Predictive value of impaired evacuation at proctography in diagnosing anismus

[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.

[Dynamic magnetic resonance imaging of the pelvic floor: Technical aspects]

BACKGROUND

Dynamic magnetic resonance imaging (MRI) of the pelvic floor plays a key role in imaging complex pelvic floor dysfunction. High-quality examination is crucial for diagnostic benefit but can be technically challenging.

OBJECTIVES

The most important technical aspects (patient selection, patient preparation, MRI technology, MRI scan protocol, success control) for obtaining a state-of-the-art 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 panels of European Society of Urogenital Radiology/European Society of Gastrointestinal and Abdominal Radiology (ESUR/ESGAR) in 2016 and Society of Abdominal Radiology (SAR) in 2019.

RESULTS

Examination with at least 1.5 T and a surface coil after rectal instillation of ultrasound gel is clinical standard. Dynamic MRI in a closed magnet with the patient in supine position is the most widespread technique. No clinically significant pathologies of the pelvic floor are missed compared to the sitting position in an open magnet. The minimum scan protocol should encompass static, high-resolution T2-imaging (i.e., T2-TSE) in three planes and dynamic sequences with high temporal resolution in sagittal (and possibly axial) plane (i.e., steady-state or balanced steady-state free precession) during squeezing, straining and evacuation. Detailed patient instruction and practicing prior to the scan improve patients' compliance and hence diagnostic quality.

CONCLUSIONS

A technically flawless dynamic MRI of the pelvic floor according to these standards 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.

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.

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.

Spontaneous Internal Anal Sphincter Relaxation During High-resolution Anorectal Manometry Is Associated With Peripheral Neuropathy and Higher Charlson Comorbidity Scores in Patients With Defecatory Disorders

Background/Aims

We aimed to evaluate associations between comorbidities, peripheral neuropathy, and spontaneous internal anal sphincter relaxation (SAR) in patients with defecatory disorders.

Methods

A patient was considered to exhibit SAR during high-resolution anorectal manometry (HR-ARM) when the nadir pressure is < 15 mmHg and the time from onset to relaxation was ≥ 15 seconds in the resting pressure frame. A case-control study was performed using HR-ARM data collected from 880 patients from January 2010 to May 2015. We identified 23 cases with SAR (median age 75 years; 15 females; 12 fecal incontinence and 11 constipation). We compared HR-ARM values, Charlson index comorbidity scores, neuropathy, and the prevalence of diseases that potentially cause neuropathy between controls and SAR patients. Each SAR case was compared to 3 controls. Controls were selected to match the age, gender, and examination year of each SAR case.

Results

Compared to controls (26.1%), SAR patients (52.2%) exhibited a significantly higher frequency of fecal incontinence. SAR patients also had higher Charlson index scores (5 vs 4, P = 0.028). Nine of 23 SAR patients (39.1%) exhibited peripheral neuropathy— this frequency was higher than that for the control group (11.6%; P = 0.003). Diseases that potentially cause neuropathy were observed in 17 of 23 SAR cases and 32 of 69 controls (P = 0.022).

Conclusions

SAR develops in patients with constipation and fecal incontinence but is more common in patients with fecal incontinence. Our controlled observational study implies that SAR is associated with peripheral neuropathy and more severe comorbidities.

American Urogynecologic Society Best-Practice Statement on Evaluation of Obstructed Defecation

The symptoms of constipation and obstructed defecation are common in women with pelvic floor disorders. Female pelvic medicine and reconstructive surgery specialists evaluate and treat women with these symptoms, with the initial consultation often occurring when a woman has the symptom or sign of posterior compartment pelvic organ prolapse (including rectocele or enterocele) or if a rectocele or enterocele is identified in pelvic imaging. This best-practice statement will review techniques used to evaluate constipation and obstructed defecation, with a special focus on the relationship between obstructed defecation, constipation, and pelvic organ prolapse.

Defecography: An Overview of Technique, Interpretation, and Impact on Patient Care

Pelvic floor and defecatory dysfunction are common in the female patient population. When combined with physical examination, barium defecography allows for accurate and expanded assessment of the underlying pathology and helps to guide future intervention. Understanding the imaging findings of barium defecography in the spectrum of pathology of the anorectum and pelvic floor allows one to appropriately triage and treat patients presenting with defecatory dysfunction.

