[Computed tomography and anorectal malformations. Their preoperative evaluation].

The anatomical patterns of anorectal malformations have so far been studied according to the principles which inspire Peña's technique for the surgical treatment of anorectal anomalies. Thus, the diagnostic study of anorectal malformations has by the authors been considered a work of classification, but of identification. Among the diagnostic procedures in use in our Institute, preoperative CT of pelvis is performed to assess the presence and to define the development of muscular sphincteric structures towards prognostic evaluation of continence, the major long-term goal. Seven patients, aged 1-30 months, with anorectal anomalies were studied with preoperative CT of the pelvis. CT scans showed well-developed sphincteric muscles in 3 patients (2 with rectoureteral and 1 with rectovestibular fistulas), poorly developed muscular structures in 3 patients (with rectovaginal, cloacal and prostatic fistulas), absence of muscular structures in 1 case (with rectovesical fistula). CT findings were always confirmed at surgery, except for the case with rectovesical malformation where CT scans did not allow to identify the thin sphincteric musculature. The authors believe preoperative CT of the pelvis, together with other clinical and radiological examinations, to be a valid mean in the prognostic evaluation of continence.