Evidence from dynamic integrated proctography to redefine anismus

Non-drug therapies for the management of chronic constipation in adults: the CapaCiTY research programme including three RCTs

Background

Chronic constipation affects 1–2% of adults and significantly affects quality of life. Beyond the use of laxatives and other basic measures, there is uncertainty about management, including the value of specialist investigations, equipment-intensive therapies using biofeedback, transanal irrigation and surgery.

Objectives

(1) To determine whether or not standardised specialist-led habit training plus pelvic floor retraining using computer-assisted direct visual biofeedback is more clinically effective than standardised specialist-led habit training alone, and whether or not outcomes of such specialist-led interventions are improved by stratification to habit training plus pelvic floor retraining using computer-assisted direct visual biofeedback or habit training alone based on prior knowledge of anorectal and colonic pathophysiology using standardised radiophysiological investigations; (2) to compare the impact of transanal irrigation initiated with low-volume and high-volume systems on patient disease-specific quality of life; and (3) to determine the clinical efficacy of laparoscopic ventral mesh rectopexy compared with controls at short-term follow-up.

Design

The Chronic Constipation Treatment Pathway (CapaCiTY) research programme was a programme of national recruitment with a standardised methodological framework (i.e. eligibility, baseline phenotyping and standardised outcomes) for three randomised trials: a parallel three-group trial, permitting two randomised comparisons (CapaCiTY trial 1), a parallel two-group trial (CapaCiTY trial 2) and a stepped-wedge (individual-level) three-group trial (CapaCiTY trial 3).

Setting

Specialist hospital centres across England, with a mix of urban and rural referral bases.

Participants

The main inclusion criteria were as follows: age 18–70 years, participant self-reported problematic constipation, symptom onset > 6 months before recruitment, symptoms meeting the American College of Gastroenterology’s constipation definition and constipation that failed treatment to a minimum basic standard. The main exclusion criteria were secondary constipation and previous experience of study interventions.

Interventions

CapaCiTY trial 1: group 1 – standardised specialist-led habit training alone (n = 68); group 2 – standardised specialist-led habit training plus pelvic floor retraining using computer-assisted direct visual biofeedback (n = 68); and group 3 – standardised radiophysiological investigations-guided treatment (n = 46) (allocation ratio 3 : 3 : 2, respectively). CapaCiTY trial 2: transanal irrigation initiated with low-volume (group 1, n = 30) or high-volume (group 2, n = 35) systems (allocation ratio 1 : 1). CapaCiTY trial 3: laparoscopic ventral mesh rectopexy performed immediately (n = 9) and after 12 weeks’ (n = 10) and after 24 weeks’ (n = 9) waiting time (allocation ratio 1 : 1 : 1, respectively).

Main outcome measures

The main outcome measures were standardised outcomes for all three trials. The primary clinical outcome was mean change in Patient Assessment of Constipation Quality of Life score at the 6-month, 3-month or 24-week follow-up. The secondary clinical outcomes were a range of validated disease-specific and psychological scoring instrument scores. For cost-effectiveness, quality-adjusted life-year estimates were determined from individual participant-level cost data and EuroQol-5 Dimensions, five-level version, data. Participant experience was investigated through interviews and qualitative analysis.

Results

A total of 275 participants were recruited. Baseline phenotyping demonstrated high levels of symptom burden and psychological morbidity. CapaCiTY trial 1: all interventions (standardised specialist-led habit training alone, standardised specialist-led habit training plus pelvic floor retraining using computer-assisted direct visual biofeedback and standardised radiophysiological investigations-guided habit training alone or habit training plus pelvic floor retraining using computer-assisted direct visual biofeedback) led to similar reductions in the Patient Assessment of Constipation Quality of Life score (approximately –0.8 points), with no statistically significant difference between habit training alone and habit training plus pelvic floor retraining using computer-assisted direct visual biofeedback (–0.03 points, 95% confidence interval –0.33 to 0.27 points; p = 0.8445) or between standardised radiophysiological investigations and no standardised radiophysiological investigations (0.22 points, 95% confidence interval –0.11 to 0.55 points; p = 0.1871). Secondary outcomes reflected similar levels of benefit for all interventions. There was no evidence of greater cost-effectiveness of habit training plus pelvic floor retraining using computer-assisted direct visual biofeedback or stratification by standardised radiophysiological investigations compared with habit training alone (with the probability that habit training alone is cost-effective at a willingness-to-pay threshold of £30,000 per quality-adjusted life-year gain; p = 0.83). Participants reported mixed experiences and similar satisfaction in all groups in the qualitative interviews. CapaCiTY trial 2: at 3 months, there was a modest reduction in the Patient Assessment of Constipation Quality of Life score, from a mean of 2.4 to 2.2 points (i.e. a reduction of 0.2 points), in the low-volume transanal irrigation group compared with a larger mean reduction of 0.6 points in the high-volume transanal irrigation group (difference –0.37 points, 95% confidence interval –0.89 to 0.15 points). The majority of participants preferred high-volume transanal irrigation, with substantial crossover to high-volume transanal irrigation during follow-up. Compared with low-volume transanal irrigation, high-volume transanal irrigation had similar costs (median difference –£8, 95% confidence interval –£240 to £221) and resulted in significantly higher quality of life (0.093 quality-adjusted life-years, 95% confidence interval 0.016 to 0.175 quality-adjusted life-years). CapaCiTY trial 3: laparoscopic ventral mesh rectopexy resulted in a substantial short-term mean reduction in the Patient Assessment of Constipation Quality of Life score (–1.09 points, 95% confidence interval –1.76 to –0.41 points) and beneficial changes in all other outcomes; however, significant increases in cost (£5012, 95% confidence interval £4446 to £5322) resulted in only modest increases in quality of life (0.043 quality-adjusted life-years, 95% confidence interval –0.005 to 0.093 quality-adjusted life-years), with an incremental cost-effectiveness ratio of £115,512 per quality-adjusted life-year.