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.

Review article: dyssynergic defaecation and biofeedback therapy in the pathophysiology and management of functional constipation

BACKGROUND

Functional constipation is a common clinical presentation in primary care. Functional defaecation disorders are defined as the paradoxical contraction or inadequate relaxation of the pelvic floor muscles during attempted defaecation (dyssynergic defaecation) and/or inadequate propulsive forces during attempted defaecation. Prompt diagnosis and management of dyssynergic defaecation is hindered by uncertainty regarding nomenclature, diagnostic criteria, pathophysiology and efficacy of management options such as biofeedback therapy.

AIM

To review the evidence pertaining to the pathophysiology of functional defaecation disorders and the efficacy of biofeedback therapy in the management of patients with dyssynergic defaecation and functional constipation.

METHODS

Relevant articles addressing functional defaecation disorders and the efficacy of biofeedback therapy in the management of dyssynergic defaecation and functional constipation were identified from a search of Pubmed, MEDLINE Ovid and the Cochrane Library.

RESULTS

The prevalence of dyssynergic defaecation in patients investigated for chronic constipation is as many as 40%. Randomised controlled trials have demonstrated major symptom improvement in 70%-80% of patients undergoing biofeedback therapy for chronic constipation resistant to standard medical therapy and have determined it to be superior to polyethylene glycol laxatives, diazepam or sham therapy. Long-term studies have shown 55%-82% of patients maintain symptom improvement.

CONCLUSIONS

Dyssynergic defaecation is a common clinical condition in patients with chronic constipation not responding to conservative management. Biofeedback therapy appears to be a safe, successful treatment with sustained results for patients with dyssynergic defaecation. Further studies are required to standardise the diagnosis of dyssynergic defaecation in addition to employing systematic protocols for biofeedback therapy.

Bilateral Posterior Tibial Nerve Stimulation in the Treatment of Rectal Evacuation Disorder: A Preliminary Report

BACKGROUND

Posterior tibial nerve stimulation influences both motor and sensory pathways, as well as the central nervous system. Stimulation of posterior tibial nerve roots (L4 to S3) could improve stool evacuation through S3 and/or S2 stimulation.

OBJECTIVE

This study aimed to assess the efficiency of bilateral posterior tibial nerve stimulation in the treatment of rectal evacuation disorder without anatomic obstruction.

DESIGN

This was a prospective case series studying the treatment of patients with obstructed defecation by posterior tibial nerve stimulation.

SETTING

The study was conducted at a tertiary referral academic medical center.

PATIENTS

Patients with rectal evacuation disorder without anatomic obstruction who were failing maximal conservative treatments were included.

INTERVENTION

Thirty minutes of bilateral transcutaneous posterior tibial nerve stimulation was applied 3 times weekly for each patient for 6 consecutive weeks.

MAIN OUTCOME MEASURES

The primary end point was the change in the modified obstructed defecation score. Secondary end points were changes in rectal sensitivity volumes (urge to defecate volume and maximal tolerable volume) and quality of life using the Patient Assessment of Constipation-Quality of Life questionnaire.

RESULTS

Thirty-six patients (25 women) completed the trial. The mean age of patients was 57.2 years (SD = 14.4 y). No adverse events were reported. Symptomatic successful outcome was reported in 17 patients (47%) and modified obstructed defecation score decreased over 6 weeks (mean decrease = 10 points (95% CI, 8.7-11.3 points); p < 0.0001). Patients with successful outcome (responders) had relatively lower preoperative modified obstructed defecation score compared with patients with unsuccessful outcome (nonresponders). In the successful group, there were significant improvement after 6 weeks in both Patient Assessment of Constipation-Quality of Life score (mean improvement = 43.0 points (95% CI, 35.2-50.7 points); p < 0.0001) and rectal sensitivity (significant reductions in urge to defecate volume (from 258.1 ± 21.2 to 239.6 ± 15.3; p < 0.0001) and maximal tolerable volume (from 304.5 ± 24.8 to 286.8 ± 19.7; p < 0.0001)). No significant change in Patient Assessment of Constipation-Quality of Life or rectal sensitivity was observed in the nonresponders.

LIMITATIONS

The study was designed just to proof the concept, but small sample size is a limitation. Another limitation is the short duration of study of only 6 weeks.

