MR defecography in patients with dyssynergic defecation: spectrum of imaging findings and diagnostic value

Assessment of defecation disorders using high-resolution MRI-defecography

AIMS

The aim of this retrospective study was to try to find correlations between different diagnoses established by clinical examination, anorectal manometry and MRI-defecography and, the association with psychiatric disorders.

METHODS

44 patients (median age 53.81 years) presenting with intestinal motility disorders and who underwent clinical, biological and psychiatric examination, dynamic defecographic-MRI (resting, squeezing, straining, defecation and evacuation phases), anorectal manometry, colonoscopy. MRI was performed using the 1,5 T.

RESULTS

MRI-defecography revealed the following changes: anismus (16), rectocele (12), pelvic floor dysfunction (6), peritoneocele (2), cervical-cystic-ptosis (1), rectal prolapse (6), and in 1 case the examination was normal. Hypertonic anal sphincter (16) and lack of defecation reflex (12) at anorectal manometry correlated with anismus in all patients at MRI-defecography. Lack of inhibitor anal reflex (6) was associated with rectocele (4), cervix-cysto-ptosis (1) and peritoneocele (2). Anxiety (11), depression (6) and anxiety-depressive disorders (10) were found in 27/44, somatization disorders in 9/44 and no psychiatric changes in 8/44 cases.

CONCLUSION

As multiparous women are at risk for outlet obstruction constipation, MRI-defecography is suggested in this category. There is good correlation between diagnosis using anorectal manometry and MRI-defecography in patients with terminal constipation and anismus. Lower defecation dysfunction is often associated with psychiatric disorders.

[Dynamic magnetic resonance imaging of the pelvic floor: clinical application]

BACKGROUND

Dynamic magnetic resonance imaging (MRI) of the pelvic floor plays a key role in imaging complex pelvic floor dysfunction. The simultaneous detection of multiple findings in a complex anatomic setting renders correct analysis and clinical interpretation challenging.

OBJECTIVES

The most important aspects (anatomy of the pelvic floor, three compartment model, morphological and functional analysis, reporting) for a successful clinical use of dynamic MRI of the pelvic floor are summarized.

MATERIALS AND METHODS

Review of the scientific literature on dynamic pelvic MR imaging with special consideration of the joint recommendations provided by the expert panel of ESUR/ESGAR in 2016.

RESULTS

The pelvic floor is a complex anatomic structure, mainly formed by the levator ani muscle, the urethral support system and the endopelvic fascia. Firstly, morphological changes of these structures are analysed on the static sequences. Secondly, the functional analysis using the three compartment model is performed on the dynamic sequences during squeezing, straining and defecation. Pelvic organ mobility, pelvic organ prolapse, the anorectal angle and pelvic floor relaxation are measured and graded. The diagnosis of cystoceles, enteroceles, rectoceles, the uterovaginal as well as anorectal decent, intussusceptions and dyssynergic defecation should be reported using a structured report form.

CONCLUSIONS

A comprehensive analysis of all morphological and functional findings during dynamic MRI of the pelvic floor can provide information missed by other imaging modalities and hence alter therapeutic strategies.

Diagnostic performance of dynamic MR defecography in assessment of dyssynergic defecation

PURPOSE

To assess diagnostic performance of MR defecographic findings in diagnosis of dyssynergic defecation (DD).

METHODS

This retrospective study included 46 patients with chronic constipation who met the Rome IV criteria for diagnosis of present or absent DD and underwent MRI between Jan 2015 and June 2020. Patients were divided into DD group (n = 24) and non-DD group (n = 22). Nine parameters were analyzed by two radiologists: anorectal angle (ARA) and M line at rest, defecation, and change between 2 phases; anal canal width; prominent puborectalis muscle; abnormal evacuation. Receiver operating characteristic (ROC) curves were plotted to extract the optimal cut-offs and area under the curve (AUC). Multivariate analysis was performed.

RESULTS

Seven findings showed statistically significant difference between DD and non-DD groups. M line at defecation had highest odds ratio, followed by ARA change, ARA at defecation, M line change, prominent puborectalis muscle, abnormal evacuation and anal canal width, respectively. ARA change and prominent puborectalis muscle had highest specificity (95.5% and 100%, respectively). The optimal cut-offs of ARA at defecation, ARA change, M line at defecation, M line change and anal canal width were 122°, 1.5°, 3.25 cm, 1.9 cm and 8.5 mm, respectively. Multivariate logistic regression revealed two significant findings in differentiating between DD and non-DD, including M line at defecation (OR 23.31, 95% CI 3.10-175.32) and ARA at defecation (OR 13.63, 95% CI 1.94-95.53) with sensitivity, specificity, PPV, NPV and AUC of 79.2%, 95.5%, 95%, 80.8% and 0.87(95% CI 0.78-0.97), respectively.

CONCLUSION

MR defecography has high diagnostic performance in diagnosis of DD. Although M line and ARA at defecation are two significant findings on multivariate analysis, ARA change less than 1.5 degrees and prominent puborectalis muscle have good specificity in DD diagnosis.

Dynamic ileal pouch emptying studies

Although much radiologic literature has focused on the short-term post-operative complications associated with ileal pouches, as the number of patients with long-term pouches has grown, there is increasing realization of the functional deficits that may occur long after pouch creation. Dynamic pouch imaging using fluoroscopy and MRI can provide assessment of the underlying causes of symptomatic pouch dysfunction and can provide critical insight to the management of this complex patient population. In this paper, we provide an overview of the unique problems encountered in patients with long-term ileal pouches, and provide an overview of the techniques, interpretation, and reporting for fluoroscopic and MR pouch defecography.

