The effect of standard compared to enhanced instruction and verbal feedback on anorectal manometry measurements

Study on 3D High-Resolution Anorectal Manometry Interrater Agreement in the Evaluation of Dyssynergic Defecation Disorders

Anorectal manometry measurements exhibit significant interrater variability. Newer techniques like 3D high-resolution anorectal manometry (3D-HRAM) have the potential to enhance diagnostic accuracy and our understanding of defecation disorders. However, the extent of interrater variability in 3D-HRAM is still unknown. Between January 2020 to April 2022, patients referred for pelvic floor physical therapy (PFPT) due to functional defecation complaints underwent 3D-HRAM testing. In a retrospective analysis, three expert raters independently evaluated the 3D-HRAM results in a blinded matter to assess interrater agreement. The evaluation also determined the level of agreement concerning dyssynergic patterns during simulated defecation. The 3D-HRAM results of 50 patients (37 females) were included. Twenty-nine patients had complaints of fecal incontinence, eleven patients had chronic constipation, and ten patients had several other complaints. There was a substantial agreement (kappa 0.612) between the raters concerning the 3D images on dyssynergic patterns during simulated defecation. Our study emphasizes the need for standardized guidelines in evaluating 3D-HRAM test results to reduce subjectivity and further improve agreement among raters. Implementing these guidelines could improve diagnostic consistency and enhance personalized treatment strategies, increasing the reliability and usefulness of 3D-HRAM testing in clinical practice.

Results of Anorectal Physiological Testing in Patients with Limited English Proficiency

BACKGROUND

Patients with limited English proficiency (LEP) experience barriers to healthcare. These include language barriers and difficulty accessing medical subspecialties. Consequently, patients with LEP may be underrepresented, and may be more likely to have abnormal results, among individuals referred for anorectal testing.

AIMS

To explore whether differences exist in the results of high-resolution anorectal manometry (HRM), rectal sensory testing (RST), and balloon expulsion testing (BET) between patients with LEP and English proficiency (EP).

METHODS

The electronic health records at Mayo Clinic, Rochester were used to identify constipated patients without organic anorectal disease who had undergone anorectal testing in 2018, 2019, and 2020. The language spoken by the patients was determined. HRM, RST, and BET results were compared. Nominal logistic regression explored the influence of age, gender, test operator, and LEP on the likelihood of abnormal findings.

KEY RESULTS

Among 3298 patients (80% female, mean age ± standard deviation 46 ± 16 years), 67 (2%) had LEP. HRM measurements were similar in LEP and EP patients. However, LEP patients were more likely to have abnormal BET and RST. Logistic regression revealed that age (older than 50 years), gender, test operator, and LEP influenced the results of BET and RST, with LEP having the strongest influence.

CONCLUSIONS

Results of anorectal testing in constipated patients differ between LEP and EP patients. This is likely to represent a difference in disease prevalence between these groups, for example, due to referral bias, rather than a difference in physiology or a language barrier.

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.

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.

Retrospective evaluation of operator bias in the performance of high-resolution anorectal manometry

BACKGROUND

Measurements obtained during high-resolution anorectal manometry (HRM) are subject to operator-patient interactions. For example, standardized enhanced instruction delivered by a single operator in a test-retest fashion did not consistently increase pressures generated during dynamic maneuvers. It is probable that factors other than verbal instruction effect communication during the procedure. To investigate this hypothesis, we retrospectively examined inter-operator variance in HRM results.

METHODS

The electronic health records at Mayo Clinic, Rochester, were used to identify patients who had undergone HRM in 2019 and 2020. The analysis focused on constipated patients. The instructions given to the patients they had examined, and the pressure measurements obtained during HRM, by 6 different nurse operators were compared.

KEY RESULTS

When performing HRM on their individual patients (range 126-673), the 6 nurses used similar instructions for each of the maneuvers and sensory testing thresholds. The proportion of patients with prolonged balloon expulsion tests and the rectal sensory thresholds were similar among operators. Significant variance was seen in the mean rectoanal pressures at rest, during squeeze, and during dynamic maneuvers. The proportion of patients with manometry results suggestive of a defecatory disorder differed between operators by 18% and 28% in women <50 and >50 years old, respectively.

CONCLUSIONS & INFERENCES

Operators obtain significantly different results during HRM despite using similar instructions to patients. Substantial differences in the proportion of patients with manometry findings suggestive of a defecatory disorder among operators may have a significant impact on the diagnoses and therapies offered to constipated patients.

Anorectal dysfunction in multiple sclerosis patients: A pilot study on the effect of an individualized rehabilitation approach

BACKGROUND:

Anorectal dysfunction (ARD), especially bowel incontinence, frequently compromises the quality of life in multiple sclerosis (MS) patients. The effect of rehabilitation procedures has not been clearly established.

OBJECTIVE:

To determine the effect of an individualized rehabilitation approach on bowel incontinence and anorectal pressures.

METHODS:

MS patients with ARD underwent 6-months of individually targeted biofeedback rehabilitation. High resolution anorectal manometry (HRAM) and St. Mark’s Fecal Incontinence Scores (SMIS) were completed prior to rehabilitation, after 10 weeks of supervised physiotherapy, and after 3 months of self-treatment.

