EARLY PROGNOSTIC VALUE OF SERUM CREATININE LEVELS IN CHILDREN WITH POSTERIOR URETHRAL VALVES

Purpose: We evaluated the prognostic value of serum creatinine level a t initial treatment for future renal function in children with posteri or urethral valves. Materials and Methods: We reviewed the records of 35 patients with posterior urethral valves presenting in the first yea r of life and treated initially at our institution between 1973 and 19 90 with valve ablation or vesicostomy. Initial assessment included ser um creatinine determination, urine culture, renal ultrasonography and voiding cystourethrography After 4 or 5 days of catheter bladder drain age renal ultrasound and serum creatinine measurement were repeated. A t the end of followup patients were divided into 2 groups according to glomerular filtration rate calculated by the Schwartz formula: group 1-69 ml. or less per minute per 1.73 m.(2) (median 15) and group 2-gre ater than 70 ml. per minute per 1.73 m.(2) (median 110). Median follow up was 102 months (8.5 years, range 50 to 219 months). Results: Mean s erum creatinine at diagnosis plus or minus standard deviation was 3.60 +/- 2.01 and 1.3 +/- 0.7 mg./dl. in groups 1 and 2, respectively (nor mal 0.1 to 0.6, p <0.01). Mean serum creatinine after catheterization was 2.4 +/- 1.1 and 0.6 +/- 0.2 mg./dl. in groups 1 and 2, respectivel y (p <0.01). Mean nadir creatinine during the first year of life was 1 .7 +/- 0.6 and 0.4 +/- 0.2 mg./dl. in groups 1 and 2, respectively (P <0.01). All differences were statistically significant. Linear regress ion analysis of creatinine after catheterization and glomerular filtra tion rate at last followup demonstrated a correlation coefficient of - 0.7 (p <0.01). Conclusions: Although it is well known that nadir creat inine in the first year of life correlates with prognosis, the correla tion of long-term renal function with creatinine at valve ablation or vesicostomy is more useful to the clinician. These data indicate that serum creatinine level 4 to 5 days after the initial diagnosis correla tes strongly with long-term renal function in children with posterior urethral valves.