Imaging Review of Gastrointestinal Motility Disorders

The motor function of the gastrointestinal tract relies on the enteric nervous system, which includes neurons spanning from the esophagus to the internal anal sphincter. Disorders of gastrointestinal motility arise as a result of disease within the affected portion of the enteric nervous system and may be caused by a wide array of underlying diseases. The etiology of motility disorders may be primary or due to secondary causes related to infection or inflammation, congenital abnormalities, metabolic disturbances, systemic illness, or medication-related side effects. The symptoms of gastrointestinal dysmotility tend to be nonspecific and may cause diagnostic difficulty. Therefore, evaluation of motility disorders requires a combination of clinical, radiologic, and endoscopic or manometric testing. Radiologic studies including fluoroscopy, CT, MRI, and nuclear scintigraphy allow exclusion of alternative pathologic conditions and serve as adjuncts to endoscopy and manometry to determine the appropriate diagnosis. Additionally, radiologist understanding of clinical evaluation of motility disorders is necessary for guiding referring clinicians and appropriately imaging patients. New developments and advances in imaging techniques have allowed improved assessment and diagnosis of motility disorders, which will continue to improve patient treatment options. Online supplemental material is available for this article. ^©RSNA, 2022.

Intra- and inter-observer agreement in the classification of dyssynergic defecation on high-resolution anorectal manometry using water-perfusion system

BACKGROUND AND AIMS

Dyssynergic defecation (DD) classified on anorectal manometry is based on variations in anal sphincter pressures and rectal pressure generated during bearing down. There is a paucity of data on intra- and inter-observer agreement in the classification of DD on high-resolution anorectal manometry (HRAM) using a water-perfusion system.

METHODS

This cross-sectional observational study was conducted between June 2014 and May 2016 on 70 adult patients with DD. Observer 1 did the baseline analysis and reanalyzed the readings at least 6 months later, blinded to the initial analysis results (intra-observer variability). Four other blinded observers (5-25 years in anorectal manometry and minimum 5 years of experience in HRAM) then individually analyzed the manometry data (inter-observer variability).

RESULTS

Intra-observer agreement was excellent (kappa 0.862) for classifying DD. Agreement between the six observations (i.e. two from observer 1 and four from independent observers) was also good (kappa 0.632). The highest agreement was for type 4 DD (kappa 0.738), followed by type 1 (0.680), type 2 (0.664), and type 3 (0.537). Cronbach's alpha value was 0.93, suggesting excellent internal consistency.

CONCLUSION

The diagnosis of the types of DD on anorectal manometry using a water-perfusion system has excellent intra-observer and good inter-observer agreement .

ACR Appropriateness Criteria® Pelvic Floor Dysfunction in Females

Pelvic floor disorders including pelvic organ prolapse (POP), urinary dysfunction, defecatory dysfunction, and complications after pelvic floor surgery are relatively common in the female population. Imaging tests are obtained when the initial clinical evaluation is thought to be incomplete or inconclusive or demonstrates findings that are discordant with patients' symptoms. An integrated imaging approach is optimal to evaluate the complex anatomy and dynamic functionality of the pelvic floor. Fluoroscopic cystocolpoproctography (CCP) and MR defecography are considered the initial imaging tests of choice for evaluation of POP. Fluoroscopic voiding cystourethrography is considered the initial imaging test for patients with urinary dysfunction. Fluoroscopic CCP and MR defecography are considered the initial imaging test for patients with defecatory dysfunction, whereas ultrasound pelvis transrectal is a complementary test in patients requiring evaluation for anal sphincter defects. MRI pelvis without and with intravenous contrast, MRI pelvis with dynamic maneuvers, and MR defecography are considered the initial imaging tests in patients with suspected complications of prior pelvic floor surgical repair. Transperineal ultrasound is emerging as an important imaging tool, in particular for screening of pelvic floor dysfunction and for evaluation of midurethral slings, vaginal mesh, and complications related to prior pelvic floor surgical repair. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

Diagnostic Strategy and Tools for Identifying Defecatory Disorders

This article reviews the indications, techniques, interpretation, strengths, and weaknesses of tests (anal manometry, anal surface electromyography, rectal balloon expulsion test, barium and MRI defecography, assessment of rectal compliance and sensation, and colonic transit) that are used diagnose defecatory disorders in constipated patients. The selection of tests and the sequence in which they are performed should be individualized to and interpreted in the context of the clinical features. Because anorectal functions are affected by age, results should be interpreted with reference to age- and sex-matched normal values for the same technique.

ACG Clinical Guidelines: Management of Benign Anorectal Disorders

Benign anorectal disorders of structure and function are common in clinical practice. These guidelines summarize the preferred approach to the evaluation and management of defecation disorders, proctalgia syndromes, hemorrhoids, anal fissures, and fecal incontinence in adults and represent the official practice recommendations of the American College of Gastroenterology. The scientific evidence for these guidelines was assessed using the Grading of Recommendations Assessment, Development and Evaluation process. When the evidence was not appropriate for Grading of Recommendations Assessment, Development and Evaluation, we used expert consensus to develop key concept statements. These guidelines should be considered as preferred but are not the only approaches to these conditions.

Defecatory Dysfunction

Normal defecation is a complex and coordinated physiologic process that involves the rectum, anus, anal sphincter complex, and pelvic floor muscles. Any alteration of this process can be considered defecatory dysfunction, a term that covers a broad range of disorders, including slow-transit constipation, functional constipation, and functional or anatomic outlet obstruction. Evaluation should include history, physical, and consideration of additional testing such as colonoscopy, colonic transit studies, defecography, and/or anorectal manometry. Depending on the etiology, management options can include conservative measures such as dietary or lifestyle modifications, medications, pelvic floor physical therapy, or surgical repair.

The Effect of Biofeedback Therapy Combined with Comprehensive Nursing Intervention on the Quality of Life of Patients with Functional Constipation Based on Dynamic Magnetic Resonance Defecation

In order to study the quality of life of patients with functional constipation based on dynamic magnetic resonance defecation, the biofeedback therapy combined with comprehensive nursing intervention was used to diagnose and treat the patients, so as to explore its clinical efficacy and its impact on patients' quality of life. The obstructed defecation surgical treatment carries frequent recurrences, and dynamic magnetic resonance imaging defecography evaluated and elucidated the underlying anatomic features. This research selected 80 patients who came to our hospital for treatment of functional constipation and evaluated and recorded various clinical indicators before and after treatment in the form of questionnaire survey. The results showed that the clinical symptom scores of patients with functional constipation before and after treatment were greatly different (P < 0.05). Thus, the biofeedback therapy combined with comprehensive nursing intervention showed a good clinical effect in the treatment of patients with functional constipation and significantly improved the quality of life of patients, showing high clinical application and promotion value. A convenient diagnostic procedure is represented by the dynamic magnetic resonance imaging in females, especially pelvic floor organs dynamic imaging during defecation.