RESULTS:

Ten patients (50%) completed the study. Repeated measures analysis of variance (ANOVA) demonstrated significant improvement in the SMIS questionnaire over time [14.00 baseline vs. 9.70 after supervised physiotherapy vs. 9.30 after self-treatment (p = 0.005)]. No significant improvements over time were noted in any HRAM readings: maximal pressure [49.85 mmHg baseline vs. 57.60 after supervised physiotherapy vs. 60.88 after self-treatment (p = 0.58)], pressure endurance [36.41 vs. 46.89 vs. 49.95 (p = 0.53)], resting pressure [55.83, vs 52.69 vs. 51.84 (p = 0.704)], or area under the curve [230.0 vs. 520.8 vs. 501.9 (p = 0.16)].

CONCLUSIONS:

The proposed individualized rehabilitation program supports a positive overall effect on anorectal dysfunction in MS patients.

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

INTRODUCTION

Anorectal manometry (ARM) provides comprehensive assessment of pressure activity in the rectum and anal canal. Absolute pressure values might depend on the catheter used.

OBJECTIVE

Our aim was to compare the results obtained by different anorectal catheters in children with functional anorectal disorders.

METHODS

Children diagnosed with functional defecation disorders based on the Rome IV criteria were prospectively enrolled. ARM was performed in the supine position successively using 2 different probes in each patient in random order. Resting, squeeze pressures, and bear-down maneuver variables obtained by high-resolution (2-dimensional [2D]) and high-definition (3-dimensional [3D]) catheters were compared.

RESULTS

We prospectively included 100 children {mean age 7.5 [standard deviation (SD) ± 4.3] years; 62 boys}. Mean resting pressures were significantly higher when measured with the 3D than with the 2D catheter (71 [SD ± 19.4] vs. 65 [SD ± 20.1] mm Hg, respectively; p = 0.000). Intrarectal pressure measured by 3D and 2D catheters was similar (35 vs. 39 mm Hg, respectively; p = 0.761), but the percent of anal relaxation appeared to be higher for the 3D than for the 2D probe (12 vs. 5%, respectively; p = 0.002). Dyssynergic defecation (DD) was diagnosed in 41/71 patients (57.7%) using the 3D probe and in 51/71 children (71.8%) using the 2D probe (p = 0.044). Cohen's kappa showed only fair agreement between the catheters (κ = 0.40) in diagnosis of DD.

CONCLUSIONS

Our study demonstrated significantly different values of pressures obtained with different types of catheters. Normal ranges for conventional manometry cannot be applied to high-resolution systems, and results obtained by different types of manometry cannot be compared without adjustments (NCT02812823).

ANORECTAL MANOMETRY STANDARD OF A BRAZILIAN POPULATION AT PRODUCTIVE AGE WITHOUT PELVIC FLOOR DISORDERS: A PROSPECTIVE VOLUNTEERED STUDY

Background:

Due to the lack of normal standards of anorectal manometry in Brazil, data used are subject to normality patterns described at different nationalities.

Aim:

To determine the values and range of the parameters evaluated at anorectal manometry in people, at productive age, without pelvic floor disorders comparing the parameters obtained between male and female.

Methods:

Prospective analysis of clinical data, such as gender, age, race, body mass index (BMI) and anorectal manometry, of volunteers from a Brazilian university reference in pelvic floor disorders.

Results:

Forty patients were included, with a mean age of 45.5 years in males and 37.2 females (p=0.43). According to male and female, respectively in mmHg, resting pressures were similar (78.28 vs. 63.51, p=0.40); squeeze pressures (153.89 vs. 79.78, p=0.007) and total squeeze pressures (231.27 vs. 145.63, p=0.002). Men presented significantly higher values of anorectal squeeze pressures, as well as the average length of the functional anal canal (2.85 cm in male vs. 2.45 cm in female, p=0.003).

Conclusions:

Normal sphincter pressure levels in Brazilians differ from those used until now as normal literature standards. Male gender has higher external anal sphincter tonus as compared to female, in addition a greater extension of the functional anal canal

[Recommendations for the Protocol of functional examination of the anorectal zone and disorders classification: the International Anorectal Physiology Working Group consensus and Russian real-world practice]

This manuscript summarizes consensus reached by the International Anorectal Physiology Working Group (IAPWG) for the performance, terminology used, and interpretation of anorectal function testing including anorectal manometry (focused on high-resolution manometry), the rectal sensory test, and the balloon expulsion test. Based on these measurements, a classification system for disorders of anorectal function is proposed. Aim to provide information about methods of diagnosis and new classification of functional anorectal disorders to a wide range of specialists general practitioners, therapists, gastroenterologists, coloproctologists all who face the manifestations of these diseases in everyday practice and determine the diagnostic and therapeutic algorithm. Current paper provides agreed statements of IAPWG Consensus and comments (in italics) of Russian experts on real-world practice, mainly on methodology of examination. These comments in no way intended to detract from the provisions agreed by the international group of experts. We hope that these comments will help to improve the quality of examination based on the systematization of local experience with the use of the methods discussed and the results obtained. Key recommendations: the International Anorectal Physiology Working Group protocol for the performance of anorectal function testing recommends a standardized sequence of maneuvers to test rectoanal reflexes, anal tone and contractility, rectoanal coordination, and rectal sensation. Major findings not seen in healthy controls defined by the classification are as follows: rectoanal areflexia, anal hypotension and hypocontractility, rectal hyposensitivity, and hypersensitivity. Minor and inconclusive findings that can be present in health and require additional information prior to diagnosis include anal hypertension and dyssynergia.