Conclusions

Excluding poor recruitment and underpowering of clinical effectiveness analyses, several themes emerge: (1) all interventions studied have beneficial effects on symptoms and disease-specific quality of life in the short term; (2) a simpler, cheaper approach to nurse-led behavioural interventions appears to be at least as clinically effective as and more cost-effective than more complex and invasive approaches (including prior investigation); (3) high-volume transanal irrigation is preferred by participants and has better clinical effectiveness than low-volume transanal irrigation systems; and (4) laparoscopic ventral mesh rectopexy in highly selected participants confers a very significant short-term reduction in symptoms, with low levels of harm but little effect on general quality of life.

Limitations

All three trials significantly under-recruited [CapaCiTY trial 1, n = 182 (target 394); CapaCiTY trial 2, n = 65 (target 300); and CapaCiTY trial 3, n = 28 (target 114)]. The numbers analysed were further limited by loss before primary outcome.

Trial registration

Current Controlled Trials ISRCTN11791740, ISRCTN11093872 and ISRCTN11747152.

Funding

This project was funded by the National Institute for Health Research (NIHR) Programme Grants for Applied Research programme and will be published in full in Programme Grants for Applied Research; Vol. 9, No. 14. See the NIHR Journals Library website for further project information.

Stepped-wedge randomised trial of laparoscopic ventral mesh rectopexy in adults with chronic constipation: study protocol for a randomized controlled trial

Background

Laparoscopic ventral mesh rectopexy (LVMR) is an established treatment for external full-thickness rectal prolapse. However, its clinical efficacy in patients with internal prolapse is uncertain due to the lack of high-quality evidence.

Methods

An individual level, stepped-wedge randomised trial has been designed to allow observer-blinded data comparisons between patients awaiting LVMR with those who have undergone surgery. Adults with symptomatic internal rectal prolapse, unresponsive to prior conservative management, will be eligible to participate. They will be randomised to three arms with different delays before surgery (0, 12 and 24 weeks). Efficacy outcome data will be collected at equally stepped time points (12, 24, 36 and 48 weeks). The primary objective is to determine clinical efficacy of LVMR compared to controls with reduction in the Patient Assessment of Constipation Quality of Life (PAC-QOL) at 24 weeks serving as the primary outcome. Secondary objectives are to determine: (1) the clinical effectiveness of LVMR to 48 weeks to a maximum of 72 weeks; (2) pre-operative determinants of outcome; (3) relevant health economics for LVMR; (4) qualitative evaluation of patient and health professional experience of LVMR and (5) 30-day morbidity and mortality rates.

Discussion

An individual-level, stepped-wedge, randomised trial serves the purpose of providing an untreated comparison for the active treatment group, while at the same time allowing the waiting-listed participants an opportunity to obtain the intervention at a later date. In keeping with the basic ethical tenets of this design, the average waiting time for LVMR (12 weeks) will be shorter than that for routine services (24 weeks).

Trial registration

ISRCTN registry, ISRCTN11747152. Registered on 30 September 2015. The trial was prospectively registered (first patient enrolled on 21 March 2016).

Electronic supplementary material

The online version of this article (10.1186/s13063-018-2456-3) contains supplementary material, which is available to authorized users.

Habit training versus habit training with direct visual biofeedback in adults with chronic constipation: study protocol for a randomised controlled trial

Background

Constipation affects up to 20% of adults. Chronic constipation (CC) affects 1–2% of adults. Patient dissatisfaction is high; nearly 80% feel that laxative therapy is unsatisfactory and symptoms have significant impact on quality of life. There is uncertainty about the value of specialist investigations and whether equipment-intensive therapies using biofeedback confer additional benefit when compared with specialist conservative advice.

Methods/design

A three-arm, parallel-group, multicentre randomised controlled trial.

Objectives: to determine whether standardised specialist-led habit training plus pelvic floor retraining using computerised biofeedback is more clinically effective than standardised specialist-led habit training alone; to determine whether outcomes are improved by stratification based on prior investigation of anorectal and colonic pathophysiology. Primary outcome measure is response to treatment, defined as a 0.4-point (10% of scale) or greater reduction in Patient Assessment of Constipation–Quality of Life (PAC-QOL) score 6 months after the end of treatment. Other outcomes up to 12 months include symptoms, quality of life, health economics, psychological health and qualitative experience.

Hypotheses: (1) habit training (HT) with computer-assisted direct visual biofeedback (HTBF) results in an average reduction in PAC-QOL score of 0.4 points at 6 months compared to HT alone in unselected adults with CC, (2) stratification to either HT or HTBF informed by pathophysiological investigation (INVEST) results in an average 0.4-point reduction in PAC-QOL score at 6 months compared with treatment not directed by investigations (No-INVEST).