Imaging and clinical assessment of functional defecatory disorders with emphasis on defecography

Functional defecation disorders (FDD) encompass causes of constipation associated with anorectal dysfunction, which include dyssynergia or inadequate defecatory propulsion. FDD are frequently encountered in clinical practice and may affect up to 33-50% of patients with chronic constipation. The etiology of FDD is unclear, however, it has been defined as an acquired, but subliminal behavioral disorder. Pathophysiologic mechanisms may include discoordination of rectoanal muscles, paradoxical contraction or insufficient relaxation of puborectalis and/or anal sphincter during defecation, and sluggish colonic transit. A combination of comprehensive clinical assessment, digital rectal examination and a battery of physiologic tests are needed to make an accurate diagnosis of FDD. Defecography may play a crucial role in the evaluation of FDD, especially when a balloon expulsion test (BET) and/or anorectal manometry (ARM) are equivocal or demonstrate contradictory results. In this review, we provide a thorough overview of the epidemiology, pathophysiology, diagnostic criteria, clinical and imaging evaluation, and treatment options for FDD, with an emphasis on available diagnostic imaging tools such as defecography and conventional fluoroscopic methods.

MR defecography review

Pelvic floor dysfunction is a relatively common but often complex condition, presenting with a variety of clinical symptoms, especially when it involves multiple compartments. Clinical exam alone is often inadequate and requires a complementary imaging study. Magnetic resonance defecography (MRD) is an excellent noninvasive diagnostic study with its multiplanar capability, lack of ionizing radiation and excellent soft tissue resolution. It can identify both anatomic and functional abnormalities in the pelvic floor and specifically excels in its ability to simultaneously detect multicompartmental pathology and help with vital pre-operative assessment. This manuscript reviews the relevant anatomical landmarks, describes the optimal technique, highlights an approach to the interpretation of MRD, and provides an overview of the various pelvic floor disorders in the different anatomical compartments.

Functional Constipation: Individualising Assessment and Treatment

Chronic constipation is one of the five most common symptoms seen by gastroenterologist. In the absence of alarm symptoms, a confident symptom-based diagnosis can often be made using the Rome criteria. Three different subtypes have been identified to date: normal transit constipation, defaecatory disorders and slow transit constipation. Differentiation between these subtypes can be made through functional testing using tests such as anorectal manometry with balloon expulsion and a radio-opaque marker test. In general, patients are initially advised to increase their fluid and fibre intake. When these general lifestyle recommendations do not improve patients' symptoms, a step-wise and add-on treatment approach should be applied. This review summarises the diagnostic criteria to differentiate functional constipation from other causes of chronic constipation. In addition, current drug treatment options, including discussion of new therapeutic targets are discussed. Further, practical treatment approaches (choice and dosing), include discussion of combination/augmentation, treatment failure (adherence/expectations), and relapse prevention are mentioned. Finally, treatment and management of pain and bloating aspects are included.

Seated anorectal manometry during simulated evacuation: A physiologic exercise or a new clinically useful diagnostic test?

Symptoms such as a feeling of incomplete evacuation, straining, absence of the call to stool, anal blockage, or digitation suggest the presence a functional defecation disorder. As symptoms do not distinguish between patients with and without functional defecation disorder, Rome IV criteria recommend that this disorder is diagnosed when two of three tests are positive: balloon expulsion test (BET), anorectal manometry (ARM), and defecography. However, previous studies have demonstrated that the agreement among these tests is limited. In this issue of Neurogastroenterology and Motility, Sharma et al tested the hypothesis that conducting the ARM in a seated position would increase the diagnostic accuracy of the test in discriminating between patients with normal and prolonged BET. This minireview discusses the current knowledge on the role of the techniques to diagnose defecation disorder and the potential role of the ARM in a seated position.

Mechanisms, Evaluation, and Management of Chronic Constipation

With a worldwide prevalence of 15%, chronic constipation is one of the most frequent gastrointestinal diagnoses made in ambulatory medicine clinics, and is a common source cause for referrals to gastroenterologists and colorectal surgeons in the United States. Symptoms vary among patients; straining, incomplete evacuation, and a sense of anorectal blockage are just as important as decreased stool frequency. Chronic constipation is either a primary disorder (such as normal transit, slow transit, or defecatory disorders) or a secondary one (due to medications or, in rare cases, anatomic alterations). Colonic sensorimotor disturbances and pelvic floor dysfunction (such as defecatory disorders) are the most widely recognized pathogenic mechanisms. Guided by efficacy and cost, management of constipation should begin with dietary fiber supplementation and stimulant and/or osmotic laxatives, as appropriate, followed, if necessary, by intestinal secretagogues and/or prokinetic agents. Peripherally acting μ-opiate antagonists are another option for opioid-induced constipation. Anorectal tests to evaluate for defecatory disorders should be performed in patients who do not respond to over-the-counter agents. Colonic transit, followed if necessary with assessment of colonic motility with manometry and/or a barostat, can identify colonic dysmotility. Defecatory disorders often respond to biofeedback therapy. For specific patients, slow-transit constipation may necessitate a colectomy. No studies have compared inexpensive laxatives with newer drugs with different mechanisms. We review the mechanisms, evaluation, and management of chronic constipation. We discuss the importance of meticulous analyses of patient history and physical examination, advantages and disadvantages of diagnostic testing, guidance for individualized treatment, and management of medically refractory patients.

MR defecography detects pelvic floor dysfunction in participants with chronic complete spinal cord injury

STUDY DESIGN

A prospective single arm study.

