics. DGBI subtypes were classified by Rome IV criteria. Parents and patients completed Abdominal Pain Index (API), Nausea Severity Scale (NSS), and Functional Disability Inventory (FDI) questionnaires before, during therapy and at follow-up visits up to 1 year later. RESULTS: A total of 292 subjects were included. Majority (74%) were female with median (interquartile range [IQR]) age 16.3 (14.0, 17.7) years. Most (68%) met criteria for functional dyspepsia and 61% had failed ≥4 pharmacologic therapies. API, NSS, and FDI scores showed significant declines within 3 weeks of therapy, persisting long-term in a subset. Baseline (n = 288) median (IQR) child-reported API scores decreased from 2.68 (1.84, 3.58) to 1.99 (1.13, 3.27) at 3 weeks (p < 0.001) and 1.81 (0.85, 3.20) at 3 months (n = 75; p < 0.001). NSS scores similarly improved from baseline, persisting at three (n = 74; p < 0.001) and 6 months later (n = 55; p < 0.001). FDI scores displayed similar reductions at 3 months (n = 76; p = 0.01) but not beyond. Parent-reported scores were consistent with child reports. CONCLUSIONS: This large, comprehensive, multicenter registry highlights efficacy of PENFS for gastrointestinal symptoms and functionality for pediatric DGBI.

Percutaneous Electrical Nerve Field Stimulation in Children and Adolescents With Functional Dyspepsia-Integrating a Behavioral Intervention.

OBJECTIVES: Functional dyspepsia (FD) includes postprandial distress and epigastric pain syndrome. Percutaneous electrical nerve field stimulation (PENFS) in addition to behavioral interventions (BI) has shown benefits in children with functional abdominal pain but not specifically in FD. We aimed to assess the efficacy of PENFS for treating FD and compare the outcomes with those who received the combination of PENFS + BI. MATERIALS AND METHODS: Charts of patients with FD who completed four weeks of PENFS were evaluated. A subset of patients received concurrent BI. Demographic data, medical history, and symptoms were documented. Outcomes at different time points included subjective symptom responses and validated questionnaires collected clinically (Abdominal Pain Index [API], Nausea Severity Scale [NSS], Functional Disability Inventory [FDI], Pittsburgh Sleep Quality Index [PSQI], Children's Somatic Symptoms Inventory [CSSI], Patient-Reported Outcomes Measurement Information Systems [PROMIS] Pediatric Anxiety and Depression scales). RESULT: Of 84 patients, 61% received PENFS + BI, and 39% received PENFS alone. In the entire cohort, API (p < 0.0001), NSS (p = 0.001), FDI (p = 0.001), CSSI (p < 0.0001), PSQI (p = 0.01), PROMIS anxiety (p = 0.02), and depression (p = 0.01) scores improved from baseline to three weeks and at three months. Subjective responses showed nausea improvement (p = 0.01) and a trend for improvement in abdominal pain (p = 0.07) at week three. Abdominal pain subjectively improved at week three and three months (p = 0.003 and 0.02, respectively), nausea at week three and three months (p = 0.01 and 0.04, respectively), and a trend for improvement in sleep disturbances at week three and three months (p = 0.08 and p = 0.07, respectively) in the PENFS + BI group vs PENFS alone. CONCLUSION: Abdominal pain, nausea, functioning, somatization, sleep disturbances, anxiety, and depression improved at three weeks and three months after PENFS in pediatric FD. Subjective pain and nausea improvement were greater in the PENFS + BI group than in the group with PENFS alone, suggesting an additive effect of psychologic therapy.

Robust, 3-Dimensional Visualization of Human Colon Enteric Nervous System Without Tissue Sectioning.

BACKGROUND & AIMS: Small, 2-dimensional sections routinely used for human pathology analysis provide limited information about bowel innervation. We developed a technique to image human enteric nervous system (ENS) and other intramural cells in 3 dimensions. METHODS: Using mouse and human colon tissues, we developed a method that combines tissue clearing, immunohistochemistry, confocal microscopy, and quantitative analysis of full-thickness bowel without sectioning to quantify ENS and other intramural cells in 3 dimensions. RESULTS: We provided 280 adult human colon confocal Z-stacks from persons without known bowel motility disorders. Most of our images were of myenteric ganglia, captured using a 20× objective lens. Full-thickness colon images, viewed with a 10× objective lens, were as large as 4 × 5 mm2. Colon from 2 pediatric patients with Hirschsprung disease was used to show distal colon without enteric ganglia, as well as a transition zone and proximal pull-through resection margin where ENS was present. After testing a panel of antibodies with our method, we identified 16 antibodies that bind to molecules in neurons, glia, interstitial cells of Cajal, and muscularis macrophages. Quantitative analyses demonstrated myenteric plexus in 24.5% ± 2.4% of flattened colon Z-stack area. Myenteric ganglia occupied 34% ± 4% of myenteric plexus. Single myenteric ganglion volume averaged 3,527,678 ± 573,832 mm3 with 38,706 ± 5763 neuron/mm3 and 129,321 ± 25,356 glia/mm3. Images of large areas provided insight into why published values of ENS density vary up to 150-fold-ENS density varies greatly, across millimeters, so analyses of small numbers of thin sections from the same bowel region can produce varying results. Neuron subtype analysis revealed that approximately 56% of myenteric neurons stained with neuronal nitric oxide synthase antibody and approximately 33% of neurons produce and store acetylcholine. Transition zone regions from colon tissues of patients with Hirschsprung disease had ganglia in multiple layers and thick nerve fiber bundles without neurons. Submucosal neuron distribution varied among imaged colon regions. CONCLUSIONS: We developed a 3-dimensional imaging method for colon that provides more information about ENS structure than tissue sectioning. This approach could improve diagnosis for human bowel motility disorders and may be useful for other bowel diseases as well.

