Total pelvic floor ultrasound can reliably predict long-term treatment outcomes for patients with pelvic floor defaecatory dysfunction.

AIM: Integrated total pelvic floor ultrasound (TPFUS) may provide an alternative to defaecation proctography (DP) in decision making and treatment planning for patients with pelvic floor defaecatory dysfunction (PFDD). This study evaluates the use of TPUS as a screening tool, and its likelihood to predict long-term treatment outcomes. METHODS: Two blinded clinicians reviewed 100 women who had historically presented to a tertiary referral colorectal unit with PFDD from October 2014 to April 2015. The clinical history of the patients together with TPFUS or DP results were used to decide on main impression, treatment plan, likelihood of surgery and certainty of plan. These were compared to the actual treatment received six months later and again after a median follow-up of 68 months (range 48-84). RESULTS: A total of 82 patients were treated with biofeedback only and 18 also underwent surgery. There were no complications in any of the patients who had surgery. When compared with the actual treatment received, 99 of the 100 of the TPFUS group would have been treated appropriately. The number of false positives for surgical treatment was lower with TPFUS compared to DP. Clinician confidence in the overall decision was significantly higher after review with DP. CONCLUSIONS: TPFUS is a reliable assessment tool for PFDD. It can identify patients who can go straight to biofeedback and is just as good as DP at predicting likelihood of surgery. We might be able to rely on TPFUS more significantly in the future, even for surgical planning.

The association between levator plate integrity and pelvic floor defaecatory dysfunction.

AIMS: Levator ani deficiency has been implicated in anterior pelvic floor pathology but its association with pelvic floor defaecatory dysfunction is less clear. The aim was to examine the relationship of levator ani deficiency with anatomical abnormalities (rectocoele, intussusception, enterocoele, perineal descent) and patient symptoms (bowel, vagina) in patients with pelvic floor defaecatory dysfunction. METHODS: The prospective observational case series of 223 women presenting to a tertiary colorectal pelvic floor unit with defaecatory dysfunction. Each underwent assessment with symptom severity and quality of life (QoL) scores, integrated total pelvic floor ultrasound (PFUS) (transvaginal, transperineal) and defaecation proctography (DP). Rectocoele, intussusception, enterocoele and perineal descent were assessed on both. Levator ani deficiency was scored using endovaginal ultrasound (score 0-18; mild [0-6], moderate [>6-12], severe [>12-18]). RESULTS: The proportion of patients with rectocoele, enterocoele, and intussusception increased with increasing levator ani damage (mild, moderate, severe). There was a weakly positive correlation between size of rectocoele and levator ani deficiency. On PFUS, there was a weakly positive correlation between severity of intussusception and enterocoele with levator ani deficiency. On DP, there was a weakly positive correlation between perineal descent and levator ani deficiency. There was no association between bowel symptom and QoL scores and levator ani deficiency. Vaginal symptoms were associated with levator ani deficiency. CONCLUSIONS: Anatomical abnormalities which are implicated in pelvic floor defaecatory dysfunction (rectocoele, intussusception, enterocoele, perineal descent) were associated with worsening levator ani deficiency. There was no association between bowel symptoms and levator ani deficiency. Vaginal symptoms were associated with levator ani deficiency.

Pelvic floor imaging in asymptomatic subjects.

AIM: The aim of this work was to determine the range of normal imaging features during total pelvic floor ultrasound (TPFUS) (transperineal, transvaginal, endovaginal and endoanal) and defaecation MRI (dMRI). METHOD: Twenty asymptomatic female volunteers (mean age 36.5 years) were prospectively investigated with dMRI and TPFUS. Subjects were screened with symptom questionnaires (ICIQ-B, St Mark's faecal incontinence score, obstructed defaecation syndrome score, ICIQ-V, BSAQ). dMRI and TPFUS were performed and interpreted by blinded clinicians according to previously published methods. RESULTS: The subjects comprised six parous and 14 nulliparous women, of whom three were postmenopausal. There were three with a rectocoele on both modalities and one with a rectocoele on dMRI only. There was one with intussusception on TPFUS. Two had an enterocoele on both modalities and one on TPFUS only. There were six with a cystocoele on both modalities, one on dMRI only and one on TPFUS only. On dMRI, there were 12 with functional features. Four also displayed functional features on TPFUS. Two displayed functional features on TPFUS only. CONCLUSION: This study demonstrates the presence of abnormal findings on dMRI and TPFUS without symptoms. There was a high rate of functional features on dMRI. This series is not large enough to redefine normal parameters but is helpful for appreciating the wide range of findings seen in health.

