Incidence and diagnostic performance of ultrasound for perianal abscess or fistula-in-ano in pediatric patients with perianal inflammation.

OBJECTIVES: To describe the incidence and diagnostic performance of ultrasound for perianal abscess or fistula-in-ano in pediatric patients with perianal inflammation. METHODS: We included 45 patients with perianal inflammation who underwent ultrasonography. To demonstrate the diagnostic performance of ultrasound for fistula-in-ano, a definite diagnosis of perianal abscess, and fistula-in-ano was determined as that proven through magnetic resonance imaging (MRI) or computed tomography (CT). The absence or presence of perianal abscess and fistula-in-ano on ultrasonography was recorded. RESULTS: Among the 45 patients, on ultrasound, perianal abscess and fistula-in-ano were detected in 22 (48.9%) and 30 (68.2%) patients, respectively. Nine patients had MRI or CT and a definite diagnosis of perianal abscess or fistula-in-ano; accuracy, negative predictive value, and positive predictive value of ultrasound for perianal abscess were 77.8% (7/9; 95% confidence interval [CI]: 40.0%-97.1%), 66.7% (2/3; 95% CI: 9.4%-99.2%), 83.3% (5/6; 95% CI: 35.9%-99.6%), and those of fistula-in-ano were 100% (9/9; 95% CI: 66.4%-100%), 100% (8/8; 95% CI: 63.1%-100%), and 100% (1/1; 95% CI: 2.5%-100%), respectively. CONCLUSIONS: Perianal abscess and fistula-in-ano were detected by ultrasound in half of the patients with perianal inflammation. Accordingly, ultrasound has an acceptable diagnostic performance for perianal abscess and fistula-in-ano.

Anorectal pathology in the HIV population: a guide for radiologists.

Patients with human immunodeficiency virus (HIV) can present with a wide range of different acute and chronic pathologies. Anorectal conditions are particularly common in this unique patient population, including pathologies, such as proctitis, anorectal abscess, anorectal fistula, and anal squamous cell carcinoma. The radiologist plays a critical role in the assessment of these common forms of anorectal disease, as these conditions can present with various findings on imaging assessment. Pelvic CT, MRI, and FDG-PET/CT are among the most common modalities used for assessment of anorectal disease in the HIV patient population. Knowledge of the fundamental clinical and imaging findings associated with these pathologies in HIV patients is critical for radiologists.

Feasibility and safety study of a high resolution wide field-of-view scanning endoscope for circumferential intraluminal intestinal imaging.

Global anal cancer incidence is increasing. High resolution anoscopy (HRA) currently screens for anal cancer, although the definitive test remains unknown. To improve on intraluminal imaging of the anal canal, we conducted a first-in-human study to determine feasibility and safety of a high-resolution, wide field-of-view scanning endoscope. Fourteen patients, under an IRB-approved clinical study, underwent exam under anesthesia, HRA, and imaging with the experimental device. HRA findings were photographed using an in-line camera attached to the colposcope and compared with the scanning endoscope images. Patients were followed up within 2 weeks of the procedure. The imaging device is inserted into the anal canal and the intraluminal surface is digitally photographed in 10 s and uploaded to a computer monitor for review. Ten patients completed imaging with the device. Three patients were not imaged due to severe anal stenosis. One patient was not imaged due to technical device malfunction. The device images were compared to the HRA images. No adverse event attributable to the device was reported. The intraluminal scanning endoscope can be used for circumferential anal canal imaging and is safe for clinical use. Future clinical studies are needed to evaluate the performance of this device.

[Treatment of anal abscesses].

Anal abscesses are well-known conditions worldwide. The golden standard of acute treatment is incision and drainage. Knowledge of the anatomy of the anal area and the abscess involvement of perianal spaces is crucial in order to perform safe and correct surgical treatment as summarised in this review. Pre- and perioperative imaging with magnetic resonance imaging, endoanal ultrasonography or CT facilitates correct incision and drainage, while antibiotics as conservative approach have no place in the treatment of abscesses. One third of the patients have an underlying fistula, and if suspected referral to a fistula centre is warranted.

Magnetic Resonance Imaging of Fistula-In-Ano.

