New Metrics in High-Resolution and High-Definition Anorectal Manometry

Predicting Responsiveness to Biofeedback Therapy Using High-resolution Anorectal Manometry With Integrated Pressurized Volume

Background/Aims

Biofeedback therapy is widely used to treat patients with chronic constipation, especially those with dyssynergic defecation. Yet, the utility of high-resolution manometry with novel parameters in the prediction of biofeedback response has not been reported. Thus, we constructed a model for predicting biofeedback therapy responders by applying the concept of integrated pressurized volume in patients undergoing high-resolution anorectal manometry.

Methods

Seventy-one female patients (age: 48-68 years) with dyssynergic defecation who underwent initial high-resolution anorectal manometry and subsequent biofeedback therapy were enrolled. The manometry profiles were used to calculate the 3-dimensional integrated pressurized volumes by multiplying the distance, time, and amplitude during simulated evacuation. Partial least squares regression was performed to generate a predictive model for responders to biofeedback therapy by using the integrated pressurized volume parameters.

Results

Fifty-five (77.5%) patients responded to biofeedback therapy. The responders and non-responders did not show significant differences in the conventional manometric parameters. The partial least squares regression model used a linear combination of eight integrated pressurized volume parameters and generated an area under the curve of 0.84 (95% confidence interval: 0.76-0.95, P < 0.01), with 85.5% sensitivity and 62.1% specificity.

Conclusions

Integrated pressurized volume parameters were better than conventional parameters in predicting the responsiveness to biofeedback therapy, and the combination of these parameters and partial least squares regression was particularly promising. Integrated pressurized volume parameters can more effectively explain the physiology of the anorectal canal compared with conventional parameters.

Pudendal Nerve Terminal Motor Latency Compared by Anorectal Manometry Diagnosing Fecal Incontinence: A Retrospective Study

OBJECTIVE

The aim of the study was to compare the clinical value of pudendal nerve terminal motor latency in fecal incontinence patients with that of another diagnostic test-anorectal manometry.

DESIGN

This study used a cross-sectional design. Medical records of fecal incontinence patients who underwent pudendal nerve terminal motor latency and anorectal manometry testing were reviewed. Greater than 2.4 ms of pudendal nerve terminal motor latency was determined to be abnormal. Anorectal manometry was performed using a station pull-through technique. Mean resting anal pressure, maximal resting anal pressure, mean squeezing anal pressure, and maximal squeezing anal pressure were investigated. For normal and abnormal pudendal nerve terminal motor latency groups, comparative analyses were performed on anorectal manometry results.

RESULTS

A total of 31 patients were included. Thirteen patients showed normal pudendal nerve terminal motor latency. For anorectal manometry results, there was no significant difference between normal and abnormal pudendal nerve terminal motor latency groups. Fourteen patients had diabetes mellitus. Subgroup analysis of the 14 diabetic patients showed no significant difference between normal and abnormal pudendal nerve terminal motor latency groups. For 17 nondiabetic patients, there was a significant difference between the groups with positive correlations with mean/maximal resting anal pressures.

CONCLUSIONS

Pudendal nerve terminal motor latency significantly correlates with anorectal manometry in fecal incontinence only in nondiabetic patients.

[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.

The relationships between the results of contemporary tests of anorectal structure and sensorimotor function and the severity of fecal incontinence

BACKGROUND

Diagnostic investigations for fecal incontinence (FI) assess the structure and sensorimotor function of the anorectum. Investigations include anorectal manometry, anorectal sensory testing, pudendal nerve terminal motor latencies (PNTML), and endoanal sonography. The severity of FI and results of investigations are often discordant and the rate of symptom resolution following treatment remains <40%. High-resolution anorectal manometry (HRAM) and three-dimensional endoanal ultrasound (3D-US) have been introduced during the last decade. This study aims to assess the strength of relationships between contemporary investigation results and FI severity.

METHODS

Adults presenting for investigation of FI were assessed using the St Mark's FI severity score (SMIS), HRAM, anorectal sensory testing, PNTML, and 3D-US.

KEY RESULTS

246 patients were included. There were significant relationships between the SMIS and HRAM (resting pressure r_s = -0.23, 95% CI = (-0.34, -0.11), P < .001; squeeze pressure (r_s  = -0.26, 95% CI = (-0.37, -0.14), P < .001) and 3D-US (anterior EAS length r_s = -0.22, 95% CI = (-0.34, -0.09), P = .001). The relationships between SMIS and HRAM had a greater effect size in those with urge-predominant symptoms (resting pressure: r_s = -0.40, 95% CI = (-0.57, -0.20), P < .001, squeeze pressure: r_s = -0.34, 95% CI = (-0.52, -0.12), P = .003). Overall, the variance in SMIS accounted for by anorectal investigations was 8.6% (R² = 0.098, adjusted R² = 0.086, P < .001).

CONCLUSIONS AND INFERENCES

Anorectal investigations are not strong predictors of FI severity. These findings may reflect the multifactorial, heterogeneous pathophysiology of FI, the limitations of the SMIS and anorectal investigations, and contributing factors extrinsic to the anorectum.

