MP54-05 THE FATE OF PRIMARY OBSTRUCTIVE MEGAURETER (POM): A PROSPECTIVE OUTCOME ANALYSIS OF 72 INFANTS

Abstract

INTRODUCTION AND OBJECTIVES: Previous studies have assessed risk factors for febrile urinary tract infection (fUTI) in pts with prenatal hydronephrosis (HN), identifying those with POM as being at the highest risk. We sought to examine data from a prenatal HN cohort to identify those with POM, in order to determine their fUTI, surgical intervention and spontaneous resolution rates. METHODS: POM pts were consecutively sampled from 200814 in a prospective fashion. Only those who had a VCUG to rule out VUR were included. Six a priori variables were studied: HN grade [low(I,II) vs. high(III,IV)], continuous antibiotic prophylaxis (CAP) use, gender, circumcision status, ureteral dilation ( 12mm) and tortuosity. fUTI was defined as a >100000 CFU/ml positive culture from a catheterized urine sample, with a fever 38 C. Univariate and multivariable analyses (cox proportional regression) for fUTI risk factors were carried out. Resolution trends by surgery and ureteral dilation were analyzed using Kaplan-Meier curves and log-rank tests. RESULTS: Mean and median pt age at 1st clinic visit were 3.4 3.9 and 2 mos (0-21). Median follow-up time was 2 years (6-60 mos). Overall, 21 of 72 infants (29%) developed a fUTI at a median age of 3 (mean1⁄46;1-24) mos. The majority were males (n1⁄464, 89%), and 21 (33%) were circumcised. High-grade HN was present in 63 (87%) pts and CAP was prescribed for 31 (43%). Univariate analysis is displayed in table 1. Cox regression identified uncircumcised males (HR1⁄45.7, p1⁄40.01) and lack of CAP (HR1⁄45.9, p1⁄40.01) as independent risk factors for fUTI. HN grade, ureteral diameter and tortuosity were not associated with higher fUTI rates. Pts who underwent surgery (n1⁄417, 20%) had a larger mean ureteral diameter vs. those treated conservatively (18 12 vs. 11 3mm, p<0.01). Kaplan-Meier curves showed that only 30% of surgical pts had resolution of their HN by 36 mos vs. 60% of those whose POM was managed conservatively (p1⁄40.04). CONCLUSIONS: Most POM infants developed fUTIs within the first 3 months of life. Circumcision and use of CAP significantly reduced fUTI rates in those pts. Ureteral diameter 12mm was significantly associated with a higher operation rate, but not with increased UTI rates as one would expect. Resolution of HN after tapered ureteral reimplantation may take longer than 3 years.