A Study Comparing Transperineal Ultrasound, Magnetic Resonance Imaging, Endoscopic Ultrasound, and Examination Under Anesthesia to Detect and Classify Perianal Fistulas in Patients With Crohn's Disease or Fistulas of Unknown Cause

NCT07794410 | Recruiting DMC

• 1 other identifier: AIG/IEC- BH&R 72/07.2025/03
• Study Type: interventional
• Target: 50
• Locations: 1 country
• Sites: 1

Brief Summary

The goal of this study is to learn how well different imaging tests detect and describe perianal fistulas in adults with Crohn's disease or fistulas with no known cause (cryptogenic). Perianal fistulas are painful tunnels that form near the anus and can lead to discharge, swelling, or infection. The main questions this study aims to answer are: How accurate is transperineal ultrasound (TPUS) compared to magnetic resonance imaging (MRI) in finding fistulas? How well do these tests identify key features like internal openings and abscesses? Do the test results help doctors make better treatment decisions? Researchers will compare TPUS and MRI to two other imaging methods: Endoscopic ultrasound (EUS), which uses a small camera and ultrasound inside the rectum Examination under anesthesia (EUA), in which a surgeon checks the area while the participant is asleep All participants will: Be adults between the ages of 18 and 75 Have a suspected or confirmed perianal fistula Be able to complete all four tests-TPUS, MRI, EUS, and EUA-within 10 days Participants will not receive any experimental treatments. The tests are part of routine care and will be done using advanced equipment by expert doctors. Each test result will be used to compare how accurate and useful the test is in real-life diagnosis and treatment planning. This study may help make fistula diagnosis faster, safer, and more affordable-especially in settings where access to MRI or surgery is limited. It may also support the use of TPUS as a first step in evaluating perianal fistulas in people with Crohn's disease.

Conditions

Crohn Disease (CD); Cryptoglandular Perianal Fistula

Keywords

fistula; crohn disease; transperineal ultrasound; magnetic resonance imaging; endoscopic ultrasound; examination under anaesthesia

Outcome Measures

Primary Outcomes (1)

• Per-lesion sensitivity of transperineal ultrasound (TPUS) and magnetic resonance imaging (MRI) for detecting perianal fistulas

  To determine and compare the diagnostic sensitivity of TPUS and MRI for identifying individual fistulous tracts, using endoscopic ultrasound (EUS) as the reference standard and examination under anesthesia (EUA) as the gold standard.

  Within 10 days of enrollment (all four imaging modalities completed within this window)

Secondary Outcomes (4)

• Sensitivity of TPUS vs MRI for detecting internal openings

  Within 10 days of enrollment

• Classification accuracy (Parks criteria) of transperineal ultrasound (TPUS) versus magnetic resonance imaging (MRI)

  Within 10 days of enrollment

• Sensitivity of transperineal ultrasound (TPUS) vs magnetic resonance imaging (MRI) for detecting perianal abscesses

  Within 10 days of enrollment

• Impact on clinical management based on imaging modality

  Up to 14 days after imaging

Study Arms (1)

Single Group: Quadrimodal Imaging Assessment

EXPERIMENTAL

All participants in this arm will undergo four diagnostic imaging procedures-transperineal ultrasound (TPUS), magnetic resonance imaging (MRI), endoscopic ultrasound (EUS), and examination under anesthesia (EUA)-in a predefined sequence. Each imaging modality will be used to evaluate the presence, type, and extent of perianal fistulas. This single-arm design allows within-subject comparison of diagnostic accuracy and clinical impact across modalities.

Diagnostic Test: Transperineal Ultrasound (TPUS); Diagnostic Test: Magnetic Resonance Imaging (MRI); Diagnostic Test: Endoscopic Ultrasound (EUS); Diagnostic Test: Examination Under Anesthesia (EUA)

Interventions

Transperineal Ultrasound (TPUS) DIAGNOSTIC_TEST

Participants will undergo TPUS using a high-frequency linear and microconvex probe to evaluate fistula tracts, internal openings, and abscesses.

