Significance of pelvic floor muscles in anal incontinence

A case of ischemic stroke in the basal ganglia presenting with fecal and urinary incontinence as initial clinical manifestations

Limb disorders and slurred speech are common clinical symptoms associated with acute ischemic stroke. Although urinary incontinence is a known symptom in many cases of acute ischemic stroke, the simultaneous impairment of both bowel and bladder function is relatively rare. The occurrence of fecal and urinary incontinence as the primary clinical manifestation in minor acute ischemic stroke is especially uncommon. In this study, we present the case of a 67-year-old male patient who experienced a minor acute ischemic stroke in the basal ganglia region, notably presenting with both fecal and urinary incontinence. We also review the relevant literature to explore the potential causes behind this unusual presentation.

Relationship of female pelvic floor muscle function and body composition: cross-sectional study

PURPOSE

Investigate the relationship between female pelvic floor muscle (PFM) function and body composition.

METHODS

Cross-sectional study-participants answered sociodemographic and urogynecological questions. The amount of fat mass was measured by dual-emission X-ray densitometry (DXA), and subcutaneous fat thickness was assessed by abdominal ultrasound. PFM assessment was performed using the Modified Oxford Scale and vaginal manometry. Descriptive analysis, independent t test, spearman correlation, and univariate regression were performed.

RESULTS

Ninety-nine women were included. All body composition variables evaluated, except subcutaneous fat thickness, indicated that women with a higher concentration of fat in the pelvic, android, and visceral region have lower maximum voluntary PFM contraction strength assessed by Modified Oxford Scale and manometry. The univariate model pointed out that the fat concentration increases the chances of reduced PFM strength in the entire body (0.6%), android (5.4%), visceral region (25.3%), and pelvic (89.9%). There was a correlation between the concentration of total, pelvic, and android fat with MVC/average peak.

CONCLUSION

The accumulation of "total", "pelvic", "android", and "visceral" fat mass is correlated with reduction in PFM strength, and there is an association between MVC and the variables of total and segmented fat. However, pelvic fat concentration is predictive in 89.9% of cases.

Functional Assessment of Anal Sphincter with Transperineal Ultrasound and Its Relationship to Anal Continence

BACKGROUND/OBJECTIVES

Anal incontinence is linked to pelvic floor dysfunction. Diagnosis involves assessing both the function and structure of the anorectal unit. Although transperineal ultrasound has gained attention as a less invasive option, its effectiveness as a diagnostic tool for evaluating the relationship between structure and function is still debated. This study aimed to explore the relationship between quantitative measurements of anal sphincter and pelvic floor structures as well as the subjective symptoms and objective assessments of sphincter function regarding anal incontinence.

METHODS

50 women with pelvic floor dysfunction were recruited for the study. The severity of anal incontinence was assessed using the CACP score. Ultrasound imaging was employed to measure anal sphincter area, while sphincter pressures were evaluated through manometry. The relationships between variables were analyzed using Pearson's and Spearman's correlation tests.

RESULTS

The mean anal sphincter area was 5.51 cm2 at rest and 4.06 cm2 during maximal contraction. Resting anal sphincter pressure had an average of 46.29 mmHg, and contraction pressure averaged 103.25 mmHg. No significant correlation was found between the anal sphincter area and pressure at rest (r = 0.018) or during contraction (r = -0.210). However, a moderate correlation was observed between the change in sphincter pressure and area during contraction (r = 0.312). The CACP score showed no significant correlation with the sphincter area at rest (r = -0.084) but was weakly correlated during contraction (r = -0.270).

CONCLUSIONS

Conventional diagnostic tools for evaluating anal incontinence can be uncomfortable and are not always readily available. Perineal sonography presents a promising, less invasive alternative for dynamic assessment of the anal sphincter.

Assessment of Anorectal Function and Related Quality of Life of 27 Patients with Bladder Exstrophy or Epispadias After Kelly Radical Soft Tissue Mobilisation

INTRODUCTION

The Radical soft-tissue mobilisation (RSTM) described by J.H. Kelly for bladder exstrophy repair implies a detachment of levator ani muscle insertions from the pelvic wall. The aim of this controlled study was to evaluate the impact of this procedure on subsequent anorectal function.

METHODS

Monocentric controlled study of prospectively collected data of children who underwent RSTM for BEEC from 2010 to 2017. Patients born after 2017 were not included, as they were below the theoretical age of continence acquisition at the time of the study. Anorectal function was assessed using the Childhood Bladder and Bowel Dysfunction Questionnaire, and quality of life (QoL) related to fecal continence using the CINCY FIS questionnaire. The control group was paired on age and sex with a 1:3 patient/control ratio. Answers to questionnaires were collected from September 2021 to January 2022. Univariate statistical analysis comparing two groups and subgroup analysis following age were also performed.

RESULTS

During the period of study, 55 children with BEEC underwent Kelly RSTM. Twenty-seven (49%) were included and paired with 81 healthy children on age and sex. Median age at surgery was 15 months [0.5-93] and median follow-up was 10 years [4-13]. Patient's group median age at evaluation was 11 years [5-19]. There was no difference between patients and control group in anorectal function for both incontinence and constipation items. No significant difference was found in QoL related to fecal incontinence assessment. Subgroup analysis did not show difference.

CONCLUSION

This study suggests that the levator ani detachment during Kelly procedure, realised in a paediatric population under the age of 8, did not impact anorectal function with a mid-term follow-up.

LEVEL OF EVIDENCE

III.

Contouring of emerging organs-at-risk (OARS) of the female pelvis and interobserver variability: A study by the Italian association of radiotherapy and clinical oncology (AIRO)

Purpose

To provide straightforward instructions for daily practice in delineating emerging organs-at-risk (OARs) of the female pelvis and to discuss the interobserver variability in a two-step multicenter study.

Methods and materials

A contouring atlas with anatomical boundaries for each emerging OAR was realized by radiation oncologists and radiologists who are experts in pelvic imaging, as per their knowledge and clinical practice. These contours were identified as quality benchmarks for the analysis subsequently carried out. Radiation oncologists not involved in setting the custom-built contouring atlas and interested in the treatment of gynecological cancer were invited to participate in this 2-step trial. In the first step all participants were supplied with a selected clinical case of locally advanced cervical cancer and had to identify emerging OARs (Levator ani muscle; Puborectalis muscle; Internal anal sphincter; External anal sphincter; Bladder base and trigone; Bladder neck; Iliac Bone Marrow; Lower Pelvis Bone Marrow; Lumbosacral Bone Marrow) based on their own personal knowledge of pelvic anatomy and experience. The suggested OARs and the contouring process were then presented at a subsequent webinar meeting with a contouring laboratory. Finally, in the second step, after the webinar meeting, each participant who had joined the study but was not involved in setting the benchmark received the custom-built contouring atlas with anatomical boundaries and was requested to delineate again the OARs using the tool provided. The Dice Similarity Coefficient (DSC) and the Jaccard Similarity Coefficient (JSC) were used to evaluate the spatial overlap accuracy of the different volume delineations and compared with the benchmark; the Hausdorff distance (HD) and the mean distance to agreement (MDA) to explore the distance between contours. All the results were reported as sample mean and standard deviation (SD).

Results

Fifteen radiation oncologists from different Institutions joined the study. The participants had a high agreement degree for pelvic bones sub-structures delineation according to DICE (IBM: 0.9 ± 0.02; LPBM: 0.91 ± 0.01). A moderate degree according to DICE was showed for ovaries (Right: 0.61 ± 0.16, Left: 0.72 ± 0.05), vagina (0.575 ± 0.13), bladder sub-structures (0.515 ± 0.08) and EAS (0.605 ± 0.05), whereas a low degree for the other sub-structures of the anal-rectal sphincter complex (LAM: 0.345 ± 0.07, PRM: 0.41 ± 0.10, and IAS: 0.4 ± 0.07).