Is there any association between symptoms and findings on imaging in pelvic floor defaecatory dysfunction? A prospective study.

AIM: To compare features on imaging (integrated total pelvic floor ultrasound (transperineal, transvaginal) and defaecation proctography) with bowel, bladder and vaginal symptoms in pelvic floor defaecatory dysfunction. METHOD: A prospective observational case series of 216 symptomatic women who underwent symptom severity scoring (bowel, bladder and vaginal), integrated total pelvic floor ultrasound and defaecation proctography. Anatomical (rectocele, intussusception, enterocele, cystocele) and functional (co-ordination, evacuation) features were examined. RESULTS: Irrespective of imaging modality, patients with a rectocele had higher International Consultation on Incontinence Modular Questionnaire - Vaginal Symptoms (ICIQ-VS) scores than patients without. On integrated total pelvic floor ultrasound, ICIQ-VS quality of life scores were higher in those with a rectocele. There was a higher International Consultation on Incontinence Modular Questionnaire - Bowel Symptoms (ICIQ-BS) bowel pattern score in those with a rectocele, and a lower ICIQ-BS bowel pattern and sexual impact score in those with intussusception. Poor co-ordination was associated with increased ICIQ-BS bowel control scores and obstructed defaecation symptom scores. On defaecation proctography, ICIQ-VS symptom scores were lower in patients with poor co-ordination. CONCLUSION: Patients with a rectocele on either imaging modality may have qualitative vaginal symptoms on assessment. In patients with bowel symptoms but no vaginal symptoms, it is not possible to predict which anatomical abnormalities will be present on imaging.

Hidradenitis suppurativa: MRI features in anogenital disease.

BACKGROUND: Hidradenitis suppurativa is a rare chronic inflammatory disorder of apocrine gland-bearing skin, which commonly affects the anogenital region. There has been very little literature to date on the MRI appearances of anogenital hidradenitis suppurativa. OBJECTIVE: The aim of this study was to assess the MRI features of anogenital hidradenitis suppurativa in the largest cohort of patients to be published to date. DESIGN: After an institutional review board waiver, patients with hidradenitis suppurativa who were undergoing MRI for anogenital disease between 2005 and 2012 were identified from our institutional database. The MRI appearances were recorded by 2 radiologists in consensus, blinded to clinical details. Location of disease, number of tracts, presence of anal fistula, and supralevator involvement were recorded. Patient demographics were also noted. SETTINGS: This study was conducted at the Department of Radiology, Guy's and St Thomas' National Health Service Foundation Trust. PATIENTS: Patients included were those undergoing MRI for anogenital disease in hidradenitis suppurativa between 2005 and 2012. MAIN OUTCOME MEASURES: The distribution of sinus tracts in anogenital hidradenitis suppurativa on MRI was measured. RESULTS: Thirty-one MRIs were performed in 18 patients (15 men; mean age, 46 years). On the baseline MRI, multiple tracts were seen in the natal cleft (16/18; 83%), the perianal (12/18; 61%), the perineal (13/18; 56%), and the gluteal (8/18; 44%) regions. A communication with the anal canal was present in only 4 patients. Three patients had supralevator extension. Seven patients had follow-up MRIs with variable response to interval treatment: 3 of 7 showed responding disease, 3 of 7 showed stable disease, and 1 of 7 showed progressive disease. LIMITATIONS: This study was limited by its relatively small cohort of patients. CONCLUSIONS: In hidradenitis suppurativa, anogenital disease is usually subcutaneous but extensive, with only a minority of patients demonstrating deeper involvement. MRI may help define the extent of anogenital disease and assess response to treatment.

Outcomes in non-surgical management for bowel dysfunction.