Development of Entrustable Professional Activities and Standards in Training in Pediatric Neurogastroenterology and Motility: North American Society for Pediatric Gastroenterology, Hepatology and Nutrition and American Neurogastroenterology and Motility Society Position Paper.

ABSTRACT: Neurogastroenterology and motility (NGM) disorders are common in childhood and are often very debilitating. Although pediatric gastroenterology fellows are expected to obtain training in the diagnosis and management of patients with these disorders, there is an ongoing concern for unmet needs and lack of exposure and standardized curriculum. In the context of tailoring training components, outcome and expressed needs of pediatric gastroenterology fellows and programs, members of the North American Society for Pediatric Gastroenterology, Hepatology and Nutrition (NASPGHAN) and American Neurogastroenterology and Motility Society (ANMS) developed guidelines for NGM training in North America in line with specific expectations and goals of training as delineated through already established entrustable professional activities (EPAs). Members of the joint task force applied their expertise to identify the components of knowledge, skills, and management, which are expected of NGM consultants. The clinical knowledge, skills and management elements of the NGM curriculum are divided into domains based on anatomic regions including esophagus, stomach, small bowel, colon and anorectum. In addition, dedicated sections on pediatric functional gastrointestinal (GI) disorders, research and collaborative approach, role of behavioral health and surgical approaches to NGM disorders and transition from pediatric to adult neurogastroenterology are included in this document. Members of the NASPGHAN-ANMS task force anticipate that this document will serve as a resource to break existing barriers to pursuing a career in NGM and provide a framework towards uniform training expectations at 3 hierarchical tiers corresponding to EPA levels.

Barriers in Neurogastroenterology and Motility Training Experience for Pediatric Gastroenterology Fellows.

BACKGROUND: Neurogastroenterology and motility (NGM) disorders are common and have a high health care burden. Although pediatric gastroenterology fellows are expected to obtain comprehensive training in the diagnosis and management of NGM disorders, there is ongoing concern for unmet training needs and lack of exposure in treating patients who suffer from NGM problems. METHODS: We conducted a cross-section survey of trainees listed as pediatric gastroenterology fellows in North American training programs in 2018 via direct E-mail and the pediatric gastroenterology listserv. Eighty-one pediatric gastroenterology fellows responded to the anonymous survey. RESULTS: A total of 53.1% of the fellows reported interest in NGM; however, 75.1% of the fellows believed they had not been adequately trained in NGM during their fellowship. Eighty percent of fellows with 2 weeks or less of dedicated motility training reported that they received inadequate NGM training, compared to 46.2% fellows who received 1 or more months of dedicated motility training (P = 0.0148). The majority of fellows reported not being comfortable in performing gastrointestinal (GI) motility studies. The majority of fellows also reported not being comfortable in interpreting GI motility studies. CONCLUSIONS: Although most pediatric gastroenterology fellows expressed interest in NGM, the lack of exposure and dedicated training in motility during fellowship were identified as barriers to pursuing motility-focused careers. Furthermore, most fellows reported limited comfort with performing and/or interpreting motility studies. Changes are needed to encourage fellows to develop their interest and expertise in NGM.

High amplitude propagated contractions with Glycerin versus Bisacodyl: A within-subject comparison in children undergoing colonic manometry.

BACKGROUND: The presence of high amplitude propagated contractions (HAPCs) measured by colonic manometry (CM) reflect an intact neuromuscular function of the colon. Bisacodyl and Glycerin are colonic stimulants that induce HAPCs and are used for the treatment of constipation. HAPCs characteristics with each drug have not been compared before. We aimed to compare the HAPC characteristics with Bisacodyl and Glycerin in children undergoing CM for constipation. METHODS: This is a prospective single-center cross-over study of children aged 2-18 years undergoing CM. All patients received both Glycerin and Bisacodyl during CM. They were randomized to group A with Bisacodyl first (n = 22) and group B with Glycerin first (n = 23), with 1.5 hours in between each dose. Differences in patient and HAPC characteristics between groups were summarized using descriptive statistics and compared using Chi-square test or Wilcoxon rank sum test as appropriate. KEY RESULTS: A total of 45 patients were included. HAPCs post Bisacodyl had a longer duration of action (median of 40 vs 21.5 min, p < 0.0001), longer propagation (median of 70 vs 60 cm, p = 0.02), and more HAPCs (median of 10 vs 5, p < 0.0001) compared Glycerin. No differences were found in the HAPC amplitude and onset of action between both medications.

