The myenteric plexus of the esophagus is abnormal in an experimental congenital diaphragmatic hernia model

Infants surviving congenital diaphragmatic hernia (CDH) suffer from anatomical and functional esophageal abnormalities. Previous work in the nitrofen animal model of CDH demonstrated malformations in neural crest-derived structures, including the vagus and recurrent laryngeal nerves. The aim of the present study was to assess whether the esophageal myenteric plexus is abnormal in rats with CDH.

We used the nitrofen-induced CDH fetal rat model. Two sections of the proximal, medium and distal esophagus from both groups were processed for immunohistochemical staining with anti-neuron specific enolase and anti-S-100 antibodies; the number of stained areas was recorded for each group. Whole-mount preparations of the entire esophagus of Control and CDH animals were histochemically stained for acetylcholinesterase; the density and area of the ganglia and the number of cells/ganglia were determined. Comparisons between groups were made by standard statistical methods.

The number of immunohistochemically stained areas in transversal sections were decreased in CDH animals for anti-enolase (11.5+/-6.06 vs. 1.93+/-1.49, control vs. CDH, p<0.001) and anti S-100 antibodies (8.57+/-4.1 vs. 4.06+/-2.82, p<0.001). In whole-mount preparations the number of ganglia per high power field (35.16+/-6.57 vs. 29.29+/-10.26, p<0.05), the number of cells per ganglia (11.85+/-3.52 vs. 2.28+/-4.61, p<0.0001) and the relative area of the ganglia (0.35+/-0.32 vs. 0.18+/-0.42%, p<0.001), were also significantly decreased in CDH animals compared with Controls.

Esophageal intrinsic innervation is defective in rat fetuses with CDH. If patients with CDH bear the same anomalies, this may explain some of their esophageal motility disorders. Finally, these findings support the concept of neural crest involvement in the pathogenic pathways of CDH.