Development of an MRI-Based Prediction Model for Anti-TNF Treatment Failure in Perianal Crohn's Disease: A Multicenter Study.

BACKGROUND & AIMS: Clinical and radiologic variables associated with perianal fistula (PAF) outcomes are poorly understood. We developed prediction models for anti-tumor necrosis factor (TNF) treatment failure in patients with Crohn's disease-related PAF. METHODS: In a multicenter retrospective study between 2005 and 2022 we included biologic-naive adults (>17 years) who initiated their first anti-TNF therapy for PAF after pelvic magnetic resonance imaging (MRI). Pretreatment MRI studies were prospectively reread centrally by blinded radiologists. We developed and internally validated a prediction model based on clinical and radiologic parameters to predict the likelihood of anti-TNF treatment failure, clinically, at 6 months. We compared our model and a simplified version of MRI parameters alone with existing imaging-based PAF activity indices (MAGNIFI-CD and modified Van Assche MRI scores) by De Long statistical test. RESULTS: We included 221 patients: 32 ± 14 years, 60% males, 76% complex fistulas; 68% treated with infliximab and 32% treated with adalimumab. Treatment failure occurred in 102 (46%) patients. Our prediction model included age at PAF diagnosis, time to initiate anti-TNF treatment, and smoking and 8 MRI characteristics (supra/extrasphincteric anatomy, fistula length >4.3 cm, primary tracts >1, secondary tracts >1, external openings >1, tract hyperintensity on T1-weighted imaging, horseshoe anatomy, and collections >1.3 cm). Our full and simplified MRI models had fair discriminatory capacity for anti-TNF treatment failure (concordance statistic, 0.67 and 0.65, respectively) and outperformed MAGNIFI-CD (P = .002 and < .0005) and modified Van Assche MRI scores (P < .0001 and < .0001), respectively. CONCLUSIONS: Our risk prediction models consisting of clinical and/or radiologic variables accurately predict treatment failure in patients with PAF.

Comparative Study of Diluted Hydrogen Peroxide and Sulfur Hexafluoride in the Contrast-Enhanced Ultrasound Assessment of Anal Fistulas.

