Role of Mr Fistulogram in preoperative assessment of anorectal fistulas and its correlation with intraoperative findings

Abstract

The anorectal fistulas can be inter sphincteric, Trans sphincteric, extra sphincteric or supra sphincteric. Detailed understanding of anorectal anatomy is needed for identification and management of anorectal fistulas. Park's and St James University Hospital classification are used of which the latter gives better details of perianal fistulas. Unenhanced and enhanced MRI helps in identification of primary and secondary tracks, complications like abscesses and hence guides the surgeons to plan appropriate treatment strategy. During the study period, around 30 patients who were diagnosed to have perianal fistula clinically and referred for MR fistulogram to the Department of Radiology were included in the study. In our study, there was significant correlation between the fistulous tracts identified on MRI and the surgical findings. Fistulotomy is the preferred method of management in our institution. And for patients with abscess, abscess drainage is done. Fistulotomy was done in about 24 out of 30 patients which correlated well with the MRI findings for grades III to V. Grade I and II fistulas showed discrepancies in identification. Abscess drainage was also done in 5 patients (8.35%) which were also in accordance with MRI findings.