INNERVATION PATTERNS OF THE RECTAL POUCH AND FISTULA IN ANORECTAL-MALFORMATIONS - A PRELIMINARY-REPORT

The innervation patterns of the rectal pouch and fistula of 52 childre n with anorectal malformations were investigated. Posterior sagittal a norectoplasty was used for intermediate and high anomalies; for the la tter it was combined with an abdominal approach. Perineoproctoplasty w as performed for low anomalies. The specimens were investigated by ace tylcholinesterase staining. lactate dehydrogenase, and succinyldehydro genase reaction. They consisted of fistula material only in 23 patient s and of parts of the rectal pouch in 29. Fourty-four patients (84.6%) had follow-up, and information on bowel movements and continence was obtained after a mean of 3.3 years. Abnormal innervation patterns were found in 96% of the specimens. All fistulas were found to be aganglio nic, including the adjacent part of the rectum involving the internal sphincter equivalent. Classical aganglionosis was found in 31% of the rectal pouch specimens, hypoganglionosis in 38%, neuronal intestinal d ysplasia (NID) type B in 14%, and dysganglionosis in 10%. All patients with severe constipation or soiling at the time of follow-up had some histopathological correlation. Of the 25 patients for whom the specim ens had consisted of rectal pouch material, nine (31%) had severe cons tipation. All four patients with a low-type malformation who had follo w-up and pathological innervation patterns in the rectal pouch suffere d from severe constipation; this was true of only five of the 19 child ren with intermediate or high malformations (P < .05). However, numero us pathological innervation patterns had been identified in patients w ho had normal bowel function at the time of follow-up. It is concluded that partial denervation of the rectum may not be the only cause in t he pathogenesis of constipation after posterior sagittal anorectoplast y and perineoproctoplasty. The high frequency of neuronal intestinal m alformations in the rectal pouch may be related to the higher frequenc y of bowel disturbances in patients with low malformations, in whom th e resection was less radical. However, the clinical course is not nece ssarily related to specific histopatological findings. In the authors' opinion, the recommendation to use the distal rectal pouch and parts of the fistula in the reconstruction of anorectal malformations should be reconsidered. Copyright (C) 1996 by W.B. Saunders Company