Inclusion: chronic constipation in adults (aged 18–70 years) defined by self-reported symptom duration of more than 6 months; failure of previous laxatives or prokinetics and diet and lifestyle modifications. Consenting participants (n = 394) will be randomised to one of three arms in an allocation ratio of 3:3:2: [1] habit training, [2] habit training and biofeedback or [3] investigation-led allocation to one of these arms. Analysis will be on an intention-to-treat basis.

Discussion

This trial has the potential to answer some of the major outstanding questions in the management of chronic constipation, including whether costly invasive tests are warranted and whether computer-assisted direct visual biofeedback confers additional benefit to well-managed specialist advice alone.

Trial registration

International Standard Randomised Controlled Trial Number: ISRCTN11791740. Registered on 16 July 2015.

Electronic supplementary material

The online version of this article (doi:10.1186/s13063-017-1880-0) contains supplementary material, which is available to authorized users.

Anismus, Physiology, Radiology: Is It Time for Some Pragmatism? A Comparative Study of Radiological and Anorectal Physiology Findings in Patients With Anismus

Purpose

Anismus is a functional disorder featuring obstructive symptoms and paradoxical contractions of the pelvic floor. This study aims to establish diagnosis agreement between physiology and radiology, associate anismus with morphological outlet obstruction, and explore the role of sphincteric pressure and rectal volumes in the radiological diagnosis of anismus.

Methods

Consecutive patients were evaluated by using magnetic resonance imaging proctography/fluoroscopic defecography and anorectal physiology. Morphological radiological features were associated with physiology tests. A categorical analysis was performed using the chi-square test, and agreement was assessed via the kappa coefficient. A Mann-Whitney test was used to assess rectal volumes and sphincterial pressure distributions between groups of patients. A P-value of <0.05 was significant.

Results

Forty-three patients (42 female patients) underwent anorectal physiology and radiology imaging. The median age was 54 years (interquartile range, 41.5–60 years). Anismus was seen radiologically and physiologically in 18 (41.8%) and 12 patients (27.9%), respectively. The agreement between modalities was 0.298 (P = 0.04). Using physiology as a reference, radiology had positive and negative predictive values of 44% and 84%, respectively. Rectoceles, cystoceles, enteroceles and pathological pelvic floor descent were not physiologically predictive of animus (P > 0.05). The sphincterial straining pressure was 71 mmHg in the anismus group versus 12 mmHg. Radiology was likely to identify anismus when the straining pressure exceeded 50% of the resting pressure (P = 0.08).

Conclusion

Radiological techniques detect pelvic morphological abnormalities, but lead to overdiagnoses of anismus. No proctographic pathological feature predicts anismus reliably. A stronger pelvic floor paradoxical contraction is associated with a greater likelihood of detection by proctography.

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.

Diagnostic accuracy study of anorectal manometry for diagnosis of dyssynergic defecation

OBJECTIVE

The diagnostic accuracy of anorectal manometry (AM), which is necessary to diagnose functional defecatory disorders (FDD), is unknown. Using blinded analysis and standardised reporting of diagnostic accuracy, we evaluated whether AM could discriminate between asymptomatic controls and patients with functional constipation (FC).

DESIGN

Derived line plots of anorectal pressure profiles during simulated defecation were independently analysed in random order by three expert observers blinded to health status in 85 women with FC and 85 age-matched asymptomatic healthy volunteers (HV). Using accepted criteria, these pressure profiles were characterised as normal (ie, increased rectal pressure coordinated with anal relaxation) or types I-IV dyssynergia. Interobserver agreement and diagnostic accuracy were determined.

RESULTS

Blinded consensus-based assessment disclosed a normal pattern in 16/170 (9%) of all participants and only 11/85 (13%) HV. The combined frequency of dyssynergic patterns (I-IV) was very similar in FC (80/85 (94%)) and HV (74/85 (87%)). Type I dyssynergia ('paradoxical' contraction) was less prevalent in FC (17/85 (20%) than in HV (31/85 (36.5%), p=0.03). After statistical correction, only type IV dyssynergia was moderately useful for discriminating between FC (39/85 (46%)) and HV (17/85 (20%)) (p=0.001, positive predictive value=70.0%, positive likelihood ratio=2.3). Interobserver agreement was substantial or moderate for identifying a normal pattern, dyssynergia types I and IV, and FDD, and fair for types II and III.

CONCLUSIONS

While the interpretation of AM patterns is reproducible, nearly 90% of HV have a pattern that is currently regarded as 'abnormal' by AM. Hence, AM is of limited utility for distinguishing between FC and HV.

Diagnostic testing for dyssynergic defecation in chronic constipation: meta-analysis

BACKGROUND

Dyssynergic defecation (DD) results from inadequate relaxation of the pelvic floor on attempted defecation. The prevalence of DD in patients with chronic constipation (CC) is not certain. Aims of this study are to estimate the prevalence of abnormal findings associated with DD across testing modalities in patients referred for physiological testing for CC.

METHODS

Systematic search of MEDLINE, EMBASE and PUBMED databases were conducted. We included full manuscripts reporting DD prevalence in CC, and specific findings at pelvic floor diagnostic tests. Random effects models were used to calculate pooled DD prevalences (with 95% CI) according to individual tests and specific findings.

KEY RESULTS

A total of 79 studies on 7581 CC patients were included. The median prevalence of any single abnormal finding associated with DD was 37.2%, ranging from 14.9% (95% CI 7.9-26.3) for absent opening of the anorectal angle (ARA) on defecography to 52.9% (95% CI 44.3-61.3) for a dyssynergic pattern on ultrasound. The prevalence of a dyssynergic pattern on manometry was 47.7% (95% CI 39.5-56.1). The prevalence of DD was similar across specialty and geographic area as well as when restricting to studies using Rome criteria to define constipation.