Dyssynergic patterns of defecation in constipated adolescents and young adults with anorectal malformations

We aimed to evaluate the etiologies of constipation in patients with anorectal malformations having a good prognosis for bowel control but a high risk of constipation. We included twenty-five patients from the Odense university hospital in Denmark. Patients were subjected to colon transit time examination and high resolution anorectal manometry (HRAM). The median age was 18 (14–24) and 48% (12/25) were females. Fifty-two % (13/25) of patients were diagnosed with constipation. Types of anorectal malformation were perineal fistula (9/25), rectovestibular fistula (8/25), rectourethral bulbar fistula (5/25) and no fistula (3/25). No difference in neither total colon transit time nor segmental colon transit times were found based on the presence of constipation. Only four of the constipated patients fulfilled criteria for dyssynergic defecation with a dyssynergic pattern at HRAM and prolonged colon transit time. A Type I dyssynergic pattern was dominant in constipated patients (7/13). A Dyssynergic defecation pattern was due to isolated contraction of puborectalis muscle in 9 out of 13constipated patients. We found a dyssynergic pattern during attempted defecation in patients with anorectal malformations disregarded the presence of constipation. In the majority of constipated patients an isolated contraction of the puborectalis muscle was visualized with HRAM.

Comparison between high-resolution water-perfused anorectal manometry and THD® Anopress anal manometry: a prospective observational study

AIM

Anorectal physiology tests provide a functional assessment of the anal canal. The aim of this study was to compare the results generated by standard high-resolution water-perfused manometry (WPM) with the newer THD^® Anopress manometry system.

METHOD

This was a prospective observational study. Conventional manometry was carried out using a water-perfused catheter with high-resolution manometry and compared with the Anopress system with air-filled catheters. All patients underwent the two procedures successively in a randomized order. Time to arrive at the resting pressure plateau, resting, squeeze, straining pressure and visual analogue scale (VAS) scores for pain were recorded. A qualitative analysis of the two devices was performed.

RESULTS

Between 2016 and 2017, 60 patients were recruited. The time from insertion of the catheter to arriving at the resting pressure plateau was significantly lower with the Anopress compared with WPM: 12 s [interquartile range (IQR) 10-17 s] versus 100 s (IQR 67-121 s) (P < 0.001). A strong correlation between the manometric values of WPM and the Anopress was observed. Both procedures were well tolerated, although the VAS score for insertion of the WPM catheter was significantly higher. The Anopress was easier to use and more time-efficient than the WPM.

CONCLUSION

The pressure values obtained with Anopress correlated well with those of conventional manometry. The Anopress has the advantage of being less time-consuming, user-friendly and better tolerated by patients.

Tools for fecal incontinence assessment: lessons for inflammatory bowel disease trials based on a systematic review

BACKGROUND

Fecal incontinence is a disabling condition affecting up to 20% of women.

OBJECTIVE

We investigated fecal incontinence assessment in both inflammatory bowel disease and non-inflammatory bowel disease patients to propose a diagnostic approach for inflammatory bowel disease trials.

METHODS

We searched on Pubmed, Embase and Cochrane Library for all studies on adult inflammatory bowel disease and non-inflammatory bowel disease patients reporting data on fecal incontinence assessment from January 2009 to December 2019.

RESULTS

In total, 328 studies were included; 306 studies enrolled non-inflammatory bowel disease patients and 22 studies enrolled inflammatory bowel disease patients. In non-inflammatory bowel disease trials the most used tools were the Wexner score, fecal incontinence quality of life questionnaire, Vaizey score and fecal incontinence severity index (in 187, 91, 62 and 33 studies). Anal manometry was adopted in 41.2% and endoanal ultrasonography in 34.0% of the studies. In 142 studies (46.4%) fecal incontinence evaluation was performed with a single instrument, while in 64 (20.9%) and 100 (32.7%) studies two or more instruments were used. In inflammatory bowel disease studies the Wexner score, Vaizey score and inflammatory bowel disease quality of life questionnaire were the most commonly adopted tools (in five (22.7%), five (22.7%) and four (18.2%) studies). Anal manometry and endoanal ultrasonography were performed in 45.4% and 18.2% of the studies.

CONCLUSION

Based on prior validation and experience, we propose to use the Wexner score as the first step for fecal incontinence assessment in inflammatory bowel disease trials. Anal manometry and/or endoanal ultrasonography should be taken into account in the case of positive questionnaires.

Improvement of Patient Satisfaction and Anorectal Manometry Parameters After Biofeedback Therapy in Patients with Different Types of Dyssynergic Defecation

Biofeedback is a well-known and effective treatment for patients with fecal evacuation disorder (FED). The main purpose of this study was to investigate the outcome and the effects of biofeedback therapy on physiological parameters as assessed by manometry in patients with FED. Data from 114 consecutive patients with FED who underwent biofeedback therapy in Sara Gastrointestinal clinic in Tehran, Iran during 2015-2018 were retrospectively reviewed and analyzed. All participants underwent a comprehensive evaluation of anorectal function that included anorectal manometry and a balloon expulsion test at the baseline and after biofeedback therapy. Maximum anal squeeze pressure and sustained anal squeeze pressure were improved up to 100% and 94.7% of normal values in the patients after biofeedback, respectively (P < 0.001). First rectal sensation, was significantly decreased (25 ± 18.5 vs. 15.5 ± 5.2) while the maximum tolerable volume was significantly increased (233.6 ± 89.7 vs. 182.4 ± 23.1) after biofeedback therapy (P < 0.001). Type I dyssynergia was the most common type, effecting 82 cases (71.9%) of our patients. Dyssynergia parameters were improved 50-80% in 34 (41.5%) and 10 (31.3%) type I and non-type I patients, respectively. Over 80% improvement of dyssynergia parameters occurred in 48 (58.5%) and 22 (68.8%) type I and non-type I patients, respectively. These differences were not statistically significant between the two groups (P = 0.3). In addition, the ability to reject the balloon was significantly better in post intervention measurements (P < 0.001). Biofeedback not only improves the symptoms in patients of FED but also reverses more than 80% the dyssynergic parameters of defecation. However, due to the general effectiveness of biofeedback treatment in different types of DD, there were no significant differences between their improvement scores.

