Anorectal manometry in pediatric settings: A systematic review of 227 studies

Clinical Utility of Anorectal Manometry in Children with Functional Constipation: Can Anorectal Manometry Help Predict the Therapeutic Response?

Background: Anorectal Manometry (ARM) plays a crucial role in diagnosing potential motility disorders of anorectum in pediatric gastroenterology. Despite its prevalence, the predictive utility of ARM in guiding therapeutic response remains poorly characterized. Objectives: This study aims to evaluate the effectiveness of ARM in predicting therapeutic responses among children with functional constipation. Methods: A retrospective chart review was conducted at two tertiary centers examining pediatric patients who underwent ARM between January 2018 and July 2022. Key ARM parameters were analyzed, including anal resting pressure, recto-anal inhibitory reflex (RAIR), first rectal sensation, and bear-down maneuver (BDM). Therapeutic responses were assessed post-ARM, with success defined as an increase in bowel movement frequency and/or a decrease in fecal incontinence. In addition, we also intended to evaluate the eventual need for surgical intervention as another outcome. Results: The study included 327 patients, with a median age of 8.2 years. The overall therapeutic response rate was 40.7%, with stimulant laxatives showing a 48% response. Notably, lower anal resting pressures and delayed rectal sensations were associated with better therapeutic outcomes. Abnormal BDM correlated with a lack of response to therapies, while the presence of abnormal RAIR was linked to a higher eventual need for surgical intervention. Conclusions: ARM is instrumental in predicting therapeutic responses in pediatric patients with functional constipation. In addition to diagnosing HD, ARM could be an instrumental tool in identifying patients with dyssynergic defecation for early intervention with targeted therapy in age-appropriate patients.

Testing in functional constipation-What's new and what works

BACKGROUND

Constipation is among the most common symptoms prompting a consultation with a paediatric gastroenterologist. While most patients will respond to lifestyle and dietary changes and conventional therapy, some may require diagnostic studies.

AIM

To review the diagnostics studies used to evaluate children with functional constipation.

MATERIALS AND METHODS

There is no evidence to support the routine use of abdominal X-rays in the evaluation of paediatric constipation. Colon transit by radiopaque markers (ROM) should be indicated when medical history does not match clinical findings, to guide colon manometry (CM) performance and to discriminate between faecal incontinence from functional constipation and non-retentive faecal incontinence. Colon scintigraphy may be useful as an alternative to ROM. Lumbar spine MRI may be indicated to evaluate for spinal abnormalities. The role of defecography has not been properly evaluated in children. Anorectal manometry in children is indicated primarily to evaluate anal resting pressure, presence and quality of the recto-anal inhibitory reflex and simulated defecation manoeuvres. The CM is indicated to guide surgical interventions after failing medical therapy.

CONCLUSIONS

The goal of these studies is to identify treatable causes of constipation. Most of these studies are designed to evaluate anatomy, transit and/or colon/rectum motility function and are primarily indicated in those who fail to respond to conventional therapy.

Anorectal Manometry in Pediatric Colorectal Surgical Care

BACKGROUND

Pediatric colorectal specialists care for patients with a variety of defecation disorders. Anorectal (AR) manometry testing is a valuable tool in the diagnosis and management of these children. This paper provides a summary of AR manometry techniques and applications as well as a review of AR manometry findings in pediatric patients with severe defecation disorders referred to a pediatric colorectal center. This is the first study describing multi-year experience using a portable AR manometry device in pediatric patients.

METHODS

An electronic medical record review was performed (1/2018 to 12/2023) of pediatric patients with defecation disorders who had AR manometry testing. Demographics, diagnostic findings, and outcomes are described.

KEY RESULTS

A total of 297 unique patients (56.9% male, n = 169) had AR manometry testing. Of these, 72% (n = 188) had dyssynergic defecation patterns, of which 67.6% (n = 127) had fecal soiling prior to treatment. Pelvic rehabilitation (PR) was administered to 35.4% (n = 105) of all patients. A total of 79.5% (n = 58) of the 73 patients that had fecal soiling at initial presentation and completed PR with physical therapy and a bowel management program were continent after therapy. AR manometry was well tolerated, with no major complications.

CONCLUSIONS

AR manometry is a simple test that can help guide the management of pediatric colorectal surgical patients with defecation disorders. As a secondary finding, PR is a useful treatment for patients with dyssynergic stooling.

High-resolution anorectal manometry in children

Anorectal manometry is one of the motility tests in children performed by pediatric gastroenterologist. It evaluates the motility function of anorectal tract. It is helpful for diagnosing children with constipation, rectal hypersensitivity, fecal incontinence, Hirschsprung disease, anal achalasia, and anorectal malformations. The most common indication to perform anorectal manometry is to diagnose Hirschsprung disease. It is a safe procedure. This paper discusses recent advances and reviews on anorectal motility disorders in children.

Sampling Reflex as a New Manometric Marker in the Diagnosis of Defecation Disorders - Systematic Review

Introduction Distension of the rectum wall and subsequent momentary relaxation of the internal anal sphincter (IAS) trigger a reflex called the rectoanal inhibitory reflex (RAIR). This same rectal distension causes a reflex contraction of the external anal sphincter (EAS), responsible for conscious continence called rectoanal excitatory reflex (RAER). This set of reflexes are named sampling reflex.

Objectives The sampling reflex is necessary to initiate defecation or flatulence. The objective of this study is to evaluate the sampling reflex and its practical applicability as a manometric marker of the main defecation disorders.