This article explains the pathogenesis of fistula-in-ano and details the different classifications of fistula encountered, describe their features on MR imaging, and explains how imaging influences subsequent surgical treatment and ultimate clinical outcome. Precise preoperative characterization of the anatomic course of the fistula and all associated infection via MR imaging is critical for surgery to be most effective. MR imaging is the preeminent imaging modality used to answer pertinent surgical questions.

Imaging features of Benign Perianal lesions.

Magnetic resonance imaging provides detailed visualisation, identification and extent assessment of many anal disorders. While many studies are performed in the evaluation of malignant processes such as anorectal carcinoma, the primary focus of this pictorial review is benign lesions, which involve the anal canal and perianal spaces. This pictorial review will illustrate the MRI appearances of a variety of benign conditions, which predominantly affect the anal canal, including abscess, fistulae, lipomas, developmental cysts and inflammatory conditions. MRI aids in the identification and characterisation of these abnormalities, of coexisting complications and differentiation from other perineal abnormalities. This pictorial review highlights the spectrum of non-malignant processes involving the perianal region.

MRI anatomy and pathology of the anal canal.

The normal function of the anal sphincter complex is crucial for quality of life, as it is the mechanism by which fecal continence is maintained. Additionally, the anal sphincter complex is an integral part of the coordinated effort of defecation. As imaging plays an important role in assessment of pathologic conditions involving the anal region, understanding the normal anatomy of the anal sphincter complex is important for correct image interpretation and accurate diagnosis. This review discusses the anatomy and function of the anal sphincter complex, important technical considerations for MRI, and various inflammatory, infectious, and neoplastic processes, as well as pathologic structural conditions that affect the anal region. Level of Evidence: 5 Technical Efficacy Stage: 3 J. Magn. Reson. Imaging 2019;50:1018-1032.

Perianal sepsis: surgical perspective and practical MRI reporting for radiologists.

This article describes the development of a structured MRI reporting template and diagrammatic worksheet for perianal sepsis through collaboration between radiologists and colorectal surgeons at our institution, and the rationale behind each component of the worksheet. Benefits of this reporting worksheet include optimizing communication of key imaging findings that have a real impact on patient management, less time spent on reporting the study, and easier comparison between studies. We illustrate the utility of the report template with case studies. We summarize the current surgical approaches to perianal sepsis to help radiologists focus on reporting the findings relevant to surgical planning.

Three-dimensional high-resolution anorectal manometry in functional anorectal disorders: results from a large observational cohort study.

BACKGROUND: The aim of the study was to describe the results of 3D high-resolution anorectal manometry (3DHRAM) in a large cohort of patients with functional anorectal disorders. METHODS: In this single-center retrospective study, all consecutive patients referred for investigation of fecal incontinence (FI) or dyssynergic defecation (DD) underwent 3DHRAM. The parameters analyzed were usual manometric data, repartition of dyssynergic patterns, and the prevalence of a new "muscular subtype classification" underlying dyssynergia, anal sphincter defects, and pelvic floor disorders. RESULTS: Final analyses were performed in 1477 patients with a mean age 54 ± 16 years; 825 patients suffered from DD, and 652 patients suffered from FI. Among these patients, 86% met the diagnostic criteria for dyssynergia. Type II dyssynergia was the most frequently observed (56%) in women and men suffering from FI and in women with DD. Type I was the most frequently observed in men with DD (49%). Regarding the muscle type subgroups, combined puborectalis muscle involvement with an external anal sphincter profile was the most frequently observed. The global prevalence of rectal intussusception and excessive perineal descent were 12% and 21%, respectively. Type III dyssynergia was more frequently associated with pelvic floor disorders than were other types of dyssynergia (p < 0.001). CONCLUSION: This large cohort study provides reference values for 3DHRAM in patients with functional anorectal disorders. Further studies are necessary to assess the prevalence of pelvic floor disorders in healthy volunteers and to develop new scores and classifications including all of these new parameters.

Levator ani muscle morphology and function in women with obstetric anal sphincter injury.