CONCLUSIONS & INFERENCES

Dyssynergic defecation is highly prevalent in CC and is commonly detected across testing modalities, type of patient referred, and geographical regions. We believe that the lower prevalence of findings associated with DD by defecography supports use of manometry and balloon expulsion testing as an initial evaluation for CC.

Treatment of obstructed defecation

Obstructed defecation is a common problem that adversely affects the quality of life for many patients. Known causes of obstructed defecation include pelvic dyssynergy, rectocele, rectal intussusception, enterocele, pelvic organ prolapse, and overt rectal prolapse. Management of this condition requires an understanding of urinary, defecatory, and sexual function to achieve an optimal outcome. The goal of surgical treatment is to restore the various pelvic organs to their appropriate anatomic positions. However, there is a poor correlation between anatomic and functional results. As the pelvis contains many structures, a pelvic support or function defect frequently affects other pelvic organs. Optimal outcomes can only be achieved by selecting appropriate treatment modalities that address all of the components of a patient's problem.

Excellent response rate of anismus to botulinum toxin if rectal prolapse misdiagnosed as anismus ('pseudoanismus') is excluded

AIM

Anismus causes obstructed defecation as a result of inappropriate contraction of the puborectalis/external sphincter. Proctographic failure to empty after 30 s is used as a simple surrogate for simultaneous electromyography/proctography. Botulinum toxin is theoretically attractive but efficacy is variable. We aimed to evaluate the efficacy of botulinum toxin to treat obstructed defecation caused by anismus.

METHOD

Botulinum toxin was administered, under local anaesthetic, into the puborectalis/external sphincter of patients with proctographic anismus. Responders (resolution followed by recurrence of obstructed defecation over a 1- to 2-month period) underwent repeat injection. Nonresponders underwent rectal examination under anaesthetic (EUA). EUA-diagnosed rectal prolapse was graded using the Oxford Prolapse Grade 1-5.

RESULTS

Fifty-six patients were treated with botulinum toxin. Twenty-two (39%) responded initially and 21/22 (95%) underwent repeat treatment. At a median follow up of 19.2 (range, 7.0-30.4) months, 20/21 (95%) had a sustained response and required no further treatment. Isolated obstructed defecation symptoms (OR = 7.8, P = 0.008), but not proctographic or physiological factors, predicted response on logistic regression analysis. In 33 (97%) of 34 nonresponders, significant abnormalities were demonstrated at EUA: 31 (94%) had a grade 3-5 rectal prolapse, one had internal anal sphincter myopathy and one had a fissure. Exclusion of these alternative diagnoses revised the initial response rate to 96%.

CONCLUSION

Simple proctographic criteria overdiagnose anismus and underdiagnose rectal prolapse. This explains the published variable response to botulinum toxin. Failure to respond should prompt EUA seeking undiagnosed rectal prolapse. A response to an initial dose of botulinum toxin might be considered a more reliable diagnosis of anismus than proctography.

Electromyographic Activity of the Anterolateral Abdominal Wall Muscles During Rectal Filling and Evacuation

BACKGROUND

The role of the anterolateral abdominal wall muscles (AAWMs) at defecation has not received sufficient attention in the literature. We investigated the hypothesis that the AAWMs exhibit increased electromyographic (EMG) activity on rectal distension, which presumably assists in rectal evacuation.

MATERIALS AND METHODS

The effect of rectal balloon distension on the AAWMs EMG and on anal and rectal pressure was examined in 23 healthy volunteers (37.2 +/- 9.4 SD years, 14 men, 9 women); this effect was tested before and after rectal and AAWMs anesthetization.

RESULTS

The rectal and anal pressures increased gradually upon incremental rectal balloon distension starting at 70 mL balloon distension until, at a mean of 113.6 +/- 5.6 mL, the balloon was expelled to the exterior. The AAWMs showed no EMG activity at rest or on rectal distension up to the time of balloon expulsion when they exhibited significant increase of EMG. This effect was abolished on individual rectal or AAWMs anesthetization but not with saline administration.

CONCLUSIONS

AAWMs appear to contract simultaneously with rectal contraction; this action seems to increase the intra-abdominal pressure and assist rectal evacuation. The AAWMs contraction upon rectal contraction appears to be mediated through a reflex, which we call the "recto-abdominal wall reflex". Further studies are required to investigate the role of this reflex in defecation disorders.

Dynamic MR assessment of the anorectal angle and puborectalis muscle in pediatric patients with anismus: technique and feasibility

PURPOSE

To assess the feasibility of dynamic breath-hold MRI for evaluating changes in the anorectal angle and movements of the pelvic-floor musculature (puborectalis) during resting and straining states in pediatric patients presenting with anismus.

MATERIALS AND METHODS

Six pediatric patients (7-13 years old) with chronic constipation and manometric evidence of anismus were assessed by dynamic breath-hold MRI. Changes in the anorectal angle, the degree of pelvic-floor descent, and the thickness and length of the puborectalis muscles were measured during rest and straining. The findings were compared with those obtained in six age- and sex-matched controls.

RESULTS

The children with anismus had a smaller anorectal angle during straining, and the angle decreased from rest to defecation. The puborectalis also became paradoxically shortened and thickened during straining in the anismus group. There were significant differences between the two groups in terms of the change of degree of the anorectal angle, and the thickness and length of the puborectalis muscle during straining.

