Megaureter

This is an abnormally enlarged ureter and may occur as a result of abnormal peristalsis of the lower ureter and resultant gross proximal dilatation.

It presents as recurrent urinary infections in young children.

Megaureters can be classified as obstructive, refluxing, obstructed and refluxing, or neither obstructing nor refluxing.

• Primary obstructive megaureter occurs when the ureter is too narrow at the point where it enters the bladder; peristalsis of the ureter proves insufficient and blockage results.
• An obstructive process characterizes secondary obstructive megaureter occurring secondary to elevated intravesical pressure of some other cause such as neuro genic bladder, ectopic ureter, ureteral vesicular junction problem, retroperitoneal mass and enlarged prostate.
• The primary and second ary refluxing megaureters represent a refluxing ureter that happens to be dilated. This may be associated with abnormalities of uretero-vesicular junction problem.
• In the refluxing obstructed megaureter, some degree of obstruction occurs, perhaps due to ectopic insertion of the ureter into the neck of the bladder.

Reference

1. Melovitz-Vasan, C et al. Megaureter and hydronephrosis: Consequences of ureteric dysfunction. Italian Journal of Anatomy and Embryology 127(2): 19-28, 2023