High-Resolution Anorectal Manometry as a Screening Tool for Hirschsprung's Disease: A Comprehensive Retrospective Analysis

Hirschsprung's disease (HD) is characterized by a congenital absence of enteric ganglion cells in the intestine, posing challenges in diagnosis, particularly in pediatric patients. The gold standard, rectal suction biopsy (RSB), carries risks, prompting an exploration of non-invasive alternatives such as high-resolution anorectal manometry (HR-ARM) for HD screening. We conducted a retrospective analysis of 136 patients suspected of HD between 2018 and 2022, which were stratified into three age groups: ≤12 months, ≤24 months, and >24 months. Criteria for suspicion included delayed meconium passage, unresponsive chronic constipation, and abnormal prior test results. HR-ARM, supplemented by additional tests, confirmed 16 HD cases. HR-ARM exhibited 93.75% sensitivity, 89.47% specificity, 99.03% negative predictive value (NPV), and 55.56% positive predictive value (PPV). Notably, HR-ARM consistently performed well in patients ≤ 2 years old but demonstrated reduced efficacy in older children, which was likely due to complications from chronic constipation. This study underscores HR-ARM's promise as a non-invasive HD screening tool, especially in younger patients. However, its limitations in older children warrant consideration. Establishing standardized protocols, particularly for assessing the recto-anal inhibitory reflex, is crucial. Further research is imperative to optimize HR-ARM's diagnostic role across varied age groups in HD assessment.

Rectal Sensory and Compliance Testing: A Method Comparison Study between High-Resolution Anorectal Manometry and Barostat Investigations

Abnormal visceral perception and motor function are often observed in patients with fecal incontinence, evacuation disorders and irritable bowel syndrome. The international anorectal physiology working group has proposed a standardization for anorectal function assessment, where rectal sensitivity testing is performed using an elastic balloon attached to a high-resolution anorectal manometry (HRAM) catheter. Rectal compliance, another component of rectal function evaluation, is a pressure-volume relationship that refers to the rectum's ability to stretch and expand as it receives and holds fecal matter. There are no data available regarding the possibility of compliance testing using HRAM, although this is theoretically possible by correcting for the elastic balloon's intrinsic properties. The gold standard for measurement of visceral sensitivity and compliance is the rectal barostat, according to the procedure described by the European COST action GENIEUR group. Data on the agreement between the two different procedures are scarce. Hence, we performed a comparative study of the HRAM and barostat investigations in 26 healthy individuals. We hypothesized that by inflating the balloon before the examination, rectal compliance can be measured with HRAM investigations, and we examined correlations and levels of agreement between the methods. Our results demonstrate that assessing rectal compliance with HRAM is technically possible; however, a strong correlation with the rectal barostat was only observed at the maximum tolerable volume (Spearman's rho = 0.7, p = 0.02). We only found moderate correlations (Spearman's rho = 0.562, p = 0.019) for compliance according to the barostat methodology and for rectal sensibility testing (Spearman's rho = 0.57, p = 0.03 for maximum tolerable volume). Bland-Altman plots showed poor levels of agreement between the methods. We conclude that HRAM and the rectal barostat cannot be used interchangeably for compliance or sensitivity assessments. We suggest the development of a non-elastic balloon with a fixed size and shape to assess rectal sensory function and compliance in HRAM testing.

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.

Evaluation of Anorectal Function in Perianal Crohn's Disease: A Pilot Study

Background: Perianal Crohn’s disease is a disabling condition, with little known about anorectal function in healed/inactive perianal Crohn’s disease; Aim: To evaluate anorectal function in a cohort of patients with treated/healed perianal Crohn’s disease; Methods: Prospective cohort study, including high-resolution anorectal manometry, balloon expulsion test, and 3D-endoanal ultrasound in all patients; Results: Of the 16 patients studied (mean age ± SD, 42 ± 13 years), 12 (75%) were men. A laceration of the internal anal sphincter and/or anal scarring was seen in nine (56%) patients; there was no laceration of the external anal sphincter. Five (56%) of these nine patients had never experienced faecal incontinence. All had normal anal resting and squeeze pressures. Manometry suggested dyssynergia in 11 (69%) patients, with only one (6%) fulfilling the criteria for obstructed defecation. Hyposensitivity for at least one sensory parameter was seen in 11 (69%) patients and hypersensitivity in five (31%) patients; Conclusions: This study detected sphincter abnormalities in more than half of patients, many of whom were asymptomatic. Alterations in rectal sensation were frequently seen, more commonly with rectal hyposensitivity. Trial registration: ClinicalTrials.gov (NCT03819257).

