Inflamm Bowel Dis. 2023 Jul 31;izad134. doi: 10.1093/ibd/izad134. Online ahead of print.

Eileen Crowley ^1 2, Christopher Ma ^2 3 4, Leonard Guizzetti ², Guangyong Zou ^2 5, Peter J Lewindon ^6 7, Michael S Gee ^8 9, Jeffrey S Hyams ¹⁰, Michael J Rosen ¹¹, Daniel von Allmen ^12 13, Anthony de Buck van Overstraeten ¹⁴, Lisa M Shackelton ², Julie Remillard ², Lauren Schleicher ², Jonathan R Dillman ^15 16, Jordi Rimola ¹⁷, Stuart A Taylor ¹⁸, Joel G Fletcher ¹⁹, Peter C Church ^20 21, Brian G Feagan ^2 5 22, Anne M Griffiths ²⁰, Vipul Jairath ^2 5 22, Mary-Louise C Greer ²³

Author information

¹Department of Pediatrics, Division of Pediatric Gastroenterology, Children's Hospital Western Ontario, Western University, London Health Sciences Centre, London, Ontario, Canada.

²Alimentiv Inc, London, ON, Canada.

³Division of Gastroenterology and Hepatology, Department of Medicine, University of Calgary, Calgary, AB, Canada.

⁴Department of Community Health Sciences, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada.

⁵Department of Epidemiology and Biostatistics, Western University, London, Ontario, Canada.

⁶Department of Gastroenterology, Queensland Children's Hospital, University of Queensland, Brisbane, Queensland, Australia.

⁷Children's Medical Research Institute, University of Queensland, Brisbane, Queensland, Australia.

⁸Department of Radiology, Massachusetts General Hospital Boston, MA, USA.

⁹Department of Radiology, Harvard Medical School, Boston, MA, USA.

¹⁰Division of Digestive Diseases, Hepatology, and Nutrition, Connecticut Children's Medical Center, Hartford, CT, USA.

¹¹Division of Pediatric Gastroenterology, Hepatology and Nutrition, Department of Pediatrics, Stanford Medicine, Stanford, CA, USA.

¹²Department of Pediatric Surgery and Surgical Services, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, USA.

¹³Department of Surgery, University of Cincinnati College of Medicine, Cincinnati, OH, USA.

¹⁴Department of Surgery, Mount Sinai Hospital, University of Toronto, Toronto, ON, Canada.

¹⁵Department of Radiology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, USA.

¹⁶Department of Radiology, University of Cincinnati College of Medicine, Cincinnati, OH, USA.

¹⁷IBD Unit, Radiology Department, Hospital Clinic Barcelona, IDIBAPS, Spain.

¹⁸Centre for Medical Imaging, Charles Bell House, University College London, London, UK.

¹⁹Department of Radiology, Mayo Clinic, Rochester, MN, USA.

²⁰Division of Gastroenterology, Hepatology & Nutrition, Department of Paediatrics and IBD Centre, The Hospital for Sick Children, University of Toronto, Toronto, ON, Canada.

²¹Institute of Health Policy, Management and Evaluation, University of Toronto, Toronto, ON, Canada.

²²Department of Medicine, Division of Gastroenterology, Western University, London, ON, Canada.

²³Department of Diagnostic Imaging, The Hospital for Sick Children, Department of Medical Imaging, University of Toronto, Toronto, ON, Canada.

Abstract

Background: Perianal fistulas and abscesses occur commonly as complications of pediatric Crohn's disease (CD). A validated imaging assessment tool for quantification of perianal disease severity and activity is needed to evaluate treatment response. We aimed to identify magnetic resonance imaging (MRI)-based measures of perianal fistulizing disease activity and study design features appropriate for pediatric patients.

Methods: Seventy-nine statements relevant to MRI-based assessment of pediatric perianal fistulizing CD activity and clinical trial design were generated from literature review and expert opinion. Statement appropriateness was rated by a panel (N = 15) of gastroenterologists, radiologists, and surgeons using modified RAND/University of California Los Angeles appropriateness methodology.

Results: The modified Van Assche Index (mVAI) and the Magnetic Resonance Novel Index for Fistula Imaging in CD (MAGNIFI-CD) were considered appropriate instruments for use in pediatric perianal fistulizing disease clinical trials. Although there was concern regarding the use of intravascular contrast material in pediatric patients, its use in clinical trials was considered appropriate. A clinically evident fistula tract and radiologic disease defined as at least 1 fistula or abscess on pelvic MRI were considered appropriate trial inclusion criteria. A coprimary clinical and radiologic end point and inclusion of a patient-reported outcome were also considered appropriate.

Conclusion: Outcomes of treatment of perianal fistulizing disease in children must include MRI. Existing multi-item measures, specifically the mVAI and MAGNIFI-CD, can be adapted and used for children. Further research to assess the operating properties of the indices when used in a pediatric patient population is ongoing.