Timing of ligation of the intersphincteric fistula tract after loose seton drainage in complex anal fistulas

Figure 4 Pre- and post-seton pelvic magnetic resonance imaging illustrating abscess cavity evolution in complex anal fistulas. A: Preoperative pelvic magnetic resonance imaging (MRI) showing an abscess cavity (orange arrow); B: Follow-up MRI showing resolution of the abscess cavity (orange arrow) after seton placement, and that the loose seton remained visible (white arrow); C: Preoperative pelvic MRI in a different patient showing an abscess cavity (orange arrow); D: Same MRI as in (C) showing a persistent abscess and sinus tract (orange arrow) despite ongoing drainage through a loose seton (white arrow).