Duplex renal collecting system with ureteric calculi in upper pole moiety
Presentation
Right renal colic. No relief following the insertion of a ureteric stent.
Patient Data
Very thin residual mantle of cortex in the upper pole of the right kidney with a dilated ureter to the pelvic brim containing 4 small calculi.
Post stent insertion
Following insertion of a ureteric stent, there is a JJ in the lower pole renal pelvis and ureter with a persistent upper pole dilated ureter. The stones are shown to be anterior to the stent in the upper pole ureter. No contrast in this dilated ureter despite delayed scanning as it is obstructed and there is very little residual cortical tissue.
Case Discussion
This case demonstrates the typical findings of duplex kidney. The upper pole moiety is usually obstructed with an ectopic entrance to the bladder or beyond. In this case a stent was placed up the normal ureteric orifice and entered the unobstructed lower pole moiety. Upper pole orifice not seen at cystoscopy and the dilated ureter contains 4 small stones. Note the lack of overlying cortex indicating the long term duration of obstruction with backflow atrophy. The stones are presumed to be due to chronic urinary "stasis".