Conclusion

This study found a moderate to low level of agreement in the delineation of the female pelvis emerging OARs, with a high degree of variability among observers. The development of delineation tools should be encouraged to improve the routine contouring of these OARs and increase the quality and consistency of radiotherapy planning.

Three-dimensional High-resolution Anorectal Manometry in Children With Non-retentive Fecal Incontinence

Background/Aims

Three-dimensional high-resolution anorectal manometry (3D-HRAM) is a precise tool to assess the function of the anorectum. Our aim is to evaluate children diagnosed with non-retentive fecal incontinence (NRFI) using 3D-HRAM.

Methods

In all children diagnosed with NRFI, manometric parameters and 3-dimensional reconstructions of the anal canal subdivided into 8 segments were recorded. All data were compared to raw data that were obtained from asymptomatic children, collected in our laboratory and published previously (C group).

Results

Forty children (31 male; median age, 8 years; range, 5-17) were prospectively included in the study. Comparison of the NRFI group and C group revealed lower values of mean resting pressure (74.4 mmHg vs 89.2 mmHg, P < 0.001) and maximum squeeze pressure (182 mmHg vs 208.5 mmHg, P = 0.018) in the NRFI group. In the NRFI group, the thresholds of sensation, urge and discomfort (40 cm³, 70 cm³, and 140 cm³, respectively) were significantly higher than those in the C group (20 cm³, 30 cm³, and 85 cm³, respectively; P < 0.001). In the NRFI group, 62.5% presented a mean resting pressure above the fifth percentile, and 82.5% of patients presented a maximum squeeze pressure above the fifth percentile. The comparisons between segments obtained from these patients and those obtained from the C group revealed several segments with significantly decreased pressure values in the NRFI group.

Conclusions

Our study demonstrated lower pressure parameters in children with NRFI. In patients with normal resting pressures, 3D-HRAM may reveal segments with decreased pressures, which may play a potential role in the pathomechanism of incontinence.

Use of a motion-based digital therapeutic in women with fecal incontinence: A pilot study

AIMS

There is limited data addressing the value of vaginal biofeedback (VBF) on fecal incontinence (FI) symptoms. The objective of this pilot study was to evaluate whether use of a motion-based VBF device and app was effective for at-home treatment of women with FI. We hypothesized that VBF would result in improvement in FI symptoms.

METHODS

A single-arm 10-week prospective pilot trial in women with FI was conducted using the VBF device. The primary outcome was change in St. Mark's score from baseline to week 10. Secondary outcomes included change in 2-week bowel diary and FI quality of life (FIQoL). Statistical analysis included paired t test and Wilcoxon's signed-rank test.

RESULTS

Of 29 enrolled women, 27 had data available for analysis. Mean (±SD) age was 60.9 (±14.4). 63% (17) subjects were White, 33% (9) were Black. Mean St. Mark's score was 14.6 (±4.4) at baseline and 11.6 (±5.1) at 10-weeks (p = 0.005). Changes in the total FIQol, and three of four subsets of the FIQoL scores were also significantly improved (p < 0.001). Bowel diary showed decrease in FI episodes, baseline 8.4 (±8.73) to 10 weeks 4.8 (±3.79), (p = 0.052).

CONCLUSIONS

In this pilot study, there was significant improvement in FI symptom-specific severity and quality of life using a vaginal, motion-based device for biofeedback. A larger study is needed to better understand the value of this device, which may be useful for women who prefer a vaginal device, which can be utilized at home compared with standard anal biofeedback for treatment of FI in the clinical setting.

Current Incidence and Risk Factors of Fecal Incontinence After Acute Stroke Affecting Functionally Independent People

Background: Previously published retrospective series show a high prevalence of fecal incontinence (FI) in stroke patients. We aimed to analyze in a prospective series the current incidence of FI in acute stroke in functionally independent patients and its evolution over time and the patient characteristics associated with the appearance of FI in acute stroke. Methods: We included consecutive patients with acute stroke admitted in our stroke unit who fulfilled the following inclusion criteria: a first episode of stroke, aged >18 years, with no previous functional dependency [modified Rankin Scale (mRS) ≤ 2] and without previous known FI. FI was assessed by a multidisciplinary trained team using dedicated questionnaires at 72 ± 24 h (acute phase) and at 90 ± 15 days (chronic phase). Demographic, medical history, clinical and stroke features, mortality, and mRS at 7 days were collected. Results: Three hundred fifty-nine (48.3%) of 749 patients (mean age 65.9 ± 10, 64% male, 84.1% ischemic) fulfilled the inclusion criteria and were prospectively included during a 20-month period. FI was identified in 23 patients (6.4%) at 72 ± 24 h and in 7 (1.9%) at 90 days ± 15 days after stroke onset. FI was more frequent in hemorrhagic strokes (18 vs. 5%, p 0.007) and in more severe strokes [median National Institute of Health Stroke Scale (NIHSS) 18 (14-22) vs. 5 (3-13), p < 0.0001]. No differences were found regarding age, sex, vascular risk factors, or other comorbidities, or affected hemisphere. Patients with NIHSS ≥12 (AUC 0.81, 95% CI 0.71 to 0.89) had a 17-fold increase for the risk of FI (OR 16.9, IC 95% 4.7-60.1) adjusted for covariates. Conclusions: At present, the incidence of FI in acute stroke patients without previous functional dependency is lower than expected, with an association of a more severe and hemorrhagic stroke. Due to its impact on the quality of life, it is necessary to deepen the knowledge of the underlying mechanisms to address therapeutic strategies.

Is pelvic floor muscle contractility an important factor in anal incontinence?

OBJECTIVE

Pelvic floor muscle contractility (PFMC) may contribute to anal continence. The aim of this study was to assess the association between clinical and sonographic measures of PFMC and anal incontinence (AI) symptoms, after controlling for anal sphincter and levator ani muscle (LAM) trauma.

METHODS

This was a retrospective study of 1383 women assessed at a tertiary center between 2013 and 2016. All patients underwent an interview, including the St Mark's incontinence score (SMIS) in those who reported AI symptoms, a clinical examination, including assessment of PFMC using the modified Oxford scale (MOS), and four-dimensional translabial ultrasound (TLUS). Sonographic measures of PFMC, i.e. cranioventral shift of the bladder neck (BN) and reduction of anteroposterior (AP) diameter of the levator hiatus, were measured offline using ultrasound volumes obtained at rest and on maximum pelvic floor contraction. The reviewer was blinded to all clinical data.

RESULTS

Of the 1383 patients assessed during the study period, seven were excluded due to missing imaging data, leaving 1376 for analysis. Mean age of the participating women was 55 years and mean body mass index was 29 kg/m² . AI was reported by 221 (16.1%) women, with a mean SMIS of 11.8. Mean MOS grade was 2.3. On TLUS, mean BN cranioventral shift was 5.9 mm and mean AP diameter reduction was 8.1 mm. LAM avulsion and significant external anal sphincter (EAS) defect were diagnosed in 24.8% and 8.7% patients, respectively. On univariate analysis, sonographic measures of PFMC were not associated with AI. Lower MOS grade was associated with symptoms of AI; however, statistical significance was lost on multivariate analysis.

CONCLUSION

Clinical and sonographic measures of PFMC were not significantly associated with AI symptoms after controlling for EAS and LAM trauma. © 2020 International Society of Ultrasound in Obstetrics and Gynecology.

