Use of Anal Acoustic Reflectometry in the Evaluation of Men With Passive Fecal Leakage

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.

Fecal incontinence subtype assessment (FI-SA): A new tool to distinguish among subtypes of fecal incontinence in a neurogenic population

INTRODUCTION

Two subtypes of fecal incontinence (FI) are defined in the literature (urge and passive FI). The pertinence of this classification is unknown due to conflicting findings and heterogeneity of definitions. However, no questionnaire is available to clearly classify patients among subtypes. The objective of the present study was to develop and validate a new tool (Fecal incontinence subtype assessment, FI-SA) in order to better classify patients among the different subtypes of FI.

METHODS

A prospective monocentric study was conducted in consecutive patients with FI according to Rome IV criteria. To validate psychometric properties of the FI-SA questionnaire, a literature review and qualitative interviews were performed and discussed with an expert panel. A feasibility study was realized to assess acceptability and comprehension of items. The reproducibility was investigated in a validation study.

RESULTS

Comprehension and acceptability were excellent in 90% of patients in the feasibility study (n = 30). Validation study (n = 100) showed a good reproducibility with an intra-class correlation coefficient of 0.91 and 0.89 for questions 1 and 2. Time to fill the questionnaire was 40.0 s. 98.0% patients were classified among subtypes of FI: 34.0% passive FI, 32.0% urge FI and 32.0% mixed FI.

CONCLUSION

FI-SA is the first questionnaire to classify patients among subtypes of FI with good psychometric characteristics and the first questionnaire introducing the concept of mixed FI. FI-SA could help to determine the pertinence of this classification of FI in the management of these patients.

A missing distal complex of the external and internal anal sphincters: a macroscopic and histologic study using Japanese and German elderly cadavers

The lower margin of the internal anal sphincter (IAS) is considered to lie on a J-shaped, subcutaneous part (SCP) of the external anal sphincter (EAS). The lower IAS is united with the J-shaped SCP to form a smooth-striated muscle complex. In the first part of this study, we ensured the presence of the J-shaped EAS in the lateral wall of the anal canal from 12 near-term fetuses. Second, in the lateral anal wall, the examination of the longitudinal section from 20 male and 24 female Japanese cadavers (72-95 years-old) demonstrated that the J-shaped EAS was lost in 15 (34%) due to the very small SCP. Third, we demonstrated that the J-shaped EAS was restricted in the latera anal wall using longitudinal histological sections of the anal canal from 11 male Japanese cadavers (75-89 years-old). Therefore, a site-dependent difference in the IAS-EAS configuration was evident. Finally, we compared a frequency of the lost J-shape between human populations using 10 mm-thick frontal slices from 36 Japanese and 28 German cadavers. The two groups of cadavers were compatible in age (a 0.2-years' difference in males). The macroscopic observations revealed that the J-shaped EAS was absent from 13 (36%) Japanese and six (20%) German specimens, suggesting that the SCP degeneration occurred more frequent in elderly Japanese than elderly German individuals (p < 0.05). The distal IAS-EAS complex seemed to push residual feces out of the anal canal at a transient phase from evacuation to closure. The absence might be the first sigh of anal dysfunction.