Idiopathic constipation in childhood is associated with thickening of the internal anal sphincter

Role of 3D high resolution anorectal manometry compared to conventional technique in management of constipation and fecal incontinence in children

BACKGROUND

Anorectal manometry is a valuable tool for objective assessment of motility motor and sensory function of the anorectum. The aim of this study was to investigate role of water-perfused (WP) three dimensional high-resolution anorectal manometry (3D-HRARM) compared to WP conventional manometry (CM) in the management of chronic idiopathic constipation (CIC) and faecal incontinence (FI) in children.

METHODS

This was a retrospective review of 122 consecutive children, who had WP 8-channel CM or 24 channel 3D-HRARM and endosonography under ketamine anaesthesia from September 2012 to February 2019. All patients had a validated symptom severity score questionnaire ranging from 0 (best) to 65 (worst). Mann-Whitney-U test and Spearman rank test were used and p<0.05 was considered significant.

RESULTS

Subjects were divided according to investigation: CM group (n = 75) and 3D-HRAM (n = 47), who were otherwise comparable. Median anal resting pressure was 50 mmHg and rectoanal inhibitory reflex (RAIR) threshold volume was 10mls across the entire cohort. There were no significant differences in resting pressure or RAIR threshold when using conventional or 3D-HRARM. Rectal capacity was significantly higher in the CM group (p = 0.002). Rectal capacity and internal anal sphincter (IAS) thickness positively correlated with symptom severity, duration and patient age. 3D-HRARM provided a more detailed depiction of the anorectal pressure profile. Botulinum toxin was injected into the external anal sphincter (EAS) muscle (n = 75, 61%) and an anterograde colonic enema (ACE) stoma was needed subsequently in 19 (16%) to treat recurrent constipation and soiling symptoms. Rectal biopsy was done in 43(35%) patients, if RAIR was absent or inconclusive.

CONCLUSION

CM and 3D-HRARM are comparable in terms of resting pressure and RAIR threshold. 3D-HRAM is safe and provides detailed functional morphology of anal sphincters and it is useful to understand underlying pathophysiology of constipation and faecal incontinence in children and plan further treatment.

LEVEL OF EVIDENCE

Level I.

Surgical Management of Idiopathic Constipation in Pediatric Patients

Constipation is a common childhood problem, but an anatomic or physiologic cause is identified in fewer than 5% of children. By definition, idiopathic constipation is a diagnosis of exclusion. Careful clinical evaluation and thoughtful use of imaging and other testing can help exclude specific causes of constipation and guide therapy. Medical management with laxatives is effective for the majority of constipated children. For those patients unresponsive to medications, however, several surgical options can be employed, including anal procedures, antegrade colonic enemas, colorectal resection, and intestinal diversion. Judicious use of these procedures in properly selected patients and based on appropriate preoperative testing can lead to excellent outcomes. This review summarizes the surgical options available for managing refractory constipation in children and provides guidance on how to choose the best procedure for a given patient.

Anal endosonography and bowel function in patients undergoing different types of endorectal pull-through procedures for Hirschsprung disease

BACKGROUND

The reasons for fecal incontinence after surgery for Hirschsprung disease (HD) remain unclear. The aim of this study was to examine the anal sphincters by anal endosonography and manometry after transanal endorectal pull-through, with or without laparotomy or laparoscopy, in HD patients. Furthermore, we aimed to correlate these findings to bowel function.

PATIENTS AND METHODS

Fifty-two HD patients were followed after endorectal pull-through. Anal endosonography and manometry were performed without sedation at the age of 3 to 16 years.

RESULTS

Endosonographic internal anal sphincter (IAS) defects were found in 24/50 patients, more frequently after transanal than transabdominal procedures (69 vs. 19%, p=0.001). In a multiple variable logistic regression model, operative approach was the only significant predictor for IAS defects. Anal resting pressure (median 40mm Hg, range 15-120) was not correlated to presence of IAS defects. Daily fecal incontinence occurred more often in patients with IAS defects (54 vs. 25%, p=0.03).

CONCLUSIONS

Postoperative IAS defects were frequently detected and were associated with daily fecal incontinence. IAS defects occurred more often after solely transanal procedures. We propose that these surgical approaches are compared in a randomized controlled trial before solely transanal endorectal pull-through is performed as a routine procedure.

