Chronic intestinal pseudo-obstruction in infants and children caused by diverse abnormalities of the myenteric plexus.

BACKGROUND: Chronic intestinal pseudo-obstruction is a motility disorder that leads to severe disability in infants and children. Our purpose was to study the myenteric plexus in infants and children with pseudo-obstruction

METHODS: Using cross sections stained with H&E and frozen tangential sections of the myenteric plexus processed using Smith's silver technique, the myenteric plexus of the stomach, small intestine, and colon from 26 affected infants and children was analyzed quantitatively.

RESULTS: Under H&E staining, there were decreased neuron scores of 34.1 +/- 7.4 and 25.3 +/- 7.1 in the jejunum and ileum (normal, 57.5 +/- 6.2 and 55.0 +/- 4; P = 0.005 for both). Using Smith's technique, the specimens had decreased argyrophilic neuron counts of 3.1 +/- 1.4, 3.6 +/- 1.1, 3.4 +/- 1.0, and 2.8 +/- 0.6 in the duodenum, jejunum, ileum, and colon, respectively (normal, 14.0 +/- 1, 14.8 +/- 1, 14.7 +/- 0.5, and 13.6 +/- 1.1; P < 0.0003). The abnormalities included (1) absence of myenteric plexus in 3 patients; (2) small numbers of neuronal structures present on H&E stains but the absence of the plexus on silver stains in 2; and (3) myenteric plexus present but decreased argyrophilic neurons and axons on silver stains in 18. The abnormalities would have been missed in 10 patients if H&E had been used alone, whereas Smith's technique identified the deficiency of argyrophilic neurons in all patients tested.

CONCLUSIONS: Pseudo-obstruction in infants and children may be caused by diverse abnormalities of the myenteric plexus.