CONCLUSION

Fast dynamic MRI is feasible for evaluating pelvic-floor movement in pediatric patients. Preliminary results suggest that children with anismus have a smaller anorectal angle and a different puborectalis configuration compared to controls.

Treatment of obstructed defecation

Obstructed defecation is a common problem that adversely affects the quality of life for many patients. Known causes of obstructed defecation include pelvic dyssynergy, rectocele, rectal intussusception, enterocele, pelvic organ prolapse, and overt rectal prolapse. Management of this condition requires an understanding of urinary, defecatory, and sexual function to achieve optimal outcomes. The goal of surgical treatment is to restore the various pelvic organs to their appropriate anatomic positions. However, there is a poor correlation between anatomic and functional results. It must be remembered that the pelvis contains many structures and that defects of pelvic support or function frequently affect other pelvic organs. Optimal outcomes can be achieved only by selecting appropriate treatment modalities that address all of the components of an individual patient's problem.

Avaliação do ângulo ano-retal por meio de defecograma em voluntárias assintomáticas nulíparas e multíparas

OBJETIVO: Fizemos um protocolo para compararmos as medidas dos ângulos ano-retais em três situações diferentes, em voluntárias assintomáticas nulíparas e multíparas. CASUÍSTICA E MÉTODOS: Foram realizados defecogramas em 30 mulheres (15 nulíparas e 15 multíparas), de maio de 1997 a dezembro de 1998, e obtidas incidências radiográficas em perfil do reto após introdução de contraste baritado texturizado: em repouso, durante contração do músculo puborretal e durante a evacuação. Na análise estatística foi utilizada a análise de medidas repetidas. RESULTADOS: A média do ângulo não apresentou diferença significante entre as voluntárias nulíparas e multíparas. O ângulo mediu, nas nulíparas, 92,9° em repouso, 78,8° durante a contração do músculo puborretal e 117,9° durante a evacuação, e nas multíparas mediu 94,3° em repouso, 79,7° durante a contração do músculo puborretal e 121,4° durante a evacuação. Foi observada diferença significante entre os ângulos em repouso, durante a contração do músculo puborretal e durante a evacuação. CONCLUSÃO: Não houve diferença significante entre os dois grupos examinados.

Obstructed defecation

BACKGROUND

In the last decade our understanding of pelvic floor function and dysfunction has improved significantly. A more rational diagnostic and therapeutic approach is now possible for the group of patients with constipation due to obstructed defecation (OD).

METHODS

The review is based on a literature search using the PubMed database focusing mainly on recent literature addressing the subject.

RESULTS

Obstructed defecation occurs in about 7% of the adult population. Different pathophysiological mechanisms, either functional or anatomical, eventually lead to OD. Different tests (defecography, balloon evacuation test, manometry, electromyography, colonic transit time measurementmanometry) play an important role to quantify the problem. These tests are not without problems as abnormal results are also found in asymptomatic controls. Also, there is poor agreement between different tests and a poor correlation with symptomatology. Thus, for most syndromes conservative treatment including biofeedback is appropriate. Surgery can yield excellent results in selected cases.

CONCLUSION

Validation of scoring systems and quantitative tests is still needed. More uniform and strict criteria for anismus should be applied to make therapeutic approaches comparable. Appropriate selection of patients for surgery is the key to success.

Anorectal functional testing: review of collective experience

Anorectal manometry includes a number of specific tests that are helpful in the diagnostic assessment of patients with fecal incontinence and constipation; their purpose is to delineate the pathophysiological mechanism for these symptoms. Some of these tests may also provide helpful information in the assessment of patients with rectal pain or diarrhea, but their sensitivity and specificity are less well established for these symptoms. Tests for which there is consensus regarding their clinical utility include 1) resting anal canal pressure, 2) anal canal squeeze pressure (peak pressure and duration), 3) the rectoanal inhibitory reflex elicited by balloon distension of the rectum, 4) anal canal pressure in response to a cough, 5) anal canal pressure in response to defecatory maneuvers, 6) simulated defecation by means of balloon or radiopaque contrast, 7) compliance of the rectum in response to balloon distension, and 8) sensory thresholds in response to balloon distension. Anal endosonography and pelvic floor electromyography from intra-anal plate electrodes are nonmanometric tests that are also specifically useful in the evaluation of constipation and fecal incontinence. The clinical utility of all anorectal manometric tests is limited by the relative absence of 1) standardization of test protocols and 2) normative data from a large number of healthy individuals. The interpretation of these diagnostic tests is also complicated by the fact that patients are able to compensate for deficits in specific physiological mechanisms maintaining continence and defecation by utilizing other biological and behavioral mechanisms.

Predictive value of impaired evacuation at proctography in diagnosing anismus

OBJECTIVE

We aimed to determine the positive predictive value of impaired evacuation during evacuation proctography for the subsequent diagnosis of anismus.

SUBJECTS AND METHODS

Thirty-one adults with signs of impaired evacuation (defined as the inability to evacuate two thirds of a 120 mL contrast enema within 30 sec) during evacuation proctography underwent subsequent anorectal physiologic testing for anismus. A physiologic diagnosis of anismus was based on a typical clinical history of the condition combined with impaired rectal balloon expulsion or abnormal surface electromyogram.