Pathophysiology of chronic childhood constipation: functional and morphological evaluation by anorectal manometry and endosonography and colonic transit study

BACKGROUND

Chronic idiopathic constipation (IC) is a common problem in children. We hypothesised that hypertonicity and overactivity of the internal anal sphincter (IAS) contributed to childhood IC.

METHOD

This was a prospective study of children who were admitted for investigation and treatment of chronic constipation at the gastrointestinal motility clinic in Guy's and St. Thomas' Hospital, NHS Foundation Trust, London. All children had a colonic transit marker study followed by anorectal manometry and anal endosonography under ketamine anesthesia. We used a validated symptom severity (SS) score questionnaire for assessment of constipation and fecal incontinence on admission to hospital and during follow-up for 12months. The SS score of 0 was the best and 65 the worst.

RESULTS

Of 92 children, 57 were male and median (range) age was 8.46years (3.35-14.97). Duration of symptoms was 4.7years (0.3-13). Soiling was present in 88 (96%) patients, delay in defecation of once every 2 to 3days or less frequently in 86 (93%) and a palpable fecaloma (megarectum) on abdominal examination in 76 (83%). 42 children had 'fecal impaction' requiring disimpaction of stool from the rectum under general anesthesia and 50 had 'no impaction'. The median IAS resting pressure was within the normal range measuring 55mm Hg (25-107) and median amplitude and frequency of the IAS contractions were 10mm Hg (2.0-58) and 17cycles per min (5.0-34), respectively. The median IAS thickness was 0.93mm (0.5-2.0). There was no correlation between amplitude and frequency of anorectal contractions and anal sphincter resting pressure. The mean right colonic transit time was 8.55 (standard deviation ±13.22) h, left colonic transit time was 11.51h (±13.21), rectosigmoid transit time was 25.91h (±18.89) and total colonic transit time was 45.97h (±17.69).

CONCLUSION

The anal sphincter resting pressure is normal in children with chronic IC. Increased frequency and amplitude of IAS contractions seen in these patients do not cause raised anal sphincter resting pressure or obstructive defecation. Further studies should be done to investigate the role of external anal sphincter dysfunction in pathophysiology of childhood constipation and fecal incontinence.

Endosonographic evaluation of anal sphincters in healthy children

PURPOSE

To describe the endosonographic anatomy of anal sphincters in healthy children and to evaluate the reproducibility of sphincter thickness measurements.

METHODS

Forty-five healthy children with median age of 3.6 years (range, 1.0-14.5 years) were studied while under general anesthesia for minor surgery. Anal endosonography was performed with a 7- to 10-MHz rotating transducer with a diameter of 19 mm. The internal anal sphincter (IAS) and the external anal sphincter (EAS) were assessed by 2 independent observers.

RESULTS

IAS and EAS were identified in all children. The mean thickness of IAS and EAS were 1.3 mm and 5.3 mm, respectively. Identification of the inner and outer border of IAS was difficult, especially in children younger than 3 years. The thickness of EAS was easier to assess, and the interrater reliability for EAS thickness measurements was excellent. EAS thickness was positively correlated with the children's age. Reflectivity varied within the EAS with frequent hyporeflective areas.

CONCLUSIONS

Anal endosonography provided visualization of the IAS and EAS in children. Assessment of exact IAS thickness was difficult, especially in the youngest children. Mean EAS thickness was 5.3 mm, increasing with age. Hyporeflective areas of the intact EAS should not be misinterpreted as sphincter defects.

Endosonography of the anal canal: findings in children

PURPOSE

The aim of this study was to determine the endosonographic anatomy in children to define normal age-related differences in sphincter morphology and measurements.

METHODS

One hundred ten consecutive children (76 males and 34 females; mean age, 3.94 years; range, 1.10-15.09) with endoanal ultrasonography were studied. The thickness of the anal canal of the internal and external anal sphincter of each child was registered and correlated with the age.

RESULTS

At the high level, the puborectalis muscles were clearly visualized, with a median thickness of 4.73 mm, and the internal anal sphincters were observed, with a mean thickness of 1.21 mm. At the mid level, both the internal and external anal sphincters were visualized, as well. The mean internal anal sphincter thickness was 1.23 mm and the median thickness of the external anal sphincter was 4.47 mm. At the lower level, the median external anal sphincter thickness was 5.39 mm. There was no significant correlation between the thickness of the internal and external sphincters and sex. The puborectalis and the external anal sphincter thickness showed a highly significant positive correlation with age. There was no significant correlation between the internal sphincter thickness and age.

