Radiographic changes following excisional tapering and reimplantation of megaureters in childhood: long-term outcome in 46 renal units

Abstract

Purpose: Despite the routine use of renal ultrasonography to document progressive improvement in hydronephrosis following ureteral tailoring and reimplantation of megaureters, there have been few reports characterizing the serial radiographic changes to be expected following this procedure. We evaluated the radiographic outcomes following surgical repair of megaureters at single institution, and assessed potential preoperative factors for predicting outcome.

Materials and methods: We conducted a retrospective analysis of all patients who underwent surgical correction of clinically significant megaureters at our center between 1996 and 2003. Demographic data, indications for surgery, and preoperative and postoperative radiographic imaging data were recorded.

Results: A total of 46 megaureters (39 patients) were tapered and reimplanted. Average patient age at surgery was 4.0 years (range 5 months to 19 years). Indications for surgery included recurrent or breakthrough urinary tract infections, decreased renal function and increased hydroureteronephrosis. Mean followup was 3.9 years (range 4 months to 7 years). Postoperative voiding studies showed vesicoureteral reflux in 3 reimplanted ureters (7%). There was no evidence of obstruction on postoperative nuclear renal scans in any patient. Renal ultrasonography revealed improvement or resolution of hydroureteronephrosis in 29 reimplanted units (63%). In general, male patients, those operated on at a younger age and those with a lower preoperative grade of hydronephrosis were most likely to demonstrate improvement or resolution of hydronephrosis. The best results were seen in ectopic megaureters, followed in decreasing order by refluxing megaureters, megaureters associated with ureteroceles and primary obstructive megaureters.

Conclusions: Despite functional improvement on postoperative radiographic imaging, it is not uncommon to see persistent hydroureteronephrosis following excisional tapering and reimplantation of megaureters in childhood.