Endoscopic classification and endourologic therapy in proximal incomplete ureteral duplication pathology

To assess whether patients with proximal incomplete ureteral duplication (PIUD) had functional or anatomical Y junction zone pathology. In such cases, stasis and infection, with or without associated renal scarring, are often found. The results after minimally invasive treatment (retrograde endoincision of ureteral stenosis, localized on one limb) can be evaluated.

In a retrospective analysis of 807 ureteroscopies, we found 29 cases with PIUD pathology dating from July 1996 to March 1999. The investigative protocol involved: intravenous pyelography (IVP) with delayed films, voiding cystourethrogram, and duplex Doppler renal ultrasonography (DDRU) for the resistive index. We used semirigid ureteroscopes (7.5 and 8.5 french) and the Storz cold knife/scissor. The mean follow-up period was 17 months (range 5-33 months).

In 22 cases (76%) we found functional obstruction of the Y junction region and in 7 cases (24%) a ureteral stricture shorter than 1 cm of lower or upper limbs. We described four particular morphologies of the Y junction zone: double-barrelled (wide bifid limbs) with larger Y junction, lateral insertion, punctiform insertion and valvular insertion of one of the limbs. The first type is associated with functional obstruction and the others are characteristic of anatomic obstruction. After retrograde cold endoincision, normal PIUD was found in 85% of cases.

Pathological aspects of PIUD may pose interesting problems in diagnosis and therapy. Endoscopic particularities of the Y junction zone could be correlated with IVP and DDRU. Retrograde endoureterotomy appears to be an effective minimally invasive procedure for treatment of anatomical obstruction where the ureteral stenosis of one limb is shorter than 1 cm.