Diagnosis or exclusion of Hirschsprung disease (HSCR) is a frequent exercise in any pediatric hospital. Although HSCR may present at different ages and with varied clinical findings, the most common presentation is a neonate with severe constipation or signs of intestinal obstruction. A variety of diagnostic tests including contrast enema and anorectal manometry may be used as diagnostic screens, but diagnosis ultimately rests upon histopathological evaluation of a rectal biopsy. For the experienced pathologist, conventional hematoxylin-and-eosin-stained sections often suffice to exclude HSCR or establish the diagnosis. However, ancillary diagnostic tests such as acetylcholinesterase histochemistry or calretinin immunohistochemistry are complementary and extremely helpful in some cases. In this Perspectives article, we review the clinical and pathological features of HSCR, highlight those that are found in most patients, and discuss how to address particularly challenging aspects of the diagnostic workup.

3D HDARM allows for a detailed characterization of intra-anal pressures. 3D topographic pressure measurements demonstrate longitudinal and radial asymmetry of the anal canal at rest and during squeeze. This is the first time longitudinal and radial asymmetry of the anal canal has been described in children. 3D HDARM may allow for a better understanding of the mechanisms of fecal continence in children.

Endorectal pullthrough surgery is integral in the treatment of patients with Hirschsprung disease. Several different surgical procedures exist, which share as common goals to excise the aganglionic segment and upstream transition zone and attach ganglionic bowel just proximal to the anal canal. The operation requires collaboration between surgeon and pathologist to localize ganglionic bowel and prevent retention of transition zone. Intraoperative frozen sections are extremely important, first to establish that ganglion cells are present and subsequently to exclude features of transition zone (partial circumferential aganglionosis, myenteric hypoganglionosis, and submucosal nerve hypertrophy) at the proximal surgical (anastomotic) margin. Postoperative histopathological analysis of resection specimens should be tailored to document distal aganglionosis, document the length of the aganglionic segment and its proximity to the anastomotic margin, and confirm that transition zone has been resected completely. Adherence to the recommendations described in this review will reduce the likelihood of transition zone pullthrough and should decrease the incidence of persistent postoperative obstructive symptoms.

The efficacy of high-load, short-duration isometric contractions, delivered as one vs. two sessions per day, on blunting inactivity-induced adaptations in the medial gastrocnemius (MG) were compared. Adult rats were assigned to a control (Con) or spinal cord-isolated (SI) group where one limb was stimulated (SI-Stim) while the other served as a SI control (SI-C). One bout of stimulation (BION microstimulator) consisted of a 100-Hz, 1-s stimulus, delivered every 30 s for 5 min with a 5-min rest period. This bout was repeated six times consecutively (SI-Stim1) or with a 9-h rest interval after the third bout (SI-Stim2) for 30 consecutive days. MG weights (relative to body weight) were 63, 72, and 79% of Con in SI-C, SI-Stim1, and SI-Stim2, respectively. Mean fiber size was 56% smaller in SI-C than in Con, and it was 19 and 31% larger in SI-Stim1 and SI-Stim2, respectively, compared with SI-C. Maximum tetanic tension was 42, 60, and 73% of Con in SI-C, SI-Stim1, and SI-Stim2, respectively. Specific tension was 77% of Con in SI-C, and at Con levels in both SI-Stim groups. SI increased the percent IIb myosin heavy chain composition (from 49 to 77%) and IIb+ fibers (from 63 to 79%): these adaptations were prevented by both Stim paradigms. These results demonstrate that 1) brief periods of high-load isometric contractions are effective in reducing inactivity-induced atrophy, functional deficits, and phenotypic adaptations in a fast hindlimb extensor, and 2) the same amount of stimulation distributed in two compared with one session per day is more effective in ameliorating inactivity-related adaptations.

