PROXIMAL URINARY-DIVERSION IN THE MANAGEMENT OF POSTERIOR URETHRAL VALVES - IS IT NECESSARY

Purpose: In infants with posterior urethral valves in whom renal funct ion fails to normalize following decompression of the lower urinary tr act supravesical urinary diversion is customarily recommended for pres umed concomitant ureterovesical junction obstruction, We determined th e true incidence of fixed or permanent ureterovesical junction obstruc tion and the renal prognosis for infants treated with proximal urinary diversion, Materials and Methods: We evaluated 26 patients with poste rior urethral valves treated with supravesical urinary diversion. Mean gestational age at birth was 35 weeks (range 27 to 40). After initial decompression via an indwelling catheter for a median of 7 days (rang e 4 to 18) persistently high serum creatinine was present (median 2.5 mg./dl., range 1.9 to 3.5). One month after proximal. urinary diversio n median creatinine was 1.3 mg./dl. (range 0.5 to 2.8). At 1 year, med ian nadir creatinine was 1.0 mg./dl. (range 0.3 to 2.5). At reconstruc tion a Whitaker test in all 26 patients (52 renal units) demonstrated fixed ureterovesical junction obstruction in 2 units (4%). Results: Re nal biopsy in 44 of the 52 renal units (85%) revealed renal dysplasia. At a median followup of 9 years (range 1 to 14) end stage renal disea se developed in 11 patients (42%). Conclusions: In neonates with poste rior urethral valves who undergo proximal urinary diversion fixed uret erovesical junction obstruction is rare, renal biopsy invariably demon strates areas of renal dysplasia and end stage renal disease frequentl y develops despite proximal diversion. These findings lead us to quest ion the necessity of supravesical urinary diversion.