Anal endosonography and fistulography for fistula-in-ano

Purpose. In this study, a comparison was made of the
accuracy and clinical usefulness of anal endosonography
and fistulography in the preoperative classification of
fistulas-in-ano.
Materials and methods. A total of 113 patients with a
clinical diagnosis of cryptoglandular fistula-in-ano who
were awaiting surgery were included in this retrospective
review. Patients were preoperatively investigated by anal
endosonography and/or modified fistulography by
inserting a Foley catheter into the rectum and a metal ring
close to the anus. The catheter and ring served as
radiopaque anal markers. Fistula classification obtained by
the two diagnostic modalities was compared with surgical
classification as the criterion standard.
Results. Endoanal ultrasound and fistulography identified
82.8% and 100% of primary tracks, 79% and 74.2% of
internal openings, 98% and 91.8% of secondary tracks and
92.9% and 87.8% of abscesses, respectively.
Conclusions. Anal endosonography and fistulography with
radiopaque markers are important complements to surgical
exploration for investigating anal sepsis and may be of
value to the surgeon in planning a therapeutic strategy.