Physiotherapy for Prevention and Treatment of Fecal Incontinence in Women-Systematic Review of Methods

Fecal incontinence (FI) affects approximately 0.25-6% of the population, both men and women. The most common causes of FI are damage to/weakness of the anal sphincter muscle and/or pelvic floor muscles, as well as neurological changes in the central or peripheral nervous system. The purpose of this study is to report the results of a systematic review of the possibilities and effectiveness of physiotherapy techniques for the prevention and treatment of FI in women. For this purpose, the PubMed, Embase, and Web of Science databases were searched for 2000-2020. A total of 22 publications qualified for detailed analysis. The studies showed that biofeedback (BF), anal sphincter muscle exercises, pelvic floor muscle training (PFMT), and electrostimulation (ES) are effective in relieving FI symptoms, as reflected in the International Continence Society recommendations (BF: level A; PFMT and ES: level B). Research has confirmed that physiotherapy, by improving muscle strength, endurance, and anal sensation, is beneficial in the prevention of FI, both as an independent method of conservative treatment or in pre/post-surgery treatment. Moreover, it can significantly improve the quality of life of patients. In conclusion, physiotherapy (in particular, BF, PFMT, or ES, as effective methods) should be one of the key elements in the comprehensive therapy of patients with FI.

Puborectalis Muscle Involvement on Magnetic Resonance Imaging in Complex Fistula: A New Perspective on Diagnosis and Treatment

PURPOSE

According to recent studies, magnetic resonance imaging (MRI) assessment of complex fistulas provides a significant benefit compared to fistulography, computed tomography, and ultrasonography. The aim of this study was to describe the accuracy of MRI and the importance of identifying puborectalis muscle involvement on MRI in patients with complex fistula.

METHODS

All patients who were clinically diagnosed with 'complex' or showed multiple fistula tracts underwent fistula MRI. Eligible patients were consecutive patients who underwent fistula MRI between September 2018 and September 2019 at our hospital.

RESULTS

A total of 83 patients (74 males, 9 females; 116 tracts) were included in this study. The sensitivity and specificity of MRI in diagnosing fistula tracts were 94.8% and 98.2%, respectively. The sensitivity and specificity in identifying internal opening were 93.9% and 97.3%, respectively. Of the 35 patients with puborectalis muscle involvement in the MRI, 31 images of suprasphincteric-type patients on the Park's classification were classified. The patients of puborectalis involvement were divided into 2 groups according to the surgical procedure that was performed. There were 12 sphincter-saving procedures and 19 sphincter division procedures performed. Recurrence was seen in 2 patients in the sphincter-saving procedure group, while no case was seen in the sphincter division procedure group. Five complications were found in the sphincter division procedure group, of which 2 reported incontinence.

CONCLUSION

Fistula MRI is a highly accurate examination for evaluating complex fistulas, and the puborectalis muscle involvement findings are very important for diagnosis and treatment.

Downregulation of P2Y2 and HuD during the development of the enteric nervous system in fetal rats with anorectal malformations

Certain patients with anorectal malformations (ARMs) continue to suffer from postoperative dysphoria. The enteric nervous system (ENS) is closely associated with defecation. The purinergic receptor P2Y2 (P2Y2) and Hu antigen D (HuD) proteins contain multiple motifs that enable their activation and direct coupling to integrin and growth factor receptor signaling pathways; thus, they may serve as key points in ENS development. The aim of the present study was to investigate the expression pattern of P2Y2 and HuD proteins during anorectal development in ARM embryos. The embryogenesis of ARM in rats was induced by ethylenethiourea (ETU) on the 10th gestational day. The expression patterns of P2Y2 and HuD proteins were evaluated by immunohistochemistry and western blot analysis in normal, ETU and ARM rat embryos on embryonic days E17, E19 and E21; their mRNA levels were assessed via reverse transcription-quantitative polymerase chain reaction (RT-qPCR) of the distal rectum of fetal rats. Immunohistochemistry of the distal rectum demonstrated that on E17, the expression levels of the two proteins were not different between the three groups. On E19, the expression of HuD was significantly decreased in the ARM group. On E21, the two proteins were significantly decreased in the ARM group. Additionally, the expression levels of the two proteins on E17 were significantly lower than on E21 in the ARM group. Western blotting and RT-qPCR also revealed that the P2Y2 and HuD proteins and mRNA expression levels were significantly decreased in the ARM groups when compared with the normal group on E17 and E21 (P<0.01). Thus, the present study demonstrated that downregulation of P2Y2 and HuD may partly be related to the development of the ENS in ARM embryos.

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.

Spatiotemporal expression of Wnt3a during striated muscle complex development in rat embryos with ethylenethiourea-induced anorectal malformations

Numerous patients with anorectal malformations (ARMs) continue to experience fecal incontinence and constipation following surgical procedures. One of the most important factors that influences defecation is the striated muscle complex (SMC). Wnt signaling regulates the expression of myogenic regulatory factors, which serve an important role in muscle development. Therefore, the present study aimed to investigate the expression pattern of Wnt3a protein (by immunohistochemistry and western blot analysis) and mRNA [by reverse transcription-quantitative polymerase chain reaction (RT-qPCR)] in the SMC of ARM model rats that were exposed to ethylenethiourea. Immunostaining revealed that the expression of Wnt3a exhibits space- and time-dependent changes in the developing SMC of ARM model rat embryos. Immunohistochemistry demonstrated that on embryonic day 17 (E17), Wnt3a-positive cells were observed in the SMC in normal embryos, and expression levels gradually increased as the rat embryos developed. Similar changes in Wnt3a protein expression were detected in ARM model rat embryos; however, the expression of Wnt3a was significantly reduced compared with the normal rat embryos. Western blotting and RT-qPCR also revealed lower expression levels of Wnt3a protein and mRNA, respectively, in the SMC of ARMs model rat embryos compared with normal rat embryos. These data revealed that the expression of Wnt3a in ARM embryos was notably reduced, indicating a potential role for Wnt3a in the maldevelopment of the SMC in patients with ARMs.

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.

Normal tissue complication probability (NTCP) models for late rectal bleeding, stool frequency and fecal incontinence after radiotherapy in prostate cancer patients

BACKGROUND AND PURPOSE

Curative radiotherapy for prostate cancer may lead to anorectal side effects, including rectal bleeding, fecal incontinence, increased stool frequency and rectal pain. The main objective of this study was to develop multivariable NTCP models for these side effects.

MATERIAL AND METHODS

The study sample was composed of 262 patients with localized or locally advanced prostate cancer (stage T1-3). Anorectal toxicity was prospectively assessed using a standardized follow-up program. Different anatomical subregions within and around the anorectum were delineated. A LASSO logistic regression analysis was used to analyze dose volume effects on toxicity.

RESULTS

In the univariable analysis, rectal bleeding, increase in stool frequency and fecal incontinence were significantly associated with a large number of dosimetric parameters. The collinearity between these predictors was high (VIF>5). In the multivariable model, rectal bleeding was associated with the anorectum (V70) and anticoagulant use, fecal incontinence was associated with the external sphincter (V15) and the iliococcygeal muscle (V55). Finally, increase in stool frequency was associated with the iliococcygeal muscle (V45) and the levator ani (V40). No significant associations were found for rectal pain.

CONCLUSIONS

Different anorectal side effects are associated with different anatomical substructures within and around the anorectum. The dosimetric variables associated with these side effects can be used to optimize radiotherapy treatment planning aiming at prevention of specific side effects and to estimate the benefit of new radiation technologies.

Functional Anorectal Disorders

This report defines criteria and reviews the epidemiology, pathophysiology, and management of common anorectal disorders: fecal incontinence (FI), functional anorectal pain and functional defecation disorders. FI is defined as the recurrent uncontrolled passage of fecal material for at least 3 months. The clinical features of FI are useful for guiding diagnostic testing and therapy. Anorectal manometry and imaging are useful for evaluating anal and pelvic floor structure and function. Education, antidiarrheals and biofeedback therapy are the mainstay of management; surgery may be useful in refractory cases. Functional anorectal pain syndromes are defined by clinical features and categorized into three subtypes. In proctalgia fugax, the pain is typically fleeting and lasts for seconds to minutes. In levator ani syndrome (LAS) and unspecified anorectal pain the pain lasts more than 30 minutes, but in LAS there is puborectalis tenderness. Functional defecation disorders are defined by >2 symptoms of chronic constipation or irritable bowel syndrome with constipation, and with >2 features of impaired evacuation i.e., abnormal evacuation pattern on manometry, abnormal balloon expulsion test or impaired rectal evacuation by imaging. It includes two subtypes; dyssynergic defecation and inadequate defecatory propulsion. Pelvic floor biofeedback therapy is effective for treating LAS and defecatory disorders.