CONCLUSIONS

The endosonographic morphology of children is similar to that of adults, although the structures in children less than 5 years of age are difficult to differentiate. We detected a significant increase in the thickness of the external anal sphincter as patients grow older, but not in the internal anal sphincter.

Ultrasonographic patterns in patients with obstructed defaecation

BACKGROUND

Anal ultrasound is helpful in assessing organic anorectal lesions, but its role in functional disease is still questionable. The purpose of the present study is to assess anal-vaginal-dynamic perineal ultrasonographic findings in patients with obstructed defecation (OD) and healthy controls.

MATERIALS AND METHODS

Ninety-two consecutive patients (77 women; mean age 51 years; range 21-71) with symptoms of OD were retrospectively evaluated. All patients underwent digital exploration, endoanal and endovaginal ultrasound (US) with rotating probe. Forty-one patients underwent dynamic perineal US with linear probe. Anal manometry and defaecography were performed in 73 and 43 patients, respectively. Ultrasonographic findings of 92 patients with symptoms of OD were compared to 22 healthy controls. Anismus was defined on US when the difference in millimetres between the distance of the inner edge of the puborectalis muscle posteriorly and the probe at rest and on straining was less then 5 mm. Sensitivity and specificity were calculated by assuming defaecography as the gold standard for intussusception and rectocele and proctoscopy for rectal internal mucosal prolapse. Since no gold standard for the diagnosis of anismus was available in the literature, the agreement between anal US and all other diagnostic procedures was evaluated.

RESULTS

The incidence of anismus resulted significantly higher (P < 0.05) in OD patients than healthy controls on anal (48 vs 22%), vaginal (44 vs 21%), and dynamic perineal US (53 vs 22%). A significantly higher incidence of rectal internal mucosal prolapse was observed in OD patients when compared to healthy controls on both anal (61.9 vs 13.6%, P < 0.0001) and dynamic perineal US (51.2 vs.9% P = 0.001). For the diagnosis of rectal internal mucosal prolapse, anal US had a 100% sensitivity and specificity. For diagnosis of rectal intussusception, anal US had an 83.3% sensitivity and 100% specificity and perineal US had a 66.6% sensitivity and 100% specificity. In the diagnosis of anismus, anal ultrasonography resulted in agreement with perineal and vaginal US, manometry, defaecography, and digital exam (P < 0.05). Other lesions detected by US in patients with OD include solitary rectal ulcer, rectocele and enterocele. Damage of internal and/or external sphincter was diagnosed at anal US in 19/92 (20%) patients, all continent and with normal manometric values.

CONCLUSION

Anal, vaginal and dynamic perineal ultrasonography can diagnose or confirm many of the abnormalities seen in patients with OD. The value of the information obtained by this non-invasive test and its role in the diagnostic algorithm of OD is yet to be defined.

Psychological evaluation of children with idiopathic constipation and their parents

BACKGROUND

Constipation is one of the most common problems in childhood. In idiopathic constipation it is not possible to identify primary cause in every case. Child behavioral problems and disturbances in parent-child relationships have been cited as causes of constipation. Constipation is a source of anxiety to the child and to the family. The purpose of the present study was to evaluate psychological characteristics of constipated children and their parents.

METHODS

Thirty-two otherwise healthy children with idiopathic constipation over 4 years old were prospectively evaluated between January 2002 and June 2003. The Child Behavior Checklist (CBCL) and Symptom Checklist-90 revised (SCL-90-R) were used to assess the psychological profiles of the children and the parents, respectively. Thirty children with inguinal hernia who had no constipation or other problems, and their parents were asked to complete the checklists as controls. The scores of the constipation group were compared statistically with those of the control group.

RESULTS

In the constipation group there were 19 boys and 13 girls with a mean age of 7.3 years (4-14 years). All the patients responded to medical treatment. Constipated children and their parents were not found to have more behavior problems than the control group (P > 0.05).

CONCLUSIONS

Children with idiopathic constipation and their parents do not show significant behavioral and emotional problems. Their psychological profiles are not different from the general population.