Methodology This review followed the Preferred Reporting Items for Systematic reviews and Meta-Analysis (PRISMA) items. The development method consisted of searching for articles in the research platforms BVS, PubMed, Cochrane Library, SciELO and ScienceDirect and for the selection of articles the Rayyan Platform was used. The articles resulting from the search strategies were added to the platform and five collaborators were invited for the blind selection. Finally, 6 articles were included in the final review.

Results An intact sampling reflex allows the individual to facilitate discrimination between flatus and stool and to choose whether to discharge or retain rectal contents. On the other hand, an impaired sampling reflex can predispose an individual to incontinence.

Therefore, it was observed that patients with defecation disorders had an impaired sampling reflex, since it was found that constipated patients have incomplete opening of the IAS, lower amplitude of RAIR and increase of RAER. Most incontinent patients present a failure in the recruitment of the EAS, a decrease in the RAER and an increase in the RAIR, in duration and amplitude.

Conclusion The improvement of high-resolution anorectal manometric techniques was essential for understanding the pathophysiology of defecation disorders, as well as the physiological understanding and importance of RAIR and RAER.

Anorectal manometry findings in relation with long-term functional outcomes of the patients operated on for Hirschsprung's disease compared to the reference-based population

PURPOSE

This study investigated anorectal manometry (AM) findings and bowel function of patients operated on for Hirschsprung's disease (HD).

METHODS

A cross-sectional study was conducted at Children's Hospital 2. Patients operated on for HD from January 2015 to January 2020 were reviewed. Their clinical characteristics, bowel function, and manometric findings were investigated and compared with the references.

RESULTS

Ninety-five patients and 95 references were enrolled. Mean ages were 6.6 ± 2.2 years and 7.2 ± 2.9 years,; fecal incontinence rates were 25.3% and 2.1%, and constipation rates were 12.6% and 4.2 for the patients versus the references, respectively. Anal resting pressures were significantly decreased in the patients compared to the references (53.2 ± 16.1 mmHg versus 62.2 ± 14.0 mmHg; p < 0.05). Among the patients, the anal resting pressure was significantly decreased in the incontinents than in the continents (46.0 ± 10.6 mmHg versus 55.6 ± 16.9 mmHg, p < 0.05). During the sensation test, the value of maximum tolerated volume was significantly decreased in the incontinents than in the continents (135.9 ± 47.9 mL versus 166.6 ± 58.3 mL, p < 0.05).

CONCLUSION

AM is an objective method providing beneficial information that could guide a more adapted management in HD patients with defecation disorders.

THE FATIGUE RATE INDEX IS HIGHER IN CHILDREN WITH FUNCTIONAL CONSTIPATION AND RETENTIVE FECAL INCONTINENCE

BACKGROUND

The Fatigue Rate Index (FRI) is a parameter in anorectal manometry (ARM) to assess sustained voluntary contraction, considering the squeeze pressure and fatigability of the external anal sphincter. It is used in adults to detect fecal incontinence even in patients who present normal squeeze pressures. The FRI in adult patients with functional constipation is similar to controls.

OBJECTIVE

The aim of this study was to evaluate the feasibility and values of FRI in children in relation to the values previously established in adults and comparing children with functional constipation and retentive fecal incontinence to children without retentive fecal incontinence.

METHODS

This retrospective study evaluated 105 ARM performed from Jan 2014 to Apr 2015. 42 patients were selected (were able to perform a voluntary contraction and had no co-morbidities other than functional constipation). 14 (33.3%) of those collaborated in sustaining contraction for 40 seconds (s), allowing the evaluation of the FRI. Patients with retentive fecal incontinence secondary to functional constipation (n=7, aged 6 to 13 years, six boys) were our interest group. Patients with functional constipation without fecal incontinence (n=7, aged 6 to 13 years, four boys) were considered a reference group. The ARM were performed with a radial eight-channel perfusion catheter (DynamedTM, São Paulo, Brazil) and the FRI was calculated (Proctomaster 6.4) in the first 20 s and overall 40 s of sustained voluntary contraction.

RESULTS

14 of the selected 42 collaborated in sustaining contraction for 40 s, allowing the evaluation of the FRI. In the first 20 s of contraction, the fecal incontinence group showed a significantly higher mean FRI (2.48±1.39 min) compared to the reference group (1.13±0.72 min, P=0.042), which was not observed in the 40 s interval due to less uniform contraction. The anal resting pressure was higher in the fecal incontinence group (76.83 mmHg) than in the reference group (54.13 mmHg), but the statistical study did not reach significance (P=0.051).

CONCLUSION

The FRI is feasible in children. The mean FRI obtained in this study is lower than the reported in constipated adults. The mean FRI among children with functional constipation and retentive fecal incontinence is higher than among constipated children without retentive fecal incontinence.

Anorectal Manometry in Children: The Update on the Indications and the Protocol of the Procedure

Anorectal disorders are common in children. They are related to structural and/or functional abnormalities of the anorectum or pelvic floor with a variety of symptoms. Therefore, diagnostic tests to evaluate anorectal function can help to better understand the underlying pathophysiology and aetiology as well as facilitate patient management. During the past decades, substantial efforts have been made to improve anorectal function testing; however, more advanced investigations might lead to difficulties in interpretation. Additionally, a great diversity of equipment and protocols are used among centres, which may lead to heterogeneous interpretation of results. More studies to standardize methods of testing and validate reference values are strongly recommended in children. This review updates on the current indications and the protocol of anorectal manometry.