Optimizing techniques for measuring anal resting and squeeze pressures with high-resolution manometry

Defecatory disorders are a common cause of chronic constipation in Parkinson disease

BACKGROUND AND AIMS

Up to 50% of patients with Parkinson disease have constipation (PD-C), but the prevalence of defecatory disorders caused by rectoanal dyscoordination in PD-C is unknown. We aimed to compare anorectal function of patients with PD-C versus idiopathic chronic constipation (CC).

METHODS

Anorectal pressures, rectal sensation, and rectal balloon expulsion time (BET) were measured with high-resolution anorectal manometry (HR-ARM) in patients with PD-C and control patients with CC, matched for age and sex.

RESULTS

We identified 97 patients with PD-C and 173 control patients. Eighty-six patients with PD-C (89%) had early PD, and 39 (40%) had a defecatory disorder, manifest by a prolonged rectal balloon expulsion time (37 patients) or a lower rectoanal pressure difference during evacuation (2 patients). PD-C patients with a prolonged BET had a greater anal resting pressure (p = 0.02), a lower rectal pressure increment (p = 0.005), greater anal pressure (p = 0.047), and a lower rectoanal pressure difference during evacuation (p < 0.001). Rectal sensory thresholds were greater in patients with abnormal BET. In the multivariate model comparing CC and PD-C (AUROC = 0.76), PD-C was associated with a lower anal squeeze increment (odds ratio [OR] for PD-C, 0.93 [95% CI, 0.91-0.95]), longer squeeze duration (OR, 1.05 [95% CI, 1.03-1.08]), lower rectal pressure increment (OR per 10 mm Hg, 0.72 [95% CI, 0.66-0.79]), and negative rectoanal gradient during evacuation (OR per 10 mm Hg, 1.16 [95% CI, 1.08-1.26]).

CONCLUSIONS

Compared with CC, PD-C was characterized by impaired squeeze pressure, longer squeeze duration, lower increase in rectal pressure, and a more negative rectoanal gradient during evacuation.

A randomized double-blind trial of clonidine and colesevelam for women with fecal incontinence

BACKGROUND

Diarrhea and rectal urgency are risk factors for fecal incontinence (FI). The effectiveness of bowel modifiers for improving FI is unclear.

METHODS

In this double-blind, parallel-group, randomized trial, women with urge FI were randomly assigned in a 1:1 ratio to a combination of oral clonidine (0.1 mg twice daily) with colesevelam (1875 mg twice daily) or two inert tablets for 4 weeks. The primary outcome was a ≥50% decrease in number of weekly FI episodes.

KEY RESULTS

Fifty-six participants were randomly assigned to clonidine-colesevelam (n = 24) or placebo (n = 32); 51 (91%) completed 4 weeks of treatment. At baseline, participants had a mean (SD) of 7.5 (8.2) FI episodes weekly. The primary outcome was met for 13 of 24 participants (54%) treated with clonidine-colesevelam versus 17 of 32 (53%) treated with placebo (p = 0.85). The Bristol stool form score decreased significantly, reflecting more formed stools with clonidine-colesevelam treatment (mean [SD], 4.5 [1.5] to 3.2 [1.5]; p = 0.02) but not with placebo (4.2 [1.9] to 4.1 [1.9]; p = 0.47). The proportion of FI episodes for semiformed stools decreased significantly from a mean (SD) of 76% (8%) to 61% (10%) in the clonidine-colesevelam group (p = 0.007) but not the placebo group (61% [8%] to 67% [8%]; p = 0.76). However, these treatment effects did not differ significantly between groups. Overall, clonidine-colesevelam was well tolerated.

CONCLUSIONS AND INFERENCES

Compared with placebo, clonidine-colesevelam did not significantly improve FI despite being associated with more formed stools and fewer FI episodes for semiformed stools.