Functional Anorectal Disorders

This report defines criteria and reviews the epidemiology, pathophysiology, and management of common anorectal disorders: fecal incontinence (FI), functional anorectal pain and functional defecation disorders. FI is defined as the recurrent uncontrolled passage of fecal material for at least 3 months. The clinical features of FI are useful for guiding diagnostic testing and therapy. Anorectal manometry and imaging are useful for evaluating anal and pelvic floor structure and function. Education, antidiarrheals and biofeedback therapy are the mainstay of management; surgery may be useful in refractory cases. Functional anorectal pain syndromes are defined by clinical features and categorized into three subtypes. In proctalgia fugax, the pain is typically fleeting and lasts for seconds to minutes. In levator ani syndrome (LAS) and unspecified anorectal pain the pain lasts more than 30 minutes, but in LAS there is puborectalis tenderness. Functional defecation disorders are defined by >2 symptoms of chronic constipation or irritable bowel syndrome with constipation, and with >2 features of impaired evacuation i.e., abnormal evacuation pattern on manometry, abnormal balloon expulsion test or impaired rectal evacuation by imaging. It includes two subtypes; dyssynergic defecation and inadequate defecatory propulsion. Pelvic floor biofeedback therapy is effective for treating LAS and defecatory disorders.

Establishment of a new anal sphincter injury model in rats based on cardiotoxin

BACKGROUND/PURPOSE

Mainstream models for anal sphincter injury use large animals. We developed a simple and stable anal sphincter injury model in a small animal (i.e., rats) to obtain manometry measurements by using a miniaturized probe and applying cardiotoxin.

METHODS

The histological structure of the anal canal was evaluated by using manometry in normal rats (n=40). We damaged the internal and external anal sphincters by locally administering snake poison (cardiotoxin; 20 uM, 100μL 8 points). We evaluated the anal canal function through manometry measurements (n=5) and examined the histology using hematoxylin-eosin staining (at each time point, n=3; total n=15).

RESULTS

The manometry parameters and structure of the anal canal of normal rats were similar to those of humans, because rats have resting pressure, rectoanal reflex in the manometry, and an external and internal anal sphincter. After inducing injury, the following findings were observed: rhythmic wave loss and a remarkable reduction in the anal sphincter resting pressure; and local bleeding and advanced infiltration of the inflammatory cells (day 1) and the loss of muscle fibers (day 3).

CONCLUSION

This new rat model will contribute to increasing the knowledge on the anal canal.

Reduced Wnt3a expression correlates with poor development of the hindgut in rats with anorectal malformations

Embryogenesis is orchestrated by the wingless-type MMTV integration site family (WNT) signaling pathways, including Wnt3a. This study was performed to investigate the expression of Wnt3a in the terminal hindgut in ethylenethiourea (ETU)-exposed rat embryos with anorectal malformations (ARMs) and its potential association between Wnt3a and the maldevelopment of the terminal hindgut in ARMs. ARM rat embryos were induced by ethylenethiourea on embryonic day 10 (E10). The expression levels of protein and mRNA of Wnt3a were confirmed using immunohistochemistry staining, Western blotting analyses, and quantitative real-time PCR (qRT-PCR) in normal rat and ARM embryos. Immunostaining revealed a variation in the expression of Wnt3a in the developing terminal hindgut of ARM embryos. The expression of Wnt3a in the terminal hindgut of ARM rat embryos decreased at both the mRNA level and protein level (P<0.05) compared with normal tissues. This study demonstrated that the expression of Wnt3a in the ARMs of ETU-exposed rat embryos was remarkably reduced, which indicated its potential role in the pathogenesis of the terminal hindgut maldevelopment in ARMs.

Neurostimulated levator augmentation--a new approach in restoring continence

PURPOSE

Restoration of continence remains a major challenge in patients after abdominoperineal rectal excision (APE) or with end-stage fecal incontinence. A new surgical technique, the neurostimulated levator augmentation, was introduced for pelvic floor augmentation using dynamic graciloplasty in order to restore anorectal angulation. The aim of this study was to assess feasibility and efficiency.

METHODS

From November 2009 to March 2014, n = 17 patients underwent neurostimulated levator augmentation (n = 10 after APE, n = 5 intractable idiopathic fecal incontinence, n = 2 traumatic anal amputation). Gracilis muscle was transposed through the obturator foramen into the pelvic cavity, positioned in a U-shaped sling behind the rectum, fixed to the contralateral os pubis to restore anorectal angulation, and then conditioned by neurostimulation. Questionnaires analyzing function and quality of life were administered.

RESULTS

For neurostimulated levator augmentation, four patients suffered from complications that needed operative intervention (n = 3 wound infection, n = 1 colon perforation); three pharmacological treatment and two complications needed no further invasive intervention. One patient died due to causes unrelated to the operation, and no complication required intensive care management. Fecal incontinence in patients with idiopathic incontinence improved significantly after surgery as well as incontinence episodes, urgency, and disease-specific quality of life through all dimensions. Generic quality of life was significantly better after surgery in all patients. After median follow-up of 17 months (2-45), all but one patient would undergo the procedure again.

CONCLUSIONS

Neurostimulated levator augmentation was feasible in all patients with acceptable morbidity. It may represent a new therapeutic option in selected patients with intractable fecal incontinence.

Abnormal neural crest innervation in Sox10-Venus mice with all-trans retinoic acid-induced anorectal malformations

BACKGROUND/PURPOSE

Despite technical advances in the surgical/medical care of anorectal malformation (ARM), persistent unsatisfactory postoperative bowel habit has been attributed to histopathologic abnormalities of the distal rectum/pouch (DRP) and hypoplasia of anal sphincter muscles (ASM). We used Sox10-Venus mice with ARM induced by all-trans retinoic acid (ATRA) to investigate neural crest cell (NCC) innervation in the DRP and ASM.

METHOD

Pregnant Sox10-Venus mice were administered single doses of 50, 70, or 100 mg/kg of ATRA on embryonic day 8.5 (E8.5) then sacrificed on either E16.5 or E19.5. Bowel specimens comprising the anorectum were examined using fluorescence microscopy without immunohistochemical staining (FMIS). Anti-PGP9.5 was used to delineate ganglion cells and anti-SMA for smooth muscles.

RESULTS

The appropriate dose of ATRA for inducing ARM was 50 mg/kg. Under FMIS, all ARM embryos (n = 5; all high type; 3 male:2 female) had less NCC innervation with thick Venus-positive nerve fibers in the DRP compared with normal embryos (n = 8); there was abnormal NCC innervation in the DRP and absent ASM in ARM mice.

CONCLUSION

We are the first to delineate abnormal enteric nervous system innervation in the DRP of ARM mice without using immunohistochemical staining techniques thus allowing specimens to be examined without any distortion.

Longitudinal and radial characteristics of intra-anal pressures in children using 3D high-definition anorectal manometry: new observations

OBJECTIVES

The pathophysiology of fecal incontinence is not well understood. Standard or high-resolution anorectal manometry (ARM) provides simple two-dimensional (2D) intra-anal pressure measurements and do not identify radial asymmetry or localize abnormal sphincter function. 3D high-definition ARM (HDARM) has 256 pressure sensors distributed circumferentially and provides a detailed topographical and 3D pressure gradient representation of the anal canal. The objective of this study was to use HDARM to characterize intra-anal pressure profiles in children during rest and squeeze.

