AB196. SOH26AB_0305. Rogue ureters: disobeying the Weigert-Meyer rule—a case report

Background: A duplex kidney is one of the most common congenital anomalies of the urinary tract. The Weigert-Meyer rule states that the upper pole moiety inserts ectopically and is prone to obstruction, while the lower pole moiety inserts normally and is prone to reflux. We present an interesting case of bilateral duplex kidneys with unilateral reflux in both the upper and lower renal moieties, contrary to the Weigert-Meyer rule.

Case Description: This is a case report of a 5-month-old boy who was diagnosed with bilateral antenatal urinary tract dilation. Antenatal ultrasound suspected, and postnatal renal ultrasound confirmed bilateral duplex kidneys with moderate urinary tract dilation bilaterally, with unilateral ureteric dilatation (UTD P2). A micturating cystogram demonstrated an unusual pattern: severe vesicoureteric reflux (VUR) into the left lower moiety and moderate VUR in the upper moiety ureter on the left side. No VUR was demonstrated on the contralateral side. Ultrasound surveillance confirmed deterioration of the left duplex kidney with progressive cortical thinning, reduced corticomedullary differentiation, and pelvicalyceal dilatation. Subsequent renal dimercaptosuccinic acid (DMSA) scintigraphy demonstrated reduced split function of 28.6% on the left side.

Conclusions: Although it can appear in a variety of different presentations, complications related to duplex kidneys are generally moiety specific as described by Robert Meyer in 1946. A literature review reveals only a handful of exceptions to the rule, making our case noteworthy.

Keywords: Duplex; kidneys; reflux; Weigert-Meyer; case report