Biological agents

Biological agents

The functional consequences of fistulotomy have led to a search for agents that seal the fistula track and allow ingrowth of healthy tissue to replace it. Intuitively , success must depend on the biomaterial itself and the environment into which it is - placed. Many agents have been tried with moderate success. These include fibrin glue, cross-linked porcine dermal collagen and more recently mesenchymal stem cells. Antibiotics, partic - in ularly metronidazole and ciprofloxacin, are of value in treating fistula-associated sepsis and many have immune-modulating e ff ects of value in Crohn’s disease. Patients must be warned - of potential side e ff ects of prolonged therapy , including peripheral neuropathy (metronidazole) and tendinopathy (ciprofloxacin). Biological therapies, including the anti-tumour necrosis factor drug vedolizumab and ciclosporin, are of value as part of multimodality treatment of perianal Crohn’s disease ( Chapter 75 ).