MAIN MANOMETRIC FINDINGS AND POTENTIAL FOR ANORECTAL PHYSICAL THERAPY IN THE TREATMENT OF PATIENTS WITH EVACUATION DISORDERS

BACKGROUND

Evacuation disorders are prevalent in the adult population, and a significant portion of cases may originate from pelvic floor muscle dysfunctions. Anorectal manometry (ARM) is an important diagnostic tool and can guide conservative treatment.

OBJECTIVE

To evaluate the prevalence of pelvic dysfunction in patients with evacuation disorders through clinical and manometric findings and to evaluate, using the same findings, whether there are published protocols that could be guided by anorectal manometry.

METHODS

A retrospective analysis of a prospective database of 278 anorectal manometries performed for the investigation of evacuation disorders in patients seen at the anorectal physiology outpatient clinic of Hospital das Clínicas da Faculdade de Medicina de Ribeirão Preto between January 2015 to June 2019 was conducted. The following parameters were calculated: resting pressure (RP), squeeze pressure (SP), high-pressure zone (HPZ), rectal sensitivity (RS) and rectal capacity (RC). The pressure measurements and manometric plots were reviewed to determine the diagnosis and to propose potential pelvic physical therapy procedures. Analysis of variance (ANOVA) and Fisher's exact test were used to compare the continuous variables and to evaluate the equality of variances between groups of patients with fecal incontinence (FI) and chronic constipation (CC). Results with a significance level lower than 0.05 (P-value <0.05) were considered statistically significant. Statistical analysis was performed using IBM® SPSS® Statistics version 20.

RESULTS

The mean age of the sample was 45±22 years, with a predominance of females (64.4%) and economically inactive (72.7%) patients. The indications for exam performance were FI (65.8%) and CC (34.2%). Patients with FI had lower RP (41.9 mmHg x 67.6 mmHg; P<0.001), SP (85.4 mmHg x 116.0 mmHg; P<0.001), HPZ (1.49 cm x 2.42 cm; P<0.001), RS (57.9 mL x 71.5 mL; P=0.044) and RC (146.2 mL x 195.5 mL; P<0.001) compared to those of patients with CC. For patients with FI, the main diagnosis was the absence of a functional anal canal (49.7%). For patients with CC, the main diagnosis was outflow tract obstruction (54.7%). For patients with FI, the main protocol involved a combination of anorectal biofeedback (aBF) with tibial nerve stimulation (TNS) (57.9%). For patients with CC, the most indicated protocol was aBF combined with TNS and rectal balloon training (RBT) (54.7%).

CONCLUSION

There was a high prevalence of pelvic floor changes in patients with evacuation disorders. There was a high potential for performing pelvic floor physical therapy based on the clinical and manometric findings.

The international anorectal physiology working group (IAPWG) recommendations: Standardized testing protocol and the London classification for disorders of anorectal function

BACKGROUND

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.

METHODS

Twenty-nine working group members (clinicians/academics in the field of gastroenterology, coloproctology, and gastrointestinal physiology) were invited to six face-to-face and three remote meetings to derive consensus between 2014 and 2018.

KEY RECOMMENDATIONS

The IAPWG 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.

CONCLUSIONS AND INFERENCES

This framework introduces the IAPWG protocol and the London classification for disorders of anorectal function based on objective physiological measurement. The use of a common language to describe results of diagnostic tests, standard operating procedures, and a consensus classification system is designed to bring much-needed standardization to these techniques.

Relationships between the results of anorectal investigations and symptom severity in patients with faecal incontinence

PURPOSE

Anorectal dysfunction is the focus of diagnostic investigations for faecal incontinence. However, severity of incontinence and anorectal investigation results can be discordant. The aim of this study was to define the relationships between anorectal investigation results and incontinence severity to determine which measures, if any, were predictive of incontinence severity.

METHODS

Patients presenting for investigation of faecal incontinence completed a symptom questionnaire, anorectal manometry, rectal sensation, pudendal nerve terminal motor latency, and endoanal ultrasound. Bivariate analyses were conducted between the Jorge-Wexner score and investigation results. Subgroup analyses were performed for gender and symptom subtypes (urge, passive, mixed). A multiple regression analysis was performed.

RESULTS

Five hundred and thirty-eight patients were included. There were weak correlations between the Jorge-Wexner score and maximal squeeze pressure [r = - 0.24, 95%CI(- 0.31, - 0.16), p < 0.001], and resting pressure [r = - 0.18, (95%CI(- 0.26, - 0.10), p < 0.001]. In men only, there were significant associations between the Jorge-Wexner score and endoanal sonography [IAS defects: t(113) = - 2.26, p = 0.03, d = 0.58, 95%CI(- 4.38, - 0.29)] and rectal sensation (MTV: r_s = - 0.24, 95%CI(- 0.41, - 0.06), p = 0.01). No substantial differences were observed in the urge/passive/mixed subgroup analyses. Multiple regression analysis included three variables: age (β = 0.02, p = 0.17), maximal resting pressure (β = - 0.01, p = 0.28), and maximal squeeze pressure (β = - 0.01, p < 0.01). The variance in the Jorge-Wexner score accounted for by this model was < 10%, (R² = 0.07, p = < 0.01, adjusted R² = 0.06).

CONCLUSION

Anorectal investigations cannot predict the severity of faecal incontinence. This may be due to limitations of diagnostic modalities, the heterogeneity of anorectal dysfunction in these patients, or contributing factors which are extrinsic to the anorectum.