MRI” A GOOD TOOL FOR EVALUATION OF PERIANAL FISTULAS

Abstract

OBJECTIVES: To determine the accuracy of pelvic MRI in identifying different types of anal fistulas, their anatomical relationship with surrounding structures and correlating with intraoperative findings. MATERIALS AND METHODS: A prospective study with 34 cases
with complaints of chronic pain and discharge from the perianal region. The MRI findings are then correlated with the intraoperative findings and statistical analysis was done.
RESULTS: Among 30 patients, in 1,only a blind ending sinus tract and in 2,sinus with internal abscess is noted. In the remaining 27 patients, obvious fistulas are demonstrated with internal opening at 5 & 6 O clock position in 16 patients(59%),at 12 O clock position in
8 (30%) and at other positions in the rest(11%) indicating posterior internal openings are more common than anterior.6 patients are with grade I (simple linear Intersphincteric fistula),3 with grade II(Intersphincteric fistula with abscess in 2 patients & with secondary
ramification in 1),11 with grade III(transsphincteric fistula), 4 with grade IV(transsphincteric with abscess in 2 & with ramification in 2) and 3 with grade V(Intersphincteric with supralevator extension in 1 & transsphincteric with supralevator extension in 2). Correlating with intraoperative findings among the 27 patients, in 25, fistulous tract and its course are in correlation with MRI and in 2; internal opening is not adequately demonstrated. CONCLUSION: MRI is imperative in diagnosing fistulas, their course and relationship with surrounding structures thereby helping in planning proper surgical management thus decreasing the incidence of recurrence.