New pathogenetic aspects of gut dysmotility in aplastic and hypoplastic desmosis of early childhood.

The peristaltic movement of the gut is a function of the alternating contraction and relaxation of circular and longitudinal muscles. This movement is induced by a tendon-like connective-tissue net (TCTN) in the circular and longitudinal muscles, which are both rooted in a connective-tissue plexus layer (CTPL). In children with a therapy-resistant aperistaltic or hypoperistaltic syndrome who had normally-developed enteric innervation, a lack of the TCTN in the muscularis propria was observed. Over the last 2 years, 241 children with chronic constipation were investigated histopathologically; 46 children surgically treated by partial resection of the gut or diagnostically investigated by whole-mount biopsy. Fifteen children had a hypoperistalsis syndrome and 3 had an aperistalsis syndrome. All specimens were native and cut in a cryostat. Enteric innervation was examined by acetylcholinesterase and dehydrogenase reactions. The TCTN in the muscularis propria was stained with picric acid/sirius red. In the children with an aperistalsis syndrome, a complete lack of the TCTN in circular and longitudinal muscles was observed. A CTPL was not developed. The children with a hypoperistalsis syndrome had no CTPL, but had a partly-developed TCTN in the circular and longitudinal muscles, which gradually faded in the direction of the plexus layer. Independent of a well-developed enteric nervous system, a lack of the TCTN in longitudinal and circular muscles and a missing CTPL (aplastic desmosis) abolishes the coordinated peristaltic movement of the gut. An isolated lack of the CTPL in the myenteric plexus (hypoplastic desmosis) results in a hypoperistalsis syndrome. An anomaly of the TCTN in the muscularis propria disturbs gut-muscle mechanics, and is another cause of gut dysmotility.