Experimental porcine model of complex fistula-in-ano

Figure 1 Porcine model creation process. A: Intramuscular injection with anesthetic Zoteil 50 at 1 mL/kg; B: A 0.5 cm minimal incision made in the anus at 3, 9, and 12 o’clock position and ligated rubber used; C: Directly cross through the anal sphincter with rubber band seton.

Figure 2 Magnetic resonance imaging evaluation of created fistulas. A: Created fistulas; B and C: Typical fistula imaging was found and it was very similar to human anal fistula imaging of magnetic resonance imaging.

Figure 3 Pathological findings of created fistulas. A: Epithelization in the created fistula tract; B and C: Epithelization and granulation were found in the created fistula tract.