The role of minimal surgery with renal preservation in abnormal complete duplex systems

Among 36 children, mostly less than 1 year of age, referred for a complete duplex-system anomaly, 18 were diagnosed before birth by obstetrical ultrasonography where a diagnosis of dilated upper urinary tract was the most frequent report; in the remaining cases urinary tract infection was the main presenting symptom. Five children had bilateral anomalies. Principal diagnoses associated with the complete duplex system were: 18 ureteroceles (UC) (11 extravesical [EUC] with bladder-neck or urethral extension, 7 intravesical [IUC]), 5 ectopic ureters without UC and 28 lower-polar vesicoureteral reflux (VUR) associated in 6 with upper polar VUR. The initial assessment was based on a voiding cystogram and radionuclide scan. Renal-polar function was severely impaired when major ureteral ectopia or severe primary reflux was present. Primary surgery was performed in 8 patients, demolitive in 4 (3 upper-polar nephrectomies, 1 nephrectomy) and reconstructive in 4 (duplex en-bloc reimplantation); staged management with minimal endoscopic incision was undertaken in 15 UCs (9 EUCs and 6 IUCs). Expectant management was elected in all cases of mild primary, single, or double VUR not associated with UC and was followed by spontaneous reduction in one-half of the cases. Secondary VUR complicated endoscopic incision in 2 of 6 IUCs and 5 of 9 EUCs; a certain degree of functional improvement after decompression could be observed in all IUCs versus only 2 EUCs. Twenty-one patients requested secondary surgery; 17 needed an open intravesical procedure for ureteral reimplantation, combined in 8 with UC excision and bladder-floor reconstruction and in 5 with upper-pole nephrectomy. A nephrectomy was required in 4 cases. All primary or secondary demolitive procedures involved 9 of 11 EUCs extravesical and 2 of 5 ectopic ureters. EUCs and ureteral ectopia were associated with severe renal-polar damage, and function was rarely affected by primary decompressive procedures even in prenatally detected, uninfected cases. Endoscopic incision of EUCs was frequently followed by secondary VUR, which made secondary intravesical operations more complex. For these reasons, primary elective resection of a dysplastic upper pole is preferable in most cases to temporary decompressive measures. Conservative surgery is always indicated in IUC, which may benefit from endoscopic decompression. Isolated VUR involving the lower pole of a completely duplicated system may respond to expectant management in a significant number of cases. Accepted: 5 January 1999