Duodenal stenosis is usually a congenital disorder with stenosis of the lumen of the duodenum, but it can also occur as an acquired disease. Anatomically, the stenosis is divided in relation to its location to the major duodenal papilla.
In the less common high obstruction, the occlusion is above the Vater's papilla. In deep obstruction, the stenosis is below the papilla of Vater. Furthermore, one differentiates between an inner and outer obstruction.
Internal obstruction may be due to either a duodenal membrane, an annular constriction, a connective tissue alteration of the bowel wall, or an incomplete atresia. The external obstruction is much more common and is caused by congenital bridging, vascular anomalies, malrotations, duplication, or pancreatic anulare.
Frequently, in addition to congenital duodenal stenosis, additional malformations, e.g. heart defect, one third of the children have a trisomy 21. Acquired forms can occur after a trauma (with vascular injuries), inflammation, reduced blood flow or surgical intervention as a complication.
The symptoms of duodenal stenosis depend heavily on the extent of the passage disturbance. In high-grade stenoses or atresias, the diagnosis can already be noticed intrauterine by first indications of a polyhydramnios.
Severe duodenal stenosis is manifested by massive vomiting in the first days of life, depending on the location of the stenosis, it may be bilious or non-bilious vomiting. Some cases of mild duodenal stenosis may be delayed beyond the neonatal period or may go unnoticed for a lifetime.