Percutaneous electrical nerve field stimulation compared to standard medical therapy in adolescents with functional abdominal pain disorders.

Introduction: Standard medical therapy (SMT) in children with functional abdominal pain disorders (FAPD) includes cyproheptadine and amitriptyline. While percutaneous electrical nerve field stimulation (PENFS) has shown benefit, no study has compared outcomes of PENFS to SMT. We aimed to examine changes in abdominal pain, nausea and disability before and after treatment and compare outcomes between treatments. Methods: The records of FAPD patients ages 11-21 years, treated with 4 weeks of PENFS, cyproheptadine or amitriptyline were reviewed. Outcomes were evaluated using validated questionnaires [Abdominal Pain Index (API), Nausea Severity Scale (NSS), and the Functional Disability Inventory (FDI)] at baseline and follow-up within 3 months (FU). Result: Of 101 patients, 48% received PENFS, 31% cyproheptadine and 21% received amitriptyline. Median ages were 17 (15-19), 16 (15-18) and 15 (11-16) years respectively and the majority were females (75%, 90% and 52% respectively). In the PENFS group, API (p = 0.001), NSS (p = 0.059) and FDI (p = 0.048) were significantly lower at FU. API (p = 0.034) but not NSS and FDI (p > 0.05) decreased significantly at FU in the amitriptyline group. API, NSS and FDI did not change significantly with cyproheptadine at FU (p > 0.05). FU API scores were lower in PENFS vs. cyproheptadine (p = 0.04) but not vs. amitriptyline (p = 0.64). The FDI scores were significantly lower in the amitriptyline vs. cyproheptadine group (p = 0.03). Conclusion: Therapy with PENFS showed improvements in abdominal pain, nausea and disability while amitriptyline showed improvements in abdominal pain within 3 months of treatment. PENFS was more effective than cyproheptadine in improving abdominal pain. Amitriptyline improved disability scores more than cyproheptadine and showed promise for treatment. PENFS may be a good non-pharmacologic alternative for FAPD.

Anal Sphincter Defect and Fecal Incontinence.

Anal sphincter defects can lead to fecal incontinence. The relationship between the extent of defect and continence is controversial. Magnetic resonance imaging (MRI) of the pelvis can assess anal sphincter defects. Transrectal ultrasonography (TRUS) is used to assess sphincter integrity in adults. We present a 17-year-old male with history of sexual abuse, rectal prolapse, and fecal incontinence. MRI showed a small defect that did not explain his clinical presentation. TRUS identified more extensive defects which were not picked up by MRI. The patient had rectopexy, and his rectal prolapse and fecal incontinence resolved. TRUS was superior in identifying sphincter defects compared with MRI. Our case also highlights that continence is possible despite large sphincter defects in pediatric patients. This may reflect the compensatory mechanism of residual sphincter in the absence of the aggravating factors like rectal prolapse.

Effect of percutaneous electrical nerve field stimulation on mechanosensitivity, sleep, and psychological comorbidities in adolescents with functional abdominal pain disorders.

BACKGROUND: Percutaneous electrical nerve field stimulation (PENFS) improves symptoms in adolescents with functional abdominal pain disorders (FAPDs). However, little is known about its impact on sleep and psychological functioning. We evaluated the effects of PENFS on resting and evoked pain and nausea, sleep and psychological functioning, and long-term outcomes. METHODS: Patient ages 11-19 years with FAPD requiring PENFS as standard care were recruited. Evoked pain was elicited by a Water Load Symptom Provocation Task (WL-SPT) before and after four weeks of treatment. Pain, gastrointestinal symptoms, sleep, somatic symptoms, and physical and psychological functioning were assessed. Actigraphy was used to measure daily sleep-wake patterns. KEY RESULTS: Twenty patients (14.3 ± 2.2 years old) with FAPD were enrolled. Most patients were females (70%) and white (95%). During pain evoked by WL-SPT, visual analog scale (VAS) pain intensity and nausea were lower following PENFS compared with baseline (p = 0.004 and p = 0.02, respectively). After PENFS, resting VAS pain unpleasantness (p = 0.03), abdominal pain (p < 0.0001), pain catastrophizing (p = 0.0004), somatic complaints (0.01), functional disability (p = 0.04), and anxiety (p = 0.02) exhibited significant improvements, and some were sustained long-term. Self-reported sleep improved after PENFS (p's < 0.05) as well as actigraphy-derived sleep onset latency (p = 0.03). CONCLUSIONS AND INFERENCES: We demonstrated improvements in resting and evoked pain and nausea, sleep, disability, pain catastrophizing, somatic complaints, and anxiety after four weeks of PENFS therapy. Some effects were sustained at 6-12 months post-treatment. This suggests that PENFS is a suitable alternative to pharmacologic therapy.