Evaluation of constipation in children using high-resolution anorectal manometry

This prospective, cross-sectional study, conducted from July 2018 to March 2019, aimed to determine the causes of constipation using high-resolution anorectal manometry. Among 33 children enrolled in the study, 31 (94%) children presented with complaints of constipation with mean duration of 2.3 ± 2.5 years and 12 (36.4%) children also had associated complaints of faecal incontinence with mean duration of 3.5 ± 2.8 years. Seven children (21.2%) had normal high-resolution anorectal manometry parameters; anal sphincter hypotonia with decreased squeeze in one child, anal sphincter hypertonia with other abnormal parameters were noted in 25 and absent recto-anal inhibitory reflex in two. The causes of constipation determined were functional constipation in 30 (91%) children, suspected Hirschsprung's disease in two and suspected dyssynergic defecatory disorder in one. Almost 90% had functional constipation of which anal hypotension and anal hypertension may be a part of chronic functional constipation.

Systematic evaluation of cough-anorectal pressure responses in health and in fecal incontinence: A high-resolution anorectal manometry study

BACKGROUND

Anorectal manometry is the most commonly performed test of anorectal function. The cough-anorectal response is frequently assessed as part of a routine manometric investigation but has not previously been the subject of detailed analysis. This study systematically examined anorectal pressure responses to cough in health and evaluated the impact of parity and symptoms of fecal incontinence (FI) on measurements.

METHODS

High-resolution anorectal manometry (HR-ARM) traces from nulliparous (n = 25) and parous (n = 25) healthy volunteers (HV: aged 41, range 18-64), and 57 parous patients with FI (age 47, range 28-72) were retrospectively reviewed. Cough-anorectal pressure responses were analyzed between groups by qualitative and quantitative approaches.

KEY RESULTS

In health, traditional anal pressure measurements ("rest" and "squeeze") were similar between nulliparous and parous women. In contrast, incremental anal-rectal pressure difference during cough significantly differed: nulliparous 42 mm Hg (95% CI: 21-64) vs. parous 6 mm Hg (-14-25), P < 0.036). This measure also differed significantly between nulliparous HVs and patients with FI (-2 mm Hg (95% CI: -15-12), P < 0.001), but not between parous HVs and FI. Qualitatively, a color-contour trace resembling a "spear" in the upper anal canal was observed uniquely in FI. Of 25 patients with normal anal function by traditional measures, cough parameters were abnormal in 52%.

CONCLUSIONS AND INFERENCES

Novel HR-ARM measures during coughing revealed differences in anal function between nulliparous and parous HV, and patients with FI, which were not detected by traditional measures. Cough-anorectal measurements may improve manometric yield, though clinical utility would require assessment by longitudinal studies.

Altered anal slow-wave pressure activity in low anterior resection syndrome: short case series in two independent specialist centres provide new mechanistic insights

AIM

Conventional parameters (anal resting and squeeze pressures) measured with anorectal manometry (ARM) fail to identify anal sphincter dysfunction in many patients with low anterior resection syndrome (LARS). We aimed to assess whether there are differences in anal canal slow-wave pressure activity in LARS patients and healthy individuals.

METHOD

High-resolution ARM (HR-ARM) traces of 21 consecutive male LARS patients referred to the Royal London Hospital, UK (n = 12) and Aarhus University Hospital, Denmark (n = 9) were compared with HR-ARM data from 37 healthy men.

