Variable expression of the congenital obstructive posterior urethral membrane.

OBJECTIVES

To assess the variability of membranous folds in the posterior urethra and their relationship to urethral obstruction.

METHODS

Endoscopic video recordings of 19 boys with a membranous lesion in the posterior urethra were obtained over a 2.5-year period. Six had an endoscopy after a prenatal diagnosis of obstructive uropathy and 13 boys presented with either a urinary tract infection or hematuria.

RESULTS

Young's type I and type III appearances were seen in all with an obstructive membrane, and those with a less obstructing membrane probably had incidental pathologic conditions.

CONCLUSIONS

These observations support the thesis that the congenital attachment of the verumontanum to the anterior wall of the posterior urethra is the embryologic fore-runner to the congenital obstruction of the posterior urethra, and that there may be a variable degree of persistence of that attachment, which in some boys is not obstructive.