CONCLUSIONS

Current data showed that bilateral transcutaneous posterior tibial nerve stimulation can improve symptoms in a considerable percentage of patients with obstructed defecation without anatomic obstruction. The procedure is more effective in patients with a less-modified obstructed defecation score. Additional studies are needed to discover the predictive factors for success.

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.

Accuracy of integrated total pelvic floor ultrasound compared to defaecatory MRI in females with pelvic floor defaecatory dysfunction

OBJECTIVE

Defaecatory MRI allows multicompartmental assessment of defaecatory dysfunction but is often inaccessible. Integrated total pelvic floor ultrasound (transperineal, transvaginal, endoanal) may provide a cheap, portable alternative. The accuracy of total pelvic floor ultrasound for anatomical abnormalities when compared with defaecatory MRI was assessed.

METHODS

The dynamic images from 68 females who had undergone integrated total pelvic floor ultrasound and defaecatory MRI between 2009 and 2015 were blindly reviewed. The following were recorded: rectocoele, enterocoele, intussusception and cystocoele.

RESULTS

There were 26 rectocoeles on MRI (49 rectocoeles on ultrasound), 24 rectocoeles with intussusception on MRI (19 rectocoeles on ultrasound), 23 enterocoeles on MRI (24 enterocoeles on ultrasound) and 49 cystocoeles on MRI (35 cystocoeles on ultrasound). Sensitivity and specificity of total pelvic floor ultrasound were 81% and 33% for rectocoele, 60% and 91% for intussusception, 65% and 80% for enterocoele and 65% and 84% for cystocoele when compared with defaecatory MRI. This gave a negative-predictive value and positive-predictive value of 74% and 43% for rectocoele, 80% and 79% for intussusception, 82% and 63% for enterocoele and 48% and 91% for cystocoele.

CONCLUSION

Integrated total pelvic floor ultrasound may serve as a screening tool for pelvic floor defaecatory dysfunction; when normal, defaecatory MRI can be avoided, as rectocoele, intussusception and enterocoele are unlikely to be present. Advances in knowledge: This is the first study to compare integrated total pelvic floor ultrasound with defaecatory MRI. The results support the use of integrated total pelvic floor ultrasound as a screening tool for defaecatory dysfunction.

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.

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.

Evacuation proctography: a reappraisal of normal variability

AIM

Interpretation of evacuation proctography (EP) images is reliant on robust normative data. Previous studies of EP in asymptomatic subjects have been methodologically limited. The aim of this study was to provide parameters of normality for both genders using EP.

METHOD

Evacuation proctography was prospectively performed on 46 healthy volunteers (28 women). Proctograms were independently analysed by two reviewers. All established and some new variables of defaecatory structure and function were assessed objectively: anorectal dimensions; anorectal angle changes; evacuation time; percentage contrast evacuated; and incidence of rectal wall morphological 'abnormalities'.

RESULTS

Normal ranges were calculated for all main variables. Mean end-evacuation time was 88 s (95% CI: 63-113) in male subjects and 128 s (95% CI: 98-158) in female subjects; percentage contrast evacuated was 71% (95% CI: 63-80) in male subjects and 65% (95% CI: 58-72) in female subjects. Twenty-six (93%) of 28 female subjects had a rectocoele with a mean depth of 2.5 cm (upper limit = 3.9 cm). Recto-rectal intussusception was found in nine subjects (approximately 20% of both genders); however, recto-anal intussusception was not observed. Only rectal diameter differed significantly between genders. Qualitatively, three patterns of evacuation were present.

CONCLUSION

This study defines normal ranges for anorectal dimensions and parameters of emptying, as well as the incidence and characteristics of rectal-wall 'abnormalities' observed or derived from EP. These ranges can be applied clinically for subsequent disease comparison.

Comparison between dynamic cystocolpoproctography and dynamic pelvic floor MRI: pros and cons: which is the "functional" examination for anorectal and pelvic floor dysfunction?