RESULTS

Qualitatively (by visual inspection of HR-ARM recordings), the frequency of slow-wave pressure activity was strikingly different in 11/21 (52.4%) LARS patients from that observed in all the healthy individuals. Quantitative analysis showed that peaks of the mean spectrum in these 11 LARS patients occurred at approximately 6-7 cycles per minute (cpm), without activity at higher frequencies. An equivalent pattern was found in only 2/37 (5.4%) healthy individuals (P < 0.0001). Peaks of the mean spectrum in healthy individuals were concentrated at 16 cpm and 3-4 cpm.

CONCLUSION

Over half of the male LARS patients studied had altered anal slow-wave pressure activity based on analysis of HR-ARM recordings. Further studies could investigate the relative contributions of sex, human baseline variance and neoadjuvant/surgical therapies on anal slow waves, and correlate the presence of abnormal activity with symptom severity.

High-resolution anorectal manometry in children with functional constipation with or without fecal incontinence

BACKGROUND

High-resolution anorectal manometry (HR-ARM) is expected to be better than conventional manometry. Our aim was to characterize HR-ARM pressures in children with functional constipation (FC), with or without fecal incontinence (FI).

METHODS

Children with diagnosis of FC, with or without FI, according to Rome-IV criteria, were enrolled. All patients underwent HR-ARM using 24-channel water-perfused catheter.

RESULTS

Twenty-nine consecutive children (M/F: 21/8; mean age ± SD: 9.5 ± 3.1 years; range 4-15), of whom 21 affected by FC without FI (mean age ± SD: 9.3 ± 3.23 years) and 8 affected by FC with FI (mean age ± SD: 10.2 ± 3.08 years), were enrolled. No significant differences were found regard to gender and age. The analysis of HR-ARM 3D plots demonstrated asymmetry of the anal canal, with higher pressures in distal halves. Comparing pressures between the two groups, we found lower values in FC with FI than in FC without FI group, with a statistically significance for maximum and mean resting pressures (P = .032 and P = .008, respectively). When evaluating our study population respect to asymptomatic children, we found lower resting pressures, lower maximum squeeze pressure, and higher rectoanal inhibitory reflex (RAIR) values.

CONCLUSIONS

Our data demonstrate that HR-ARM pressures at rest and during squeezing in FC with FI children are lower than FC without FI subjects, particularly in anteroposterior quadrants. Compared to children without lower gastrointestinal symptoms, children with FC with or without FI show lower pressures and higher values of RAIR.

Epidemiologic Trends and Diagnostic Evaluation of Fecal Incontinence

Fecal incontinence (FI) is a prevalent condition that occurs in up to 15% of the Western population and significantly impairs quality of life. The current understanding of the epidemiology of FI is shifting because of an increasing recognition of FI in men, better appreciation for the impact of changing obstetric practices on FI in women, and comprehension of the effect of modifiable risk factors on the development of FI over time. The pathophysiology of FI is complex and multifactorial, which necessitates the use of multiple diagnostic tests, including tests of anorectal sensorimotor function, peripheral nerve function, and anatomic structure. Translumbosacral anorectal magnetic stimulation is an emerging noninvasive diagnostic test for assessing lumbosacral neuropathy. This article is not intended as a comprehensive recitation of the literature, but rather focuses on recent developments in the understanding of the epidemiology of FI, as well as on the diagnostic evaluation of this condition. This article aims to increase awareness of FI and to outline an initial diagnostic approach to affected patients.

Functional anal canal length measurement using high-resolution anorectal manometry to investigate anal sphincter dysfunction in patients with fecal incontinence or constipation

BACKGROUND

Using high-resolution anorectal manometry, we aimed to evaluate the: (a) optimal threshold to measure functional anal canal length (FACL) with intra- and inter-observer variability; (b) relationship between abnormal FACL and other phenotypic findings; and (c) utility of FACL measurement to discriminate between healthy volunteers (HV) and patients with fecal incontinence (FI) or chronic constipation (CC).

METHODS

Consecutive patients referred for investigation of FI or CC in isolation were included. FACL was calculated at 5, 10, 20, 30, and 50 mm Hg above rectal pressure. 5th-95th percentile in HV defined limits of normality.

