The use of computerized tomography to evaluate anorectal anomalies.

Computerized tomography (CT) was applied to various types of anorectal anomalies to directly image the anal sphincters. In normal cases and low type anomalies, CT demonstrated clear images of the puborectal muscle and external sphincters. Among high type anomalies, the distribution of sphincter muscle in patients with rectovesical fistula is totally different from that seen in patients with rectourethral fistula. In the latter, the puborectal muscle is attached not only around urethra, but also around the distal part of the blind rectum; external sphincters are present as a mass beneath the perineum. In the rectovesical fistula, however, the puborectal muscle cannot be identified and the external sphincters exist only as a string-like structure. CT done postoperatively identified two different causes for incontinence. In one type, the pull-through colon missed the sphincteric musculature, and in the other, sphincters were markedly hypoplastic. CT, therefore, provides adequate imaging to determine the type of operation needed to correct the abnormality.

[Our new operative method for high-type anorectal malformations based on the histological studies].

From 1971 onwards we have been examining the anatomy and histology of sphincter components in patients with several anorectal malformation who died of associated anomalies. These histological studies demonstrated that not only puborectal muscle but also the superficial and deep external sphincters exist, even in the high type anomalies, and that the mass of external sphincter is located above the anal dimple. Moreover, the inner circular muscle of rectum is thickened at the level of the closest part to the fistula. Based on our histological studies, we devised our new operation to use all the sphincter musculature effectively for the newly reconstructed anal canal. Our new surgical procedure is clearly different from Kiese wetter-Rehbein's method in that the puborectal muscle is penetrated from the outside of rectal wall and might be damaged, since puborectal muscle is attached to the blind pouch of rectum. Moreover, the puborectal muscle and the external sphincters can be easily identified by electrical stimulation under direct vision from extended sacroperineal approach. And the colon can be pulled exactly through the centre of the external sphincters and puborectal muscle under direct vision without causing any damage to these important sphincters, unlike Pena's operation.

Abdomino-extended sacroperineal approach in high-type anorectal malformation--and a new operative method.

From 1971 onwards we have been examining the anatomy and histology of sphincter components in patients with several anorectal malformation who died of associated anomalies. These histological studies demonstrated that not only puborectal muscle but also the superficial and deep external sphincters exist, even in the high type anomalies, and that the mass of external sphincter is located above the anal dimple. Moreover, the inner circular muscle of rectum is thickened at the level of the closest part of the fistula. Based on our histological studies, we devised our new operation to use all the sphincter musculature effectively for the newly reconstructed anal canal. Our new surgical procedure is clearly different from Kiesewetter-Rehbein's method in that the puborectal muscle is penetrated from the outside of rectal wall and might be damaged, since puborectal muscle is attached to the blind pouch of rectum. Moreover, the puborectal muscle and the external sphincters can be easily identified by electrical stimulation under direct vision from extended sacroperineal approach. And the colon can be pulled exactly through the centre of the external sphincters and puborectal muscle under direct vision without causing any damage to these important sphincters, unlike Pena's operation.