This retrospective review considers clinical outcomes of patients following non-surgical management of bowel dysfunction (faecal incontinence and constipation), within a tertiary centre's pelvic floor unit. Between November 2010 and January 2013, 443 patients were entered into a database and the results of their treatment were recorded. To capture the treatment modalities that patients received they were grouped into three categories: defaecatory techniques and/or pelvic floor exercises; dietary advice and/or medication recommendations; rectal irrigation or the use of anal plugs. Patients received a median number of three sessions with a specialist nurse or physiotherapist. After completing a programme of therapy, 81% of patients had an improved St Mark's incontinence score and 75% of patients had an improved Thompson's functional constipation score. Subjective symptom improvement was reported in 78% of patients. The majority of these patients were discharged in 2011 and 2012 and have not required follow-up, suggesting that non-surgical management is effective on a medium-term basis.

Anal carcinomas: the role of endoanal ultrasound and magnetic resonance imaging in staging, response evaluation and follow-up.

Anal carcinoma is an important but rare condition, managed in specialist centres. Both endoanal ultrasound and magnetic resonance imaging (MRI) can be used in the locoregional staging and follow-up of patients with anal cancer, and both may assist in treatment planning and prognosis. Recent guidelines published by the European Society for Medical Oncology have recommended MRI as the technique of choice for assessment of locoregional disease. This paper describes the techniques for both endoanal ultrasound and MRI, and compares the relative merits and disadvantages of each in the local assessment of anal carcinoma.

Anal canal vector volume manometry.

BACKGROUND: Anal manometry is routinely used in the assessment of the anal sphincters in patients with fecal incontinence or suspected sphincter injury. Such physiological information is complementary to the anatomical assessment provided by anal endosonography. The evolution of 3-dimensional anal endosonography provides more diagnostically useful information in complex cases. Vector volume manometry has been developed to give a 3-dimensional view of the anal sphincters. OBJECTIVE: We reviewed the published literature on this technique, with the intention of deriving a system of standardization based on the published literature and to summarize the derivation and physiological meaning of the parameters measurable by vector volume studies, as well. DATA SOURCES: We undertook a MEDLINE search using the terms "vector volume" or "vector manometry" and "anal canal." We also reviewed further publications found from references cited in the original articles identified from the above search. STUDY SELECTION: Only English language articles of studies performed on humans were reviewed. INTERVENTION: Anal canal vector volume manometry was the intervention. RESULTS: With the development of automated puller systems and associated software, parameters such as total vector volume, maximum pressure, mean pressure, anal canal symmetry, anal canal length, and the length of the high-pressure zone can be readily calculated. LIMITATIONS: There are conflicting studies related to the clinical value of both anal manometry and vector volume manometry, in part, because of the lack of standardization of equipment and technique. CONCLUSIONS: The vector volume parameters have been shown to correlate with both imaging results and incontinence scores with automated puller systems. The clinical utility of vector volume manometry would be improved further by the standardization of equipment and technique. The main clinical utility may lie in the treatment selection and preoperative assessment of patients awaiting surgery for anal pathology that has yet to be evaluated.

Association of plasma and urine NGAL with acute kidney injury after elective colorectal surgery: A cohort study.

BACKGROUND: Acute kidney injury (AKI) is common in surgical patients. We aimed to investigate the validity of plasma and urine neutrophil gelatinase-associated lipocalin (NGAL) in the detection of AKI and prediction of outcomes in patients undergoing major colorectal surgery. MATERIALS AND METHODS: This was a pre-specified post-hoc analysis of a randomized controlled trial comparing oesophageal doppler and Lithium dilution cardiac output monitoring in high risk patients undergoing major colorectal surgery as part of an Enhanced Recovery After Surgery protocol in a tertiary care hospital. Plasma and urine samples for NGAL measurement were taken before surgery (T1), immediately after surgery (T2), and on postoperative day 1 (T3). AKI was defined according to the KDIGO criteria. RESULTS: A total of 89 patients were included of whom 12 (13.5%) developed AKI. Plasma NGAL significantly increased from T1 to T3 in both AKI (p < 0.001) and non-AKI (p = 0.048) patients, while urine NGAL did not change over time. There were no significant differences in plasma and urine NGAL in patients with and without AKI at all time points. Postoperative day 1 urine NGAL concentrations were significantly higher in non-survivors than survivors (41.2 versus 25 ng/mL, p = 0.026). One-year mortality was significantly higher in AKI patients with a raised urine NGAL compared to AKI patients without elevated urine NGAL levels. CONCLUSIONS: Plasma and urine NGAL poorly predicted AKI post-colorectal surgery. Non-survivors had higher urine NGAL results. More research is required to explore the association between NGAL and long-term outcomes.