OBJECTIVES

Previously we have demonstrated that magnetic resonance (MR) defecography is feasible in participants with complete spinal cord injury (SCI). The main aim of this study is to evaluate whether MR defecography can provide objective parameters correlating with the clinical manifestations of neurogenic bowel dysfunction (NBD) in participants with SCI.

SETTING

A monocentric study in a comprehensive care university hospital Spinal Cord Injury Center.

METHODS

Previously published MR defecography parameters (anorectal angle (ARA), hiatal descent (M-line) and hiatal width (H-line)) of twenty participants with SCI were now compared to a standardized clinical assessment of NBD. Descriptive statistics, correlations and t-tests for independent samples were calculated.

RESULTS

The significantly higher values for the ARA at rest and M-line at rest in participants with SCI correlated with the clinical assessment of bowel incontinence. Furthermore, in nearly half of the investigated SCI cohort the normally positive difference between ARA, M-line and H-line at rest and during defecation became negative suggesting pelvic floor dyssynergia as a potential mechanism underlying constipation in people with complete SCI. In fact, these participants showed a more severe clinical presentation of NBD according to the total NBD score.

CONCLUSIONS

MR defecography provides objective parameters correlating with clinical signs of NBD, such as constipation and bowel incontinence. Therefore, MR defecography can support pathophysiology-based decision-making with respect to specific therapeutic interventions, which should help to improve the management of NBD.

Colonic transit, high-resolution anorectal manometry and MRI defecography study of constipation in Parkinson's disease

INTRODUCTION

Despite clinical relevance and potential role on the disease pathogenesis, underlying mechanisms of constipation in Parkinson's disease (PD) remain poorly understood. A systematic assessment using complementary physiological investigations was performed to elucidate constipation pathophysiology in order to improve its symptomatic management.

METHODS

PD patients with constipation were evaluated with clinical questionnaires, colonic transit, high-resolution anorectal manometry and MRI defecography. Results were compared and correlated with clinical features.

RESULTS

A total of 42 patients (69% male; age 68 ± 8 years; disease duration 10.5 ± 6.1 years) were included, of whom 33 (78.6%) had objective constipation defined by < 3 bowel movements per week or straining. Severity of constipation measured by self-administered questionnaires correlated with disease severity, burden of motor and non-motor symptoms but not with age, disease duration or Parkinson's medications. Colonic transit and anorectal function (high-resolution anorectal manometry and/or MRI defecography) was assessed in 15 patients. A combination of both delayed colonic transit and anorectal dysfunction was the pattern most commonly found (60% of patients) and overall anorectal dysfunction was more prevalent than isolated slow transit constipation. Physiological findings were heterogeneous including reduced colonic motility, rectal hyposensitivity, defecatory dyssynergia and poor motor rectal function.

CONCLUSION

Subjective constipation in PD is poorly correlated with commonly used definition, assessment questionnaires and physiological results. Multiple complex overlapping pathophysiological mechanisms are responsible including slow transit and anorectal dysfunction. Complementary investigations to assess colonic transit and anorectal function are required in those with refractory symptoms for a systematic assessment and appropriate symptomatic management.

Dynamic MRI of the pelvic floor: comparison of performance in supine vs left lateral body position

OBJECTIVE:

To investigate the performance of MR-defecography (MRD) in lateral body position as an alternative to supine position.

METHODS:

22 consecutive patients (16 females; mean age 51 ± 19.4) with obstructed defecation and 20 healthy volunteers (11 females; mean age 33.4 ± 11.5) underwent MRD in a closed-configuration 3T-MRI in supine and lateral position. MRD included T₂ weighted images at rest and during defecation after filling the rectum with 250 ml water-based gel. Measurements were performed in reference to the pubococcygeal line and grade of evacuation was assessed. Image quality (IQ) was rated on a 5-point-scale (5 = excellent).

RESULTS:

In patients grades of middle and posterior compartment descent were similar in both body positions (p > 0.05). Grades of anterior compartment descent were significantly higher in lateral position (21/22 vs 17/22 patients with normal or small descent, p < 0.034). In volunteers grades of descent were similar for all compartments in supine and lateral position (p > 0.05). When attempting to defecate in supine position 6/22 (27%) patients showed no evacuation, while in lateral position only 3/22 (14%) were not able to evacuate. IQ in patients was equal at rest (4.4 ± 0.5 and 4.7 ± 0.6, p > 0.05) and slightly better in supine compared to the lateral position during defecation (4.5 ± 0.4 vs 3.9 ± 0.9, p < 0.017). IQ in volunteers was equal in supine and lateral position (p > 0.05).

CONCLUSION:

In lateral position, more patients were able to evacuate with similar grades of pelvic floor descent compared to supine position. MRD in lateral position may be a valuable alternative for patients unable to defecate in supine position.

ADVANCES IN KNOWLEDGE:

In lateral position, more patients were able to evacuate during MRD. MRD in lateral position may be an alternative for patients unable to defecate in supine position.

Pelvic MRI: Is Endovaginal or Rectal Filling Needed?

Magnetic resonance imaging is the optimal modality for pelvic imaging. It is based on T2-weighted magnetic resonance (MR) sequences allowing uterine and vaginal cavity assessment as well as rectal evaluation. Anatomical depiction of these structures may benefit from distension, and conditions either developing inside the lumen of cavities or coming from the outside may then be better delineated and localized. The need for distension, either rectal or vaginal, and the way to conduct it are matters of debate, depending on indication for which the MR examination is being conducted. In this review, we discuss advantages and potential drawbacks of this technique, based on literature and our experience, in the evaluation of various gynecological and rectal diseases.

The Mexican consensus on chronic constipation

INTRODUCTION

Significant advances have been made in the knowledge and understanding of the epidemiology, pathophysiology, diagnosis, and treatment of chronic constipation, since the publication of the 2011 guidelines on chronic constipation diagnosis and treatment in Mexico from the Asociación Mexicana de Gastroenterología.

AIMS

To present a consensus review of the current state of knowledge about chronic constipation, providing updated information and integrating the new scientific evidence.