Anorectal pressures measured with high-resolution manometry in healthy people-Normal values and asymptomatic pelvic floor dysfunction

BACKGROUND

High-resolution manometry (HRM) is used to measure rectoanal pressures in defecatory disorders and fecal incontinence. This study sought to define normal values for rectoanal HRM, ascertain the effects of age and BMI on rectoanal pressures, and compare pressures in asymptomatic women with normal and prolonged balloon expulsion time (BET).

METHODS

High-resolution manometry pressures and BET were measured in 163 asymptomatic healthy participants. Women (96) and men (47) with normal BET were used to estimate normal values and the effects of age/BMI on pressures using a Medtronic 4.2-mm-diameter rectoanal catheter.

KEY RESULTS

Age is associated with lower resting pressure, higher rectal pressure during evacuation, and a higher rectoanal gradient during evacuation in women and men. In women, the BET is also inversely correlated with age while the BMI is correlated with a higher threshold volume for discomfort and a longer BET. The anal squeeze pressure increment, squeeze duration, and HPZ length are higher in men than women. The rectoanal gradient during evacuation is also lower (ie, more negative) in asymptomatic women with an abnormal than a normal BET.

CONCLUSIONS & INFERENCES

These findings provide an expanded database of normal values for anorectal HRM in men and women. Age and sex affect anal resting and squeeze pressures, respectively; rectal pressure during evacuation is also higher in older people. Less than 15% of asymptomatic people have BET >60 seconds, which is associated with manometry features of impaired evacuation.

Three-dimensional high-resolution anorectal manometry in functional anorectal disorders: results from a large observational cohort study

BACKGROUND

The aim of the study was to describe the results of 3D high-resolution anorectal manometry (3DHRAM) in a large cohort of patients with functional anorectal disorders.

METHODS

In this single-center retrospective study, all consecutive patients referred for investigation of fecal incontinence (FI) or dyssynergic defecation (DD) underwent 3DHRAM. The parameters analyzed were usual manometric data, repartition of dyssynergic patterns, and the prevalence of a new "muscular subtype classification" underlying dyssynergia, anal sphincter defects, and pelvic floor disorders.

RESULTS

Final analyses were performed in 1477 patients with a mean age 54 ± 16 years; 825 patients suffered from DD, and 652 patients suffered from FI. Among these patients, 86% met the diagnostic criteria for dyssynergia. Type II dyssynergia was the most frequently observed (56%) in women and men suffering from FI and in women with DD. Type I was the most frequently observed in men with DD (49%). Regarding the muscle type subgroups, combined puborectalis muscle involvement with an external anal sphincter profile was the most frequently observed. The global prevalence of rectal intussusception and excessive perineal descent were 12% and 21%, respectively. Type III dyssynergia was more frequently associated with pelvic floor disorders than were other types of dyssynergia (p < 0.001).

CONCLUSION

This large cohort study provides reference values for 3DHRAM in patients with functional anorectal disorders. Further studies are necessary to assess the prevalence of pelvic floor disorders in healthy volunteers and to develop new scores and classifications including all of these new parameters.

Anal sphincter function as assessed by 3D high definition anorectal manometry

PURPOSE

High resolution anorectal manometry has been developed over the past years, as well as 3D high definition manometry (HDARM). However, the clinical impact of the results obtained with these new technologies remains to be determined. We thus analyzed various HDARM parameters of anal sphincter function and tested their capacity to discriminate between patients with constipation and those with fecal incontinence.

METHODS

One hundred and fourteen consecutive patients underwent the same HDARM protocol (Medtronic), including 2 short duration voluntary anal contractions (5seconds) and 1 sustained (as long as possible) contraction. Various parameters evaluating the anal sphincter function were measured, based on automatic software analysis and Smartmouse™ item of the software; resting anal pressures, anal pressures and incremental pressures during voluntary squeeze and cough anal reflex. The ability of these parameters to discriminate between patients with fecal incontinence and chronic constipation was assessed using areas under the curves of ROC curves.

RESULTS

All parameters were highly correlated. The most discriminant variable was found to be the mean anal pressure during sustained squeeze. The 3D lambda aspect of the anal sphincter during voluntary contraction was as frequently absent in both groups of patients (13% in patients with chronic constipation, versus 23% in those with fecal incontinence, P=0.18). There was a significant correlation between the fecal incontinence Wexner score and the voluntary anal contraction variables.

CONCLUSIONS

Several parameters to assess the quality of voluntary anal contraction have been proposed. We observed with HDARM that the most discriminant parameter was the mean anal pressure during sustained squeeze. This may help to standardize and simplify HDARM protocols.