Single Group: Quadrimodal Imaging Assessment

Magnetic Resonance Imaging (MRI) DIAGNOSTIC_TEST

MRI of the pelvis will be performed using standardized T2-weighted, STIR, and post-contrast sequences for anatomical characterization of fistulas.

Single Group: Quadrimodal Imaging Assessment

Endoscopic Ultrasound (EUS) DIAGNOSTIC_TEST

EUS of the anorectal canal will be performed using a linear echoendoscope to visualize internal openings, fistula tracts, and perirectal collections. EUS serves as the reference standard.

Single Group: Quadrimodal Imaging Assessment

Examination Under Anesthesia (EUA) DIAGNOSTIC_TEST

Participants will undergo EUA by a colorectal surgeon to probe fistula tracts and identify internal openings. EUA serves as the gold standard comparator.

Single Group: Quadrimodal Imaging Assessment

Eligibility Criteria

• Age: 18 Years - 75 Years
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• Adults between 18 and 75 years of age
• Clinical suspicion or diagnosis of perianal fistula
• Fistula etiology can be Crohn's disease or cryptogenic/tubercular (non-Crohn's)
• Ability to undergo all four imaging procedures (TPUS, MRI, EUS, and EUA) within a 10-day period
• Willing and able to provide written informed consent

You may not qualify if:

• Known or suspected anorectal malignancy
• Pregnancy or breastfeeding
• Contraindications to any of the imaging procedures:
• MRI (e.g., presence of metal implants or claustrophobia)
• EUS (e.g., severe anal stenosis or intolerance to procedure)
• Anesthesia required for EUA (e.g., significant cardiopulmonary disease)
• Prior surgery or seton placement at the index fistula site
• Incomplete or failed imaging in any one of the modalities
• Inability to provide informed consent

Sponsors & Collaborators

• Asian Institute of Gastroenterology, India: lead

Study Sites (1)

Asian Institute of Gastroenterology

Hyderabad, Telanagana, 500082, India

RECRUITING

MeSH Terms

Conditions

Crohn Disease; Fistula

Interventions

Magnetic Resonance Imaging; Endosonography

Condition Hierarchy (Ancestors)

Inflammatory Bowel Diseases; Gastroenteritis; Gastrointestinal Diseases; Digestive System Diseases; Intestinal Diseases; Pathological Conditions, Anatomical; Pathological Conditions, Signs and Symptoms

Intervention Hierarchy (Ancestors)

Tomography; Diagnostic Imaging; Diagnostic Techniques and Procedures; Diagnosis; Ultrasonography

Central Study Contacts

Partha Pal, MD, DNB, MRCP (UK), FASGE

CONTACT

+918945906823; partha0123456789@gmail.com

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: NA
• Masking: NONE
• Masking Details: Although outcome assessors for each imaging modality (TPUS, MRI, EUS, EUA) are independently blinded to the findings of other modalities, the study design is a single-arm diagnostic comparison. Therefore, "No Masking" is selected to comply with ClinicalTrials.gov system requirements.
• Purpose: DIAGNOSTIC
• Intervention Model: SINGLE GROUP
• Sponsor Type: OTHER
• Responsible Party: SPONSOR

Model Details: All participants will undergo four diagnostic imaging procedures-transperineal ultrasound (TPUS), magnetic resonance imaging (MRI), endoscopic ultrasound (EUS), and examination under anesthesia (EUA)-in a predefined sequence. Each participant receives the same set of assessments, allowing within-subject comparisons across modalities. The goal is to evaluate the diagnostic accuracy and clinical impact of each imaging test for perianal fistulas in Crohn's disease and cryptogenic cases.

Study Record Dates

• First Submitted: August 3, 2025
• First Posted: August 31, 2026
• Study Start: July 25, 2025
• Primary Completion (Estimated): April 15, 2027
• Study Completion (Estimated): April 30, 2027
• Last Updated: August 31, 2026

Record last verified: 2026-08

Data Sharing

• IPD Sharing: Will not share

Locations

IN (1)