[Endo-anal ultrasound. Indications and results].

Between July 1991 and November 1993 106 patients have been examined by endoanal ultrasound with a 7.0 MHz transducer and a special hard plastic cone which is attached over the transducer. Indications for endoanal ultrasound have been anal carcinoma, perirectal or perianal fistulas, perianal abscesses and sphincter insufficiencies. All anal carcinomas and 2 anal cancer recurrences could be visualized with regard to their size and extension as well as the lymphnode infiltration. 28 of 35 fistulas have been seen by endoanal ultrasound. Endosonographical differentiation in inter- (10), trans- (12) extra- (1) or suprasphincteric (5) was possible in all detected fistulas and confirmed by operation in 27 of 28 cases. 34 cryptogen abscesses could be detected (15 intersphincteric, 12 ischiorectal, 7 pelvirectal) and confirmed by the operative situs with regard to their size and localisation. In 9 patients with a myogen sphincter insufficiency the morphological defect of the sphincter muscle could be localized by endoanal ultrasound and confirmed by the operative situs in all cases.