METHODS

Three general coordinators reviewed the literature published within the time frame of January 2011 and January 2017. From that information, 62 initial statements were formulated and then sent to 12 national experts for their revision. The statements were voted upon, using the Delphi system in 3 voting rounds (2 electronic and one face-to-face). The statements were classified through the GRADE system and those that reached agreement >75% were included in the consensus.

RESULTS AND CONCLUSIONS

The present consensus is made up of 42 final statements that provide updated knowledge, supplementing the information that had not been included in the previous guidelines. The strength of recommendation and quality (level) of evidence were established for each statement. The current definitions of chronic constipation, functional constipation, and opioid-induced constipation are given, and diagnostic strategies based on the available diagnostic methods are described. The consensus treatment recommendations were established from evidence on the roles of diet and exercise, fiber, laxatives, new drugs (such as prucalopride, lubiprostone, linaclotide, plecanatide), biofeedback therapy, and surgery.

The usefulness of MR defecography in the evaluation of pelvic floor dysfunction: our experience using 3T MRI

PURPOSE

To assess the usefulness of MR defecography in evaluating pelvic floor dysfunction, and to correlate several pelvic organ abnormalities with each other and with patients' symptoms and characteristics.

METHODS

MR defecographic examinations performed in 3T MRI machine of 95 patients (70 females, 25 males; mean age 48) were retrospectively reviewed. Pelvic organ abnormalities from all three compartments were recorded, including the anorectal junction descent, anterior rectocele, and cystocele. These were graded according to the known HMO system in relation to the pubococcygeal line. The correlation between these different abnormalities and their relation to patient symptoms and characteristics were evaluated.

RESULTS

Anorectal junction descent and anterior rectocele were most commonly observed, predominantly manifesting in female patients. Both were associated with abnormalities from all compartments. The middle compartment was the least affected, and its abnormality of uterine/vaginal descent tended to occur in association with the anterior compartment abnormality (cystocele). Anismus was low in incidence, and was not associated with other compartments abnormalities. Both enterocele/peritoneocele and intussusception were uncommon.

CONCLUSION

MR defecography is the modality of choice in assessing pelvic floor dysfunction, because it can neatly show various pelvic organ abnormalities from all compartments in a dynamic fashion, which are frequently coexistent. It can even show clinically silent or unsuspected abnormalities which can impact the management of patients.

Defecographic Findings in Patients with Severe Idiopathic Chronic Constipation

Background/Aims

Chronic constipation is a common gastrointestinal disorder diagnosed using Rome III criteria. Defecography is a radiographic method used to identify anatomic abnormalities of anorectum. The present study aimed to evaluate the defecographic findings in patients with severe idiopathic chronic constipation.

Methods

One hundred patients, who complained of severe idiopathic chronic constipation with abnormal balloon expulsion test, underwent defecography after injection of barium. An analysis of radiographs was performed by an expert radiologist for the diagnosis of descending perineum syndrome, rectocele, enterocele, rectal ulcer, rectal prolapse, fecal residue of post defecation, and etc. Then, they were compared between the two sexes.

Results

Normal defecography was only observed in two participants. Descending perineum syndrome was the most common abnormality (73.3%). The results showed that rectocele (80.8%) and descending perineum syndrome (69.2%) were most frequent in women. In males, descending perineum syndrome and rectal prolapse were more prevalent (87% and 43.5%, respectively). Compared with men, rectocele and rectal ulcer were more frequently observed in women (p<0.001, and p=0.04, respectively), while men were more affected by descending perineum syndrome (p=0.04). In total, women had a greater incidence of abnormal defecographic findings compared with men (p=0.02).

Conclusions

Defecography can be performed to detect anatomic abnormalities in patients with severe idiopathic chronic constipation and abnormal balloon expulsion test. This technique can assist physicians in making the most suitable decision for surgical procedure.

Relevance of the Clinical and Psychophysiological Variables in the Dyssynergic Defecation: A Comparative Study in Elderly Subjects

The relevance of several clinical and psychophysiological variables in the dyssynergic defecation in elderly subjects was investigated in this study. To accomplish this, 30 elderly subjects (10 without anorectal disorders, 10 with chronic constipation and 10 with dyssynergic defecation) were repeatedly assessed once per week for 4 weeks, with the following measures being collected at each session: EMG-activity (µV) of the external anal sphincter (at rest, during squeezing, and during straining to defecate), stool frequency, difficulty defecation level, pain grade during defecation, and satisfaction level after evacuation. A 3 (group) × 4 (sessions) mixed-measures MANOVA revealed a significant main effect for group (Wilks's lambda = 0.006; F = 28.45; p < 0.01), but not for sessions (Wilks's lambda = 0.874; F = 0.94; p > 0.05) or for the group x sessions interaction (Wilks's lambda = 0.811; F = 1.45; p > 0.05). One-way ANOVA and Scheffé's posthoc tests were used to isolate the differences between the groups with respect to the seven different measures. These analysis showed significant differences between the groups on all four clinical variables but only for one psychophysiological variable, EMG-activity during straining to defecate. Significant differences were evidenced between all pairs examined for the difficulty defecation level and pain grade. The complete results of these analysis are presented and the conclusions drawn from them are discussed.

High-resolution Anorectal Manometry for Identifying Defecatory Disorders and Rectal Structural Abnormalities in Women

BACKGROUND & AIMS

Contrary to conventional wisdom, the rectoanal gradient during evacuation is negative in many healthy people, undermining the utility of anorectal high-resolution manometry (HRM) for diagnosing defecatory disorders. We aimed to compare HRM and magnetic resonance imaging (MRI) for assessing rectal evacuation and structural abnormalities.

METHODS

We performed a retrospective analysis of 118 patients (all female; 51 with constipation, 48 with fecal incontinence, and 19 with rectal prolapse; age, 53 ± 1 years) assessed by HRM, the rectal balloon expulsion test (BET), and MRI at Mayo Clinic, Rochester, Minnesota, from February 2011 through March 2013. Thirty healthy asymptomatic women (age, 37 ± 2 years) served as controls. We used principal components analysis of HRM variables to identify rectoanal pressure patterns associated with rectal prolapse and phenotypes of patients with prolapse.