"Functional" imaging of anorectal and pelvic floor dysfunction has assumed an important role in the diagnosis and management of these disorders. Although defecography has been widely practiced for decades to evaluate the dynamics of rectal emptying, debate concerning its clinical relevance, how it should be done and interpreted continues. Due to the recognition of the association of defecatory disorders with pelvic organ prolapse in women, the need to evaluate the pelvic floor as a unit has arisen. To meet this need, defecography has been extended to include not only evaluation of defecation disorders but also the rest of the pelvic floor by opacifying the small bowel, vagina, and the urinary bladder. The term "dynamic cystocolpoproctography" (DCP) has been appropriately applied to this examination. Rectal emptying performed with DCP provides the maximum stress to the pelvic floor resulting in complete levator ani relaxation. In addition to diagnosing defecatory disorders, this method of examination demonstrates maximum pelvic organ descent and provides organ-specific quantification of organ prolapse, information that is only inferred by means of physical examination. It has been found to be of clinical value in patients with defecation disorders and the diagnosis of associated prolapse in other compartments that are frequently unrecognized by history taking and the limitations of physical examination. Pelvic floor anatomy is complex and DCP does not show the anatomical details pelvic magnetic resonance imaging (MRI) provides. Technical advances allowing acquisition of dynamic rapid MRI sequences has been applied to pelvic floor imaging. Early reports have shown that pelvic MRI may be a useful tool in pre-operative planning of these disorders and may lead to a change in surgical therapy. Predictions of hypothetical increase cancer incidence and deaths in patients exposed to radiation, the emergence of pelvic floor MRI in addition to questions relating to the clinical significance of DCP findings have added to these controversies. This review analyses the pros and cons between DCP and dynamic pelvic floor MRI, addresses imaging and interpretive controversies, and their relevance to clinical management.

Does conventional defecography has a role to play in evaluation of evacuatory disorders in Indian population?

Barium studies are one of the best investigations for evaluating submucosal and extrinsic mass lesions. However, barium studies bring less money, are operator dependent and one of the more difficult investigations for radiologists to master. Economic factors have acted as powerful disincentives for performing gastrointestinal (GI) fluoroscopy in most radiology practices. In this pictorial essay, we discuss the role of conventional defecography in evaluating evacuatory disorders in the Indian population.

Significance of defecographic parameters in diagnosing pelvic floor dyssynergia

PURPOSE

Defecography is known to be a sensitive and specific measurement of pelvic floor dyssynergia (PFD). However, its standardized parameter for diagnostic analysis is still incomplete. We attempted to determine which defecographic findings are most significant for PFD, and how closely they match other physiologic tests and clinical symptoms of functional pelvic outlet obstruction.

METHODS

Ninety-six patients with constipation who completed work-up of their symptoms with defecography, anorectal manometry and electromyography (EMG) were included in the study. Internal consistency of defecographic findings, and agreements between defecographic findings and results of other tests were statistically analyzed (Crohnbach's α, Cohen's κ, respectively).

RESULTS

Of the 96 patients evaluated, obstructive symptoms of constipation were obvious in 35 (36.5%) by obstructive symptom score. As known defecographic findings for PFD, poor opening of the anal canal was found in 33 (34.4%), persistent posterior angulation of the rectum in 33 (34.4%), and poor emptying of the rectum in 61 (63.5%). Manometric defecation index, manometric evacuation index, and EMG findings compatible with PFD were in 81 (84.4%), 72 (75%), and 73 (76%), respectively. Internal consistency of three defecographic findings was good (α = 0.78). Agreements between each defecographic findings and each result of other tests were all poor.

CONCLUSION

Among known defecographic findings for PFD, one specific finding cannot be considered more important than the others for its diagnosis. It is hard to expect consistent results of various diagnostic tests and to predict the presence of defecographic PFD by use of anorectal manometry, EMG, or even by clinical symptoms.

Dynamic transperineal ultrasound in the workup of men with obstructed defecation: a pilot study

BACKGROUND

Dynamic transperineal ultrasound has been used in women for the noninvasive investigation of functional disorders of the posterior pelvic floor, but its use in men has been limited by technical difficulties related to the consistency of the male perineum.

OBJECTIVES

The aim of this study was to explore the efficacy of dynamic transperineal ultrasound in diagnosing posterior pelvic floor dysfunction in men.

DESIGN

This is a study of diagnostic accuracy.

SETTINGS

This study was performed at a public hospital.

PATIENTS

Forty-six men with symptoms of obstructed defecation were included.