OBJECTIVES: To estimate the prevalence of, and explore the risk factors for, levator ani muscle (LAM) injury in women with clinically diagnosed obstetric anal sphincter injury (OASI). The secondary aim was to assess the association between LAM injury and pelvic floor muscle contraction, anal incontinence (AI) and urinary incontinence (UI) in women with OASI. METHODS: This was a cross-sectional study of 250 women with OASI, recruited between 2013 and 2015 from a tertiary referral center at Croydon University Hospital, UK. AI symptoms were assessed using the modified St Mark's incontinence score and UI was assessed using the International Consultation on Incontinence modular Questionnaire for Urinary Incontinence - Short Form. All participants underwent three/four-dimensional transperineal ultrasound at rest and on maximum pelvic floor muscle contraction. Major LAM injury was defined as a unilateral or bilateral defect in all three central slices on tomographic ultrasound imaging. Muscle contraction was assessed using the modified Oxford scale (MOS) and measured on ultrasound as the proportional change in the anteroposterior (AP) levator hiatal diameter between rest and contraction. Multivariable logistic regression analysis was used to study risk factors for LAM injury. Differences in contraction and AI and UI symptoms between women with intact and those with injured LAM were studied using multivariable ANCOVA and the Mann-Whitney U-test. RESULTS: Of the 248 women with OASI for whom ultrasound volumes of adequate quality were available, 29.4% were found to have major LAM injury. The prevalence of LAM injury was 23.6% after normal vaginal delivery and 40.2% after operative vaginal delivery (adjusted odds ratio, 4.1 (95% CI, 1.4-11.9); P = 0.01). LAM injury was associated with weaker pelvic floor muscle contraction, with an adjusted mean difference for proportional change in AP diameter of 5.0 (95% CI, 3.0-6.9) and MOS of 0.6 (95% CI, 0.3-0.9) (P < 0.001 for both). AI and UI symptom scores were similar between women with intact and those with injured LAM. CONCLUSIONS: Operative vaginal delivery was a risk factor for LAM injury in women with OASI. LAM injury was associated with weaker pelvic floor muscle contraction. Special attention is recommended for women with OASI and LAM injury, as they are at high risk for future pelvic floor disorders. The benefits of implementation of an intensive, focused and structured pelvic floor rehabilitation program need to be evaluated in these women. Copyright © 2018 ISUOG. Published by John Wiley & Sons Ltd.

Morfología y función del músculo elevador del ano en mujeres con lesión obstétrica del esfínter anal OBJETIVOS: Estimar la prevalencia y explorar los factores de riesgo de lesión del músculo elevador del ano (MEA) en mujeres con lesión obstétrica del esfínter anal (LOEA) diagnosticada clínicamente. El objetivo secundario fue evaluar la asociación entre la lesión del MEA y la contracción muscular del suelo pélvico, la incontinencia anal (IA) y la incontinencia urinaria (IU) en mujeres con LOEA. MÉTODOS: Este fue un estudio transversal de 250 mujeres con LOEA, reclutadas entre 2013 y 2015 en un centro de referencia terciario del Hospital Universitario de Croydon en el Reino Unido. Los síntomas de IA se evaluaron mediante una modificación de la puntuación de incontinencia de San Marcos y los de la IU mediante el Formulario resumido del Cuestionario Modular de la Consulta Internacional sobre Incontinencia para la Incontinencia Urinaria. Todas las participantes se sometieron a una ecografía transperineal tridimensional en reposo y en máxima contracción de los músculos del suelo pélvico. Las lesiones importantes del MEA se definieron como un defecto unilateral o bilateral en los tres cortes centrales de la ecografía tomográfica. La contracción muscular se evaluó mediante la escala de Oxford modificada (EOM) y se midió en la ecografía como el cambio proporcional en el diámetro hiatal del elevador anteroposterior (AP) entre el reposo y la contracción. Se utilizó un análisis de regresión logística multivariable para estudiar los factores de riesgo de lesión del MEA. Se estudiaron las diferencias en la contracción y los síntomas de IA e IU entre las mujeres con el MEA intacto y las lesionadas, mediante un ANCOVA multivariable y la prueba U de Mann-Whitney. RESULTADOS: De las 248 mujeres con LOEA para las que se disponía de una cantidad de ecografías de calidad adecuada, se encontró que el 29,4% tenía una lesión importante del MEA. La prevalencia de lesiones del MEA fue del 23,6% después de un parto vaginal normal y del 40,2% después de un parto vaginal quirúrgico (razones de momios ajustadas, 4,1 (IC 95%: 1,4-11,9); P=0,01). Las lesiones del MEA se asociaron con una contracción muscular más débil del suelo pélvico, con una diferencia de medias ajustada para el cambio proporcional en el diámetro del AP de 5,0 (IC 95%: 3,0-6,9) y para la EOM de 0,6 (IC 95%: 0,3-0,9) (P<0,001 para ambos). Las puntuaciones de los síntomas de la IA y la IU fueron similares entre mujeres con el MEA intacto y mujeres con lesiones. CONCLUSIONES: El parto vaginal quirúrgico fue un factor de riesgo de lesión del MEA en mujeres con LOEA. La lesión del MEA se asoció con una contracción muscular más débil del suelo pélvico. Se recomienda prestar una atención especial a las mujeres con LOEA y con lesiones del MEA, ya que tienen un alto riesgo de futuros trastornos del suelo pélvico. Es necesario evaluar en estas mujeres los beneficios de la implementación de un programa intensivo, focalizado y estructurado de rehabilitación del suelo pélvico.