RESULTS

Twenty-eight (90%) of the 31 patients with impaired proctographic evacuation were found to have anismus at subsequent physiologic testing. Among the 28 were all 10 patients who evacuated no contrast medium and all 11 patients with inadequate pelvic floor descent, giving evacuation proctography a positive predictive value of 90% for the diagnosis of anismus. A prominent puborectal impression was seen in only three subjects during proctography, one of whom subsequently showed no physiologic sign of anismus.

CONCLUSION

Impaired evacuation during evacuation proctography is highly predictive for diagnosis of anismus.

Outlet Dysfunction Constipation

The diagnosis of outlet dysfunction constipation in patients with idiopathic constipation that responds poorly or not at all to conservative measures, such as fiber supplements, fluids, and stimulant laxatives, is based upon diagnostic testing. These tests include colonic transit of radio-opaque markers, anorectal manometry or electromyography, barium defecography, and expulsion of a water-filled balloon. The literature suggests that conditions such as pelvic floor dyssynergia exist but may be over-diagnosed as a laboratory artifact. In our laboratory, we screen patients with balloon expulsion studies, and then test for dyssynergia only if the result of the balloon expulsion test is abnormal. In my opinion, anal sphincter electromyogram and manometry are equivalent in establishing the diagnosis. Barium defecography is helpful in making a diagnosis of a rectocele, but I prefer to document that vaginal pressure on the rectocele significantly improves rectal evacuation. Manometry also helps to establish the presence of megarectum, hypotonia, and weak expulsion efforts. Conceptually, biofeedback training, which incorporates simulated defecation, is the most logical approach to pelvic floor dyssynergia. It incurs no risk and benefits 60% to 80% of patients. The drawbacks are the time-intensive nature of the therapy and the short-term costs, which are offset if there is sustained benefit. There is no evidence that biofeedback is helpful in children with constipation. Habit training has established benefits, but recurrences are frequent and long-term reinforcement is helpful to maintain success. Laxatives and enemas are adjunctive therapies in both habit training and biofeedback. Surgery is effective in those uncommon patients with physiologically significant rectoceles, but surgical division of the puborectalis muscle is risky and unproven. Likewise, botulinum toxin injection into the puborectalis is unproven, but the effects are rarely permanent should incontinence occur. Diagnostic measures and therapeutic success are enhanced when patients are seen in centers experienced with the evaluation of these disorders.

Imaging of anorectal disease

BACKGROUND

Over the past two decades developments in imaging have changed the assessment of patients with anorectal disease.

METHODS

The literature on imaging techniques for anorectal diseases was reviewed over the period 1980-1999.

RESULTS

For the staging of primary rectal tumours, phased array magnetic resonance imaging (MRI) may be regarded as the most appropriate single technique. The combination of endosonography or endoluminal MRI with ultrasonography or spiral computed tomography yields similar results. All techniques have limitations both for local staging and in the assessment of distant metastases. MRI or positron emission tomography is preferable for tumour recurrence. For perianal fistula, high-resolution MRI (phased array or endoluminal) is the technique of choice. For constipation, defaecography is the preferred technique, nowadays with emphasis on functional information. The role of magnetic resonance defaecography is currently being evaluated. For faecal incontinence, endosonography and endoluminal MRI give similar results in detecting sphincter defects; endoluminal MRI has the advantage of detecting external sphincter atrophy.

CONCLUSION

High-resolution MRI, endosonography and defaecography are currently the optimal imaging techniques for anorectal disease.

Comparative study of two sites of colonic conduit placement in the treatment of constipation due to rectal evacuatory disorders

BACKGROUND

Chronic constipation may be treated by antegrade colonic irrigation via a colonic conduit.

METHODS

Two alternative sites of colonic conduit construction were evaluated for their effect on the symptoms of 21 consecutive women with intractable constipation primarily due to rectal evacuatory disorders. The conduit was constructed in the sigmoid colon in the first 11 patients and in the transverse colon in the subsequent ten. Symptomatic outcome was evaluated clinically and by questionnaires, with a prospective quality of life assessment in the transverse group.

RESULTS

During a median follow-up of 12 (range 6-60) months, reflux or stenosis necessitated revision or dilatation in six patients. Irrigation with a median of 1.3 (0.8-2.0) litres of water achieved evacuation in all patients. Improvements in abdominal pain and bloating were reported by seven of the ten patients in the transverse conduit group, but benefit was found in only three of 11 in the sigmoid group. There was no significant improvement in quality of life scores. In the medium term, seven patients retained a transverse conduit compared with three with a sigmoid conduit.

CONCLUSION

The transverse colonic conduit offers better relief from the symptoms of constipation due to rectal evacuatory dysfunction than the sigmoid conduit.

Identification of patients likely to benefit from biofeedback for outlet obstruction constipation

BACKGROUND

Biofeedback for outlet obstruction constipation has a varying success rate. The aim of this study was to identify which patients are likely to respond to biofeedback.

METHODS

Thirty patients with severe outlet obstruction constipation were treated by a specialist nurse using three or four sessions of visual and auditory feedback of anal sphincter pressures. All patients were assessed by evacuating proctography, whole-gut transit studies and anorectal physiology before treatment.

RESULTS

Two patients did not complete the course of biofeedback. Nine patients improved. Before treatment these patients had predominantly normal anorectal physiology and were all able to open the anorectal angle at evacuating proctography. Nineteen patients did not improve, of whom only three had no measured abnormality other than inability to empty the rectum. Ten of these patients had abnormal anorectal physiology which may have been due to previous vaginal delivery.