Optimizing the Utility of Anorectal Manometry for Diagnosis and Therapy: A Roundtable Review and Recommendations

BACKGROUND & AIMS

Anorectal manometry (ARM) is a comprehensive diagnostic tool for evaluating patients with constipation, fecal incontinence, or anorectal pain; however, it is not widely utilized for reasons that remain unclear. The aim of this roundtable discussion was to critically examine the current clinical practices of ARM and biofeedback therapy by physicians and surgeons in both academic and community settings.

METHODS

Leaders in medical and surgical gastroenterology and physical therapy with interest in anorectal disorders were surveyed regarding practice patterns and utilization of these technologies. Subsequently, a roundtable was held to discuss survey results, explore current diagnostic and therapeutic challenges with these technologies, review the literature, and generate consensus-based recommendations.

RESULTS

ARM identifies key pathophysiological abnormalities such as dyssynergic defecation, anal sphincter weakness, or rectal sensory dysfunction, and is a critical component of biofeedback therapy, an evidence-based treatment for patients with dyssynergic defecation and fecal incontinence. Additionally, ARM has the potential to enhance health-related quality of life and reduce healthcare costs. However, it has significant barriers that include a lack of education and training of healthcare providers regarding the utility and availability of ARM and biofeedback procedures, as well as challenges with condition-specific testing protocols and interpretation. Additional barriers include understanding when to perform, where to refer, and how to use these technologies, and confusion over billing practices.

CONCLUSIONS

Overcoming these challenges with appropriate education, training, collaborative research, and evidence-based guidelines for ARM testing and biofeedback therapy could significantly enhance patient care of anorectal disorders.

Defecatory disorders in patients with type 1 diabetes and chronic constipation

BACKGROUND AND OBJECTIVES

Chronic constipation (CC) may be caused by defecatory disorders (DDs) and associated with reduced rectal sensation. Among patients with type 1 diabetes (T1D) and CC (T1DCC patients), the prevalence of DDs and reduced rectal sensation is unknown. We sought to compare complications of T1D, anorectal dysfunction, and CC symptoms, among T1DCC patients with versus without a DD.

METHODS

Anorectal pressures at rest and during squeeze and evacuation, as well as rectal sensation and rectal balloon expulsion time (BET) were measured with high-resolution anorectal manometry in 114 consecutive T1DCC patients.

RESULTS

Thirty-seven patients (32%) had prolonged BET, suggestive of a DD. Complications of T1D included peripheral neuropathy (n = 67, 59%), retinopathy (n = 42, 37%), and nephropathy (n = 26, 23%). Among these complications, only retinopathy was associated with, that is, more prevalent in patients with normal (45%) than prolonged BET (19%). Compared with patients with normal BET, patients with prolonged BET had a lower rectal pressure (mean [SD], 32 [23] mm Hg vs. 23 [19] mm Hg, p = 0.03), greater anal pressure (91 [23] mm Hg vs. 68 [36] mm Hg, p < 0.001), and lower rectoanal gradient (-67 [30] mm Hg vs. -36 [32] mm Hg, p < 0.0001) during evacuation. Anal resting pressure and anal squeeze increment were below normal in 14 (13%) and 32 (29%) of patients and one or more rectal sensory thresholds were above normal in 34 (30%) patients; these abnormalities affected similar proportions in the normal and prolonged BET cohorts.

CONCLUSIONS

Among T1DCC patients, 37 (32%) had prolonged BET, which was associated with anorectal pressures indicative of a DD but was not associated with reduced rectal sensation, suggesting that DDs are more likely explained by abdomino-anal dyscoordination than visceral disturbance.

Comparison of Anorectal Manometry, Rectal Balloon Expulsion Test, and Defecography for Diagnosing Defecatory Disorders

BACKGROUND & AIMS

The utility of high-resolution anorectal manometry (HR-ARM) for diagnosing defecatory disorders (DDs) is unclear because healthy people may have features of dyssynergia. We aimed to identify objective diagnostic criteria for DD and to ascertain the utility of HR-ARM for diagnosing DD.