METHODS

HDARM manometric tracings of 30 children with constipation referred for ARM were reviewed. 2D pressure profiles using high-resolution manometry were used to measure the length of the high-pressure zone (HPZ). The HPZ was divided into four equal segments from the anal verge to adjust for the variable sphincter length. Longitudinal and radial measurements of the HPZ during rest and squeeze (anterior, left, posterior, right quadrants of the HPZ) were taken along each segment in 2D and 3D topographical views. A 3D reconstruction combining all patients was then constructed.

RESULTS

Mean age was 149.3±1.8 months and mean HPZ length was 3.0±0.1 cm. Using 2D manometry, the mean peak HPZ pressure at rest was 72.0±2.5 mm Hg, and was located in the second segment of the HPZ. The mean peak HPZ pressure at squeeze was 202.9±13.1, and was located in the second segment. 3D measurement demonstrated both longitudinal and radial asymmetry along the anterior, left, posterior, and right quadrants of the HPZ. Left and right quadrant pressures were higher than anterior and posterior pressures at the anal verge and segment 1 during rest and squeeze. Anterior pressures were lower than posterior pressures longitudinally and radially in segments 2, 3, and 4 both during rest and squeeze. Our findings also suggest that in pediatrics it may be necessary to adjust pressure measurement to the anal canal length to get a more accurate picture.

CONCLUSIONS

3D HDARM allows for a detailed characterization of intra-anal pressures. 3D topographic pressure measurements demonstrate longitudinal and radial asymmetry of the anal canal at rest and during squeeze. This is the first time longitudinal and radial asymmetry of the anal canal has been described in children. 3D HDARM may allow for a better understanding of the mechanisms of fecal continence in children.

Anatomical disruption and length-tension dysfunction of anal sphincter complex muscles in women with fecal incontinence

BACKGROUND

Anal sphincter complex muscles, the internal anal sphincter, external anal sphincter, and puborectalis muscles, play an important role in the anal continence mechanism. Patients with symptoms of fecal incontinence have weak anal sphincter complex muscles; however, their length-tension properties and relationship to anatomical disruption have never been studied.

OBJECTIVE

This study aimed to assess the anatomy of the anal sphincter complex muscles with the use of a 3-dimensional ultrasound imaging system and to determine the relationship between the anatomical defects and the length-tension property of external anal sphincter and puborectalis muscles in women with incontinence symptoms and in control subjects.

DESIGN

Severity of anal sphincter muscle damage was determined by static and dynamic 3-dimensional ultrasound imaging. The length-tension property was determined by anal and vaginal pressure with the use of custom-designed probes.

PATIENTS

Forty-four asymptomatic controls and 24 incontinent patients participated in this study.

MAIN OUTCOME MEASURES

The anatomical defects and length-tension dysfunction of anal sphincter complex muscles in patients with fecal incontinence were evaluated.

RESULTS

The prevalence of injury to sphincter muscles is significantly greater in the incontinent patients than in the controls. Eighty-five percent of patients but only 9% controls reveal damage to ≥2 of the 3 muscles of the anal sphincter complex. Anal and vaginal squeeze pressures increased with the increase in the probe size (length-tension curve) in the majority of controls. In patients, the increase in anal and vaginal squeeze pressures was either significantly smaller than in controls or it decreased with the increasing probe size (abnormal length-tension).

LIMITATIONS

We studied patients with severe symptoms. Whether our findings are applicable to patients with mild to moderate symptoms remains to be determined.

CONCLUSIONS

The length-tension property of the external anal sphincter and puborectalis muscles is significantly impaired in incontinent patients. Our findings have therapeutic implications for the treatment of anal incontinence.

Functional luminal imaging probe: a new technique for dynamic evaluation of mechanical properties of the anal canal

BACKGROUND

The muscle structures surrounding the anal canal are of major importance in maintaining continence but their anatomy and function vary along its length. Standard manometry does not provide detailed information about mechanical properties of the anal canal. A new functional luminal imaging probe (FLIP) has been developed for this purpose. The aim of our study was to investigate whether FLIP allows detailed evaluation of dynamic biomechanical properties along the length of the anal canal.

METHODS

The in vitro validity and reproducibility of the FLIP system were tested. Fifteen healthy volunteers (age 32-65 years, mean 51 years), of whom 12 were females, were investigated. The integrity and dimensions of the anal sphincter apparatus were evaluated with endoanal ultrasonography and standard anal manometry. During standardized distensions with the FLIP, 16 cross-sectional areas of the anal canal were measured at 5-mm intervals. Distensibility of the following three segments was evaluated: upper anal canal (surrounded by the internal anal sphincter and the puborectalis muscle), mid-anal canal (surrounded by the internal anal sphincter and the external anal sphincter) and lower anal canal (surrounded by the external anal sphincter). Color contour plots were generated from the FLIP-based dynamic recordings of serial cross-sections.

RESULTS

In vitro tests confirmed the validity and reproducibility of the FLIP system. The luminal geometry during distension and the biomechanical properties of the anal canal differed at the three levels. Both at rest and during squeeze the mid-anal canal was significantly less distensible than the upper (p < 0.01) and the lower (p < 0.05) anal canal.

CONCLUSIONS

FLIP is a promising method for evaluation of the nonhomogeneous biomechanical properties along the length of the anal canal.

Electrical stimulation of the dorsal clitoral nerve reduces incontinence episodes in idiopathic faecal incontinent patients: a pilot study

AIM

Faecal incontinence (FI) has a significant impact on quality of life. This study investigates whether stimulation of the dorsal genital nerve (DGN) improves FI symptoms.

METHOD

Ten female patients suffering from idiopathic FI (median age 60 years) were included in the study. Stimulation was applied twice daily for 3 weeks at the maximal tolerable stimulation amplitude (pulse width, 200 μs; pulse rate, 20 Hz). Patients kept a 3-week bowel diary prior to stimulation, during stimulation and after the final stimulation. FI severity scores, FI Severity Visual-Analogue Score (VAS), FI Quality of Life Score (FIQL), sphincter function and rectal volume tolerance were assessed at baseline, immediately after stimulation and 3 weeks after stimulation.

RESULTS

Nine patients completed the study. The Wexner score (P=0.027) and the St Mark's score (P=0.035) improved after stimulation in seven and six of the patients and improvement was maintained 3 weeks after stimulation (P=0.048 and P=0.049, respectively). The number of incontinent episodes was reduced in seven out of nine patients (P=0.025). Improvement was maintained for 3 weeks after stimulation (P=0.017). Subjective assessments of FI severity using the VAS score and the FIQl score did not improve during stimulation. Sphincter function and rectal volume tolerability were unaffected.

CONCLUSION

DGN stimulation reduced the number of FI episodes in most patients suffering from idiopathic FI. Sphincter function and rectal volume tolerability were not affected. DGN stimulation may represent a new treatment for idiopathic FI.

Dose-effect relationships for individual pelvic floor muscles and anorectal complaints after prostate radiotherapy

PURPOSE

To delineate the individual pelvic floor muscles considered to be involved in anorectal toxicity and to investigate dose-effect relationships for fecal incontinence-related complaints after prostate radiotherapy (RT).

METHODS AND MATERIALS

In 48 patients treated for localized prostate cancer, the internal anal sphincter (IAS) muscle, the external anal sphincter (EAS) muscle, the puborectalis muscle (PRM), and the levator ani muscles (LAM) in addition to the anal wall (Awall) and rectal wall (Rwall) were retrospectively delineated on planning computed tomography scans. Dose parameters were obtained and compared between patients with and without fecal urgency, incontinence, and frequency. Dose-effect curves were constructed. Finally, the effect of an endorectal balloon, which was applied in 28 patients, was investigated.