Thickening of the internal anal sphincter in idiopathic constipation in children

Thickening of the internal anal sphincter (IAS) is observed in chronic idiopathic constipation (IC) and solitary rectal ulcer syndrome (SRUS), where it has been correlated with the presence and severity of rectal intussusception. Alternatively, thickened IAS may be a feature of the obstructed megarectum in a similar way to the hypertrophy of bladder neck seen in dyssynergic bladders. The aim of this study was to investigate the significance of thickening of the IAS in children with chronic IC and to determine any association between the thickened IAS and anorectal manometry findings and patient's symptoms. A total of 144 children were admitted for investigations and treatment of chronic IC and evaluated prospectively between April 2001 and April 2003. IAS thickness was measured by endosonography using B&K axial endosonic probe type 1850 with a 10-MHz rotating transducer. The thickness of IAS was measured at 3, 6, and 9 o'clock, and the mean value of the three measurements was used for analysis. Functional assessment was done by anorectal manometry pressure studies under ketamine anaesthesia. A validated symptom score (SS) was used to assess the severity of symptoms. The sum of SS ranged between 0 and 65. Spearman's rho two-tailed test was used to correlate the thickness of IAS with patients' symptoms and anorectal manometry findings. Results were expressed as median and range and p-value of less than 0.05 was considered significant. Of 144 children, 84 were boys, median age 8.1 years (range 3.1-15). Soiling was present in 137 (94%) patients, delay in defecation in 132 (91%), and a palpable megarectum on abdominal examination in 117 (80%). The median duration of symptoms and duration of laxative treatment were 4 years (range 0.3-14.5) and 3.3 years (0.2-13.5), respectively. The average severity score for soiling, delay in defecation, palpable megarectum, and the total SS were 8 (range 0-10), 5 (0-10), 2 (0-12), and 33 (11-51), respectively. The median thickness of IAS was 0.9 mm (range 0.3-2.8) and the median resting anal sphincter pressure was 54 mmHg (19-107). The median amplitudes of rectal and anal sphincter contraction were 3 mmHg (1-25) and 9 mmHg (1-35), respectively. The thickness of IAS correlated significantly with total symptom severity score (r=0.31, p=0.0001), soiling score (r=0.28, p=0.001), megarectum score on abdominal palpation (r=0.29, p=0.001), size of megarectum on manometry (r=0.36, p=0.0001), amplitude of rectal contraction (r=0.23, p=0.007), and age of patient (r=0.55, p=0.0001). There was also a significant correlation between the amplitude of rectal and anal sphincter contraction (r=0.32, p=0.0001). There was no correlation between thickness of IAS and resting anal sphincter pressure and amplitude of anal sphincter contraction on anorectal manometry study. A total of 24 children had myectomy of thickened and overactive IAS in addition to the medical treatment of their chronic IC. The histology examination of myectomy specimen with eosin and haematoxylin staining and histochemical acetylcholine esterase staining showed smooth muscle fibres and ganglion cells. Thickening of IAS correlates significantly with duration and severity of symptoms, size of megarectum, and amplitude of rectal contraction. The pathogenesis is secondary to the continuous presence of faeces in the rectum, resulting in chronic abnormal stimulus to the IAS, which leads to hypertrophic changes in the rectum wall and IAS.

Hirschsprung's disease: functional and psychological follow up comparing total colonic and rectosigmoid aganglionosis

AIMS

To compare the long term functional and psychosocial outcomes following surgical treatment for total colonic aganglionosis (TCA) with those in an age and gender matched group of patients with rectosigmoid aganglionosis (RSA).

METHODS

Fifteen patients with TCA matched for age and gender with 15 patients with RSA were studied 7-17 years after the definitive operation. The internal and external sphincters were examined using anal endosonography. Functional outcome (faecal continence) was assessed by a surgeon not involved in the patients' care, and by a research psychologist in separate assessment sessions. The behavioural and emotional status of the patients was also assessed.

RESULTS

Based on the surgeon's assessment, 6/15 TCA and 7/15 RSA patients were continent. In comparison, based on the psychological interview, 2/15 TCA and 6/15 RSA patients were continent. The TCA patients reported significantly more behavioural/emotional problems and lower levels of self esteem than the RSA patients. The parent and teacher assessments of psychosocial status revealed no differences between the groups. There was no association between incontinence and psychosocial adjustment in either group. There was no association between the assessments of functional outcome and the endosonographic appearance of the anal sphincters.

CONCLUSIONS

The proportion of patients with faecal incontinence 7-17 years after definitive surgery was high in both groups, but no association was found between incontinence and the psychosocial outcome measures. TCA patients perceived themselves as less well adjusted than their matched pairs. Differences between the groups in length of hospitalisation and severity of illness, especially in infancy and early childhood, may account for these differences.