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

In spite of great progress in surgical treatment of anorectal malformations, fecal incontinence is still, in variable degrees, a frequent and unpleasant postsurgical sequela. The most frequent causes of incontinence are: i) the incorrect placement of the pulled-through colon in the levator ani and sphincteric muscular complex during abdominoperineal surgical procedures; ii) the poor development of sphincteric musculature; iii) the associated sacral anomalies. Postoperative CT helps to evaluate all the above-mentioned conditions, in view of possible new surgical procedure for improving continence (besides postoperative CT can help in choosing the more suitable surgical technique). Nine patients, aged 3 to 13 years, (2 with good continence and 7 with various degrees of incontinence), were studied with pelvic postoperative CT. In the cases (2) with good continence the CT picture was: good development of sphincteric musculature and neo-anorectum correctly placed into sphincteric musculature; in the cases (3) with low degree of continence: neoanorectum correctly placed, but hypoplastic puborectal muscle; in the cases (4) with complete incontinence, neoanorectum incorrectly placed and poor development of sphincteric musculature. A further posterior sagittal anorectoplasty (according Peña) is only suitable in the incontinence cases with: i) neoanorectum seriously misplaced; ii) good development of sphincteric musculature; iii) absence of sacral anomalies. Postoperative CT is a valid mean for demonstrating all the above-mentioned conditions and for choosing the best surgical technique in each case.