Comparison of Anorectal Function as Measured with High-Resolution and High-Definition Anorectal Manometry

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.

Recto-anal Pressures in Constipated Men and Women Undergoing High-Resolution Anorectal Manometry

BACKGROUND

In constipated individuals, high-resolution anorectal manometry (HRM) may suggest the presence of a defecatory disorder. Despite known physiological differences between men and women, our understanding of functional anorectal pathophysiology is based upon predominantly female cohorts. Results are generalized to men.

AIMS

To evaluate whether recto-anal pressure patterns in constipated men are similar to those in constipated women.

METHODS

The electronic health records at Mayo Clinic, Rochester were used to identify constipated adult patients, without organic anorectal disease, who had undergone HRM and balloon expulsion testing (BET) in 2018, 2019, and 2020. Comparative analyses were performed.

RESULTS

Among 3,298 constipated adult patients (2,633 women, 665 men), anal and rectal pressures were higher in men. Women more likely to have HRM findings suggestive of a defecatory disorder (39% versus 20%, P < 0.001). Women were more likely to exhibit a type 4 pattern (27% versus 14%, P < 0.001), and less likely to exhibit a type 1 pattern (14% versus 38%, P < 0.001), of dyssynergia. Men were more likely to have an abnormal balloon expulsion test (BET, 34% versus 29%, P = 0.006). Nominal logistic regression demonstrates that male sex, age over 50 years, reduced recto-anal gradient during simulated evacuation, and types 2 and 4 dyssynergia are associated with an abnormal BET.

CONCLUSIONS

In this large retrospective study, constipated men and women exhibited different patterns of dyssynergia both in the presence and absence of an abnormal BET. These findings were independent of sex-specific baseline physiological differences.

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.

Pelvic floor muscle exercises alleviate symptoms and improve mental health and rectal function in patients with low anterior resection syndrome

Background

Pelvic floor rehabilitation has been reported to be effective in improving fecal incontinence. The aim of this study was to prospectively evaluate the effectiveness of combined pelvic floor muscle exercises (PFMEs) and loperamide treatment on rectal function and mental health for low anterior resection syndrome (LARS) patients after sphincter-saving operation (SSO) for rectal cancer.

Methods

A total of 60 inpatients diagnosed with LARS were enrolled and randomly assigned to one of two groups: patients in Group A (n = 30) were treated with a PFME intervention and those in Group B (n = 30) with a control intervention for 4 weeks. High-resolution anorectal manometry (HRAM) was performed for all LARS patients. Demographic information was collected for all patients, and they subsequently also completed several questionnaires, including the Hospital Anxiety and Depression Scale (HADS), a measure of Wexner score, a measure of stool frequency per day, and the Bristol Stool Form Scale (BSFS).

Results

No significant differences between the groups were observed in baseline data. With regard to rectal function, we found significant improvements at week 4 in maximal resting pressure (MRP) (39.93 ± 5.02 vs. 28.70 ± 5.40 mmH₂O, p < 0.001) and maximal squeeze pressure (MSP) (132.43 ± 8.16 mmH₂O vs. 113.33 ± 9.87 mmH₂O, p < 0.001) among Group A patients compared to Group B patients. Additionally, Wexner scores were significantly lower in Group A than in Group B at week 4 (8.10 ± 1.24 vs. 9.87 ± 1.29 ml, p = 0.018), as were stool frequency (6.47 ± 0.90 vs. 7.83 ± 0.93, p < 0.001) and BSFS scores (5.17 ± 0.65 vs. 6.10 ± 0.80, p = 0.020). Notably, HADS scores were also significantly lower in Group A than in Group B at week 4 (8.25 ± 2.36 vs. 10.48 ± 3.01, p < 0.001). Additionally, both anxiety scores (4.16 ± 1.38 vs. 5.33 ± 1.69, p < 0.001) and depression scores (4.09 ± 1.56 vs. 5.15 ± 1.89, p < 0.001) were significantly lower in Group A than in Group B at week 4.

Conclusion

Pelvic floor muscle exercises are an effective treatment that can alleviate symptoms and improve rectal function and mental health in patients with low anterior resection syndrome.

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.