Chronic constipation in adults: Contemporary perspectives and clinical challenges. 2: Conservative, behavioural, medical and surgical treatment.

BACKGROUND: Chronic constipation is a prevalent disorder that affects quality of life of patients and consumes resources in healthcare systems worldwide. In clinical practice, it is still considered a challenge as clinicians frequently are unsure as to which treatments to use and when. Over a decade ago, a Neurogastroenterology and Motility journal supplement devoted to the investigation and management of constipation was published (Neurogastroenterol Motil 2009;21(Suppl 2):1). In October 2018, the 3rd London Masterclass, entitled "Contemporary management of constipation" was held. The faculty members of this symposium were invited to write two reviews to present a collective synthesis of talks presented and discussions held during this meeting. The first review addresses epidemiology, diagnosis, clinical associations, pathophysiology, and investigation. PURPOSE: The present is the second of these reviews, providing contemporary perspectives and clinical challenges regarding behavioral, conservative, medical, and surgical treatments for patients presenting with constipation. It includes a management algorithm to guide clinical practice.

A simple quality of life questionnaire for patients with faecal incontinence.

INTRODUCTION: A simple quality of life questionnaire was designed to triage patients with faecal incontinence to the most appropriate level of support, investigation and treatment. METHOD: A questionnaire was developed to include a 'symptom' score, similar in content to St Mark's questionnaire and a 'bothersome' score. A pilot study (34 patients) assessed the clarity of questions. Once content validity was established, it was sent to 360 patients who attended a pelvic floor clinic. Its external validity was assessed against the established standards of the short form 36 (SF-36) and the Manchester Health Questionnaires. Ease of use for these was assessed using a separate form. RESULTS: Of the 360 patients, 86 replied. The questionnaire was shown to be reliable both by measurement of its internal consistency and by test-retest analysis. There was a significant correlation between the scores of the new questionnaire and the Manchester Health Questionnaire as well as the SF-36. Divergence validity, assessed by correlating the number of pads used and the overall symptom score, was established. The new questionnaire was easiest to complete, taking on average 4 min. CONCLUSION: We have demonstrated that the new questionnaire is reliable and valid. It is easy and quick to complete and assesses both severity and impact of symptoms.

IDOCS: intelligent distributed ontology consensus system--the use of machine learning in retinal drusen phenotyping.

PURPOSE: To use the power of knowledge acquisition and machine learning in the development of a collaborative computer classification system based on the features of age-related macular degeneration (AMD). METHODS: A vocabulary was acquired from four AMD experts who examined 100 ophthalmoscopic images. The vocabulary was analyzed, hierarchically structured, and incorporated into a collaborative computer classification system called IDOCS. Using this system, three of the experts examined images from a second set of digital images compiled from more than 1000 patients with AMD. Images were annotated, and features were identified and defined. Decision trees, a machine learning method, were trained on the data collected and used to extract patterns. Interrelationships between the data from the different clinicians were investigated. RESULTS: Six drusen classes in the structured vocabulary were largely sufficient to describe all the identified features. The decision trees classified the data with 76.86% to 88.5% accuracy and distilled patterns in the form of hierarchical trees composed of 5 to 15 nodes. Experts were largely consistent in their characterization of soft, and to a lesser extent, hard drusen, but diverge in definition of other drusen. Size and crystalline morphology were the main determinants of drusen type across all experts. CONCLUSIONS: Machine learning is a powerful tool for the characterization of disease phenotypes. The creation of a defined feature set for AMD will facilitate the development of an IDOCS-based classification system.

Patient optimization for surgery relating to Crohn's disease.

The majority of patients with Crohn's disease require abdominal surgery during their lifetime, some of whom will require multiple operations. Postoperative complications are seen more frequently in patients requiring abdominal surgery for Crohn's disease than in patients requiring abdominal surgery for other conditions. In this article, we review the evidence supporting preoperative optimization, discussing strategies that potentially improve surgical outcomes and reduce perioperative morbidity and mortality. We discuss the roles of adequate cross-sectional imaging, nutritional optimization, appropriate adjustments of medical therapy, management of preoperative abscesses and phlegmons, smoking cessation and thromboembolic prophylaxis. We also review operation-related factors, and discuss their potential implications with respect to postoperative complications. Overall, the literature suggests that preoperative management has a major effect on postoperative outcomes.