RESULTS

The total volume of the pelvic floor muscles together was about three times that of the Awall. The PRM was exposed to the highest RT dose, whereas the EAS received the lowest dose. Several anal and rectal dose parameters, as well as doses to all separate pelvic floor muscles, were associated with urgency, while incontinence was associated mainly with doses to the EAS and PRM. Based on the dose-effect curves, the following constraints regarding mean doses could be deduced to reduce the risk of urgency: ≤ 30 Gy to the IAS; ≤ 10 Gy to the EAS; ≤ 50 Gy to the PRM; and ≤ 40 Gy to the LAM. No dose-effect relationships for frequency were observed. Patients treated with an endorectal balloon reported significantly less urgency and incontinence, while their treatment plans showed significantly lower doses to the Awall, Rwall, and all pelvic floor muscles.

CONCLUSIONS

Incontinence-related complaints show specific dose-effect relationships to individual pelvic floor muscles. Dose constraints for each muscle can be identified for RT planning. When only the Awall is delineated, substantial components of the continence apparatus are excluded.

Functional morphology of anal sphincter complex unveiled by high definition anal manometery and three dimensional ultrasound imaging

BACKGROUND

Anal sphincter complex consists of anatomically overlapping internal anal sphincter (IAS), external anal sphincter (EAS) and puborectalis muscle (PRM). We determined the functional morphology of anal sphincter muscles using high definition anal manometery (HDAM), three dimensional (3D)-ultrasound (US) and Magnetic resonance (MR) imaging.

METHODS

We studied 15 nulliparous women. High definition anal manometery probe equipped with 256 pressure transducers was used to measure the anal canal pressures at rest and squeeze. Lengths of IAS, PRM, and EAS were determined from the 3D-US images and superimposed on the HDAM plots. Movements of anorectal angle with squeeze were determined from the dynamic MR images.

KEY RESULTS

High definition anal manometery plots reveal that anal canal pressures are highly asymmetric in the axial and circumferential direction. Anal canal length determined by the 3D-US images is slightly smaller than that measured by HDAM. The EAS (1.9 ± 0.5 cm long) and PRM (1.7 ± 0.4 cm long) surround distal and proximal parts of the anal canal, respectively. With voluntary contraction, anal canal pressures increase in the proximal (PRM) and distal (EAS zone) parts of anal canal. Posterior peak pressure in the anal canal moves cranially in relation to the anterior peak pressure, with squeeze. Similar to the movement of peak posterior pressure, MR images show cranial movement of anorectal angle with squeeze.

CONCLUSIONS & INFERENCES

Our study proves that the PRM is responsible for the closure of the cranial part of anal canal. HDAM, in addition to measuring constrictor function can also record the elevator function of levator ani/pelvic floor muscles.

Triple-target treatment versus low-frequency electrostimulation for anal incontinence: a randomized, controlled trial

BACKGROUND

In the nonsurgical treatment of anal incontinence, the combination of amplitude-modulated medium-frequency stimulation and electromyographic biofeedback (EMG-BF), known as triple-target treatment (3T), is superior to EMG-BF alone. The aim of this trial is to compare 3T with the standard treatment, low-frequency stimulation (LFS).

METHODS

80 patients with anal incontinence of Grade I or higher who presented to physicians or centers specialized in coloproctology were enrolled in this multicenter randomized trial with blinded observer. The trial had an open parallel-group design. Randomization was performed centrally by telephone. The primary endpoint was the Cleveland Clinic Score (CCS) after self-training at home with either 3T or LFS in two 20-minute sessions per day for 6 months. The secondary endpoints included the proportion of patients regaining continence, and the patients' quality of life (QoL). On completion of the trial as planned, the results were evaluated with an intention-to-treat analysis.

STUDY REGISTRATION

DRKS00000138 (http://register.germanctr.de).

RESULTS

39 patients were randomized to 3T, and 41 to LFS. After 6 months of treatment, the CCS (mean ± standard deviation) was 3.1 ± 4.2 in the 3T group and 9.6 ± 3.9 in the LFS group. The median improvement in the CCS at 6 months compared to baseline was 7 points greater in the 3T group than in the LFS group (95% CI: 5-9, p<0.001). Anal continence was regained by 54% of the 3T patients, but none of the LFS patients (95% CI for the difference: 37.18% - 69.91%, p<0.001). QoL scores were higher in all dimensions in the 3T group than in the LFS group. No major adverse effects occurred in either group.

CONCLUSION

3T is superior to LFS in the treatment of anal incontinence. The available evidence suggests that the success of 3T is based on the combined effect of biofeedback and medium-frequency stimulation. LFS of the type applied in this trial has no effect. 3T should be used in routine clinical practice instead of LFS.

Evaluation of the role of the puborectal part of the levator ani muscle in anal incontinence: a prospective study of 78 female patients with anal incontinence

BACKGROUND

Anal incontinence is most often linked with sphincter rupture and/or stretching the pudendal nerves.

OBJECTIVE

The aim of our study was to investigate the involvement of the puborectal part of the levator ani muscle in anal incontinence.

PATIENTS AND MAIN OUTCOME MEASURES

Seventy-eight female patients were studied by anorectal manometry, 3-dimensional ultrasound examination, and concentric needle electromyography of the external anal sphincter, puborectal muscle, and bulbocavernous muscles, completing with the evaluation of the pudendal nerve terminal motor latencies. Damage to the puborectal muscle was defined by an abnormal ultrasound and/or abnormal electromyography.

RESULTS

Rupture of the anal sphincter apparatus and puborectal muscle was found in 23% and 3.8%. The EMG showed damage to the puborectal part in 39 cases: this was isolated in 4 cases and combined with external anal sphincter damage in 35 patients. Unilateral or bilateral increase in the terminal motor latencies of the pudendal nerves was found in 36% (28/78) of the patients. The frequency of peripheral neurogenic lesions varied from 36% to 90% according to the electromyographic tests used. There was no correlation between puborectal part damage and resting pressure, perception threshold, and maximum tolerable rectal volume. The mean Wexner index score was not increased by the existence of a defect involving the puborectal part found by echography or by damage to the puborectal part shown by the EMG. Investigating puborectal muscle lesions reduced the percentage of idiopathic anal incontinence to 2.5%.

CONCLUSION

Our study confirms the feasibility and usefulness of combined electromyography and 3-dimensional ultrasound examination of the puborectal muscle in anal incontinence.

Anal sphincter complex muscles defects and dysfunction in asymptomatic parous women

INTRODUCTION AND HYPOTHESIS

We aimed to determine anatomy and function of anal sphincter complex using three-dimensional ultrasound (3D-US) and manometry in asymptomatic parous women.

METHODS

3D-US of puborectalis muscle (PRM), external (EAS), and internal anal sphincters (IAS) anatomy was performed in 45 women without pelvic floor dysfunction. To assess function, rest and squeeze vaginal and anal pressures were measured. Based on 3D-US, subjects were divided into injured and uninjured groups.

RESULTS

Forty-four of 45 subjects had adequate PRM images. The injured PRM (N = 14) group had significantly lower vaginal pressures as compared with uninjured PRM group (N = 30; p = 0.001). Four of 45 subjects with IAS and EAS defects had lower resting and squeeze anal canal pressure. Muscle injury to IAS, EAS and PRM in the same individual was uncommon.

CONCLUSIONS

In asymptomatic parous women, PRM defects were more common than the EAS/IAS defects but defects in more than one muscle were infrequent. Subjects with injured PRM had low vaginal pressure than the ones without.