MRI evaluation of anal and perianal diseases.

Anal and perianal region is a commonly affected area in the course of several inflammatory, infectious, and neoplastic diseases. Several imaging modalities may be used in imaging evaluation of this area and magnetic resonance imaging (MRI) emerges as the imaging modality of choice due to its superb soft tissue resolution. MRI is not only useful for initial detection of anal/perianal pathologies but also in the follow-up of these disorders. In this article, we aimed to illustrate MRI findings of several diseases affecting this area including perianal fistula as well as anal fissure, hypertrophic myopathy of internal anal sphincter, hidradenitis suppurativa, pilonidal sinus, rectovaginal/anovaginal fistula and anal canal carcinoma. We think that this article will serve to familiarize the imaging specialists to the MRI findings of these diseases.

MRI of anal canal: common anal and perianal disorders beyond fistulas: Part 2.

A broad spectrum of disease, from benign processes to life-threatening pathologies, can cause anal pain. MR imaging (MRI) has become increasingly widely used method over the past two decades for the evaluation of individuals with anorectal symptoms. Although imaging is rarely necessary to determine the etiology of the majority of cases, MRI is particularly useful as a noninvasive method of excluding severe neoplastic conditions. In this article, MRI findings of a number of pathologies such as anal and perianal neoplasms, hemorrhoidal disease, arteriovenous malformation of the perianal region, and anal sphincter lesions (defects, scarring, atrophy) which may lead to fecal incontinence are presented.

Can MR enterography screen for perianal disease in pediatric inflammatory bowel disease?

BACKGROUND: Pediatric Crohn's disease is associated with perianal disease (PAD). Magnetic resonance enterography (MRE) assesses small bowel involvement in pediatric inflammatory bowel disease (PIBD). Pelvic MRI (P-MRI) is the gold standard for assessing PAD. PURPOSE: To determine if MRE can accurately detect PAD in PIBD, distinguishing perianal fistulae (PAF) from perianal abscesses (PAA), referenced against P-MRI. STUDY TYPE: Retrospective. POPULATION: Seventy-seven PIBD patients, 27 females (mean age 14.1 years), with P-MRI and MRE within 6 months. FIELD STRENGTH/SEQUENCE: 1.5T and 3T; P-MRI: sagittal fat suppressed (FS) T2 fast spin-echo (FSE), coronal short tau inversion recovery, axial T1 FSE, coronal and axial postcontrast FS T1 FSE; MRE: coronal balanced steady-state free-precession (SSFP), coronal cine SSFP, coronal and axial single-shot T2 FS, axial SSFP, coronal ultrafast 3D T1 -weighted gradient echo FS (3D T1 GE), axial diffusion-weighted imaging, coronal and axial postcontrast 3D T1 GE FS. ASSESSMENT: Two radiologists independently, then by consensus, assessed randomized MRI exams, recording PAF number, location, and length; and PAA number, location, length, and volume. Sensitivity analysis used clinical disease as the gold standard, calculated separately for P-MRI and MRE. STATISTICAL TESTS: Comparing MRE and P-MRI consensus data, sensitivity, specificity, positive, and negative predictive values (P/NPV) were calculated. Inter- and intrareader reliability were assessed using kappa statistics. RESULTS: P-MRI and MRE were paired, detecting PAD in 73 patients, PAF in 63, and PAA in 31 P-MRI. MRE sensitivities, specificities, PPV, and NPV were: PAD 82%, 100%, 100%, 23%; PAF 74%, 71%, 92%, 38%; PAA 51%, 85%, 69%, 72%; clinical 82%, 22%, 37%, 69%; clinical P-MRI 96%, 8%, 37%, 80%. MRE interreader agreement for PAD was moderate (kappa = 0.51 [0.29-0.73]), fair for PAF and PAA. DATA CONCLUSION: Using a standard technique, MRE can detect PAD with high specificity and moderate sensitivity in PIBD, missing some PAF and small PAA. LEVEL OF EVIDENCE: 3 Technical Efficacy: Stage 2 J. Magn. Reson. Imaging 2018;47:1638-1645.