Evaluation of 153 Asymptomatic Subjects Using the Anopress Portable Anal Manometry Device

Background/Aims

The Anopress device is a new portable manometry system. The aim of this study is to formulate normative data using this new device by recording the anorectal function of asymptomatic subjects. Patient comfort was also assessed.

Methods

Anorectal function was assessed in asymptomatic volunteers using the Anopress. All volunteers were examined in a standardized way in accordance with the study protocol. Normative values for the Anopress were obtained from the recorded data and patient comfort was assessed using a visual analogue scale.

Results

We recruited 153 healthy volunteers. Eighty were female (23 parous; median age 39.5 [interquartile range {IQR}, 28.75–53.00]) and 73 were male (median age 40.5 [IQR, 29.00–52.25]). For the female cohort, the following normal range (2.5–97.5 percentile) values were recorded across the whole anal canal: resting pressure 40.0–103.0 mmHg; squeeze increment 35.0–140.6 mmHg; endurance 1.3–9.0 seconds; involuntary squeeze 41.1–120.8 mmHg; and strain pressure 22.1–77.9 mmHg. Similarly, the following male normal range (2.5–97.5 percentile) values were recorded across the whole anal canal: resting pressure 38.3–99.6 mmHg; squeeze increment 42.5–154.8 mmHg; involuntary squeeze 40.0–123.6 mmHg; endurance 2.0–10.0 seconds; and strain pressure 11.0–72.1 mmHg. The median visual analogue scale scores for discomfort during the measurement was 0.0 (IQR, 0.00–0.00).

Conclusions

Normative values for the Anopress device have been calculated by this study. The Anopress appears to be a safe and well tolerated way of measuring pressures from the entire anal canal. Further comparisons with other standard and commonly used manometry tests are, however, required to verify its reliability.

Update on the Pathophysiology and Management of Anorectal Disorders

Anorectal disorders are common and present with overlapping symptoms. They include several disorders with both structural and functional dysfunction(s). Because symptoms alone are poor predictors of the underlying pathophysiology, a diagnosis should only be made after evaluating symptoms and physiologic and structural abnormalities. A detailed history, a thorough physical and digital rectal examination and a systematic evaluation with high resolution and/or high definition three-dimensional (3D) anorectal manometry, 3D anal ultrasonography, magnetic resonance defecography and neurophysiology tests are essential to correctly identify these conditions. These physiological and imaging tests play a key role in facilitating a precise diagnosis and in providing a better understanding of the pathophysiology and functional anatomy. In turn, this leads to better and more comprehensive management using medical, behavioral and surgical approaches. For example, patients presenting with difficult defecation may demonstrate dyssynergic defecation and will benefit from biofeedback therapy before considering surgical treatment of coexisting anomalies such as rectoceles or intussusception. Similarly, patients with significant rectal prolapse and pelvic floor dysfunction or patients with complex enteroceles and pelvic organ prolapse may benefit from combined behavioral and surgical approaches, including an open, laparoscopic, transabdominal or transanal, and/or robotic-assisted surgery. Here, we provide an update on the pathophysiology, diagnosis, and management of selected common anorectal disorders.

High-resolution anorectal manometry: A comparison of solid-state and water-perfused catheters

BACKGROUND

Anorectal manometry is the most commonly performed investigation for assessment of anorectal dysfunction. Findings from previous studies comparing water-perfused (WP) and solid-state (SS) techniques in the anorectum are conflicting. We compared anal sphincter pressure at rest and during dynamic maneuvers (squeezing and coughing) in healthy volunteers using SS and WP high-resolution anorectal manometry (HR-ARM) employing equivalent catheter configurations, a standardized protocol, and identical data acquisition and analysis software.

METHODS

Sixty healthy volunteers (40F; median age: 40; range: 18-74) underwent WP and SS HR-ARM in randomized order. Anal resting pressure, and squeeze and cough increments were measured. Median pressure and 5th and 95th percentiles were calculated for each maneuver and compared using Wilcoxon signed-rank test. Bland and Altman plots were used to assess agreement between the systems. The impact of gender and parity was also explored.

KEY RESULTS

Anal sphincter pressure measurements during squeeze (P<.001) and cough (P<.001) were significantly higher using SS HR-ARM than WP HR-ARM. No differences were seen at rest between the two types of catheter (nulliparous: P=.304; parous: P=.390; males: P=.167). Normal ranges for SS and WP manometry from this small group of healthy volunteers are presented.

CONCLUSIONS & INFERENCES

Greater sensitivity to rapid pressure change is one of the advantages associated with SS HR-ARM. This is reflected in the differences observed during dynamic maneuvers performed during this study. Catheter type should be taken into consideration when selecting normal ranges for comparison to disease states.

Review article: dyssynergic defaecation and biofeedback therapy in the pathophysiology and management of functional constipation

BACKGROUND

Functional constipation is a common clinical presentation in primary care. Functional defaecation disorders are defined as the paradoxical contraction or inadequate relaxation of the pelvic floor muscles during attempted defaecation (dyssynergic defaecation) and/or inadequate propulsive forces during attempted defaecation. Prompt diagnosis and management of dyssynergic defaecation is hindered by uncertainty regarding nomenclature, diagnostic criteria, pathophysiology and efficacy of management options such as biofeedback therapy.

AIM

To review the evidence pertaining to the pathophysiology of functional defaecation disorders and the efficacy of biofeedback therapy in the management of patients with dyssynergic defaecation and functional constipation.