RESULTS

Compared with patients with normal findings from the rectal BET, patients with an abnormal BET had lower median rectal pressure (36 vs 22 mm Hg, P = .002), a more negative median rectoanal gradient (-6 vs -29 mm Hg, P = .006) during evacuation, and a lower proportion of evacuation on the basis of MRI analysis (median of 40% vs 80%, P < .0001). A score derived from rectal pressure and anorectal descent during evacuation and a patulous anal canal was associated (P = .005) with large rectoceles (3 cm or larger). A principal component (PC) logistic model discriminated between patients with and without prolapse with 96% accuracy. Among patients with prolapse, there were 2 phenotypes, which were characterized by high (PC1) or low (PC2) anal pressures at rest and squeeze along with higher rectal and anal pressures (PC1) or a higher rectoanal gradient during evacuation (PC2).

CONCLUSIONS

In a retrospective analysis of patients assessed by HRM, measurements of rectal evacuation by anorectal HRM, BET, and MRI were correlated. HRM alone and together with anorectal descent during evacuation may identify rectal prolapse and large rectoceles, respectively, and also identify unique phenotypes of rectal prolapse.

Constipation: Pathophysiology and Current Therapeutic Approaches

Chronic constipation is a common, persistent condition affecting many patients worldwide, presenting significant economic burden and resulting in substantial healthcare utilization. In addition to infrequent bowel movements, the definition of constipation includes excessive straining, a sense of incomplete evacuation, failed or lengthy attempts to defecate, use of digital manoeuvres for evacuation of stool, abdominal bloating, and hard consistency of stools. After excluding secondary causes of constipation, chronic idiopathic or primary constipation can be classified as functional defecation disorder, slow-transit constipation (STC), and constipation-predominant irritable bowel syndrome (IBS-C). These classifications are not mutually exclusive and significant overlap exists. Initial therapeutic approach to primary constipation, regardless of aetiology, consists of diet and lifestyle changes such as encouraging adequate fluid and fibre intake, regular exercise, and dietary modification. Laxatives are the mainstay of pharmacologic treatment for potential long-term therapy in patients who do not respond to lifestyle or dietary modification. After a failed empiric trial of laxatives, diagnostic testing is necessary to understand underlying anorectal and/or colonic pathophysiology. No single test provides a comprehensive assessment for primary constipation; therefore, multiple tests are used to provide complementary information to one another. Dyssynergic defecation, a functional defecation disorder, is an acquired behavioural disorder of defecation present in two-thirds of adult patients, where an inability to coordinate the abdominal, recto-anal, and pelvic floor muscles during attempted defecation exists. Biofeedback therapy is the mainstay treatment for dyssynergic defecation aimed at improving coordination of abdominal and anorectal muscles. A large percentage of patients with dyssynergic defecation also exhibit rectal hyposensitivity and may benefit from the addition of sensory retraining. Our understanding of the pathophysiology of STC is evolving. The advent of high-resolution colonic manometry allows for the improved identification of colonic motor patterns and may provide further insight into pathophysiological mechanisms. In a minority of cases of STC, identification of colonic neuropathy suggests a medically refractory condition, warranting consideration of colectomy. The pathophysiology of IBS-C is poorly understood with multiple etiological factors implicated. Pharmacological advances in the treatment of primary constipation have added therapeutic options to the armamentarium of this disorder. Drug development in the secretagogue, serotonergic prokinetic, and ileal bile acid transporter inhibition pathways has yielded current and future medical treatment options for primary chronic constipation.

Guidelines for the Diagnosis and Treatment of Chronic Functional Constipation in Korea, 2015 Revised Edition

The Korean Society of Neurogastroenterology and Motility first published guidelines for chronic constipation in 2005 and was updated in 2011. Although the guidelines were updated using evidence-based process, they lacked multidisciplinary participation and did not include a diagnostic approach for chronic constipation. This article includes guidelines for diagnosis and treatment of chronic constipation to realistically fit the situation in Korea and to be applicable to clinical practice. The guideline development was based upon the adaptation method because research evidence was limited in Korea, and an organized multidisciplinary group carried out systematical literature review and series of evidence-based evaluations. Six guidelines were selected using the Appraisal of Guidelines for Research & Evaluation (AGREE) II process. A total 37 recommendations were adopted, including 4 concerning the definition and risk factors of chronic constipation, 8 regarding diagnoses, and 25 regarding treatments. The guidelines are intended to help primary physicians and general health professionals in clinical practice in Korea, to provide the principles of medical treatment to medical students, residents, and other healthcare professionals, and to help patients for choosing medical services based on the information. These guidelines will be updated and revised periodically to reflect new diagnostic and therapeutic methods.

Diagnosis and management of chronic constipation in adults

Constipation is a heterogeneous, polysymptomatic, multifactorial disease. Acute or transient constipation can be due to changes in diet, travel or stress, and secondary constipation can result from drug treatment, neurological or metabolic conditions or, rarely, colon cancer. A diagnosis of primary chronic constipation is made after exclusion of secondary causes of constipation and encompasses several overlapping subtypes. Slow-transit constipation is characterized by prolonged colonic transit in the absence of pelvic floor dysfunction. This subtype of constipation can be identified using either the radio-opaque marker test or wireless motility capsule test, and is best treated with laxatives such as polyethylene glycol or newer agents such as linaclotide or lubiprostone. If unsuccessful, subspecialist referral should be considered. Dyssynergic defecation results from impaired coordination of rectoanal and pelvic floor muscles, and causes difficulty with defecation. The condition can be identified using anorectal manometry and balloon expulsion tests and is best managed with biofeedback therapy. Opioid-induced constipation is an emerging entity, and several drugs including naloxegol, methylnaltrexone and lubiprostone are approved for its treatment. In this Review, we provide an overview of the burden and pathophysiology of chronic constipation, as well as a detailed discussion of the available diagnostic tools and treatment options.