KEY RESULTS

FACL was analyzed in 192 patients with FI (154 females), 204 patients with CC (175 females), and 134 HV (101 females). The optimal threshold for measurement of FACL was 20 mm Hg. Using this threshold, observer reproducibility was very high (ICC 0.99, P < 0.0001). FACL was shorter in females with FI and longer in females with CC compared to HV (2.3 vs 2.9 cm; and 3.4 cm vs 2.9 cm; both P < 0.0001). Twenty percent of females and 13% males with FI had a short FACL, associated with older age, anal hypotonia or hypocontractility, and a atrophic internal anal sphincter. However, abnormal FACL in isolation was only found in 1/190 FI (0.5%) and 2/201 CC (1%) patients; all other patients had other abnormal manometric findings.

CONCLUSIONS AND INFERENCES

Considering overlap with other routinely evaluated manometric parameters, FACL measurement does not provide additional information in the diagnostic assessment of FI or CC.

A high-resolution anorectal manometry parameter based on integrated pressurized volume: A study based on 204 male patients with constipation and 26 controls

BACKGROUND

Conventional anorectal manometric parameters based on linear waves cannot properly predict balloon expulsion (BE) time. We aimed to determine the correlation between integrated pressurized volume (IPV) parameters during simulated evacuation (SE) and BE time in healthy individuals and constipated patients and to assess the correlation between each parameter and symptoms.

METHODS

A total of 230 male participants (including 26 healthy volunteers and 204 chronically constipated patients) underwent high-resolution anorectal manometry (HRAM) and BE tests. The IPV was calculated by multiplying the amplitude, distance, and time from the HRAM profile. Receiver operating characteristic curve (ROC) analysis and partial least square regression (PLSR) were performed.

KEY RESULTS

ROC analysis indicated that the IPV ratio between the upper 1 cm and lower 4 cm of the anal canal was more effective for predicting BE time (area under the curve [AUC]: 0.74, 95% confidence interval [CI]: 0.67-0.80, P < .01) than the conventional anorectal parameters, including defecation index and rectoanal gradient (AUC: 0.60, 95% CI: 0.52-0.67, P = .01). PLSR analysis of a linear combination of IPV parameters yielded an AUC of 0.79. Moreover, the IPV ratio showed a greater clinical correlation with patient symptoms than conventional parameters.

CONCLUSIONS AND INFERENCES

The IPV parameters and the combination of IPV parameters via PLSR were more significantly correlated with BE time than the conventional parameters. Thus, this study presents a useful diagnostic tool for the evaluation of pathophysiologic abnormalities in dyssynergic defecation using IPV and BE time.

Diagnostic Role of Anal Sphincter Relaxation Integral in High-Resolution Anorectal Manometry for Hirschsprung Disease in Infants

OBJECTIVE

To investigate the possible diagnostic role of anal sphincter relaxation integral (ASRI) in high-resolution anorectal manometry (HRAM) for Hirschsprung disease.

STUDY DESIGN

We performed conventional anorectal manometry (ARM) in 24 infants (8 with Hirschsprung disease and 16 without Hirschsprung disease) and HRAM in another 21 infants (9 with Hirschsprung disease and 12 without Hirschsprung disease) before and after October 2014. All infants underwent rectal suction biopsy for confirmation of Hirschsprung disease. We quantified rectoanal inhibitory reflex (RAIR) adequacy by calculating the ASRI in HRAM study at pressure cutoffs of less than 10, 15, and 20 mm Hg (ASRI10, ASRI15, and ASRI20, respectively) and investigated the diagnostic utility.

RESULTS

Patients with Hirschsprung disease who underwent HRAM had significantly lower ASRI10, ASRI15, and ASRI20 values than did infants without Hirschsprung disease (P = .0002, .0002, and .0003, respectively), indicating significant difference in internal anal sphincter relaxation during RAIR test between these 2 groups. ASRI10 exhibited a greater diagnostic accuracy, area under the curve, sensitivity, and specificity than did ASRI15 and ASRI20 for Hirschsprung disease. Moreover, the diagnostic accuracy of HRAM for Hirschsprung disease based on ASRI10 <7 mm Hg.s.cm was significantly greater than that of conventional ARM (P = .02).