METHODS

Relevant articles addressing functional defaecation disorders and the efficacy of biofeedback therapy in the management of dyssynergic defaecation and functional constipation were identified from a search of Pubmed, MEDLINE Ovid and the Cochrane Library.

RESULTS

The prevalence of dyssynergic defaecation in patients investigated for chronic constipation is as many as 40%. Randomised controlled trials have demonstrated major symptom improvement in 70%-80% of patients undergoing biofeedback therapy for chronic constipation resistant to standard medical therapy and have determined it to be superior to polyethylene glycol laxatives, diazepam or sham therapy. Long-term studies have shown 55%-82% of patients maintain symptom improvement.

CONCLUSIONS

Dyssynergic defaecation is a common clinical condition in patients with chronic constipation not responding to conservative management. Biofeedback therapy appears to be a safe, successful treatment with sustained results for patients with dyssynergic defaecation. Further studies are required to standardise the diagnosis of dyssynergic defaecation in addition to employing systematic protocols for biofeedback therapy.

Methods of anorectal manometry vary widely in clinical practice: Results from an international survey

BACKGROUND

Ano-rectal manometry (ARM) is the most commonly performed investigation for assessment of anorectal dysfunction. Its use is supported by expert consensus documents and international guidelines. Variation in technology, data acquisition, and analysis affect results and clinical interpretation. This study examined variation in ARM between institutions to establish the status of current practice.

METHODS

A 50-item web-based questionnaire assessing analysis and interpretation of ARM was distributed by the International Anorectal Physiology Working Group via societies representing practitioners that perform ARM. Study methodology and performance characteristics between institutions were compared.

KEY RESULTS

One hundred and seven complete responses were included from 30 countries. Seventy-nine (74%) institutions performed at least two studies per week. Forty-nine centers (47%) applied conventional ARM (≤8 pressure sensors) and 57 (53%) high-resolution ARM (HR-ARM). Specialist centers were most likely to use HR-ARM compared to regional hospitals and office-based practice (63% vs 37%). Most conventional ARM systems used water-perfused technology (34/49); solid-state hardware was more frequently used in centers performing HR-ARM (44/57). All centers evaluated rest and squeeze. There was marked variation in the methods used to report results of maneuvers. No two centers had identical protocols for patient preparation, setup, study, and data interpretation, and no center fully complied with published guidelines.

CONCLUSIONS & INFERENCES

There is significant discrepancy in methods for data acquisition, analysis, and interpretation of ARM. This is likely to impact clinical interpretation, transfer of data between institutions, and research collaboration. There is a need for expert international co-operation to standardize ARM.

High-resolution anorectal manometry: An expensive hobby or worth every penny?

Introduced approximately 10 years ago, high-resolution manometry catheters have fostered interest in anorectal manometry. This review, which accompanies two articles in this issue of Neurogastroenterology and Motility, reviews the methods, clinical indications, utility, and pitfalls of anorectal manometry and revisits the American Gastroenterological Association (AGA) Medical Position Statement on Anorectal Testing Techniques, which was last published in 1999. High-resolution manometry provides a refined assessment of the anorectal pressure profile, obviates the need for station pull-through maneuvers, and minimizes movement artifacts. In selected cases, this refined assessment may be useful for identifying structural abnormalities or anal weakness. However, many manometry patterns that were previously regarded as abnormal are also observed in a majority of healthy patients, which substantially limits the utility of manometry for identifying defecatory disorders. It is our impression that most conclusions of the AGA medical position statement from 1999 remain valid today. High-resolution techniques have not substantially affected the number of publications on or management of anorectal disorders. The ongoing efforts of an international working group to standardize techniques for anorectal manometry are welcome. Although high-resolution manometry is more than an expensive hobby, improvements in catheter design and further research to rigorously define and evaluate these techniques are necessary to determine if they are worth every penny.

Values From Three-dimensional High-resolution Anorectal Manometry Analysis of Children Without Lower Gastrointestinal Symptoms

BACKGROUND & AIMS

Three-dimensional high-resolution anorectal manometry (3DHRAM) provides a topographic image of pressure along the anal canal. We aimed to determine normal 3DHRAM values in children.

METHODS

We performed a prospective study of 61 children (34 male; mean age, 8.28 years) without any symptoms arising from the lower gastrointestinal tract who were evaluated at the Department of Pediatric Gastroenterology and Nutrition, Medical University of Warsaw, Poland. Manometry procedures were performed by using a rigid probe without medication. Pressure within the anal canal and 3D images of sphincters were measured. If possible, squeeze pressure and thresholds of sensation were evaluated. The population was divided into age groups of <5 years, 5-8 years, 9-12 years, and older than 12 years.

RESULTS

The mean resting and squeeze sphincter pressures were 83 ± 23 mm Hg and 191 ± 64 mm Hg, respectively. The mean length of the anal canal was 2.62 ± 0.68 cm and correlated with age (r = 0.49, P < .0001). The mean rectal balloon volume to elicit rectoanal inhibitory reflex was 15.7 ± 10.9 cm(3). The first sensation, urge, and discomfort were observed at balloon volumes of 24.4 ± 23.98 cm(3), 45.9 ± 34.55 cm(3), and 91.6 ± 50.17 cm(3), respectively. The mean resting pressure of the puborectalis muscle was 69 ± 14 mm Hg, whereas the mean squeeze pressure was 124 ± 33 mm Hg. There was no statistically significant difference in pressure parameters between age groups. We observed a positive correlation between age and balloon volume needed to elicit discomfort (r = 0.49, P < .001).