BACKGROUND: Endoanal ultrasound for the diagnosis of anal fistulas requires the injection of hydrogen peroxide, but it is often uncomfortable for the patient and has the potential to cause complications. Novel ultrasound contrast is currently available. OBJECTIVE: To assess the efficacy and safety of sulfur hexafluoride as an ultrasound contrast agent for the diagnosis of a perianal fistula by comparing it with those of 50% diluted hydrogen peroxide. DESIGN: Double-blinded superiority study with 4 consecutive visits to perform an ultrasound without contrast, a hydrogen peroxide-enhanced ultrasound, a sulfur hexafluoride-enhanced ultrasound, and a rectal exploration in the operating room (the criterion standard). The 3 expert surgeon sonographers independently reviewed the ultrasound images. SETTING: This study was conducted at a single university hospital. PATIENTS: Data from 176 patients were evaluated. MAIN OUTCOME MEASURES: Demographic and exploratory data and the ultrasound findings related to the location of the internal fistula orifice, description of the primary and secondary tracts, and presence of cavities and sphincter defects were analyzed. Complications occurring before and after the contrast agent administration and pain score measured using a visual analog scale were considered. RESULTS: Eighty-eight patients were included (men: 71.5%; mean age: 48.3 years), with 62.5% having a complex type fistula and 83.7% having a transsphincteric type fistula. Sulfur hexafluoride-enhanced ultrasounds demonstrated a higher interobserver agreement in determining the secondary tracts (κ = 0.604) and anal fistula height (κ = 0.604) compared with other methods. Both hydrogen peroxide-enhanced ultrasound (90.91%) and sulfur hexafluoride-enhanced ultrasound (89.77%) detected the internal orifice more frequently than ultrasounds without contrast (62.5%; p < 0.001), with no differences between contrast agents ( p = 0.810). Sulfur hexafluoride-enhanced ultrasound was less painful than peroxide-enhanced ultrasound ( p < 0.001). LIMITATIONS: Most of the patients had transsphincteric anal fistulas. CONCLUSIONS: Sulfur hexafluoride proved comparable to hydrogen peroxide in evaluating fistulous tracts and identifying the internal orifice, and it significantly reduced pain and discomfort. Furthermore, it demonstrated a higher interobserver agreement in determining the secondary tracts and anal fistula height compared with other methods. See Video Abstract . ESTUDIO COMPARATIVO DE PERXIDO DE HIDRGENO DILUIDO Y HEXAFLUORURO DE AZUFRE EN LA EVALUACIN ECOGRFICA CON CONTRASTE DE FSTULAS ANALES: ANTECEDENTES:La ecografía endoanal para el diagnóstico de fístulas anales requiere la inyección de peróxido de hidrógeno, pero generalmente resulta incómoda para el paciente y presenta potenciales complicaciones. Actualmente se encuentran disponibles nuevos contrastes ecográficos.OBJETIVO:Evaluar la eficacia y seguridad del hexafluoruro de azufre como agente de contraste ecográfico para el diagnóstico de fístula perianal comparándolo con el peróxido de hidrógeno diluido al 50%.DISEÑO:Estudio de superioridad doble ciego con cuatro visitas consecutivas realizando una ecografía sin contraste, ecografía potenciada con peróxido de hidrógeno, ecografía potenciada con hexafluoruro de azufre y exploración rectal en el quirófano (el estándar de oro). Las imágenes ecográficas fueron revisadas de forma independiente por tres cirujanos ecografistas expertos.AJUSTE:Estudio llevado a cabo en un único hospital universitario.PACIENTES:Se evaluaron datos de 176 pacientes.PRINCIPALES MEDIDAS DE RESULTADO:Se analizaron los datos demográficos y exploratorios y los hallazgos ecográficos relacionados con la ubicación del orificio interno de la fístula, descripción de los trayectos primario y secundario y la presencia de cavidades y defectos del esfínter. Se consideraron las complicaciones ocurridas antes y después de la administración del agente de contraste y la presencia de dolor medido mediante un puntaje.RESULTADOS:Se incluyeron 88 pacientes (hombres: 71,5%; edad media: 48,3 años). El 62,5% fueron tipo complejo y el 83,7% tipo transesfintérico. Las ecografías mejoradas con hexafluoruro de azufre demostraron mayor concordancia interobservador en la determinación de los trayectos secundarios (κ = 0,604) y la altura de la fístula anal (κ = 0,604) en comparación con otros métodos. Tanto la ecografía con peróxido de hidrógeno (90,91%) como la ecografía con hexafluoruro de azufre (89,77%) detectaron con mayor frecuencia el orificio interno que la ecografía sin contraste (62,5%) (p < 0,001), sin diferencias entre agentes de contraste (p = 0,810). La ecografía potenciada con hexafluoruro de azufre fue menos dolorosa que la ecografía potenciada con peróxido (p < 0,001).LIMITACIONES:La mayoría de los pacientes presentaron fístulas anales transesfintéricas.CONCLUSIONES:El hexafluoruro de azufre demostró ser comparable al peróxido de hidrógeno en la evaluación de los trayectos fistulosos y la identificación del orificio interno y con reducción significativa del dolor y malestar. Además, demostró mayor concordancia interobservador en la determinación de los trayectos secundarios y la altura de la fístula anal en comparación con otros métodos. (Traducción-Dr. Fidel Ruiz Healy ).

Infracoccygeal/transperineal window: new method to prenatally diagnose and classify level of anal atresia.

OBJECTIVES: To introduce a two-dimensional sonographic method to assess the fetal anus, and to evaluate the feasibility of this method to diagnose anal atresia prenatally and identify the presence or absence of anoperineal fistula (in males) and anovestibular fistula (in females). METHODS: This was an observational study of suspected cases of anal atresia referred to a single center in Israel between August 2018 and October 2023. In addition to conventional evaluation of the perineum in the axial plane, fetuses referred to our center for suspected malformation were scanned with a new method termed the 'infracoccygeal/transperineal window'. This window consisted of a midsagittal view of the fetal pelvis, including the distal rectum and the anal canal. Normal anatomy was confirmed when the anal canal was continuous with the rectum and terminated at the expected location on the perineum. In female fetuses, the normal anal canal runs parallel to the vaginal canal and diverges posteriorly, terminating at the perineal skin, distant from the vestibule. In male fetuses, the normal anal canal diverges posteriorly in relation to the corpora cavernosa, terminating at the perineal skin, distant from the scrotum. High anal atresia was identified when a blind-ending rectal pouch was demonstrated in the pelvis without a fistula to the perineum or vestibule. Low anal atresia was determined when a rectal pouch was continuous with an anteriorly deflected fistula. In females, the fistula converges with the vaginal canal, terminating at the vestibule; in males, the fistula deflects anteriorly, terminating at the base of the scrotum. Postnatally, the diagnosis and type of anal atresia were confirmed through physical examination with direct visualization of the fistula, radiographic studies, surgical examination and/or postmortem autopsy. RESULTS: Of the 16 fetuses diagnosed prenatally with anal atresia, eight were suspected to have low anal atresia and eight were suspected to have high anal atresia. The median gestational age at diagnosis was 23 (range, 14-37) weeks. All cases showed additional structural malformation. Eleven patients opted for termination of pregnancy, of which four had low anal atresia and seven had high anal atresia. Postnatal confirmation was not available in four cases due to curettage-induced mutilation or in-utero degradation following selective termination of the affected twin, leaving 12 cases for analysis, of which seven were diagnosed with low anal atresia and five with high anal atresia. In these 12 cases, all prenatal diagnoses were confirmed as correct, rendering 100% sensitivity and 100% specificity in this high-risk fetal population. CONCLUSIONS: The infracoccygeal/transperineal window is an effective method to detect and classify the level of anal atresia prenatally. This may improve prediction of postnatal fetal continence and optimize prenatal counseling. © 2024 International Society of Ultrasound in Obstetrics and Gynecology.