Assessment of Obstructive Defecation by High-Resolution Anorectal Manometry Compared With Magnetic Resonance Defecography

BACKGROUND & AIMS

Patients with obstructive defecation have abnormalities of anorectal function and/or structure. Conventional anorectal manometry (ARM) can identify abnormal function and behavior (dyssynergia); however, agreement between manometry and defecography is only fair. High-resolution (HR)-ARM may improve diagnostic agreement by differentiating pressure effects caused by dyssynergia and obstruction. We compared HR-ARM findings with magnetic resonance (MR) defecography in the clinical assessment of patients with symptoms of obstructive defecation defined by Rome III criteria.

METHODS

HR-ARM (Manoscan AR 360; Given Imaging, Yoqeam, Israel) assessed anal sphincter function and pressure during simulated defecation. Abnormal manometric findings were classified according to the Rao system and compared with MR defecography as the reference standard.

RESULTS

A total of 188 consecutive patients (155 women; age, 19-93 y) with obstructive defecation underwent a full investigation. Compared with patients with dyssynergia on MR imaging (n = 66), patients with structural pathology (n = 87) had lower resting (P < .003) and squeeze pressures (P < .011), but a higher rectoanal pressure gradient (P < .0001) on HR-ARM. High intrarectal pressure with a steep, positive pressure gradient consistent with outlet obstruction on HR-ARM was present in 24 patients with intra-anal intussusception on MR imaging. This pattern was not observed in other patients. Interobserver agreement was substantial for HR-ARM diagnoses (κ = 0.67; 95% confidence interval, 0.559-0.779). Diagnostic accuracy for dyssynergia was 82% compared with MR imaging (sensitivity, 77% [51 of 66]; specificity, 85% [104 of 122]).

CONCLUSIONS

The diagnostic agreement between anorectal HR-ARM and MR defecography is high and pressure measurements accurately identify recto-anal dyssynergia and intra-anal outlet obstruction by structural pathology as causes of obstructive defecation.

MR defecography: a diagnostic test for the evaluation of pelvic floor motion in patients with dyssynergic defecation after biofeedback therapy

BACKGROUND

Dyssynergic defecation is a major cause of chronic functional constipation as a common digestive complaint. We clinically evaluated the effects of biofeedback therapy on the pelvic floor motion indices through magnetic resonance (MR) defecography, quality of life and depression in patients with dyssynergic defecation.

METHODS

In this clinical trial study, among patients referring to the Colorectal Clinic of Hazrat Rasoul Hospital, 22 subjects were randomly assigned into two equal groups (n= 11) to receive either standard only or biofeedback and standard therapy. Dynamic changes of the pelvic floor were measured by MR defecography. During the simulated defecation, two MR defecography dynamic indices including abnormal anorectal angle change and perineal descent were measured before and after treatment. The effects of biofeedback therapy on patients' symptoms, quality of life and severity of depression were assessed and compared with the standard therapy. Statistical analysis was carried out using independent _t-test and Mann-Whitney test.

RESULTS

Paradox index (p< 0.001), perineal descent index (p< 0.001), depression (p< 0.1), physical function (p< 0.001), vitality (p< 0.001) and role emotion (p< 0.001) significantly improved in the biofeedback therapy group in contrast to the standard therapy SDT group.

CONCLUSION

Biofeedback therapy appears to be effective in improving symptoms of functional constipation and dysfunction of pelvic floor motion as well as patient's quality of life and depression state. MR defecography is able to show the changes in dynamic indices of the pelvic floor through biofeedback therapy.

High-resolution anorectal manometry and dynamic pelvic magnetic resonance imaging are complementary technologies

BACKGROUND AND AIM

Dynamic pelvic magnetic resonance imaging (DP-MRI) offers a comprehensive evaluation of pelvic organ structure in addition to functional information regarding evacuation. Opportunity to apply this technology can be limited due to regional lack of availability. Ideally, clues from standard anorectal testing could predict abnormalities on DP-MRI, leading to its efficient use. The aim of this study is to determine whether high-resolution anorectal manometry (HR-ARM) correlates with findings on DP-MRI.

METHODS

This is a retrospective study of HR-ARM performed on patients with constipation who also underwent DP-MRI. Studies were reviewed for significant findings including posterior pelvic organ prolapse, rectocele > 3 cm, rectal intussusception, and anorectal angle. Statistical analysis was performed using Pearson's correlation coefficient, Student's t-test, and Fisher's exact test.

RESULTS

Twenty-three patients undergoing HR-ARM (age range 25-78) also underwent DP-MRI. All were female; 76% were Caucasian. Twenty had significant structural findings: small pelvic prolapse (n = 2), moderate pelvic prolapse (n = 10), large pelvic prolapse (n = 9), rectocele (n = 8), or rectal intussusception (n = 3). Only intrarectal pressure on HR-ARM weakly correlated with size of rectocele (r = 0.46; P = 0.03) and degree of pelvic organ prolapse (r = 0.48; P = 0.02). The remainder of the HR-ARM parameters did not significantly correlate with DP-MRI findings. Patients with dyssynergy were not more likely to have rectoceles > 3 cm (44.4% versus 35.7%; P = 0.5) or large prolapses (44.4% versus 50%, P = 1.0), compared with those without dyssynergy, on HR-ARM.

CONCLUSION

We were unable to find a correlation between HR-ARM findings and structural pelvic defects on DP-MRI. Therefore, these two technologies provide complementary information in the evaluation of defecatory dysfunction.

Clinical and investigative assessment of constipation: a study from a referral center in western India

INTRODUCTION

Constipation may be primary or secondary. Pathophysiologic subtypes of primary constipation are dyssynergic defecation (DD), slow (STC), and normal transit constipation (NTC). Clinical subtypes are functional constipation (FC) and constipation predominant IBS (C-IBS).

AIMS

The objectives of this paper are to study the clinical profile, categorize and compare various subtypes of primary constipation, and to assess the success of biofeedback therapy (BFT) in a non-randomized, uncontrolled open-label study among patients with DD.

