New collagen plug with healing protein could fix tough anal fistulas

This study tests a new treatment for complex anal fistulas—abnormal tunnels between the rectum and skin that are hard to heal. The treatment uses a collagen plug soaked with a lab-made growth factor (rhPDGF-BB) that helps wounds heal. The trial includes 12 adults with a single fistula tract that has a draining seton in place. The main goal is to see if the plug is safe and can be implanted without serious side effects, with a secondary goal of checking if the fistula heals within 3 months.