Abnormal innervation patterns in the anorectum of ETU-induced fetal rats with anorectal malformations

To investigate whether anorectal malformations (ARMs) were associated with a global neuromuscular maldevelopment of the lower gastrointestinal (GI) tract and anorectum, the distribution of neuronal markers protein gene product (PGP9.5), nitric oxide synthases (NOs), neuromuscular junction markers (synaptophysin, SYP), interstitial cells of Cajal (ICC) marker (c-kit) within the terminal rectum were analyzed by immunohistochemistry and Western blot in rat embryos with ethylenethiourea (ETU) induced ARMs. From Gestational day16 (Gd16) to Gd21, neural crest-derived cells (NCC) migrated from the proximal gut into the terminal colon, colonising it along its entire length, gradually proliferated and differentiated to innervate the distal gut. From Gd19 to Gd21, significant gross-morphological differences of the anorectum of normal (n=90) and ARMs (n=90) embryos were found. Different myenteric plexus (MPs) development of the anorectum suggested that ARMs were associated with a global abnormal innervation patterns in the anorectum in gestational course and might have some postoperative effect.

The development of satellite cells and their niche in striated muscle complex of anorectal malformations rat embryos

BACKGROUND

It has been demonstrated that different degrees of pelvic floor muscle (PFM) maldevelop in anorectal malformations (ARMs); yet the development of satellite cells, the myogenic stem cells responsible for muscle growth, repair, and maintenance remains elusive during the embryogenesis of PFM. Striated muscle complex (SMC) is one of the most important components of PFM. The objective of this study was to observe the development pattern of satellite cells and their niche of SMC and investigate its possible role in PFM dysplasia in ARMs.

METHODS

Immunohistochemistry, cell culture, transmission electron microscopy (TEM), real-time quantitative PCR, and Western blot were performed to trace the dynamic development pattern of satellite cells during the morphogenesis of PFM in ethylenethiourea (ETU)-induced ARMs rat embryos.

RESULTS

In ARMs rat embryos, earlier presentation and higher number of Pax7-expressing cell were observed in SMC. The expression of Pax7 and vimentin were up-regulated, while the expression of myogenin, vWF, and neurofilament were down-regulated. Ultrastructure analysis of SMC was characterized by increased amount of nuclear heterochromatin of satellite cell nuclei, thickened basal lamina, widened gap between satellite cell and myofiber, and disarrangement of muscle fibers. The satellite cells demonstrated abnormal differentiation after they were isolated and cultured in vitro.

CONCLUSIONS

Our results suggest that premature origination of satellite cell from myogenic progenitor or precursor may result in the depletion of myogenic precursor and cessation of muscle growth; intrinsic defect in satellite cell structure, and extrinsic impairment of microenvironment compromised the myogenic competence of satellite cell, which might contribute substantially to the hypoplastic SMC in ARMs.

Anorectal functions after perineal and retropubic radical prostatectomy - a prospective clinical and anal manometric assessment

INTRODUCTION

The aim of this study is to evaluate the anorectal functions of prostate cancer patients who have undergone radical perineal prostatectomy (RPP) or radical retropubic prostatectomy (RRP) surgery.

MATERIAL AND METHODS

Thirty-seven patients with an indication for radical prostatectomy were included after informed consent. Anorectal manometry was performed before and one month after the surgery in 22 RPP and 15 RRP patients in our clinic. Clinical assessment was evaluated by anorectal functions with anal incontinence scoring (AIS) (Fernandez; no incontinence = 0; maximal incontinence = 12). Patients with a history of anorectal surgery were excluded from the study. The following data were recorded: external anal sphincteric pressure (EASP), internal anal sphincteric pressure (IASP), minimum ano-rectal reflex volume (MARRV) and minimum rectal sensory volume (MRSV).

RESULTS

In the RPP and RRP groups, the mean age was 66 (56-75) and 64.3 (52-73) years, respectively. In the RPP group, EASP and IASP values showed a significant decrease after the surgery. In the RRP group, EASP and IASP were also decreased after the surgery, but without statistical significance. No significant change was seen in MARRV and MRSV of either group. When the scores of AIS were analysed, no significant clinical difference between pre- or post-operative scores was seen in RPP and RRP groups.

CONCLUSIONS

Perineal or retropubic surgery may injure pelvic floor muscles and/or supplying nerves, which likely causes anorectal dysfunction. Although there is a significant decrease in early postoperative EASP and IASP after RPP, it has no clinical significance according to AIS.

Long-term effects on pressure and electromyography in a rat model of anal sphincter injury

PURPOSE

The goal of this research was to study the chronic effects of pudendal nerve transection and sphincterotomy on the anal sphincter, because there is no good animal model investigating anal sphincter injury. Clinically, anal sphincter dysfunction impacts a cohort of women who have fecal incontinence; conclusions from the study can benefit research for new effective treatments.

METHODS

Sixty-eight virgin Sprague-Dawley rats were allocated into control (n = 12), sphincterotomy (n = 28), and pudendal nerve transection (n = 28) groups and were evaluated before injury and immediately, 4 days, 14 days, and 28 days after. Anal pressures and electromyography were recorded and statistically compared. The anal sphincter was submitted to histology.

RESULTS

: Sphincterotomy data showed anal pressure recovery 14 days after injury and were comparable to controls after 28 days. Pudendal nerve transection showed a significant decrease in anal pressure 4 days after injury (P < .001), and this continued until 28 days after injury (P = .01). Electromyography showed significant loss of activity after nerve transection compared with controls. Twenty-eight days after sphincterotomy and nerve transection, fibrosis and muscle atrophy of the external anal sphincter muscle were demonstrated, respectively.

CONCLUSION

Anal pressures recover significantly after sphincterotomy. Pudendal nerve transection caused atrophy of the external anal sphincter that was reflected by decreased pressures and electromyography. The results of this study can contribute to a better understanding of the mechanisms that lead to fecal incontinence and can be used to test the efficacy of therapies.

Fecal incontinence in older women: are levator ani defects a factor?

OBJECTIVE

We sought to compare pelvic floor structure and function between older women with and without fecal incontinence (FI) and young continent (YC) women.

STUDY DESIGN

YC (n=9) and older continent (OC) (n=9) women were compared to older women with FI (older incontinent [OI]) (n=8). Patients underwent a pelvic organ prolapse quantification, measurement of levator ani (LA) force at rest and with maximum contraction, and magnetic resonance imaging. Displacement of structures and LA defects were determined on dynamic magnetic resonance imaging.

RESULTS

LA defects were more common in the OI vs the YC (75% vs 11%, P=.01) and OC (22%, P=.14) groups; women with FI were more likely to have LA defects than women without (odds ratio, 14.0, 95% confidence interval, 1.8-106.5). OI women generated 27.0% and 30.1% less force during maximum contraction vs the OC (P=.13) and YC (P=.04) groups. During Kegel, OI absolute structural displacements were smaller than in the OC group (P=.01).

CONCLUSION

OI women commonly have LA defects, and cannot augment pelvic floor strength.

Prevalence of major levator abnormalities in symptomatic patients with an underactive pelvic floor contraction

Introduction and hypothesis

Major levator ani abnormalities (LAA) may lead to abnormal pelvic floor muscle contraction (pfmC) and secondarily to stress urinary incontinence (SUI), prolapse, or fecal incontinence (FI).

Methods

A retrospective observational study included 352 symptomatic patients to determine prevalence of LAA in underactive pfmC and the relationship with symptoms. On 2D/3D transperineal ultrasound, PfmC was subjectively assessed as underactive (UpfmC) or normal (NpfmC) and quantified. LAA, defined as a complete avulsion of the pubic bone, was analyzed using tomographic ultrasound imaging.

Results

LAA were found in 53.8% of women with UpfmC versus 16.1% in NpfmC (P < 0.001). Patients with UpfmC were less likely to reduce hiatal area on pfmC (mean 7% reduction vs 25% in NpfmC (P < 0.001)). An UpfmC was associated with FI (P = 0.002), not with SUI or prolapse of the anterior and central compartment.

Conclusion

An underactive pfmC is associated with increased prevalence of LAA and FI.

