Fisteln

Fisteln (singular Fistel) is the medical term for an abnormal channel or tract that connects two epithelial surfaces, most commonly linking an internal organ to another organ or to the skin. Fistulas arise from chronic inflammation, infection, trauma, or malignancy, and they may be congenital or acquired. They typically develop when a diseased area forms a tract that remains open and continuously drains.

Common forms include perianal fistulas, which connect the anal canal to the skin around the anus; enteric fistulas, which connect segments of the intestine or involve adjacent organs such as the bladder or vagina; enterocutaneous fistulas, vesicovaginal fistulas, and ureterovaginal or urethrocutaneous fistulas. Biliary, pancreatic, and other hepatobiliary or pelvic fistulas can occur in the context of inflammatory or neoplastic disease.

Causes and risk factors vary by site but often include inflammatory bowel diseases (notably Crohn’s disease), diverticulitis, pelvic inflammatory disease, abdominal or pelvic surgery, radiation therapy, infections, and malignancy. Immunosuppression can predispose to fistula formation or impede healing.

Symptoms depend on location and may include persistent drainage with a foul smell, recurrent infections, pain, urinary leakage, fecaluria, or passage of material through an unintended route. Diagnosis relies on clinical examination and imaging, with MRI frequently preferred for anorectal fistulas; CT or ultrasound and endoscopic evaluation may also be used.

Treatment aims to close the abnormal tract while preserving function. Management may involve antibiotics and control of the underlying condition, drainage of abscesses, and definitive surgery such as seton placement, fistulotomy, advancement flap procedures, or resection. Prognosis varies; recurrences are possible, and multidisciplinary care is often required.