[Imaging of peri-anal and perirectal abscesses and fistulae using endoluminal ultrasound diagnosis].

Endoluminal sonography was performed in 31 patients with suspected perianal or perirectal abscesses or fistulas. Patients with unequivocal clinical findings underwent surgical treatment without preceding sonography. The aim of the sonographical examination was to identify the abscesses, their topographical location, and the internal opening of the fistulas. These results were compared with operative findings. An abscess was diagnosed in 22 patients and could be confirmed by surgery in 21. In one patient a hypoechogenic scar resulting from previous surgery was erroneously interpreted as an intersphincteric abscess. The remaining 9 patients suffered from a fistula without abscess. In all 21 abscesses the sonographic examination showed the correct topographical location. There were 5 perianal, 8 intersphincteric and 8 ischiorectal abscesses. The operation demonstrated the internal opening of the fistula in 17 of 35 cases. Only 9 of these 17 openings (53%) had been identified by preoperative ultrasonography. The endoluminal sonography is a good method to find a perianal or perirectal abscess and to show the topographical location. It should be performed in all cases with an obscure preoperative clinical situation.