CONCLUSION

Biofeedback for outlet obstruction constipation is more likely to be successful in patients without evidence of severe pelvic floor damage.

Clinical significance of anismus in encopresis

Treatments designed to relieve paradoxical contraction of the anal sphincters during defecation (anismus) have had limited success in children with encopresis. This has raised doubts as to the clinical relevance of this diagnosis in childhood as anorectal dysfunction. Our aim was to determine whether, in patients who had treatment-resistant encopresis, the presence of electromyographic anismus was associated with increased faecal retention. Sixty-eight children with soiling (mean age 8.7+/-2.06 years) were assessed by clinical examination, abdominal radiography and then with anorectal manometry. Patients with electromyographic anismus (n=32; 47%) had significantly increased radiographic rectal faecal retention and were significantly less likely to be able to defecate water-filled balloons. There were no significant differences in response to prior therapy, history of primary encopresis, behavioural adjustment or in sociodemographic data. Our results suggest that electromyographic anismus is associated with obstructed defecation and faecal retention.

Anismus: fact or fiction?

PURPOSE

Although anismus has been considered to be the principal cause of anorectal outlet obstruction, it is doubtful whether contraction of the puborectalis muscle during straining is paradoxical. The present study was conducted to answer this question.

METHODS

During the first part of the study, we retrospectively reviewed 121 patients with constipation and/or obstructed defecation (male:female, 10/111; median age, 51 years). All of these patients underwent electromyography (EMG) of the pelvic floor and the balloon expulsion test (BET) in the left lateral position. Evacuation proctography was performed in all of these patients in the sitting position. Both the posterior anorectal angle and the central anorectal angle were measured. EMG and BET were also performed in ten controls (male:female, 4/6; median age, 47). In 147 patients with fecal incontinence (male:female, 24/123; median age, 58) only EMG activity was recorded. Criteria for anismus during straining were increase or insufficient (<20 percent) decrease of EMG activity, failure to expel an air-filled balloon on BET, and decrease or insufficient (<5 percent) increase of anorectal angle on evacuation proctography. Between June 1994 and March 1995, we conducted a second prospective study in a consecutive series of 49 patients with constipation and/or obstructed defecation and 28 patients with fecal incontinence. Both groups were compared with 19 control subjects. In this study, all three tests were performed. EMG and BET were performed both in the left lateral position and in the sitting position.

RESULTS

The retrospective study was undertaken by comparing the constipated patients with the incontinent patients and the controls, and the anismus detected by EMG was found in, respectively, 60, 46, and 60 percent. Failure to expel the air-filled balloon was observed in 80 constipated patients (66 percent) and in 9 control subjects (90 percent). Based on posterior anorectal angle and central anorectal angle measurements, anismus was diagnosed in, respectively, 21 and 35 percent of constipated patients. In the prospective study, none of the tests showed significant differences regarding the prevalence of anismus between the two subgroups of patients and the control subjects. The prevalence of anismus only differed between constipated and incontinent patients when the diagnosis was based on BET in the sitting position (67 vs. 32 percent; P < 0.005). Our study shows that contraction of the puborectalis muscle during straining is not exclusively found in patients with constipation and/or obstructed defecation. The three tests most commonly used for the diagnosis of anismus showed an extremely poor agreement.

CONCLUSION

Based on these findings, we doubt the clinical significance of anismus.

Patterns of anismus and the relation to biofeedback therapy

PURPOSE

A study was undertaken to assess physiologic characteristics and clinical significance of anismus. Specifically, we sought to assess patterns of anismus and the relation of these findings to the success of therapy.

METHODS

Sixty-eight patients were found to have anismus based on history and diagnostic criteria including anismus by defecography and at least one of three additional tests: anorectal manometry, electromyography, or colonic transit time study. Interpretation of defecography was based on the consensus of at least three of four observers. Anal canal hypertonia (n = 32) was defined when mean and maximum resting pressures were at least 1 standard deviation higher than those in 63 controls. There were two distinct defecographic patterns of anismus: Type A (n = 26), a flattened anorectal angle without definitive puborectalis indentation but a closed anal canal; Type B (n = 42), a clear puborectalis indentation, narrow anorectal angle, and closed anal canal. Outcomes of 57 patients who had electromyographybased biofeedback therapy were reported as either improved or unimproved at a mean follow-up of 23.7 (range, 6-62) months. These two types of anismus were compared with biofeedback outcome to assess clinical relevance.

RESULTS

Patients with Type A anismus showed greater perineal descent at rest (mean, 5.1 vs. 3.5 cm; P < 0.01), greater dynamic descent between rest and evacuation (mean, 2.7 vs. 1.4 cm; P < 0.01), greater difference of anorectal angle between rest and evacuation (mean, 14.6 vs. -3.1 degrees; P < 0.001), higher mean resting pressure (mean, 77.1 vs. 62.8 mmHg; P < 0.05), lower mean squeeze pressure (58.8 vs. 80.7 mmHg; P < 0.05), and a higher incidence of anal canal hypertonia (69.2 vs. 33.3 percent; P < 0.01) than did patients with Type B anismus. Only 25 percent of patients who had Type A anismus with anal canal hypertonia were improved by biofeedback therapy. Conversely, 86 percent of patients with Type B anismus without anal canal hypertonia were successfully treated with biofeedback (P < 0.001; Fisher's exact test).

