H-type anorectal malformations: incidence and clinical characteristics.

To establish the incidence of H-type anorectal malformations (ARM), the hospital records of 629 patients with ARM were studied. Patients who had a congenital rectourogenital connection and an external anal opening in a normal or ectopic position were considered to have an H-type malformation. Twenty (3.2%; 14 females, 6 males) of the 629 patients studied had an H-type ARM. Major associated anomalies were found in 60% of these patients. Thirteen patients (12 females, 1 male) had a normally placed anus; the H fistula was low rectovestibular in 10, rectovaginal in 2, and rectourethral in 1. Seven patients had an ectopic anal opening. Three males had a rectourethral H fistula; in two of these there was a double fistula. Two males had a rectovesical H fistula. Of the two females with ectopic anal openings, one had a high rectovaginal H fistula and the other had a low fistula. In only one case was the diagnosis of H fistula made immediately after birth. Three patients died of severe cardiac abnormalities during the neonatal period or early infancy. Primary perineal repair or a limited posterior surgical anorectoplasty (PSARP) was used in 15 cases; formal PSARP was used for the other two. Four patients had between one and 4 recurrences; all but one of these fistulas were repaired subsequently. Long term (median follow-up period, 12 years; range, 4 to 38 years), 12 patients had good bowel function and no faecal soiling; four of these had constipation that was manageable with laxatives. Two patients (aged 10 and 12 years) had daily soiling. Two others were too young to evaluate, and one (with severe mental retardation) has a permanent colostomy.