METHODS

Constipated patients were assessed with HR-ARM and rectal balloon expulsion time (BET), and a subset underwent defecography. Normal values were established by assessing 184 sex-matched healthy individuals. Logistic regression models evaluated the association of abnormal HR-ARM findings with prolonged BET and reduced rectal evacuation (determined by defecography).

RESULTS

A total of 474 constipated individuals (420 women) underwent HR-ARM and BET, and 158 underwent defecography. BET was prolonged, suggesting a DD, for 152 patients (32%). Rectal evacuation was lower for patients with prolonged vs normal BET. A lower rectoanal gradient during evacuation, reduced anal squeeze increment, and reduced rectal sensation were independently associated with abnormal BETs; the rectoanal gradient was 36% sensitive and 85% specific for prolonged BET. A lower rectoanal gradient and prolonged BET were independently associated with reduced evacuation. Among constipated patients, the probability of reduced rectal evacuation was 14% when the gradient and BET were both normal, 45% when either was abnormal, and 75% when both variables were abnormal.

CONCLUSIONS

HR-ARM, BET, and defecography findings were concordant for constipated patients, and reduced rectoanal gradient was the best HR-ARM predictor of prolonged BET or reduced rectal evacuation. Prolonged BET, reduced gradient, and reduced evacuation each independently supported a diagnosis of DD in constipated patients. We propose the terms probable DD for patients with an isolated abnormal gradient or BET and definite DD for patients with abnormal results from both tests.

Reproducibility of high-resolution manometry among healthy and constipated persons

BACKGROUND AND AIMS

Although high-resolution manometry (HR_ARM) is commonly used to diagnose defecatory disorders, its intraindividual day-to-day reproducibility is unknown. Since these measurements entail voluntary effort, this study aimed to evaluate the intraindividual day-to-day reproducibility of HR_ARM.

METHODS

In 22 healthy women (35 years [14] mean [SD]) and 53 constipated patients (42 years [13], 46 women), the rectal balloon expulsion time (BET), and anorectal pressures were measured with HR_ARM on 2 days separated by a median (interquartile range) of 15 days (11-53) in healthy and 40 days (8-75) in constipated patients. Anorectal pressures were evaluated at rest (20 s), during squeeze, and during evacuation. Rectal sensation was also evaluated in constipated patients. The agreement between both measurements was evaluated with Lin's concordance correlation coefficient (CCC) and other tests.

RESULTS

Among constipated patients, the anal resting (mean CCC [95%CI] 0.62 [0.43-0.76]) and squeeze pressures (CCC 0.65 [0.47-0.79]), rectoanal gradient during evacuation (CCC 0.42 [0.17-0.62]), and rectal sensory thresholds (CCC for urgency 0.72 [0.52-0.84]) were concordant. Between days 1 and 2, one or more outcomes, characterized as normal or abnormal, differed in 79% of constipated patients, i.e., anal resting and squeeze pressures, the gradient, and the rectal BET differed in, respectively, 25%, 19%, 36%, and 10% of constipated patients. The rectal BET was prolonged in three healthy persons (both days) and either on 1 day (six patients) or 2 days (33 patients) in constipated patients.

CONCLUSIONS

While HR_ARM variables and the BET are reproducible within healthy and constipated persons, the outcome on repeat testing differed in 79% of constipated patients.

Automated extraction of anorectal pressures from high-resolution manometry reports

BACKGROUND

During high-resolution anorectal manometry (HR_ARM), the raw data are converted into software-derived summary variables (e.g., rectoanal gradient during evacuation) that capture only a snapshot of the data collected during HR_ARM and are less useful than newer indices, which are also derived from the raw data, for diagnosing defecatory disorders (DD). However, it is cumbersome and time-consuming to extract raw data from the program and calculate such indices. This study aimed to devise a user-friendly approach to extract anorectal pressures measured with HR_ARM.

