A fistula (plural: fistulas or fistulae /-li, -laɪ/; from Latin fistula, "tube, pipe") is an abnormal connection between two hollow spaces (technically, two epithelialized surfaces), such as blood vessels, intestines, or other hollow organs. Fistulas can result from an infection or inflammation, injury or surgery. Fistulas are sometimes purposefully surgically created as part of a treatment, for example arteriovenous fistulas for hemodialysis. Globally, every year between 50,000 and 100,000 women are affected by fistula relating to childbirth. The term was first used in the 14th century.