Perelman School of Medicine, and, ‡Department of Epidemiology and Biostatistics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, †Department of Pediatrics, Division of Nephrology, and, §Department of Surgery, Division of Pediatric Urology, The Children's Hospital of Philadelphia, Philadelphia, Pennsylvania.
Clin J Am Soc Nephrol. 2014 Mar;9(3):499-505. doi: 10.2215/CJN.08700813. Epub 2013 Dec 5.
Approximately 20% of boys with posterior urethral valves develop ESRD; however, few factors associated with the risk of ESRD have been identified. The objective of this study was to determine if renal parenchymal area, defined as the area of the kidney minus the area of the pelvicaliceal system on first postnatal ultrasound, is associated with the risk of ESRD in infants with posterior urethral valves.
DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: A retrospective cohort of boys who were diagnosed with posterior urethral valves at less than 6 months of age between 1988 and 2011 and followed for at least 1 year at a free-standing children's hospital was assembled. Cox proportional hazard regression and Kaplan-Meier analysis were used to estimate the association between renal parenchymal area and time to ESRD. Cox models were adjusted for age at presentation, minimum creatinine 1 month after bladder decompression, and vesicoureteral reflux.
Sixty patients were followed for 393 person-years. Eight patients developed ESRD. Median renal parenchymal area was 15.9 cm(2) (interquartile range=13.0-21.6 cm(2)). Each 1-cm(2) increase in renal parenchymal area was associated with a lower risk of ESRD (hazard ratio, 0.64; 95% confidence interval, 0.42 to 0.98). The rate of time to ESRD was 10 times higher in boys with renal parenchymal area<12.4 cm(2) than boys with renal parenchymal area≥12.4 cm(2) (P<0.001). Renal parenchymal area could best discriminate children at risk for ESRD when the minimum creatinine in the first 1 month after bladder decompression was between 0.8 and 1.1 mg/dl.
In boys with posterior urethral valves presenting during the first 6 months of life, lower renal parenchymal area is associated with an increased risk of ESRD during childhood. The predictive ability of renal parenchymal area, which is available at time of diagnosis, should be validated in a larger, prospectively-enrolled cohort.
约 20%的后尿道瓣膜男孩会发展为终末期肾病（ESRD），但与 ESRD 风险相关的因素知之甚少。本研究旨在确定出生后第一个月超声检查中肾脏实质面积（定义为肾脏面积减去肾盂肾盏系统面积）是否与后尿道瓣膜婴儿发生 ESRD 的风险相关。
设计、设置、参与者和测量方法：收集了 1988 年至 2011 年间在一家独立儿童医院确诊为后尿道瓣膜且年龄小于 6 个月并至少随访 1 年的男孩的回顾性队列。使用 Cox 比例风险回归和 Kaplan-Meier 分析来评估肾脏实质面积与 ESRD 时间之间的关联。Cox 模型调整了发病年龄、膀胱减压后 1 个月的最低肌酐值和膀胱输尿管反流。
60 例患者共随访 393 人年。8 例患者发展为 ESRD。肾脏实质面积中位数为 15.9cm²（四分位距 13.0-21.6cm²）。肾脏实质面积每增加 1cm²，发生 ESRD 的风险就降低（风险比 0.64；95%置信区间 0.42-0.98）。肾脏实质面积<12.4cm²的男孩发生 ESRD 的时间率比肾脏实质面积≥12.4cm²的男孩高 10 倍（P<0.001）。在膀胱减压后第 1 个月最低肌酐值为 0.8-1.1mg/dl 时，肾脏实质面积可最佳区分发生 ESRD 的风险患儿。
在出生后 6 个月内出现后尿道瓣膜的男孩中，较低的肾脏实质面积与儿童期发生 ESRD 的风险增加相关。在更大的、前瞻性入组队列中应验证诊断时可获得的肾脏实质面积的预测能力。
