M. M. van den Berg

Morphological Changes of the Enteric Nervous System, Interstitial Cells of Cajal, and Smooth Muscle in Children With Colonic Motility Disorders

Objectives: To evaluate the relation between colonic manometry findings and the colonic enteric nervous system, interstitial cells of Cajal, and smooth muscle morphology. Patients and Methods: Colonic specimens from surgical resections or full-thickness biopsy specimens were assessed from a cohort of children who underwent colonic manometry before surgery. Colonic manometric patterns were subdivided into high-amplitude propagating contractions, low-amplitude propagating contractions, absence of contractions, and low-amplitude simultaneous contractions. Immunohistochemistry was performed to identify abnormalities in the enteric nervous system, interstitial cells of Cajal, and smooth muscle layers. Results: Study participants included patients with Hirschsprung disease (n = 4), chronic intestinal pseudo-obstruction (n = 1), and idiopathic intractable constipation (n = 8). Thirty-seven ganglionic segments were studied. Abnormalities in myenteric plexus were recognized in segments of all manometry groups, and no differences could be identified when they were compared with segments with high-amplitude propagating contractions. All of the segments showed an abnormal interstitial cells of Cajal plexus, and no statistical difference could be identified between the 4 groups (n = 0.08). Homogeneous expression of smooth muscle actin was observed in all of the segments. Conclusions: In this cohort we were unable to classify specific manometric findings as reflective of myopathic or neuropathic abnormalities in patients with motility disorders. Caution should be used when predicting the type of neuromuscular disorder based on colonic manometry.

Rectal compliance and rectal sensation in constipated adolescents, recovered adolescents and healthy volunteers

Objectives: A subgroup of children with functional constipation (FC) are unresponsive to conventional treatment. Abnormal rectal function due to increased distensibility (compliance) might be an underlying mechanism of therapy-resistant FC. It is hypothesised that rectal compliance is normal in patients who are successfully recovered from FC (RC). Methods: Using a barostat, a pressure-controlled intermittent distension protocol was performed in FC patients, RC subjects free of symptoms for at least 4 years and healthy volunteers (HVs). Rectal compliance was calculated using a non-linear mixed-effect model for volume–pressure curves. Results: Forty-seven FC patients, median (range) age of 12 (11–17) years, and 20 RC subjects, 15 (11–18) years, were studied and compared with 22 HVs, 14 (8–16) years. The median (5th–95th percentile) rectal compliance in HVs was 16 (12–20) ml/mm Hg. FC patients had a median rectal compliance of 25 (13–47) ml/mm Hg and RC subjects 20 (12–35) ml/mm Hg, which was significantly higher compared with HVs (p<0.001 and p = 0.003). RC subjects had lower rectal compliance when compared with FC patients (p = 0.02). Forty-five percent of RC subjects had a rectal compliance above the upper limit of normal (>95th percentile of HVs), which was significantly less compared with 75% of FC patients (p = 0.02). Conclusion: While rectal compliance in RC subjects is lower when compared with adolescents with FC, almost half of the RC subjects showed an increased rectal compliance. The role of rectal compliance in therapy-resistant FC seems limited, because recovery is possible despite an increased rectal compliance.

No Change in Rectal Sensitivity After Gut-Directed Hypnotherapy in Children With Functional Abdominal Pain or Irritable Bowel Syndrome