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.

Total pelvic floor ultrasound for pelvic floor defaecatory dysfunction: a pictorial review.

Total pelvic floor ultrasound is used for the dynamic assessment of pelvic floor dysfunction and allows multicompartmental anatomical and functional assessment. Pelvic floor dysfunction includes defaecatory, urinary and sexual dysfunction, pelvic organ prolapse and pain. It is common, increasingly recognized and associated with increasing age and multiparity. Other options for assessment include defaecation proctography and defaecation MRI. Total pelvic floor ultrasound is a cheap, safe, imaging tool, which may be performed as a first-line investigation in outpatients. It allows dynamic assessment of the entire pelvic floor, essential for treatment planning for females who often have multiple diagnoses where treatment should address all aspects of dysfunction to yield optimal results. Transvaginal scanning using a rotating single crystal probe provides sagittal views of bladder neck support anteriorly. Posterior transvaginal ultrasound may reveal rectocoele, enterocoele or intussusception whilst bearing down. The vaginal probe is also used to acquire a 360° cross-sectional image to allow anatomical visualization of the pelvic floor and provides information regarding levator plate integrity and pelvic organ alignment. Dynamic transperineal ultrasound using a conventional curved array probe provides a global view of the anterior, middle and posterior compartments and may show cystocoele, enterocoele, sigmoidocoele or rectocoele. This pictorial review provides an atlas of normal and pathological images required for global pelvic floor assessment in females presenting with defaecatory dysfunction. Total pelvic floor ultrasound may be used with complementary endoanal ultrasound to assess the sphincter complex, but this is beyond the scope of this review.

Colovesical fistula: should it be considered a single disease?

PURPOSE: This research was conducted to compare the management and the outcome of patients with colovesical fistulae of different aetiologies. METHODS: Retrospective data were collected from 2002 to 2012 and analyzed with SPSS ver. 17. Age, gender, aetiology, management, hospital stay, postoperative complications, and mortality were studied and compared among colovesical fistulae of different aetiologies. RESULTS: A total of 55 patients, 46 males (84%) and 9 females (16%), with a median age of 65 years (interquartile range [IQR], 48-75 years) were studied. Diverticular disease was the most common benign cause and recto-sigmoid cancer the most common malignancy. Anterior resection and bladder repair were the most frequent operations in benign cases, as was total pelvic exenteration in the malignant group. Multiple intestinal loop involvement and subsequent resection were significantly higher in those with Crohn disease than it was in patients of colovesical fistula due to all other causes collectively (60% vs. 6%, P = 0.006). Patients with malignancy had a higher postoperative complication rate than patients who did not (12 [80%] vs. 7 [32%], P = 0.0005). Pelvic collection (11, 22%) was the most frequent early complication (predominantly in the malignant group) whereas incisional hernia (8, 22%) was the most common late complication, with a predominance in the benign group. The median hospital stay was significantly prolonged in the malignant group (32 days; IQR, 17-70 days vs. 16 days; IQR, 11-25 days; P < 0.001). CONCLUSION: Despite their having similar clinical presentation, colovesical fistulae of various aetiologies differ significantly in management and outcome.

A review of functional pelvic floor imaging modalities and their effectiveness.

The anatomy of the pelvic floor is complex and clinical examination alone is often insufficient to diagnose and assess pathology. With a greater understanding of pelvic floor dysfunction and treatment options, imaging is becoming increasingly common. This review compares three imaging techniques. Ultrasound has the potential for dynamic assessment of the entire pelvic floor. Magnetic resonance imaging is able to rapidly image the entire pelvic floor but it is expensive and tends to underestimate pathology. Dynamic defaecating proctography or cystocolpoproctography is the current gold standard for posterior compartment imaging but requires opacification of the bladder to provide a global view.

Endosonographic staging of lower intestinal malignancy.

The use of EUS in the assessment of rectal pathology is well established. The accurate staging of lower intestinal tumours predicts prognosis and guides the planning of individual patient treatment. Increased experience and the development of high resolution three-dimensional EUS has lead to the greater accuracy of rectal staging with EUS of rectal tumours now considered the gold standard showing T stage accuracy that ranges from 75% to 95%, with N stage accuracy ranging from 65% to 80%. The use of EUS in the staging of colonic pathology, however, is not so well established though advances in miniprobe EUS has improved the assessment of colonic tumours. EUS is also of benefit in the assessment of anal pathology though here, accurate correlation with histology has not been firmly established.

