[Transanal ultrasonography in the study of fistulas of perianal abscess].

The fistulous tracks and abscesses may be related anatomically to the anal sphincters and levator ani muscles. Defining the anatomical relationship between the fistulous lesion and the anal sphincters and/or adjacent organs is essential for correct management. Clinical examination can suggest possible sepsis or the direction of the fistulous track. We report the results of anal endosonography in the evaluation of 54 patients affected by perianal sepsis and fistula in ano. Anal endosonography has correctly identified 22 of 22 internal openings seen at the surgery, 14 of 16 intersphincteric tracts while only 7 of the 9 trans-sphincteric tracks described by anal endosonography were present at the surgery. All the abscesses were correctly identified. Anal endosonography provides a high-resolution image of the anatomy of anal canal and defines the anatomy of tracks and abscesses in relation to the sphincters, determines if there has been trans-sphincteric extension of the sepsis and assesses the state of the sphincters. We have observed a good correlation between the preoperative AES findings and those at surgery. We conclude that anal endosonography is a useful diagnostic procedure in patients with perianal sepsis.