Dynamic contrast-enhanced MR imaging in identifying active anal fistula after surgery.

BACKGROUND: It is challenging to identify residual or recurrent fistulas from the surgical region, while MR imaging is feasible. The aim was to use dynamic contrast-enhanced MR imaging (DCE-MRI) technology to distinguish between active anal fistula and postoperative healing (granulation) tissue. METHODS: Thirty-six patients following idiopathic anal fistula underwent DCE-MRI. Subjects were divided into Group I (active fistula) and Group IV (postoperative healing tissue), with the latter divided into Group II (≤ 75 days) and Group III (> 75 days) according to the 75-day interval from surgery to postoperative MRI reexamination. MRI classification and quantitative analysis were performed. Correlation between postoperative time intervals and parameters was analyzed. The difference of parameters between the four groups was analyzed, and diagnostic efficiency was tested by receiver operating characteristic curve. RESULTS: Wash-in rate (WI) and peak enhancement intensity (PEI) were significantly higher in Group I than in Group II (p = 0.003, p = 0.040), while wash-out rate (WO), time to peak (TTP), and normalized signal intensity (NSI) were opposite (p = 0.031, p = 0.007, p = 0.010). Area under curves for discriminating active fistula from healing tissue within 75 days were 0.810 in WI, 0.708 in PEI, 0.719 in WO, 0.783 in TTP, 0.779 in NSI. All MRI parameters were significantly different between Group I and Group IV, but not between Group II and Group III, and not related to time intervals. CONCLUSION: In early postoperative period, DCE-MRI can be used to identify active anal fistula in the surgical area. TRIAL REGISTRATION: Chinese Clinical Trial Registry: ChiCTR2000033072.

Use of 3D Anorectal Ultrasonography in the Preoperative Assessment of Complex Anal Fistulas and Patterns of Healing, Failure, and Recurrence After Ligation of the Intersphincteric Fistula Tract (LIFT).

OBJECTIVES: To use three-dimensional anorectal ultrasonography (3D-US) to evaluate the outcome of ligation of the intersphincteric fistula tract (LIFT) in patients with crypto-glandular transsphincteric fistula and describing the patterns of healing, failure, and recurrence rate. METHODS: After classifying the fistula and determining the length of the sphincter muscle to be transected, the patients were submitted to LIFT. The accuracy of pre- and postoperative 3D-US with 360° endoprobe (16 MHz) with automatic scanning and clinical findings was evaluated against surgical findings. Three outcomes were considered: healing, failure (persistent anal fistula through the original external opening or intersphincteric), and recurrence (reappearance of the anal fistula). RESULTS: Sixty-three patients of both sexes were evaluated. The 3D-US assessment revealed primary healing in 50 (79.3%) patients, although in 6 (9.5%) cases healing was delayed and the cavity was without communication with the anal canal. The procedure failed in 9 (15.9%) and fistula recurred in 4 (6.3%), all of whom underwent a second surgery based on a new 3D-US, resulting in a 92.3% (12/13) healing rate on 3D-US. CONCLUSIONS: A 3D-US was found to be useful in the preoperative assessment of fistulas by quantifying the percentage of muscle to be transected, and in the postoperative assessment by identifying healing, types of failure, and recurrence. The 3D-US was accurate and consistent with surgical findings.

Validation of a 3D-printed model of cryptoglandular perianal fistulas.