OBJECTIVES:Gut-directed hypnotherapy (HT) has recently been shown to be highly effective in treating children with functional abdominal pain (FAP) and irritable bowel syndrome (IBS). This study was conducted to determine the extent to which this treatment success is because of an improvement in rectal sensitivity.METHODS:A total of 46 patients (aged 8–18 years) with FAP (n=28) or IBS (n=18) were randomized to either 12 weeks of standard medical therapy (SMT) or HT. To assess rectal sensitivity, a pressure-controlled intermittent distension protocol (barostat) was performed before and after the therapy.RESULTS:Rectal sensitivity scores changed in SMT patients from 15.1±7.3 mm Hg at baseline to 18.6±8.5 mm Hg after 12 weeks of treatment (P=0.09) and in HT patients from 17.0±9.2 mm Hg to 22.5±10.1 mm Hg (P=0.09). The number of patients with rectal hypersensitivity decreased from 6 of 18 to 0 of 18 in the HT group (P=0.04) vs. 6 of 20 to 4 of 20 in the SMT group (P=0.67). No relationship was established between treatment success and rectal pain thresholds. Rectal sensitivity scores at baseline were not correlated with intensity, frequency, or duration of abdominal pain.CONCLUSIONS:Clinical success achieved with HT cannot be explained by improvement in rectal sensitivity. Furthermore, no association could be found between rectal barostat findings and clinical symptoms in children with FAP or IBS. Further studies are necessary to shed more light on both the role of rectal sensitivity in pediatric FAP and IBS and the mechanisms by which hypnotherapy results in improvement of clinical symptoms.

Colonic Manometry Catheter Placement with Primary Fluoroscopic Guidance

The purpose of this paper is to describe our experience with a new technique of colonic manometry catheter placement using fluoroscopic guidance. Between 2000 and 2004, 44 colonic manometry catheters were placed with primary fluoroscopic guidance in 38 patients (25 males; median age, 7 years; range, 0.4–31 years) with severe defecation disorders. Fourteen colonoscopic placements were reviewed to compare the different procedures. Manometry catheters were inserted through the rectum (16 patients), cecostomy (9), ileostomy (2), and colostomy (17). Placements through diverted colons were successful in 24 of 28 (86%). Insertion through the rectum was successful in 10 of 16 (63%) fluoroscopic-guided placements vs. 12 of 14 (86%) colonoscopic placements (P=0.23). Significantly longer fluoroscopic exposure was required for fluoroscopic compared to colonoscopic placement (P=0.004).In conclusion, placement of colonic manometry catheters with primary fluoroscopic guidance is feasible in children. An important disadvantage of the fluoroscopic methodology is the prolonged fluoroscopic exposure time.

Distention of the colon is associated with initiation of propagated contractions in children

Abstract  The presence of high‐amplitude propagating contractions (HAPCs) has been identified as a marker of colonic neuromuscular integrity. The physiologic mechanisms of HAPCs initiation have yet to be determined. Distention secondary to colonic filling has been hypothesized as physiologic initiator. The aim of this study was to study the effect of intraluminal balloon distention in the colon of children with defecatory disorders. Colonic manometry was performed with a polyethylene balloon situated at the proximal end of the catheter, which was placed in the most proximal colonic segment reached during colonoscopy. A stepwise pressure controlled distention of the balloon was performed using barostat computer (10–50 mmHg). Propagated contractions were defined as those that migrated over at least three recording sites. They were divided into HAPCs, amplitude >60 mmHg and low‐amplitude propagating contractions (LAPCs), amplitude <60 mmHg. Children with spontaneous HAPCs or HAPCs after bisacodyl provocation were considered to have normal motility. Twenty children completed the study. Among the 14 children with normal colonic motility, balloon distention elicited HAPCs in four and LAPCs in 10 children. No HAPC were elicited in six children with abnormal motility and LAPCs were seen in four of them. The balloon‐induced propagated contractions had similar characteristics as those occurring spontaneously and after bisacodyl provocation but the pressure needed to elicit them and their amplitude was inconsistent. These findings suggest that intraluminal distention can trigger propagated contractions in children. This mechanism of action for induction of propagated contractions is not as consistent as the motor response found in response to bisacodyl administration.

Brain processing of rectal sensation in adolescents with functional defecation disorders and healthy controls

Decreased sensation of urge to defecate is often reported by children with functional constipation (FC) and functional nonretentive fecal incontinence (FNRFI). The aim of this cross‐sectional study was to evaluate cerebral activity in response to rectal distension in adolescents with FC and FNRFI compared with healthy controls (HCs).