Pathophysiology of chronic constipation in anorectal malformations - Long-term results and preliminary anatomical investigations

Posterior sagittal anorectoplasty provides an optimal access to reconstruct the muscle complex in anorectal malformations. It gives much better result s than the abdominoperineal pull-through procedures performed before 1984. However, severe chronic constipation occurs postoperatively in about 10% of the patients, which can only be treated by washouts. Clinical investigatio ns of 578 patients treated from 1962 to 1984 and from 1985 to 1997 are pres ented here and both groups are compared to each other. In addition, a new c ontinence score with special regard to chronic constipation and overflow in continence was used to follow up 133 patients of the second group. The scor e distinguishes between children above and below the age of 3 years. To stu dy the underlying reasons of severe chronic constipation in children with a norectal malformations, macro- and microanatomical investigations on 4 norm al newborns, 3 neonatal piglets with imperforate anus and 25 rectal biopsie s from the caecum were performed. The following reasons have been found to be probably responsible for postoperative constipation and overflow inconti nence: 1. Malformations of the smooth and striated muscle fibres or connect ive tissue of the caecum; 2. Malformations of the intramural nerve plexus s uch as aganglionosis, hypoganglionosis or IND; 3. Malformations and/or iatr ogenic lesions of the extramural nerve supply which runs anterior to the re ctum and in front of the fascia of Denonvilliers, which can hardly be ident ified in neonates with imperforate anus. Therefore iatrogenic bladder injur ies may occur after PSARP after extended mobilisation of the caecum. The ma cro- and microanatomical situation in the piglet with imperforate anus is t otally different from the human newborn.