METHODS

Anorectal pressures at rest, during anal squeeze, and evacuation were measured with HR_ARM in 180 women, among whom 60 each were healthy, had DD, or fecal incontinence. A reverse engineering approach extracted pressure values from color images in HR_ARM reports. The summary variables generated by the software and a reverse engineering approach were compared with Lin's concordance correlation coefficient (CCC), paired t-tests, and Bland-Altman's tests.

RESULTS

Anorectal pressures summarized by the software and a reverse engineering method were highly concordant for anal resting (CCC [95% CI], 0.98 [0.97, 0.99]) and squeeze pressures (0.99 [0.99, 0.99) and the rectoanal gradient during evacuation with an empty (0.98 [0.97, 0.98]) and a filled balloon (0.99 [0.99, 0.99]). For most variables, the paired t and Bland-Altman comparisons were not significant.

CONCLUSIONS

Anorectal pressures can be accurately determined from pressure topography images in HR_ARM reports. In future, this reverse engineering approach can be harnessed to compile large HR_ARM datasets across centers and to uncover newer, potentially more useful summary rectoanal pressure variables.

Review of the indications, methods, and clinical utility of anorectal manometry and the rectal balloon expulsion test

BACKGROUND

Anorectal manometry (ARM) comprehensively assesses anorectal sensorimotor functions.

PURPOSE

This review examines the indications, techniques, interpretation, strengths, and weaknesses of high-resolution ARM (HR-ARM), 3-dimensional high-resolution anorectal manometry (3D-HR-ARM), and portable ARM, and other assessments (i.e., rectal sensation and rectal balloon expulsion test) that are performed alongside manometry. It is based on a literature search of articles related to ARM in adults. HR-ARM and 3D-HR-ARM are useful for diagnosing defecatory disorders (DD), to identify anorectal sensorimotor dysfunction and guide management in patients with fecal incontinence (FI), constipation, megacolon, and megarectum; and to screen for anorectal structural (e.g., rectal intussusception) abnormalities. The rectal balloon expulsion test is a useful, low-cost, radiation-free, outpatient assessment tool for impaired evacuation that is performed and interpreted in conjunction with ARM. The anorectal function tests should be interpreted with reference to age- and sex-matched normal values, clinical features, and results of other tests. A larger database of technique-specific normal values and newer paradigms of analyzing anorectal pressure profiles will increase the precision and diagnostic utility of HR-ARM for identifying abnormal mechanisms of defecation and continence.

Faecal incontinence in adults

Faecal incontinence, which is defined by the unintentional loss of solid or liquid stool, has a worldwide prevalence of ≤7% in community-dwelling adults and can markedly impair quality of life. Nonetheless, many patients might not volunteer the symptom owing to embarrassment. Bowel disturbances, particularly diarrhoea, anal sphincter trauma (obstetrical injury or previous surgery), rectal urgency and burden of chronic illness are the main risk factors for faecal incontinence; others include neurological disorders, inflammatory bowel disease and pelvic floor anatomical disturbances. Faecal incontinence is classified by its type (urge, passive or combined), aetiology (anorectal disturbance, bowel symptoms or both) and severity, which is derived from the frequency, volume, consistency and nature (urge or passive) of stool leakage. Guided by the clinical features, diagnostic tests and therapies are implemented stepwise. When simple measures (for example, bowel modifiers such as fibre supplements, laxatives and anti-diarrhoeal agents) fail, anorectal manometry and other tests (endoanal imaging, defecography, rectal compliance and sensation, and anal neurophysiological tests) are performed as necessary. Non-surgical options (diet and lifestyle modification, behavioural measures, including biofeedback therapy, pharmacotherapy for constipation or diarrhoea, and anal or vaginal barrier devices) are often effective, especially in patients with mild faecal incontinence. Thereafter, perianal bulking agents, sacral neuromodulation and other surgeries may be considered when necessary.