UPPER-TRACT CHANGES AFTER TREATMENT OF POSTERIOR URETHRAL VALVES

This paper discusses the long-term sequelae in the upper urinary tract with respect to hydroureteronephrosis (HUN), vesicoureteral reflux (V UR), renal parenchymal disease, and their correlation with renal funct ion in 84 boys with posterior urethral valves followed for 1 to 21 yea rs. Thirty-one boys (39.3%) were adolescents or older at the time of r eview. The incidence of high-grade VUR (grade III or more) was 47.6% a t presentation, and resolution following decompression of the lower ur inary tract occurred in 38.7% of refluxing units. VUR was associated w ith a high incidence of chronic renal failure (CRF) (30%) on long-term follow up; however, 16% of non-refluxing patients also progressed to CRF. The incidences of renal parenchymal disease and persistent upper- tract dilatation in the non-refluxing group were 25% and 50% of renal units respectively. Gross HUN persisted in 12.3% of patients despite d ecompression and reconstructive surgery, with vesicoureteral junction (VUJ) obstruction being documented in 1 patient only. Moderate and mil d upper-tract dilatation persisted in 31.6% and 43.9% of patients, res pectively. Persistent gross HUN was associated with a very high incide nce of CRF (92.3%), while 88.4% of those with persistent mild/moderate dilatation maintained normal renal function over a follow-up period r anging from 1 to 21 years. This study emphasizes the need for systemat ic evaluation to exclude VUJ obstruction and abnormal urodynamics as a cause of persistent HUN so that effective therapy can be instituted e arly to relieve back-pressure and to provide a low-pressure reservoir with effective emptying. In the absence of either of these causes, per sistent ureterectasis after treatment is presumably due to secondary p eristaltic failure as a consequence of ureteral fibrosis, ureteral tor tuosity, or developmental dysplasia.