ELECTRON MICROSCOPY OF THE PRIMARY OBSTRUCTIVE MEGAURETER

Abstract

SUMMARY The ultrastructure of the narrow segment of the obstructive megaureter has been studied. The muscle cells are normal in appearance, their connections with each other are present in normal form and number and they receive a normal autonomic innervation. As in normal ureter no ganglion cells have been found. A great increase in the amount of collagen fibres in the submucosa and the muscle coat has been demonstrated which it is suggested is responsible for the poor drainage of the ureter and its consequent dilatation. This lesion is similar to that demonstrated in the narrow pelvi‐uretenc segment of idiopathic hydronephrosis. The ætiology in either situation is obscure.