INTRODUCTION: Visualising the course of a complex perianal fistula on imaging can be difficult. It has been postulated that three-dimensional (3D) models of perianal fistulas improve understanding of the perianal pathology, contribute to surgical decision-making and might even improve future outcomes of surgical treatment. The aim of the current study is to investigate the accuracy of 3D-printed models of perianal fistulas compared with magnetic resonance imaging (MRI). METHODS: MRI scans of 15 patients with transsphincteric and intersphincteric fistulas were selected and then assessed by an experienced abdominal and colorectal radiologist. A standardised method of creating a 3D-printed anatomical model of cryptoglandular perianal fistula was developed by a technical medical physicist and a surgeon in training with special interest in 3D printing. Manual segmentation of the fistula and external sphincter was performed by a trained technical medical physicist. The anatomical models were 3D printed in a 1:1 ratio and assessed by two colorectal surgeons. The 3D-printed models were then scanned with a 3D scanner. Volume of the 3D-printed model was compared with manual segmentation. Inter-rater reliability statistics were calculated for consistency between the radiologist who assessed the MRI scans and the surgeons who assessed the 3D-printed models. The assessment of the MRI was considered the 'gold standard'. Agreement between the two surgeons who assessed the 3D printed models was also determined. RESULTS: Consistency between the radiologist and the surgeons was almost perfect for classification (κ = 0.87, κ = 0.87), substantial for complexity (κ = 0.73, κ = 0.74) and location of the internal orifice (κ = 0.73, κ = 0.73) and moderate for the percentage of involved external anal sphincter in transsphincteric fistulas (ICC 0.63, ICC 0.52). Agreement between the two surgeons was substantial for classification (κ = 0.73), complexity (κ = 0.74), location of the internal orifice (κ = 0.75) and percentage of involved external anal sphincter in transsphincteric fistulas (ICC 0.77). CONCLUSIONS: Our 3D-printed anatomical models of perianal fistulas are an accurate reflection of the MRI. Further research is needed to determine the added value of 3D-printed anatomical models in preoperative planning and education.

Postoperative three-dimensional endoanal ultrasound findings and relation to anal fistula plug failure.

OBJECTIVES: To explore the utilization of three-dimensional (3D) endoanal ultrasound (EAUS) for the follow-up of the anal fistula plug (AFP), describe morphological findings in postoperative 3D EAUS, and evaluate if postoperative 3D EAUS combined with clinical symptoms can predict AFP failure. MATERIALS AND METHODS: A retrospective analysis of 3D EAUS examinations performed during a single-centre study of prospectively included consecutive patients treated with the AFP between May 2006 and October 2009. Postoperative assessment by clinical examination and 3D EAUS was performed at 2 weeks, 3 months and 6-12 months ("late control"). Long-term follow-up was carried out in 2017. The 3D EAUS examinations were blinded and analysed by two observers using a protocol with defined relevant findings for different follow-up time points. RESULTS: A total of 95 patients with a total of 151 AFP procedures were included. Long-term follow-up was completed in 90 (95%) patients. Inflammation at 3 months, gas in fistula and visible fistula at 3 months and at late control, were statistically significant 3D EAUS findings for AFP failure. The combination of gas in fistula and clinical finding of fluid discharge through the external fistula opening 3 months postoperatively was statistically significant (p < 0.001) for AFP failure with 91% sensitivity and 79% specificity. The positive predictive value was 91%, while the negative predictive value was 79%. CONCLUSIONS: 3D EAUS may be utilized for the follow-up of AFP treatment. Postoperative 3D EAUS at 3 months or later, especially if combined with clinical symptoms, can be used to predict long-term AFP failure.ClinicalTrials.gov identifier NCT03961984.

A magnetic resonance imaging-based decision-making tool for predicting complex anal fistulas healing in the early postoperative period.

BACKGROUND: Magnetic resonance imaging (MRI) has excellent accuracy in diagnosing preoperative lesions before anal fistula surgery. However, MRI is not good in identifying early recurrent lesions and effective methods for quantitative assessment of fistula healing are still warranted. This retrospective study aimed to develop and validate a specific MRI-based nomogram model to predict fistula healing during the early postoperative period. METHODS: Patients with complex cryptoglandular anal fistulas who underwent surgery between January 2017 and October 2020 were included in this study. MRI features and clinical parameters were analyzed using univariate and multivariate logistic regression analysis. A nomogram for predicting fistula healing was constructed and validated. RESULTS: In total, 200 patients were included, of whom 186 (93%) were male, with a median age of 36 (18-65) years. Of the fistulas, 58.5% were classified as transsphincteric and 19.5% as suprasphincteric. The data were randomly divided into the training cohort and testing cohort at a ratio of 7:3. Logistic analysis revealed that CNR, ADC, alcohol intake history, and suprasphincteric fistula were significantly correlated with fistula healing. These four predictors were used to construct a predictive nomogram model in the training cohort. AUC was 0.880 and 0.847 for the training and testing cohorts, respectively. Moreover, the decision and calibration curves showed high coherence between the predicted and actual probabilities of fistula healing. CONCLUSIONS: We developed a predictive model and constructed a nomogram to predict fistula healing during the early postoperative period. This model showed good performance and may be clinically utilized for the management of anal fistulas.