MATERIAL AND METHODS

Consecutive constipation patients (April 2011 to December 2012) were evaluated. Patients <18 years and secondary constipation were excluded. FC and C-IBS were classified by Rome III module. All patients, after excluding secondary constipation, underwent anorectal manometry (ARM) with balloon expulsion test and colon transit study (CTS). Patients with DD were given BFT.

RESULTS

Out of 128 patients, 23 %, 58 %, and 19 % had secondary constipation, FC, and C-IBS, respectively. Ninety-nine patients had primary constipation. Among those with primary constipation mean age was 53.5 (21-86) years, (77 % males). Forty-six, 15, and 40 had NTC, STC, and DD, respectively. Out of those with DD, 34 had paradoxical anal contraction and 6 had impaired rectal propulsion. FC and C-IBS were clinically and pathophysiologically similar except for abdominal pain. Patients with DD were more likely to have history of finger evacuation, straining, incomplete evacuation, sensation of anorectal obstruction than no DD. Sixty-nine percent of the patients with STC had ≤3 stools/week compared to 37 % with NTC (p-value 0.018). Thirty out of 40 (75 %) patients with DD underwent BFT but 20 completed ≥4 sessions. Seventy percent with ≥4 sessions had improved complete spontaneous bowel movements (CSBM).

CONCLUSION

NTC was the most common subtype of primary constipation. Symptoms of finger evacuation, sensation of anorectal obstruction, incomplete evacuation, and straining were more prevalent in DD. ARM and CTS could easily identify patients with DD and STC.

ACR Appropriateness Criteria pelvic floor dysfunction

Pelvic floor dysfunction is a common and potentially complex condition. Imaging can complement physical examination by revealing clinically occult abnormalities and clarifying the nature of the pelvic floor defects present. Imaging can add value in preoperative management for patients with a complex clinical presentation, and in postoperative management of patients suspected to have recurrent pelvic floor dysfunction or a surgical complication. Imaging findings are only clinically relevant if the patient is symptomatic. Several imaging modalities have a potential role in evaluating patients; the choice of modality depends on the patient's symptoms, the clinical information desired, and the usefulness of the test. The ACR Appropriateness Criteria are evidence-based guidelines for specific clinical conditions; they are reviewed every 3 years by a multidisciplinary expert panel. The guideline development and review include an extensive analysis of current medical literature from peer-reviewed journals, and the application of a well-established consensus methodology (modified Delphi) to rate the appropriateness of imaging and treatment procedures by the panel. In instances in which evidence is lacking or not definitive, expert opinion may be used to recommend imaging or treatment.

Magnetic resonance imaging of pelvic floor disorders

Physical examination alone is often inadequate for evaluation of pelvic floor dysfunction. Magnetic resonance imaging (MRI) is a robust modality that can provide high-quality anatomic and functional evaluation of the pelvic floor. Although lack of standardized technique and radiologist inexperience may be relative deterrents in universal acceptance of pelvic floor MRI, the role of MRI is increasing as it is technically feasible on most magnets and offers some advantages over the traditional fluoroscopic defecography. This review focuses on the technical and interpretational aspects of anatomic and functional pelvic floor MRI.

Anorectal anatomy and imaging techniques

The rectum and anus are two anatomically complex organs with diverse pathologies. This article reviews the basic anatomy of the rectum and anus. In addition, it addresses the current radiographic techniques used to evaluate these structures, specifically ultrasound, magnetic resonance imaging, and defecography.

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.

Semi-automated vectorial analysis of anorectal motion by magnetic resonance defecography in healthy subjects and fecal incontinence

BACKGROUND

Inter-observer variability limits the reproducibility of pelvic floor motion measured by magnetic resonance imaging (MRI). Our aim was to develop a semi-automated program measuring pelvic floor motion in a reproducible and refined manner.

METHODS

Pelvic floor anatomy and motion during voluntary contraction (squeeze) and rectal evacuation were assessed by MRI in 64 women with fecal incontinence (FI) and 64 age-matched controls. A radiologist measured anorectal angles and anorectal junction motion. A semi-automated program did the same and also dissected anorectal motion into perpendicular vectors representing the puborectalis and other pelvic floor muscles, assessed the pubococcygeal angle, and evaluated pelvic rotation.

KEY RESULTS

Manual and semi-automated measurements of anorectal junction motion (r = 0.70; P < 0.0001) during squeeze and evacuation were correlated, as were anorectal angles at rest, squeeze, and evacuation; angle change during squeeze or evacuation was less so. Semi-automated measurements of anorectal and pelvic bony motion were also reproducible within subjects. During squeeze, puborectalis injury was associated (P ≤ 0.01) with smaller puborectalis but not pelvic floor motion vectors, reflecting impaired puborectalis function. The pubococcygeal angle, reflecting posterior pelvic floor motion, was smaller during squeeze and larger during evacuation. However, pubococcygeal angles and pelvic rotation during squeeze and evacuation did not differ significantly between FI and controls.

CONCLUSION & INFERENCES

This semi-automated program provides a reproducible, efficient, and refined analysis of pelvic floor motion by MRI. Puborectalis injury is independently associated with impaired motion of puborectalis, not other pelvic floor muscles in controls and women with FI.

Recent advances in the management of difficult constipation

Constipation is a highly prevalent disorder. Some patients suffer from acute, intermittent episodes of constipation. Others, however, suffer from chronic constipation, a term that refers to those patients with symptoms of constipation for more than 6 months. In clinical practice, chronic constipation is often used interchangeably with the term functional constipation, which is currently defined using the Rome III criteria. Symptoms can be burdensome, leading to a reduction in patients' quality of life. In addition, chronic constipation is important because it imposes a significant economic impact to the health care system. Some patients with chronic constipation have persistent symptoms despite implementing lifestyle changes and using either over-the-counter agents or prescription medications. These patients may be categorized as having difficult constipation. This report will focus on recent advances in the management of difficult constipation, and include a discussion of new and upcoming medications as well as new diagnostic tests and procedures.