INTERVENTIONS

All patients underwent dynamic transperineal ultrasound 1 week after standard defecography with manometric confirmation when rectoanal dyssynergy was observed.

MAIN OUTCOME MEASURES

Images were obtained, and anorectal angles were measured under resting conditions and during maximal strain. The accuracy of the sonographic method in diagnosing pelvic floor alterations was assessed against defecography (reference method).

RESULTS

: Anorectal angles measured with ultrasound and defecography were not significantly different under resting conditions or maximum strain. Sonographic and reference method findings were concordant in 41 (89.1%) of the cases (25 with rectoanal intussusceptions, 7 with rectorectal intussusceptions, 8 with rectoanal dyssynergy, and 1 with rectorectal intussusception and dyssynergy). In 1 patient with rectoanal intussusception, dynamic transperineal ultrasound was nondiagnostic (low image quality probably due to dehydration of perineal tissues). Discordant dynamic transperineal ultrasound findings included normal findings in another patient with rectoanal intussusception, diagnosis of rectoanal intussusception in 2 men with rectorectal intussusception, and failure to detect dyssynergy in a second patient with rectorectal intussusception and dyssynergy. The sensitivity, specificity, and Cohen κ indices for dynamic transperineal ultrasound were 92.6%, 90.5%, and 82% (rectoanal intussusception); 81.8%, 100%, and 87% (rectorectal intussusception); 90%, 100%, and 93% (rectoanal dyssynergy).

LIMITATIONS

This study was limited by its small size and by the absence of patients with other morphofunctional disorders associated with obstructed defecation.

CONCLUSIONS

Dynamic transperineal ultrasound is potentially useful for diagnosis and follow-up of posterior pelvic floor dysfunction in men.

Pelvic floor imaging: comparison between magnetic resonance imaging and conventional defecography in studying outlet obstruction syndrome

PURPOSE

This study prospectively compared the diagnostic capabilities of magnetic resonance (MR) imaging with conventional defecography (CD) in outlet obstruction syndrome.

MATERIALS AND METHODS

Nineteen consecutive patients with clinical symptoms of outlet obstruction underwent pelvic MR examination. The MR imaging protocol included static T2-weighted fast spin-echo (FSE) images in the sagittal, axial and coronal planes; dynamic midsagittal T2-weighted single-shot (SS)-FSE and fast imaging employing steady-state acquisition (FIESTA) cine images during contraction, rest, straining and defecation. MR images (including and then excluding the evacuation phase) were compared with CD, which is considered the reference standard.

RESULTS

Comparison between CD and MR with evacuation phase (MRWEP) showed no significant differences in sphincter hypotonia, dyssynergia, rectocele or rectal prolapse and significant differences in descending perineum. Comparison between CD and MR without evacuation phase (MRWOEP) showed no significant differences in sphincter hypotonia, dyssynergia or enterocele but significant differences in rectocele, rectal prolapse and descending perineum. Comparison between MRWEP and MRWOEP showed no significant differences in sphincter hypotonia, dyssynergia, enterocele or descending perineum but significant differences in rectocele, rectal prolapse, peritoneocele, cervical cystoptosis and hysteroptosis.

CONCLUSIONS

MR imaging provides morphological and functional study of pelvic floor structures and may offer an imaging tool complementary to CD in multicompartment evaluation of the pelvis. An evacuation phase is mandatory.

How to interpret a functional or motility test - defecography

Defecography evaluates in real time the morphology of rectum and anal canal in a physiologic setting by injection of a thick barium paste into the rectum and its subsequent evacuation. Because of its ability of structural and functional evaluation, defecography is primarily performed for work up of patients with longstanding constipation, unexplained anal or rectal pain, residual sensation after defecation or suspected prolapse. Technique and interpretation of this examination are outlined in this review.

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

OBJECTIVES

We describe the spectrum of findings and the diagnostic value of MR defecography in patients referred with suspicion of dyssynergic defecation.

METHODS

48 patients (34 females, 14 males; mean age 48 years) with constipation and clinically suspected dyssynergic defecation underwent MR defecography. Patients were divided into patients with dyssynergic defecation (n = 18) and constipated patients without dyssynergic defecation (control group, n = 30). MRIs were analysed for evacuation ability, time to initiate evacuation, time of evacuation, changes in the anorectal angle (ARA-change), presence of paradoxical sphincter contraction and presence of additional pelvic floor abnormalities. Sensitivity, specificity, positive and negative predictive values and accuracy for the diagnosis of dyssynergic defecation were calculated.