Three-dimensional modelling as a novel interactive tool for preoperative planning for complex perianal fistulas in Crohn's disease.

AIM: The aim of this study is to demonstrate the added value of three-dimensional (3D) reconstruction models and artificial intelligence for preoperative planning in complex perianal Crohn's disease. MRI is the gold standard for diagnosis of complex perianal fistulas and abscess due to its high sensitivity, but it lacks high specificity values. This creates the need for better diagnostic models such as 3D image processing and reconstruction (3D-IPR) with artificial intelligence (AI) algorithms. METHOD: This is a prospective study evaluating the utility of 3D reconstruction models from MRI in four patients with perineal Crohn's disease (pCD). RESULTS: Four pCD patients had 3D reconstruction models made from pelvic MRI. This provided a more visual representation of perianal disease and made possible location of the internal fistula orifice, seton placement in fistula tracts and abscess drainage. CONCLUSION: Three-dimensional reconstruction in CD-associated complex perianal fistulas can facilitate disease interpretation, anatomy and surgical strategy, potentially improving preoperative planning as well as intraoperative assistance. This could probably result in better surgical outcomes to control perianal sepsis and reduce the number of surgical procedures required in these patients.

Description of a new ultrasound sign to distinguish Crohn's anal fistula from cryptoglandular fistula: The rosary sign.

AIM: Endoanal and endorectal ultrasound are essential diagnostic tools for perianal fistula. Recent studies have examined ultrasound signs that help differentiate cryptoglandular anal fistula from perianal fistulizing Crohn's disease. The main aim of this work was to describe a new ultrasound sign for perianal fistula and to evaluate its ability to differentiate Crohn's disease from cryptoglandular anal fistula. METHOD: This study included 363 patients (113 women; mean age 46.5 ± 14.3 years). Overall, 287 (79.1%) patients had a cryptoglandular perianal fistula and 76 (20.9%) had fistulizing Crohn's disease. All patients underwent three-dimensional anal endosonography for perianal fistula. The reading was carried out by two observers. RESULTS: Observer 1, who was an experienced sonographer and colorectal surgeon, observed the ultrasound sign in 120 patients (33.1%), while observer 2, who was inexperienced, observed it in 129 patients (35.5%). The overall interobserver agreement was 67.22%. The Kappa coefficient measuring interobserver agreement was 0.273 (0.17-0.38). Among those patients with Crohn's disease, 48.68% had the sign and 16% did not (p = 0.001). A logistic regression study showed that the sign was a predictor of Crohn's disease (p = 0.001), with an odds ratio of 2.33 (1.39-3.91). Sensitivity, specificity, positive predictive value, negative predictive value and accuracy were 38.68%, 71.08%, 30.83%, 83.95% and 66.39%, respectively. CONCLUSION: This study provides a new ultrasound sign for perianal fistula (the rosary sign) in patients with Crohn's disease. The sign can be used to differentiate Crohn's disease from other types of fistula. This is useful in the management of patients with anal fistula.

Preoperative fistula diagnostics in male anorectal malformations after colostomy: a single-center experience.

BACKGROUND: Accurate preoperative fistula diagnostics in male anorectal malformations (ARM) after colostomy are of great significance. We reviewed our institutional experiences and explored methods for improving the preoperative diagnostic accuracy of fistulas in males with ARMs after colostomy. METHODS: A retrospective analysis was performed on males with ARMs after colostomy admitted to our hospital from January 2015 to June 2022. All patients underwent magnetic resonance imaging (MRI) and high-pressure colostogram (HPC) before anorectal reconstruction. Patients with no fistula as diagnosed by both modalities underwent a voiding cystourethrogram (VCUG). General information, imaging results and surgical results were recorded. RESULTS: Sixty-nine males with ARMs after colostomy were included. Age at the time of examination was 52 ~ 213 days, and the median age was 89 days. The Krickenbeck classification according to surgical results included rectovesical fistula (n = 19), rectoprostatic fistula (n = 24), rectobulbar fistula (n = 19) and no fistula (n = 7). There was no significant difference in the diagnostic accuracy between MRI and HPC for different types of ARMs. For determining the location of the fistula, compared to surgery, HPC (76.8%, 53/69) performed significantly better than MRI (60.9%, 42/69) (p = 0.043). Sixteen patients diagnosed as having no fistula by MRI or HPC underwent a VCUG, and in 14 patients, the results were comfirmed. However, there were 2 cases of rectoprostatic fistula that were not correctly diagnosed. CONCLUSION: High-pressure colostogram has greater accuracy than MRI in the diagnosis of fistula type in males with ARMs after colostomy. For patients diagnosed with no fistula by both methods, VCUG reduces the risk of false-negative exclusion, and rectoprostatic fistula should be considered during the operation.

