[3D endorectal sonography in the diagnosis of periproctal fistulas]

Magnetic resonance (MRI) and endorectal sonography seem to be the most contributive methods in preoperative diagnostics of perianal fistula. The right interpretation of MRI requires the radiologist performing the evaluation to be very well acquainted with the issue of surgical treatment of perianal fistulas, or the surgeon to have experience with MRI findings interpretation. On the contrary, endorectal sonography is usually performed by surgeons who are able to transfer the findings to surgical practice and who also have the feedback during the description of the endorectal sonography findings in confrontation with the peroperative findings.

There were 482 patients with the clinical diagnosis of perianal fistula in our group who were examined and underwent surgery in the period between 1 January 2001 and 31 December 2011. In evaluating the findings, we used the basic Parks classification of perianal fistulas which is modified with respect to the specific features of ultrasound examination.

In case of simple fistulas, the correspondence between preoperative diagnostics and peroperative finding was present in 304 cases (90%), in case of extrasphincteric fistulas there was correspondence in 36 patients (82%). In case of horseshoe fistulas, the correspondence was found in 16 patients (87%). The diagnosis of the fistulas with more than one sinus was accurate in 95 patients (76%). General correspondence between the preoperative examination and the peroperative finding was present in 419 patients (87%).

Endorectal sonographic examination in the diagnosis of perianal fistulas is simple, cheap and less demanding for the patient, reaching at the same time high sensitivity and specificity. It is fully sufficient as a preoperative diagnostic method in most patients with perianal fistula.