RESULTS

The most frequent finding was impaired evacuation, which was seen in 100% of patients with dyssynergic defecation and in 83% of the control group, yielding a sensitivity for MR defecography for the diagnosis of dyssynergic defecation of 100% (95% confidence interval (CI) 97-100%), but a specificity of only 23% (95% CI 7-40%). A lower sensitivity (50%; 95% CI 24-76%) and a high specificity (97%; 95% CI 89-100%) were seen with abnormal ARA-change. The sensitivity of paradoxical sphincter contraction was relatively high (83%; 95% CI 63-100%). A combined analysis of abnormal ARA-change and paradoxical sphincter contraction allowed for the detection of 94% (95% CI 81-100%) of the patients with dyssynergic defecation.

CONCLUSION

MR defecography detects functional and structural abnormal findings in patients with clinically suspected dyssynergic defecation. Impaired evacuation is seen in patients with functional constipation owing to other pelvic floor abnormalities than dyssynergic defecation.

Functional imaging of the pelvic floor

The clinical treatment of patients with anorectal and pelvic floor dysfunction is often difficult. Dynamic cystocolpoproctography (DCP) has evolved from a method of evaluating the anorectum for functional disorders to its current status as a functional method of evaluating the global pelvic floor for defecatory disorders and pelvic organ prolapse. It has both high observer accuracy and a high yield of positive diagnoses. Clinicians find it a useful diagnostic tool that can alter management decisions from surgical to medical and vice versa in many cases. Functional radiography provides the maximum stress to the pelvic floor, resulting in levator ani relaxation accompanied by rectal emptying-which is needed to diagnose defecatory disorders. It also provides organ-specific quantificative information about female pelvic organ prolapse-information that usually can only be inferred by means of physical examination. The application of functional radiography to the assessment of defecatory disorders and pelvic organ prolapse has highlighted the limitations of physical examination. It has become clear that pelvic floor disorders rarely occur in isolation and that global pelvic floor assessment is necessary. Despite the advances in other imaging methods, DCP has remained a practical, cost-effective procedure for the evaluation of anorectal and pelvic floor dysfunction. In this article, the authors describe the technique they use when performing DCP, define the radiographic criteria used for diagnosis, and discuss the limitations and clinical utility of DCP.

Measurements of pelvic floor dyssynergia: which test result matters?

PURPOSE

Failure to expel a 60-mL balloon on manometry and abnormal relaxation of anal sphincter on electromyographic testing are frequently used to diagnose pelvic floor dyssynergia. However, the relationship between these 2 test results and their relationship to defecography is poorly characterized. We aimed to describe this relationship and create a predictive model for pelvic floor dyssynergia on defecography.

METHODS

From March 2008 to April 2010 consecutive patients with symptoms suggestive of functional constipation were evaluated at our Pelvic Floor Disorders Center 125 and the results of their workups were collected prospectively. Sixty-three patients with pelvic floor dyssynergia on defecography were compared with 60 patients without dyssynergia in terms of manometry pressures, electromyographic text results, and balloon expulsion testing results (χ, t tests).

RESULTS

Of 125 patients meeting Rome II symptom criteria for constipation, 123 patients underwent defecography and, of these, 63 (51.2%) had evidence of pelvic floor dyssynergia. Patients with and without dyssynergia had a slight difference in mean resting pressures (62.8 mmHg vs 49.5 mmHg, P = .02) and no discernable differences in rectal sensitivity and compliance: first sensation (56.5 vs 62.5, P = .34) and maximum tolerated volume (164.2 vs 191.2, P = .09). It appeared that abnormalities in electromyographic relaxation and balloon expulsion occurred in the same patients: 84.1% of patients with abnormal electromyographic results also did not expel the balloon. However, the presence of these abnormalities, in isolation or together, did not predict the presence of dyssynergia on defecography.

CONCLUSION

Normal electromyographic results or the ability to expel a 60-mL balloon does not exclude the presence of pelvic floor dyssynergia on defecography. It is unclear which of these 3 tests should be used to guide the recommendation for (and to then measure response to) biofeedback.