CONCLUSIONS

In a prospective study, we determined normal values from 3DHRAM analysis of children without symptoms arising from the lower gastrointestinal tract. There were no significant differences in pressure results between children of different sexes or ages. ClinicalTrials.gov number: NCT02236507.

Diagnosis and Treatment of Dyssynergic Defecation

Dyssynergic defecation is common and affects up to one half of patients with chronic constipation. This acquired behavioral problem is due to the inability to coordinate the abdominal and pelvic floor muscles to evacuate stools. A detailed history, prospective stool diaries, and a careful digital rectal examination will not only identify the nature of bowel dysfunction, but also raise the index of suspicion for this evacuation disorder. Anorectal physiology tests and balloon expulsion test are essential for a diagnosis. Newer techniques such as high-resolution manometry and magnetic resonance defecography can provide mechanistic insights. Recently, randomized controlled trials have shown that biofeedback therapy is more effective than laxatives and other modalities, both in the short term and long term, without side effects. Also, symptom improvements correlated with changes in underlying pathophysiology. Biofeedback therapy has been recommended as the first-line of treatment for dyssynergic defecation. Here, we provide an overview of the burden of illness and pathophysiology of dyssynergic defecation, and how to diagnose and treat this condition with biofeedback therapy.

How to Perform and Interpret a High-resolution Anorectal Manometry Test

High-resolution anorectal manometry (HR-ARM) and high-definition anorectal manometry (HD-ARM) catheters have closely spaced water-perfused or solid state circumferentially-oriented pressure sensors that provide much better spatiotemporal pressurization than non-high resolution catheters. This is a comprehensive review of HR-ARM and HD-ARM anorectal manometry catheter systems, the methods for conducting, analyzing, and interpreting HR-ARM and HD-ARM, and a comparison of HR-ARM with non-high resolution anorectal manometry. Compared to non-high resolution techniques, HR-ARM and HD-ARM studies take less time and are easier to interpret. However, HR-ARM and HD-ARM catheters are more expensive and fragile and have a shorter lifespan. Further studies are needed to refine our understanding of normal values and to rigorously evaluate the incremental clinical utility of HR-ARM or HD-ARM compared to non-high resolution manometry.

The use of colonic and anorectal high-resolution manometry and its place in clinical work and in research

BACKGROUND

In the esophagus, high-resolution manometry (HRM) has become a standard diagnostic tool in the investigation of suspected motility disorders. However, at the opposite end of the digestive tract (i.e., the colon and anorectum), the use of HRM still remains in its infancy, with relatively few published studies in the scientific literature. Further, the clinical utility of those studies that have been performed is largely undetermined.

PURPOSE

This review assesses all of the HRM studies published to date from both the colon and anorectum, explores the catheter types used, and attempts to determine the worth of HRM over traditional 'low-resolution' recordings from the same regions. Ultimately, this review addresses whether HRM currently provides information that will benefit patient diagnosis and treatment.

Assessment of Obstructive Defecation by High-Resolution Anorectal Manometry Compared With Magnetic Resonance Defecography

BACKGROUND & AIMS

Patients with obstructive defecation have abnormalities of anorectal function and/or structure. Conventional anorectal manometry (ARM) can identify abnormal function and behavior (dyssynergia); however, agreement between manometry and defecography is only fair. High-resolution (HR)-ARM may improve diagnostic agreement by differentiating pressure effects caused by dyssynergia and obstruction. We compared HR-ARM findings with magnetic resonance (MR) defecography in the clinical assessment of patients with symptoms of obstructive defecation defined by Rome III criteria.

METHODS

HR-ARM (Manoscan AR 360; Given Imaging, Yoqeam, Israel) assessed anal sphincter function and pressure during simulated defecation. Abnormal manometric findings were classified according to the Rao system and compared with MR defecography as the reference standard.

RESULTS

A total of 188 consecutive patients (155 women; age, 19-93 y) with obstructive defecation underwent a full investigation. Compared with patients with dyssynergia on MR imaging (n = 66), patients with structural pathology (n = 87) had lower resting (P < .003) and squeeze pressures (P < .011), but a higher rectoanal pressure gradient (P < .0001) on HR-ARM. High intrarectal pressure with a steep, positive pressure gradient consistent with outlet obstruction on HR-ARM was present in 24 patients with intra-anal intussusception on MR imaging. This pattern was not observed in other patients. Interobserver agreement was substantial for HR-ARM diagnoses (κ = 0.67; 95% confidence interval, 0.559-0.779). Diagnostic accuracy for dyssynergia was 82% compared with MR imaging (sensitivity, 77% [51 of 66]; specificity, 85% [104 of 122]).

CONCLUSIONS

The diagnostic agreement between anorectal HR-ARM and MR defecography is high and pressure measurements accurately identify recto-anal dyssynergia and intra-anal outlet obstruction by structural pathology as causes of obstructive defecation.

High resolution and high definition anorectal manometry and pressure topography: diagnostic advance or a new kid on the block?