Comparison of MRI and Endoanal Ultrasound in Assessing Intersphincteric, Transsphincteric, and Suprasphincteric Perianal Fistula.

OBJECTIVES: Perianal fistula is a common disorder characterized by an anomalous perianal track connecting two epithelialized surfaces, most commonly the anal canal and the perianal skin. Although each has its limitations, magnetic resonance imaging (MRI) and endoanal ultrasound are currently two acceptable modalities for assessing perianal fistula. This study aimed to evaluate the accuracy of MRI and endoanal ultrasonography in diagosing perianal fistula, considering the surgical results as the references. METHODS: This prospective cohort study was performed on patients with symptomatic perianal fistulas. MRI results of patients reported by the radiologist were collected along with the findings of endoanal ultrasonography performed by a gastroenterologist. These results were compared with surgical findings as the reference standard. RESULTS: The study enrolled 126 patients. Exactly 222 definitive fistulas were identified during surgery. Sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of ultrasound for perianal fistula were 87.38, 38.46, 92.38, 26.31, and 82.25% respectively; and for MRI were 76.12, 57.69, 93.88, 22.05, and 74.19% respectively. The accuracy of endoanal ultrasound for detecting transsphincteric and intersphincteric fistulas was higher than MRI. In contrast, the diagnostic value of MRI for detecting suprasphincteric fistulas was higher than endoanal ultrasound. CONCLUSIONS: Using endoanal ultrasonography to diagnose perianal fistulas is a relatively accurate method. This method may be more sensitive than MRI in detecting patients with perianal fistulas and abscesses.

Role of ultrasonography in evaluation of perianal fistula-A study of 200 cases.

OBJECTIVE: The purpose of this study was to evaluate the role of transrectal, transvaginal, or transperineal ultrasound (US) in evaluation of perianal fistula and to assess the possibility of its role as a first-line investigation for diagnosis and for follow-up as well as a possible substitute for magnetic resonance imaging (MRI). METHODS: This is a retrospective observational study of 200 patients. All the patients complaining of discharging wound, acute or chronic pain in the perianal region and patients suspected clinically having perianal sinus/fistula, referred for ultrasound evaluation were included in the study. Male patients were scanned by transrectal and transperineal ultrasound, and females by transrectal, transvaginal and transperineal approach. All the patients were followed up with referring surgeon till surgical cure, discharge, and follow-up. Out of total 200 patients, 47 were female and 153 were male patients. Patients were in age range from 16 to 74 years. The path, direction, extent, diameter and internal branching and openings of tracts were recorded. Presence, location and extent of any collection/abscess was also noted. RESULTS: Fistulae and sinus tracts are seen as hypo to anechoic tracts ranging from 2 to 10 mm in diameter. Air and mixed echogenic moving collection were noted in active tracts. Fibrous tracts were seen as well defined, echogenic structures. Depending on the chronicity and localization, walls of abscesses appeared ill defined or well defined. Findings of transrectal, transvaginal, and transperineal USG were confirmed with intraoperative findings in 200 cases. Out of which 148 patients were followed up clinically till tracts were closed. In 54 patients, there was recurrence that were operated again and followed up with ultrasound. In total 33 had internal collection along the tracts and in the perianal region. CONCLUSION: Transrectal, transvaginal, and perineal ultrasound together have the potential to reach the sensitivity of MRI. Ultrasound has its greatest advantage in being cheap, easily reproducible and an excellent modality for follow-up.

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.

Impact of Preoperative Three-Dimensional Endoanal Ultrasound on the Surgical Outcome of Primary Fistula in Ano. A Multi-Center Observational Study of 253 Patients.