Role of enterocele in the obstructed defecation syndrome (ODS): a new radiological point of view

AIM

The aim of this study was to understand the role of enterocele in the pathogenesis of the obstructed defecation syndrome (ODS) a new defecographic classification based on function.

METHOD

A total of 597 patients (551 women, 46 men) who underwent cinedefecography between November 2001 and November 2005 were studied. A total of 567 (95%) underwent cinedefecography as they had symptoms of ODS. Enterocele was classified into three types.

RESULTS

Enterocele was found in 127 (23%) female and one (2.2%) male patients. Thirty-eight (6.9%) patients had type A, 38(6.9%) type B, and 27(4.9%) type C enterocele. A total of 24 patients (4.35%) had sigmoidocele. In patients with type C enterocele, the finding of a radiological pattern of ODS was higher (26/27) than that in the other groups (A + B + Sigmoidocele) (23/100) (P < 0.001). An obstructed evacuation pattern was found in 49 (38.5%) patients with enterocele and in 148 (34.9%) patients in the control group.

CONCLUSION

Type C enterocele is often associated with a radiological pattern of ODS and usually presents as an isolated condition. Type B is less frequently associated with ODS and is more frequently accompanied by other pathological conditions.

Work-up of the constipated patient

Constipation is a common problem. Evaluation of patients should include a detailed history and clinical examination followed by radiologic and physiologic testing. The order of testing is dependent on patient symptoms and physician preference. The options are described along with their limitations.

Functional anorectal disorders

Functional anorectal disorders include solitary rectal ulcer syndrome, rectocele, nonrelaxing puborectalis syndrome, and descending perineal syndrome. Patients usually present with "constipation," but the clinical picture of these disorders includes rectal pain and bleeding, digitalization, incomplete evacuation, and a feeling of obstruction. Diagnosis is difficult because many findings can be seen in normal patients as well. The diagnosis is made by using a combination of clinical picture, defecography, pathology, and occasionally anometry and pudendal terminal motor nerve latency. These disorders are generally treated medically with dietary changes and biofeedback. Surgical intervention is reserved for patients with intractable symptoms and has not been universally successful.

Imaging pelvic floor disorders: trend toward comprehensive MRI

OBJECTIVE

The purpose of this article is to review the relevant anatomy and sonographic, fluoroscopic, and MRI options for evaluating patients with pelvic floor disorders.

CONCLUSION

Disorders of the pelvic floor are a heterogeneous and complex group of problems. Imaging can help elucidate the presence and extent of pelvic floor abnormalities. MRI is particularly well suited for global pelvic floor assessment including pelvic organ prolapse, defecatory function, and pelvic floor support structure integrity.

Posterior pelvic floor disorders: a prospective comparison using introital ultrasound and colpocystodefecography

OBJECTIVE

To compare introital ultrasound with colpocystodefecography (CCD) in quantifying the anorectal angle and in the diagnosis of posterior pelvic floor disorders.

METHODS

Forty-three consecutive women with functional impairment of the posterior pelvic floor were enrolled after a clinical evaluation. Using both CCD and introital ultrasound examination, the anorectal angle was measured during squeezing to evaluate the strength of voluntary muscle contraction and during straining to assess pelvic floor relaxation. Rectocele depth and the presence of intussusception were assessed. The performance of CCD and that of introital ultrasound were compared.

RESULTS

Good concordance was obtained between introital ultrasound and CCD. The intraclass correlation coefficient was 0.82 (95% CI, 0.69-0.89) for measurement of the anorectal angle during squeezing and 0.67 (95% CI, 0.47-0.81) during straining. Rectoceles > 4 cm on CCD were detected by introital ultrasound in 100% of cases, and there was 91% agreement for rectal intussusception. Cohen's kappa index was moderate for rectocele assessment (0.41, P < 0.01) and excellent for intussusception (0.91, P < 0.001). It was also noted that introital ultrasound could be used to detect pelvic floor dyssynergia.

CONCLUSIONS

Introital ultrasound is a simple, accurate, non-invasive method with which to assess anorectal dynamics.