Purpose of the review: Gastroesophageal reflux disease (GERD) is frequently implicated as a cause for respiratory disease. However, there is growing evidence that upper gastrointestinal dysmotility may play a significantly larger role in genesis of respiratory symptoms and development of underlying pulmonary pathology. This paper will discuss the differential diagnosis for esophageal and gastric dysmotility in aerodigestive patients and will review the key diagnostic and therapeutic interventions for this dysmotility.Recent findings: Previous studies have shown an association between GERD and pulmonary pathology in children with aerodigestive disorders. Recent publications have demonstrated the presence of esophageal and gastric dysfunction, using fluoroscopic and nuclear medicine studies, in aerodigestive patients who commonly present to pulmonary and otolaryngology clinics. Highresolution impedance manometry (HRIM) has revolutionized our understanding of esophageal dysmotility and its role in pathogenesis of aspiration and esophageal dysfunction and subsequent respiratory compromise.Summary: Esophageal and gastric dysmotility have a profound effect on development of respiratory symptoms and pulmonary sequalae in aerodigestive patients. However, our understanding of the pathophysiology is in its infancy. Prospective studies in are needed to address key clinical questions such as: What degree of dysmotility initiates respiratory compromise? What diagnostic tests and therapeutic options best predict aerodigestive outcomes?

Background After pullthrough surgery for Hirschsprung disease (HSCR), Glut1-positive submucosal nerve hypertrophy is used to diagnose retained transition zone in the neorectum. We hypothesized that pelvic nerves, severed during pullthrough surgery, sprout into the neorectum to mimic transition zone. Methods The density (nerves/100x field) and maximum diameter of Glut1-positive submucosal nerves were measured in biopsies and redo resections from 20 patients with post-pullthrough obstructive symptoms. Their original and/or redo resections excluded unequivocal features of transition zone (myenteric hypoganglionosis or partial circumferential aganglionosis) in 17. Postoperative values were compared with control data from 28 cadaveric and 6 surgical non-HSCR specimens, and 14 primary HSCR resections. When possible, nerves were tracked from attached native pelvic soft tissue or aganglionic rectal cuff into the pulled-through colon. Results Glut1-positive submucosal nerves were not present in the 11 colons of non-HSCR infants less than 1 year of age, except sparsely in the rectum. In 17 older non-HSCR controls, occasional Glut1-positive nerves were observed in prerectal colon and were larger and more numerous in the rectum. In redo resections, Glut1-positive submucosal innervation in post-pullthrough specimens did not differ significantly from age-appropriate non-HSCR rectal controls and pelvic Glut1-positive nerves were never observed to penetrate the pulled-through colon. However, the density and caliber of Glut1-positive nerves in the neorectums were significantly greater than expected based on the prerectal location from which the pulled-through bowel originated. Conclusions Submucosal innervation in post-pullthrough specimens does not support the hypothesis that native pelvic nerves innervate the neorectum, but suggests remodeling occurs to establish the age-appropriate density and caliber of rectal Glut1-positive innervation. The latter should not be interpreted as transition zone pullthrough in a rectal biopsy from a previously done pullthrough.

No abstract

PURPOSE: Bowel dysfunction, such as constipation and fecal incontinence, has a significant impact on health, activities of daily living, and quality of life among people with spina bifida. Secondary complications may result from bowel dysfunction and include urologic dysfunction, loss of skin integrity, shunt (hydrocephalus) function, as well as loss of social opportunities and employability. METHODS: Using a consensus building methodology, the guidelines for management of bowel dysfunction in spina bifida were written by experts in the field of spina bifida and bowel function and care. RESULTS: The evidence-based guidelines are presented in table format and provide age-specific recommendations to achieve fecal continence without constipation. Recommended treatments are presented from least to most invasive options. Literature supporting the recommendations and the interval research published to date is also presented. CONCLUSION: These guidelines present a standardized approach to management of bowel dysfunction in spina bifida. Bowel management in children and young adults with spina bifida is limited by variability in clinical practice and paucity of robust research in neurogenic bowel. Collaborative multi-institutional efforts are needed to overcome research barriers and provide innovative solutions.