Ureteral Duplication and Duplex Systems

Abstract

There is a huge anatomical variety in ureteral duplications, ureteral ectopia, and ureteroceles. Embryology is complex and often not well understood. Due to the heterogeneity of patients with those issues, there is no standardized approach. The aims of treatment are to reduce urinary tract infection, eliminate obstruction, preserve renal function, and manage bladder dysfunction and incontinence. Most incomplete duplex kidneys are detected incidentally. Three clinical problems of incompletely duplicated ureters have to be mentioned: vesicoureteric reflux (VUR), ureteropelvic junction obstruction, and retrograde ureteral peristalsis. Complete duplication anomalies are associated with urinary tract infection, obstruction of the upper pole, VUR to the lower moiety, renal dysplasia, compromised renal function, ectopic ureteral insertion, ureterocele, and incontinence. The most frequent anomaly detected in completely duplicated ureters is VUR, usually into the lower moiety. In symptomatic patients, endoscopic correction or ureteric doublebarrelled ureteric reimplantation is indicated. In boys, ectopic ureters are always obstructed with varying degrees of megaureter and hydronephrosis; ureteral ectopia never causes incontinence. In girls, ureteric ectopia occurs distally to the sphincter complex and may cause incontinence. Indications for surgery in ectopic ureters are UTI, incontinence, and lower urinary tract obstruction. Surgery includes ureteric reimplantation, reconstruction of the lower urinary tract, minimal invasive heminephrectomy, and ureteroureterostomy, or pyeloureterostomy.