Value of hydrogen peroxide enhancement of three-dimensional endoanal ultrasound in fistula-in-ano.

PURPOSE: The aim of this prospective study was to compare the accuracy of three-dimensional endoanal ultrasound with that of hydrogen peroxide enhanced three-dimensional endoanal ultrasound in diagnosing recurrent or complex fistula-in-ano. METHODS: Three-dimensional endoanal ultrasound reconstructions were performed before and after hydrogen peroxide enhancement in 19 patients with suspected recurrent or complex fistula-in-ano. Two experienced observers derived a consensus fistula classification after a blinded random review of the data sets. The accuracy of three-dimensional endoanal ultrasound and that of hydrogen peroxide-enhanced three-dimensional endoanal ultrasound were compared with a reference standard derived from surgical findings and magnetic resonance imaging and modified by outcome over a median follow-up of 13 months. RESULTS: Patients had previously undergone a median of three fistula operations. Four had Crohn's disease. There were 21 internal openings and primary tracks in 19 patients: 1 superficial, 1 intersphincteric, 18 transsphincteric, and 1 extrasphincteric. Fourteen patients had 19 secondary tracks. Both techniques detected fistula tracks in 19 of 21 (90 percent) patients. There was no significant difference between three-dimensional endoanal ultrasound and hydrogen peroxide-enhanced three-dimensional endoanal ultrasound in classifying internal openings (19/21 (90 percent) vs. 18/21 (86 percent)), primary tracks (17/21 (81 percent) vs. 15/21 (71 percent)), or secondary tracks (13/19 (68 percent) vs. 12/19 (63 percent)). Where three-dimensional endoanal ultrasound correctly detected an internal opening, gas from hydrogen peroxide enhancement was present in 8 of 18 (44 percent) studies. Similarly, gas made primary tracks more conspicuous in 6 of 19 (32 percent) and secondary tracks in 6 of 13 (46 percent) of those detected. CONCLUSIONS: In recurrent or complex fistula-in-ano, endoanal ultrasound proved more accurate for detecting primary tracks and internal openings than for detecting extensions. Hydrogen peroxide improved conspicuity of some tracks and internal openings and so may be helpful in difficult cases, although no overall diagnostic benefit was demonstrated.

Clinical examination, endosonography, and MR imaging in preoperative assessment of fistula in ano: comparison with outcome-based reference standard.

PURPOSE: To prospectively evaluate the relative accuracy of digital examination, anal endosonography, and magnetic resonance (MR) imaging for preoperative assessment of fistula in ano by comparison to an outcome-derived reference standard. MATERIALS AND METHODS: Ethical committee approval and informed consent were obtained. A total of 104 patients who were suspected of having fistula in ano underwent preoperative digital examination, 10-MHz anal endosonography, and body-coil MR imaging. Fistula classification was determined with each modality, with reviewers blinded to findings of other assessments. For fistula classification, an outcome-derived reference standard was based on a combination of subsequent surgical and MR imaging findings and clinical outcome after surgery. The proportion of patients correctly classified and agreement between the preoperative assessment and reference standard were determined with trend tests and kappa statistics, respectively. RESULTS: There was a significant linear trend (P < .001) in the proportion of fistula tracks (n = 108) correctly classified with each modality, as follows: clinical examination, 66 (61%) patients; endosonography, 87 (81%) patients; MR imaging, 97 (90%) patients. Similar trends were found for the correct anatomic classification of abscesses (P < .001), horseshoe extensions (P = .003), and internal openings (n = 99, P < .001); endosonography was used to correctly identify the internal opening in 90 (91%) patients versus 96 (97%) patients with MR imaging. Agreement between the outcome-derived reference standard and digital examination, endosonography, and MR imaging for classification of the primary track was fair (kappa = 0.38), good (kappa = 0.68), and very good (kappa = 0.84), respectively, and fair (kappa = 0.29), good (kappa = 0.64), and very good (kappa = 0.88), respectively, for classification of abscesses and horseshoe extensions combined. CONCLUSION: Endosonography with a high-frequency transducer is superior to digital examination for the preoperative classification of fistula in ano. While MR imaging remains superior in all respects, endosonography is a viable alternative for identification of the internal opening.