Comparison of Transperianal Ultrasound With Colonoscopy and Magnetic Resonance Imaging in Perianal Crohn Disease.

OBJECTIVE: Perianal fistulae and/or abscesses are common complications of Crohn disease (CD), especially in children. Magnetic resonance imaging (MRI) and gross examination under anesthesia are accurate diagnostic modalities for evaluating perianal lesions. Both methods, however, are expensive and have some limitations for use in children. This study aims to assess the accuracy of transperianal ultrasound (TPUS) and colonoscopic examination, compared with MRI, in pediatric patients with perianal CD (PACD). METHODS: Thirty-eight children and adolescents with PACD who underwent MRI, TPUS, and gross colonoscopic examination under sedation were included. Fistulae were classified according to Parks' and St. James's University Hospital classifications. Abscesses were identified by their presence and location on each modality. RESULTS: Fifty-nine fistulae (26 superficial, 23 intersphincteric, 10 transsphincteric) and 16 abscesses were detected using MRI. Fifty-nine fistulae and 10 abscesses were detected using TPUS. Forty-five fistulae (sensitivity 76.3%, positive predictive value [PPV] 84.2%, and kappa value 0.296] and 9 abscesses (sensitivity 56.3%, PPV 90.0%, and kappa value 0.624) on TPUS corresponded with MRI findings. Forty-six fistulae and fifteen abscesses were detected using colonoscopy. Forty fistulae (sensitivity 67.8%, PPV 89.9%, and kappa value 0.369) and 7 abscesses (sensitivity 43.8%, PPV 48.8%, and kappa value 0.304) on colonoscopy corresponded with MRI findings. With respect to abscess, agreement between TPUS and MRI was superior to that between colonoscopy and MRI (Spearman rho 0.651 vs 0.304, P = 0.007). CONCLUSION: TPUS is an appropriate, simple, and real-time method for detecting perianal fistula and/or abscess, in children with PACD.

Transperineal Ultrasound for Perianal Fistulas and Abscesses - A Systematic Review and Meta-Analysis.

Purpose Transperineal ultrasound (TPUS) is a practical tool for assessing perianal inflammatory lesions. We systematically review its accuracy for detecting and classifying perianal fistulae and abscesses. Method The National Library of Medicine and Embase were searched for articles on TPUS for the assessment of idiopathic and Crohn's perianal fistulae and abscesses. Two reviewers independently reviewed eligible studies and rated them for quality using the QUADAS tool. The primary outcome measure was the accuracy of TPUS as measured by its sensitivity and positive predictive value (PPV) in detecting and classifying perianal fistulae, internal openings and perianal abscesses. Results We included 12 studies (565 patients). Overall, the methodological quality of the studies was suboptimal. 3 studies were retrospective and 4 showed significant risks of bias in the application of the reference standard. The sensitivity of TPUS in detecting perianal fistulae on a per-lesion basis was 98 % (95 % CI 96 - 100 %) and the PPV was 95 % (95 % CI 90 - 98 %). The detection of internal openings had a sensitivity of 91 % (95 % CI 84 - 97 %) with a PPV of 87 % (95 % CI 76 - 95 %). The classification of fistulae yielded a sensitivity of 92 % (95 % CI 85 - 97 %) and a PPV of 92 % (95 % CI 83 - 98 %). TPUS had a sensitivity of 86 % (95 % CI 67 - 99 %) and PPV of 90 % (95 % CI 76 - 99 %) in the detection of perianal abscesses. Conclusion The current literature on TPUS illustrates good overall accuracy in the assessment of perianal fistulae and abscesses. However, many studies had methodological flaws suggesting that further research is required.