DRAIN FISTULOGRAPHY - RADIOLOGICAL SPHINC TER IDENTIFICATION IN HIGH ANAL FISTULAS

To warrant permanent surgical cure of high anal fistulae, while avoidi ng at the same time faecal incontinence due to inadvertent division of the puborectalis muscle, distinction between a trans- and suprasphinc teric fistula track is essential. This differentiation is often crucia l, since digital-rectal palpation and conventional fistulography tend to be unreliable. Therefore we developed a radiological technique of i maging the anorectal fistulous track, ''drain fistulography''. After s ilicon drainage of the fistula the contrast-visualization of anal cana l, rectum and fistula drain allows to assess the topographic relation between fistula and anal sphincters as well as the sphincteric functio nal component above the fistula. A transsphincteric fistula track was demonstrated in 7 of 8 patients (5 with recurrent fistulae) by means o f ''drain fistulography'', permitting complete laying open of each fis tula in a second operation. In one patient a suprasphincteric fistula track was found and a ''mucosal flap repair'' was carried out. After a mean observation time of 53 months all patients are perfectly contine nt and free of recurrence. The method of ''drain fistulography'' is a valuable diagnostic tool to select the appropriate definitive surgical procedure in the treatment of high anal fistulae.