CONCLUSIONS

ASRI10 may be indicative of the adequacy of RAIR by HRAM in infants, thus assisting the diagnosis of Hirschsprung disease. The diagnostic accuracy of HRAM (based on the ASRI10 value) is greater than that of conventional ARM for Hirschsprung disease. ASRI10 may be used in an automatic HRAM analysis system for the diagnosis of anorectal motility disorders.

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 in newborns: normative values and diagnostic utility in Hirschsprung disease

BACKGROUND

Conventional methods of screening for Hirschsprung disease (HD) in newborns (barium enema, BE; anorectal manometry, ARM; rectal suction biopsy, RSB) have limitations and/or are invasive. High-resolution anorectal manometry (HR-ARM) is a minimally invasive technique that has potential to overcome most of these limitations, but normative data and performance characteristics have not been reported in newborns. The aims of our study were to assess anorectal sphincter metrics including resting pressure (RP), anal canal length (ACL), and rectoanal inhibitory reflex (RAIR) in healthy and asymptomatic newborns, and to explore the role of HR-ARM in the diagnosis of HD using these normal parameters.

METHODS

All procedures were performed using solid state HR-ARM equipment (Medical Measurement Systems, Enchede, The Netherland) by a single operator. In the first phase, 180 asymptomatic newborns (term newborns 95, preterm newborns 85) were studied, and anal RP, ACL, and RAIR were measured. In the second phase, 16 newborns with clinical manifestations of HD were studied (9 of whom had histopathologic confirmation), and parameters compared to asymptomatic newborns.

KEY RESULTS

Normative RP values were higher in term newborns compared with preterm newborns (p < 0.05), and correlated with age. Progressive maturation of the anal sphincter was evident with chronologic age, both in preterm and term newborns. RAIR was present in all normal subjects. Using absent RAIR as indicative of HD, HR-ARM had a sensitivity 89% and specificity of 83% compared to RSB; these performance characteristics were better than BE (sensitivity 78%, specificity 17%), with significantly higher diagnostic accuracy (80% vs 53%, respectively, p = 0.009).

CONCLUSIONS & INFERENCES

Anorectal sphincter pressure progressively matures with incremental increase in RP during the first months of life. HR-ARM is an effective and safe method that complements the diagnosis of HD in newborns.

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).

Normal values for high-resolution anorectal manometry/topography in a healthy Korean population and the effects of gender and body mass index

BACKGROUND

High-resolution manometry (HRM) based on spatiotemporal plots is increasingly being used. The aim this study was to evaluate, for the first time, the influence of gender, with adjustment for age, body mass index (BMI), and vaginal delivery, on anorectal functions in asymptomatic adults.

METHODS

Fifty-four asymptomatic healthy subjects (M : F = 27 : 27; age = 20-67 years) who were matched by age and gender were enrolled prospectively. We evaluated anorectal pressures, rectal sensation using a HRM probe, and balloon expulsion time. Multivariate linear regression analysis was performed to identify the independent effects of each factor.

KEY RESULTS

Anal resting pressure (median [IQR]; 32 [18] vs 46 [17] mmHg, p < 0.001), anal squeeze pressure (75 [28] vs 178 [72] mmHg, p < 0.001), rectal pressure (33 [16] vs 53 [46] mmHg, p = 0.009) and anal pressure (16 [17] vs 30 [36] mmHg, p = 0.019) during simulated evacuation with rectal distention, and the threshold for the desire to defecate (60 [20] vs 80 [60] mL, p = 0.020) were significantly lower in women than in men. BMI was positively correlated with anal resting pressure (95% CI: 0.598-2.947) and negatively correlated with the threshold for first sensation (95% CI: -0.099 to -0.015). Vaginal delivery did not affect any of the anorectal HRM parameters.

CONCLUSIONS & INFERENCES

HRM parameters may be associated with gender and BMI. Therefore, gender and BMI should be taken into consideration when interpreting HRM results.