PURPOSE: To evaluate the impact of preoperative three-dimensional endoanal ultrasound (3D-EAUS) on the clinical outcome of anal fistula surgery. METHODS: The research consisted of multi-center retrospective case-control study including 253 consecutive adult patients undergoing surgery for confirmed or suspected primary fistula in ano who had undergone preoperative 3D-EAUS evaluation between January 2011 and January 2021. Main outcome measures were the concordance (K value) between ultrasound results and surgery in the identification of fistulas internal openings, primary tracts and secondary extensions and the 6 and 12 months success rate in patients with concordant and discordant findings. RESULTS: A good agreement in the identification of the main fistulas characteristics between ultrasound results and operative findings was found. A significant difference (P < .0001; Fisher's exact test) in the success rate was found between patients with concordant and discordant ultrasound results and operative findings in identification or location of internal opening. Particularly, all the 11 (4.8%) patients with discordant results experimented a failure of the surgical procedure at 6 months follow-up. At re-operation, the shift from discordant to concordant results was associated with an 81.8% 12 months success-rate. CONCLUSION: The three-dimensional endoanal ultrasound preoperative evaluation may have a relevant impact on the outcome of a defined group of patients undergoing surgery for anal fistula, since the careful evaluation of ultrasound results could simplify the internal orifice intra-operative detection and improve the success rate.

Resection of an anal fistula with endoscopic submucosal dissection.

A 34-year-old man presented with paroxysmal hypogastralgia during defecation for 2 weeks. Physical and laboratory examination findings were unremarkable, other than a depression located 1 cm above the dentate line, accompanied by mild tenderness and a clubbed induration extending to the rectum. Colonoscopy showed a 2.0×0.8 cm longitudinal, protruding mass in the posterior wall of the lower rectum. Endosonography revealed a mixed echogenic mass originating from the rectal submucosa, with no sign of muscular wall disruption. There was no evidence of Crohn's or other diseases. Following anorectal consultation, we suspected a submucosal or internal blind fistula since the patient was symptomatic with a superficial mass which communicated to the rectum. The location and depth of the mass indicated that endoscopic resection might allow for removal of the lesion without impairment of the anorectal anatomy and function. After obtaining the patient's consent, endoscopic submucosal dissection (ESD) was performed. En bloc resection was achieved using a disposable, high-frequency knife (Micro-Tech, China). No adverse events occurred. Histopathological examination revealed a benign fistula composed of local submucous granulomatous tissue proliferation and a focal mucous epithelial defect. The patient's symptoms were relieved postoperatively, and no recurrence was evident after 6 months.

Efficacy and Safety of 2 Vedolizumab Intravenous Regimens for Perianal Fistulizing Crohn's Disease: ENTERPRISE Study.

BACKGROUND & AIMS: Fistulizing Crohn's disease (CD) is challenging to treat. We report results from ENTERPRISE, a randomized, double-blind, phase 4 trial evaluating 2 vedolizumab intravenous dosing regimens in patients with fistulizing CD. METHODS: Patients with moderately to severely active CD and 1-3 active perianal fistulae (identified on magnetic resonance imaging [MRI]) received vedolizumab 300 mg intravenously at weeks 0, 2, 6, 14, and 22 (VDZ) or the same regimen plus an additional vedolizumab dose at week 10 (VDZ + wk10). Reduction from baseline in draining perianal fistulae and disease activity, MRI assessments, health-related quality of life (HRQoL), and safety were evaluated. Enrollment was stopped prematurely because of recruitment challenges; analyses are descriptive. RESULTS: Of 32 patients with ≥1 active fistulae at baseline per MRI and postbaseline fistulae healing assessment, 28 (14 per dosing regimen) had ≥1 draining fistulae at baseline (assessed by gentle finger compression during clinical exam). Rapid and sustained fistula closure was observed; 53.6% (VDZ, 64.3%; VDZ + wk10, 42.9%) and 42.9% (VDZ, 50.0%; VDZ + wk10, 35.7%) of patients achieved ≥50% decrease in draining fistulae and 100% fistulae closure, respectively, at week 30. Mean (standard deviation) CD and Perianal Disease Activity Index scores decreased by 51.1 (78.3) and 4.1 (3.3), respectively, at week 30. HRQoL improved throughout the study. No new safety signals were observed. CONCLUSIONS: Sustained improvements in fistulizing CD were seen with both vedolizumab regimens. An additional dose at week 10 does not appear to alter treatment outcomes. Safety profile was consistent with other vedolizumab studies. CLINICALTRIALS: gov no: NCT02630966; EudraCT: 2015-000852-12.

Higher Anti-tumor Necrosis Factor-α Levels Correlate With Improved Radiologic Outcomes in Crohn's Perianal Fistulas.