The recent development of closely spaced circumferential solid state transducers has paved the way for novel technology that includes high resolution anorectal manometry and topography (HRAM) and 3-D high definition anorectal manometry (HDAM). These techniques are increasingly being used for the assessment of anorectal neuromuscular function. However, whether they constitute a diagnostic advantage or a mere refinement of an old technology is unknown. Unlike the traditional manometry that utilized 3 or 6 unidirectional sensors, the closely spaced circumferential arrangement facilitates superior spatiotemporal mapping of pressures at rest and during various dynamic maneuvers. HDAM can provide knowledge of the three muscles that govern the anal continence namely, the puborectalis, and the internal and external anal sphincters, and can show how they mediate the rectoanal inhibitory reflex and sensorimotor responses and the spatiotemporal orientation of these muscles. Also, anal sphincter defects can be mapped and readily detected using 3-D technology. Similarly, HRAM has facilitated confirmation and development of phenotypes of dyssynergic defecation. Recently, normative data have also been reported with HRAM and HDAM, together with the influence of age, gender, and test instructions. The greater yield of anatomical and functional information may supersede the limitations of costs, fragility, and shorter life-span associated with these new techniques. Thus, HDAM and HRAM are not just new gadgets but constitute a significant and novel diagnostic advance. However, more prospective studies are needed to better define anorectal disorders with these techniques and to confirm their superiority.

Toward more accurate measurements of anorectal motor and sensory function in routine clinical practice: validation of high-resolution anorectal manometry and Rapid Barostat Bag measurements of rectal function

BACKGROUND

Measurements of anorectal function using high-resolution anorectal manometry (HR-ARM) and rectal barostat technology provide more reliable results than standard ARM with an elastic balloon; however, HR-ARM results have not been compared to ARM and standard barostat protocols are impractical in routine clinical practice. The aim of this study was to validate HR-ARM against standard ARM and standard barostat against a novel Rapid Barostat Bag (RBB) measurement and elastic balloon measurements of rectal function.

METHODS

Twenty-six healthy volunteers (15 female, 11 male, 19-52 years) were studied. Measurements of anal function and simulated defecation were compared for 12-sensor HR-ARM and 6-sensor standard ARM using line plots from the same recording. Rectal capacity, compliance, and sensation (volume threshold) were measured by elastic balloon, standard barostat, and RBB methods using stepwise inflation of a 700-mL polyethylene bag to 40 mmHg distension by electronic barostat and handheld syringe monitored by sphygmo-manometer, respectively. Results are reported as mean ± SD. Bland-Altman plots and correlation coefficients (r) for measurements were calculated.

KEY RESULTS

There was excellent agreement between HR- and standard ARM measurements (r > 0.86, <25 mmHg difference) and between standard barostat and RBB measurements of rectal capacity (r = 0.97, <25 mL difference). Correlation coefficients of threshold volumes for initial perception, urgency and discomfort were 0.37, 0.71, and 0.95, respectively. No significant correlation was present with elastic balloon measurements. Time to complete studies was shorter for HR-ARM than standard ARM and for RBB than standard barostat in historical controls.

CONCLUSIONS & INFERENCES

HR-ARM with RBB measurements of anorectal function provides quick and reasonably accurate measurements of continence function suitable for use in routine clinical practice (ClinicalTrial.gov NCT01456442).

Traditional measures of normal anal sphincter function using high-resolution anorectal manometry (HRAM) in 115 healthy volunteers

BACKGROUND

High-resolution anorectal manometry (HRAM) is a relatively new method for collection and interpretation of data relevant to sphincteric function, and for the first time allows a global appreciation of the anorectum as a functional unit. Historically, traditional anal manometry has been plagued by lack of standardization and healthy volunteer data of variable quality. The aims of this study were: (i) to obtain normative data sets for traditional measures of anorectal function using HRAM in healthy subjects and; (ii) to qualitatively describe novel physiological phenomena, which may be of future relevance when this method is applied to patients.

METHODS

115 healthy subjects (96 female) underwent HRAM using a 10 channel, 12F solid-state catheter. Measurements were performed during rest, squeeze, cough, and simulated defecation (push). Data were displayed as color contour plots and analysed using a commercially available manometric system (Solar GI HRM v9.1, Medical Measurement Systems). Associations between age, gender and parity were subsequently explored.

KEY RESULTS

HRAM color contour plots provided clear delineation of the high-pressure zone within the anal canal and showed recruitment during maneuvers that altered intra-anal pressures. Automated analysis produced quantitative data, which have been presented on the basis of gender and parity due to the effect of these covariates on some sphincter functions. In line with traditional manometry, some age and gender differences were seen. Males had a greater functional anal canal length and anal pressures during the cough maneuver. Parity in females was associated with reduced squeeze increments.

CONCLUSIONS & INFERENCES

The study provides a large healthy volunteer dataset and parameters of traditional measures of anorectal function. A number of novel phenomena are appreciated, the significance of which will require further analysis and comparisons with patient populations.

An update on anorectal disorders for gastroenterologists

Gastroenterologists frequently encounter pelvic floor disorders, which affect 10% to 15% of the population. The anorectum is a complex organ that collaborates with the pelvic floor muscles to preserve fecal continence and enable defecation. A careful clinical assessment is critical for the diagnosis and management of defecatory disorders and fecal incontinence. Newer diagnostic tools (eg, high-resolution manometry and magnetic resonance defecography) provide a refined understanding of anorectal dysfunctions and identify phenotypes in defecatory disorders and fecal incontinence. Conservative approaches, including biofeedback therapy, are the mainstay for managing these disorders; new minimally invasive approaches may benefit a subset of patients with fecal incontinence, but more controlled studies are needed. This mini-review highlights advances, current concepts, and controversies in the area.