1911 Encyclopædia Britannica/Fistula

FISTULA (Lat. for a pipe or tube), a term in surgery used to designate an abnormal communication leading either from the surface of the body to a normal cavity or canal, or from one normal cavity or canal to another. These communications are the result of disease or injury. They receive different names according to their situation: lachrymal fistula is the small opening left after the bursting of an abscess in the upper part of the tear-duct, near the root of the nose; salivary fistula is an opening into the salivary duct on the cheek; anal fistula, or fistula in ano, is a suppurating track near the outlet of the bowel; urethral fistula is the result of a giving way of the tissues behind a stricture. These are examples of the variety of the first kind of fistula; while recto-vesical fistula, a communication between the rectum and bladder, and vesico-vaginal fistula, a communication between the bladder and vagina, are examples of the second. The abnormal passage may be straight or tortuous, of considerable diameter or of narrow calibre. Fistulae may be caused by an obstruction of the normal channel, the result of disease or injury, which prevents, for example, the tears, saliva or urine, as the case may be, from escaping; their retention gives rise to inflammation and ulceration in order that an exit may be obtained by the formation of an abscess, which bursts, for example, into the gut or through the skin; the cavity does not close, and a fistula is the result. The fistulous channel remains open as long as the contents of the cavity or canal with which it is connected can pass through it. To obliterate the fistula one must remove the obstruction and encourage the flow along the natural channel; for example, one must open up the nasal duct so as to allow the tears to reach the nasal cavity, and the lachrymal fistula will close; and so also in the salivary and urethral fistulae. Sometimes it may be necessary to lay the channel freely open, to scrape out the unhealthy material which lines the track, and to encourage it to fill up from its deepest part, as in anal fistula; in other cases it may be necessary to pare the edges of the abnormal opening and stitch them together.  (E. O.*)