Dynamic imaging of posterior compartment pelvic floor dysfunction by evacuation proctography: techniques, indications, results and limitations

The clinical management of patients with anorectal and pelvic floor dysfunction is often difficult. Evacuation proctography has evolved from a method to evaluate the anorectum for functional disorders to its current status as a practical method for evaluating anorectal dysfunction and pelvic floor prolapse. It has a high observer accuracy and yield of positive diagnosis. Clinicians find it of major benefit and has altered management from surgical to medical and vice versa in a significant number of cases.

Prospective Assessment of Interobserver Agreement for Defecography in Fecal Incontinence

OBJECTIVE

The primary aim of our study was to determine the interobserver agreement of defecography in diagnosing enterocele, anterior rectocele, intussusception, and anismus in fecal-incontinent patients. The subsidiary aim was to evaluate the influence of level of experience on interpreting defecography.

SUBJECTS AND METHODS

Defecography was performed in 105 consecutive fecal-incontinent patients. Observers were classified by level of experience and their findings were compared with the findings of an expert radiologist. The quality of the expert radiologist's findings was evaluated by an intraobserver agreement procedure.

RESULTS

Intraobserver agreement was good to very good except for anismus: incomplete evacuation after 30 sec (kappa, 0.55) and puborectalis impression (kappa, 0.54). Interobserver agreement for enterocele and rectocele was good (kappa, 0.66 for both) and for intussusception, fair (kappa, 0.29). Interobserver agreement for anismus: incomplete evacuation after 30 sec was moderate (kappa, 0.47), and for anismus: puborectalis impression was fair (kappa, 0.24). Agreement in grading of enterocele and rectocele was good (kappa, 0.64 and 0.72, respectively) and for intussusception, fair (kappa, 0.39). Agreement separated by experience level was very good for rectocele (kappa, 0.83) and grading of rectoceles (kappa, 0.83) and moderate for intussusception (kappa, 0.44) at the most experienced level. For enterocele and grading, experience level did not influence the reproducibility.

CONCLUSION

Reproducibility for enterocele, anterior rectocele, and severity grading is good, but for intussusception is fair to moderate. For anismus, the diagnosis of incomplete evacuation after 30 sec is more reproducible than puborectalis impression. The level of experience seems to play a role in diagnosing anterior rectocele and its grading and in diagnosing intussusception.

Dynamic evaluation of the anorectum

The evaluation of EP is complicated by the lack of any gold standard and a shifting clinical emphasis as management regimens go in and out of favor. As with all functional bowel disease, there is a residue of patients who are difficult to manage, and in whom a clinician will want maximum information before deciding on treatment. The examination has been criticized as lacking clinical relevance, and of having poor interobserver reliability except for rectal emptying and rectocele formation. Others have found a higher (83.3%) observer accuracy and a high yield of positive diagnoses. A questionnaire showed that clinicians found EP of major benefit in 40%, altering management from surgical to medical in 14% and vice versa in 4%. Radiographic examinations only impact on clinical management when findings alter management. Management protocols are evolving in functional disorders, but important features that EP reveals are anismus, trapping in rectoceles, IAI, and rectal prolapse. EP is the only method to diagnose some of these conditions and within defined parameters is extremely valuable in clinical management.

Predictive value of internal anal sphincter thickness for diagnosis of rectal intussusception in patients with solitary rectal ulcer syndrome

BACKGROUND

The aim of this study was to determine any association between a thickened internal anal sphincter (IAS) on anal endosonography and high-grade rectal intussusception on evacuation proctography in patients with solitary rectal ulcer syndrome.

METHODS

Anal endosonography was performed in 20 patients with solitary rectal ulcer syndrome and IAS thickness defined as normal or abnormal depending on age. Sphincter thickness was compared with the presence or absence of high-grade intussusception on subsequent evacuation proctography to determine any relationship between the two.

RESULTS

Thirteen patients had an abnormally thick IAS, two of whom were unable to evacuate. Of the remaining 11 patients, ten showed high-grade intussusception (positive predictive value 91 per cent). Only three of seven patients with a normal IAS had high-grade intussusception (negative predictive value 57 per cent). Patients with a thick IAS were significantly more likely to have proctographic evidence of high-grade intussusception (P = 0.047).

CONCLUSION

Sonographic findings of a thick IAS are highly predictive for high-grade rectal intussusception in patients with solitary rectal ulcer syndrome.