[Myohyperplasia of the lung arterioles in congenital diaphragmatic defects].

The ratio of lumen/wall thickness of pulmonary arterioles was measured in patients who died post-operatively due to a congenital diaphragmatic defect. This was compared to normal arterioles in healthy newborn lungs. The wall musculature of pulmonary arterioles was 2.8 times thicker than in normal arterioles of newborn lungs. The main cause of this enormous wall thickness is a genuine growth of substance, i.e. myohyperplasia. Myohypertrophia can be an additional reason.