Radiological Evaluation of Primary Megaloureter

Thirty-one patients with megaloureter (functional ureteral obstruction) have been encountered in the past thirteen years. Urographically, this disorder presents as a fusiform dilatation of the distal (pelvic) ureter, without pyelo-caliectasis. Cinefluoroscopy shows normal peristalsis in the proximally dilated ureter, but the contracting wave terminates abruptly when it reaches the adynamic distal ureteral segment. The juxtavesical aperistaltic “narrow” segment is not anatomically obstructed and does not permit vesicoureteral reflux as tested by retrograde catheter calibration and cystourethrography. In addition, no neurogenic bladder dysfunction is present.