Contribution of MRI in the exploration of anoperineal fistulas in Crohn's disease, descriptive retrospective study.

Abstract

Introduction : Anoperineal manifestations affect approximately 50% of patients with Crohn's disease.

MRI is the technique of choice for the preoperative evaluation of peri-anal fistulas (8,13), overcoming the inadequacies of the clinical examination (1.2), hence the interest of our work which aims to show and illustrate the contribution of MRI in the topographical diagnosis and complications of anoperineal fistulas.

Materials and methods : This is a retrospective descriptive study over a period from March 2023 to June 2024, covering a sample of 50 patients followed for Crohn's disease with clinically diagnosed anoperineal fistulas and in whom perineal MRI was indicated and done in our radiology department at Mustapha University Hospital.

We used two 1.5 Tesla Siemens MRIs (SOLA and AMIRA).

Results :  Almost half of the patients were between 20 and 40 years old with a male predominance (sex ratio of 2.8). We used the Saint James classification with the following rates: grade 1 (20%), grade 2 (8%), grade 3 (12%), grade 4 (30%) and grade 5 (30%). 70% of patients have complex fistulas.

According to the VAN ASSCH score, the majority of patients (24/50) had a high score between 15 and 22.

Conclusion : MRI data are essential for the management of anoperineal fistulas, particularly when the latter is complex and this is often the case in Crohn's disease.

For interpretation and precise analysis using MRI, it is essential to have perfect anatomical knowledge of the anal canal and the sphincter complex as well as the radiological semiology of anoperineal fistulas.