CONCLUSIONS

These two distinct physiologic patterns of anismus correlate with the success of biofeedback treatment. Therefore, knowledge of these patterns may help direct therapy.

Clinical and physiologic effects of biofeedback in outlet obstruction constipation

PURPOSE

We report the results of biofeedback (BF) on patients with outlet obstruction defecation (OOC), including those with and without measurable paradoxical puborectalis contractions (PP). Clinical and anorectal physiologic parameters (ARP) were assessed one week before and after a standardized course of BF.

METHODS

Sixty-two consecutive patients (24 men, 38 women; mean age, 48 (standard error of the mean, 2.3) years) were recruited. All had persistent constipation despite six weeks of dietary fiber supplements. Colonic inertia was excluded by transit marker studies. Defecating proctography excluded anatomic abnormalities causing outlet obstruction. Patients underwent four outpatient sessions of biofeedback, each session lasting one hour.

RESULTS

After BF, 56 patients (90.3 percent) were subjectively improved. Frequency of spontaneous bowel movements were significantly increased (P = 0.003). Frequency of laxative-induced (P = 0.004) and enema-induced (P = 0.005) stools were reduced. Anal resting (P = 0.04) and squeeze (P = 0.002) pressures were increased. Number of patients with PP was reduced from 40 to 31 (P = 0.004). Presence of PP did not affect response to BF. There were no differences in ARP between the 56 patients who improved and the 6 who did not. There were no side effects or clinical regressions after a mean follow-up of 14.9 (standard error of the means, 0.9) months.

CONCLUSIONS

BF effectively treated OOC in 90.3 percent, regardless of PP. Anal pressures were increased, and PP was decreased.

Anorectal and pelvic floor function. Relevance of continence, incontinence, and constipation

Anorectal tests need to be tailored to the presentation of the individual patient. Clearly the tests are most useful when they identify anatomic or physiologic abnormalities for which there are successful treatments. For the incontinent patient, anal manometry is the most useful test. Sphincter injuries should be repaired, whereas neurogenic incontinence is best treated initially with biofeedback. Three tests are more useful for the constipated patient: colonic transit time, degree of pelvic floor descent on straining, and balloon expulsion. Colonic inertia responds to total colectomy and pelvic floor dysfunction to biofeedback. Meanwhile, patients with irritable bowel syndrome require rereferral back to their physicians.

Intrarectal pressures and balloon expulsion related to evacuation proctography

Seventy four patients with constipation were examined by standard evacuation proctography and then attempted to expel a small, non-deformable rectal balloon, connected to a pressure transducer to measure intrarectal pressure. Simultaneous imaging related the intrarectal position of the balloon to rectal deformity. Inability to expel the balloon was associated proctographically with prolonged evacuation, incomplete evacuation, reduced anal canal diameter, and acute anorectal angulation during evacuation. The presence and size of rectocoele or intussusception was unrelated to voiding of paste or balloon. An independent linear combination of pelvic floor descent and evacuation time on proctography correctly predicted maximum intrarectal pressure in 74% of cases. No patient with both prolonged evacuation and reduced pelvic floor descent on proctography could void the balloon, as maximum intrarectal pressure was reduced in this group. A prolonged evacuation time on proctography, in combination with reduced pelvic floor descent, suggests defecatory disorder may be caused by inability to raise intrarectal pressure. A diagnosis of anismus should not be made on proctography solely on the basis of incomplete/prolonged evacuation, as this may simply reflect inadequate straining.

Obstructed defecation: current status of pathophysiology and management

Obstructed defecation poses a challenging clinical problem and in many patients presenting with this syndrome the underlying pathophysiology cannot be determined. Up to now, attempts to diagnose and treat obstructed defecation (anismus) have focused on the function of the somatic pelvic floor musculature surrounding the anorectum, and concepts such as 'puborectalis paradox' and 'spastic pelvic floor' have gained widespread acceptance despite there being no objective data to support such concepts. New evidence showing that defecation is an integrated process of colonic and rectal emptying suggests that anismus may be much more complex than a simple disorder of the pelvic floor muscles. In a small number of patients obstructed defecation is caused by a more simple mechanism, such as internal sphincter hypertonia or a large rectocele, which is easily corrected surgically. Careful selection of patients for treatment, based on identifying the underlying pathophysiological disorder, is emphasized.

[Electromyographic activity of the external anal sphincter muscle and the puborectal muscle in the defecation test in patients with obstructive defecation disorders]

In a prospective electromyographic and manometric study on 23 women (average age 52 years) with obstructive defecation disorder the activity of the external anal sphincter muscle and the puborectal muscle was investigated at rest and during contraction and straining. The control group consisted of 22 healthy women with an average age of 53 years. The main aim of the study was to investigate the functioning of the two muscles during simulated defecation (maximum strain) and to examine any changes in the pressure ratio in the rectum and the anal canal during this stimulation. There were no significant differences in the resting pressure, the contraction pressure and the straining pressure (in the rectum and the anal canal) between the two groups. The functioning of the puborectal muscle and the external anal sphincter muscle was largely the same in both the study group and the control group. No statistically significant differences were found between the two groups except in the amplitude of contraction. When we tried to list the change in the activity of the muscle as an index of anism, we were not able to objectify such a change for either the external anal sphincter muscle or the puborectal muscle. We therefore conclude that the increase in the activity of the voluntary muscle of the pelvic floor observed on electromyography during defecation does not indicate a pathologic condition but is a functional state.