BACKGROUND & AIMS: Higher anti-tumor necrosis factor-α (TNF) drug levels are associated with improved clinical healing of Crohn's perianal fistulas. It is unclear whether this leads to improved healing on radiologic assessment. We aimed to evaluate the association between anti-TNF drug levels and radiologic outcomes in perianal fistulising Crohn's disease. METHODS: A cross-sectional retrospective multicenter study was undertaken. Patients with perianal fistulising Crohn's disease on maintenance infliximab or adalimumab, with drug levels within 6 months of perianal magnetic resonance imaging were included. Patients receiving dose changes or fistula surgery between drug level and imaging were excluded. Radiologic disease activity was scored using the Van Assche Index, with an inflammatory subscore calculated using indices: T2-weighted imaging hyperintensity, collections >3 mm diameter, rectal wall involvement. Primary endpoint was radiologic healing (inflammatory subscore ≤6). Secondary endpoint was radiologic remission (inflammatory subscore = 0). RESULTS: Of 193 patients (infliximab, n = 117; adalimumab, n = 76), patients with radiologic healing had higher median drug levels compared with those with active disease (infliximab 6.0 vs 3.9 µg/mL; adalimumab 9.1 vs 6.2 µg/mL; both P < .05). Patients with radiologic remission also had higher median drug levels compared with those with active disease (infliximab 7.4 vs 3.9 µg/mL; P < .05; adalimumab 9.8 vs 6.2 µg/mL; P = .07). There was a significant incremental reduction in median inflammatory subscores with higher anti-TNF drug level tertiles. CONCLUSIONS: Higher anti-TNF drug levels were associated with improved radiologic outcomes on magnetic resonance imaging in perianal fistulising Crohn's disease, with an incremental improvement at higher drug level tertiles for both infliximab and adalimumab.

The development of a minimum dataset for MRI reporting of anorectal fistula: a multi-disciplinary, expert consensus process.

There are a range of sphincter-preserving procedures available to treat anorectal fistula, some of which can be precluded, or rendered more optimal by specific features of fistula anatomy. Magnetic resonance imaging (MRI) is the gold standard modality for assessing anorectal fistula. To maximise clinical utility, the MRI report should accurately describe these clinically relevant features. We aimed to develop a minimum dataset for reporting MRI of anorectal fistula, in order to improve the assessment and management of these patients. A longlist of 70 potential items for the minimum dataset was generated through systematic review of the literature. This longlist was presented to radiologists, surgeons and gastroenterologists in an online survey to understand the features that shape current clinical practice. The longlist and survey results were then presented to an expert consensus panel to generate the final minimum dataset through discussion and anonymous voting. The final minimum dataset details the general characteristics, features of the internal and external openings, path of the fistula through the sphincters and any associated extensions and collections that should be described in all MRI reports for anal fistula. Additional surgical and perianal Crohn's disease subsets were developed to indicate the features that aid decision-making for these patients, in addition to a minimum dataset for the clinical request. This study represents a multi-disciplinary approach to developing a minimum dataset for MRI reporting of anal fistula, highlighting the most important features to report that can assist in clinical decision-making. KEY POINTS: • This paper recommends the minimum features that should be included in all MRI reports for the assessment of anal fistula, including Parks classification, number of tracts, features of the internal and external opening, path of the tract through the sphincters, the presence and features of extensions and collections. • Additional features that aid decision-making for surgery or in the presence of Crohn's disease have been identified. • The items that should be included when requesting an MRI are specified.

Perianal Imaging in Crohn Disease: Current Status With a Focus on MRI, From the AJR Special Series on Imaging of Inflammation.

Fistulizing perianal disease, a frequent, chronic, and often debilitating manifestation of Crohn disease (CD) in adults and children, has been relatively refractory to treatment in the past. The advent of biologic agents such as anti-tumor necrosis factor-α and cellular therapies, used in conjunction with a range of surgical interventions, has greatly improved disease outcomes, although complete remission can still be elusive. This Special Series review considers current perianal imaging options, specifically pelvic MRI and endoanal and transperineal ultrasound, as well as their roles in the diagnosis, management, and assessment of treatment response. Pelvic MRI is the first-line modality for imaging perianal CD, given the complexity of fistulas encountered in CD. MRI technical acquisition parameters for adults and children and an approach to MRI interpretation and reporting are provided. Anatomic classification systems for fistulizing peri-anal disease are presented. We also explore the history, current landscape, and future developments of MRI features of perianal disease as imaging biomarkers, to quantify activity and severity and to consider CD MRI-based inflammatory activity scores. We discuss the reliability and validation of a number of indexes (including the pediatric MRI-based perianal CD [PEMPAC] index, the MR novel index for fistula imaging in CD [MAGNIFI-CD], the Van Assche index, and the modified Van Assche index), their potential to quantify treatment response, and possible prognostic capabilities.