Defects on endoanal ultrasound and anal incontinence after primary repair of fourth-degree anal sphincter rupture: a study of the anal sphincter complex and puborectal muscle

OBJECTIVES

To perform three-dimensional endoanal ultrasound (EAUS) after primary repair of fourth-degree anal sphincter rupture (ASR) and correlate the sonographic defects with anal incontinence (AI); to measure the axial and sagittal thickness and angle of the puborectal muscle (PRM) as well as the length of the anal canal, and then correlate these measures with AI; and to assess the interobserver measurement agreement between an inexperienced and an experienced sonologist.

METHODS

EAUS was offered to 84 consecutive women, who were asked to answer a validated questionnaire after fourth-degree ASR. AI was graded according to the Wexner score and EAUS defects were graded according to the Starck score.

RESULTS

Sixty-one women (73%) answered the questionnaire. The median (range) follow-up time was 5.1 (1.3-8.7) years. Thirty-three (54%) of these women underwent EAUS and were included in the study. There was no difference in the incontinence scores between women who underwent EAUS and those who did not. Eleven of the women who underwent EAUS (33%) were continent, 22 women (67%) had flatus incontinence at least once a month, of whom 12 also had incontinence for liquid stool and two had incontinence for solid stool. The median Wexner score was 2 (range, 0-12). Five of the patients (15%) had no ultrasound defects. All of the patients with Wexner scores > or = 4 had a Starck score of > or = 10. No association between ultrasound defects and AI was demonstrated, however, the angle of the PRM and parity were associated with Starck score. No clear association between the measurements of the PRM and AI was shown. The experienced observer detected more of the small defects than did the inexperienced observer.

CONCLUSION

In a 1-9-year follow-up period after primary suture of fourth-degree ASR, the frequency of AI was high, at 67%. No clear association was seen between AI and sphincter defects detected on ultrasonography. There was an association between the angle of the PRM and the extent of ultrasound defects.

Apoptosis during the development of pelvic floor muscle in anorectal malformation rats

PURPOSE

Fecal incontinence and constipation still remain as major postoperative complications after procedures for anorectal malformations (ARM). The striated muscle complex (SMC) is one of the most important factors that influence defecation. Previous studies have demonstrated different degrees of the muscle complex dysplasia dependent on the complexity of ARM. To explore the mechanisms of maldevelopment of SMC in ARM, apoptosis was investigated during pelvic floor muscle development in rat embryos with ARM.

METHODS

Anorectal malformations in rat embryos were induced by treating pregnant rats with ethylenethiourea on the 10th embryonic day (E10). Normal and ARM rat embryos from E16 to E21 were serial-sectioned transversely or sagittally, and SMCs were dissected and snap frozen. TdT mediated dUTP Nick Ending Labeling (TUNEL) staining and DNA ladder analysis were performed to identify apoptosis and expression of Bax/Bcl-2 were confirmed with immunohistochemical staining and Reverse Transcription-Polymerase Chain Reaction (RT-PCR) analysis.

RESULTS

Hypoplastic and disordered SMC sling shifted cephalad, ventrally, and converged inferior to the rectourethral fistula and infiltrated connective tissue in ARM embryos. In the normal group, TUNEL-positive cells became evident on E17; sporadic positive staining was mainly localized in 2 areas as follows: the junction area between SMC and bulbocarvernosus muscle and posterior to the rectum where bilateral SMC converged. In the ARM group, massive positive staining of nuclei was observed from E16 to E21 and was mainly distributed in the dorsal part of the SMC. Electrophoresis of DNA samples yielded a "ladder" pattern of migration both in normal and the ARM group from E17 to E21, the ladders were stronger in the ARM group. In both groups, the expression of Bax/Bcl-2 was detectable on E17, the immunoreactivity increased on E19 and E21. Compared with the normal group, the expression of Bax was increased, whereas Bcl-2 was declined in the ARM group. Significant upregulation of Bax messenger RNA (mRNA) levels and downregulation of Bcl-2 mRNA levels were observed in ARM embryos.

CONCLUSIONS

In the current study, abnormal apoptosis and disturbed expression of Bax/Bcl-2 were identified during SMC development in ARM embryos. It is suggested that precocious, excessive, and dislocated apoptosis might be a fundamental pathogenesis for the maldeveloped SMC in ARM rats. The temporospatial expressions of Bax/Bcl-2 indicate they may have an important role in the regulation of apoptosis of SMC.

Surgical reconstitution of a unilaterally avulsed symptomatic puborectalis muscle using autologous fascia lata

BACKGROUND

The puborectalis muscle is an important muscle for the maintenance of fecal continence. We present a novel surgical technique for repair of symptomatic avulsed puborectalis muscle.

CASE

This woman presented with dyspareunia and fecal incontinence since the vaginal birth of her child 2 years before. The diagnosis of an avulsed right puborectalis was made by physical examination and confirmed by magnetic resonance imaging and three-dimensional ultrasonography. Fascia lata was harvested from the patient's thigh and used to reconstitute the missing portion of the puborectalis muscle. At 12 months postoperatively, the patient was continent of stool and relieved of dyspareunia.

CONCLUSION

The patient's dyspareunia and fecal incontinence were alleviated by restoring normal anatomy.

The physiology of continence and evacuation

Continence is maintained by the coordinated function of the pelvic floor, rectum and anal sphincters. Evacuation occurs through a relaxed pelvic floor. The rectum acts to either store or expel stool both of which require cortical sensory awareness acting in conjunction with intramural and spinal reflexes that ensure timely defecation. The anal sphincters act individually and in unison in response to rectal distension and the sensation of rectal filling. Reflex relaxation of the internal anal sphincter has an additional sensory function in allowing sampling of rectal contents in the upper anal canal. Voluntary control of the external anal sphincter is key in the voluntary deferring of evacuation until a socially opportune moment. This review describes the physiological roles of each of these continence organs in order to understand the complex process of defecation.

Investigating and treating fecal incontinence: when and how

Fecal incontinence is a common disorder in our aging population and can have profound effects on patient's well-being. The present review examines the current understanding of fecal incontinence and provides a practical approach to the investigation and management of this condition. A special emphasis is placed on specialized testing, focusing on indications and impact on guiding management.

Transperineal three-dimensional ultrasound imaging for detection of anatomic defects in the anal sphincter complex muscles

BACKGROUND & AIMS

Three-dimensional ultrasound (3D-US) imaging is a powerful tool to visualize various components of the anal sphincter complex, that is, the internal anal sphincter (IAS), the external anal sphincter (EAS), and the puborectalis muscle (PRM). Our goal was to determine the reliability of the 3D-US imaging technique in detecting morphologic defects in the IAS, EAS, and PRM.

METHODS

Transperineal 3D-US images were obtained in 3 groups of women: nulliparous (n = 13), asymptomatic parous (n = 20), and patients with fecal incontinence (FI) (n = 25). The IAS and EAS were assessed to determine the craniocaudal length of defects and were scored as follows: 0 = normal, 1 = less than 25%, 2 = 25% to 50%, 3 = 50% to 75%, and 4 = greater than 75%. The 2 PRM hemislings were scored separately as follows: 0 = normal, 1 = less than 50% abnormal, and 2 = greater than 50% length abnormal. Subjects were grouped according to the score as follows: normal (score 0), minor abnormality (scores of 1 and 2), and major abnormality (scores of 3 and 4). Three observers performed the scoring.

RESULTS

The 3D-US allowed detailed evaluation of the IAS, EAS, and PRM. The inter-rater reliability for detecting the defects ranged between 0.80 and 0.95. Nullipara women did not show any significant defect but the defects were quite common in asymptomatic parous and FI patients. The prevalence of defects was greater in the FI patients as compared with the asymptomatic parous women.

CONCLUSIONS

3D-US yields reliable assessment of morphologic defects in the anal sphincter complex muscles.