Thiry-Vella fistula /thī″rē vel″ə/ [Ludwig Thiry, Austrian physiologist, 1817–1897; Luis Vella, Italian physiologist, 1825–1886] , an artificial passage from the abdominal surface of an experimental animal to an isolated intestinal loop, created surgically for the study of intestinal secretions. The continuity of the animal’s gut is restored by anastomosis of the severed sections, and the vascular connections and mesenteric attachment of the isolated loop are preserved. The ends of the isolated segment are attached to two openings in the skin of the abdomen to form a closed internal loop.
