Kaspar C D W, Lo M, Bunchman T E, Xiao N
Virginia Commonwealth University, Division of Pediatric Nephrology, Richmond, VA, USA.
Virginia Commonwealth University, Division of Pediatric Nephrology, Richmond, VA, USA.
J Pediatr Urol. 2017 Oct;13(5):485.e1-485.e7. doi: 10.1016/j.jpurol.2017.03.020. Epub 2017 Apr 21.
Urinary tract dilation (UTD) is a commonly diagnosed prenatal condition; however, it is currently unknown which features lead to benign and resolving or pathologic abnormalities. A consensus UTD classification system (antenatal UTD classification, UTD-A) was created by Nguyen et al. in 2014 [1], but has not yet been validated.
To evaluate the ability of the UTD-A system to identify kidney and urinary tract (KUT) abnormalities, assess whether UTD-A can predict severity of KUT conditions, and perform a cost analysis of screening ultrasound (US).
A retrospective single-center study was conducted at an academic medical center. Inclusion criteria were: neonates in the well or sick nursery who had a complete abdominal or limited renal US performed in the first 30 days of life between January 01, 2011 and December 31, 2013. Data were collected on prenatal US characteristics from which UTD-A classification was retrospectively applied, and postnatal data were collected up to 2 years following birth.
A total of 203 patients were identified. Of the 36 abnormal postnatal KUT diagnoses, 90% were identified prenatally as UTD A1 or UTD A2-3. The remaining 10% developed postnatal KUT abnormalities due to myelomeningocele, such as VUR or UTD, which were not evident prenatally. Overall sensitivity and specificity of the UTD-A system was 0.767 (95% CI 0.577, 0.901) and 0.836 (95% CI 0.758, 0.897), respectively, when resolved UTD was counted as a normal diagnosis. Postnatal diagnoses differed by UTD-A classification as shown in the Summary fig. Of all the obstructive uropathies, 90.9% occurred in the UTD A2-3 class and none occurred in UTD-A Normal. Rate of postnatally resolved UTD was significantly higher in the UTD A1 group (78%) compared with UTD A2-3 (31%) or UTD-A Normal (12%, all P < 0.001). There was a notable trend towards more UT surgeries, UTI, and positive VUR among UTD A2-3 patients, but statistical significance was limited by a small number of patients.
This study found that the UTD-A classification system revealed important differences in the severity of UTD abnormalities. With repeated validation in larger cohorts, the UTD-A classification may be used to offer a prognosis for parents regarding prenatally diagnosed KUT conditions. Larger prospective studies should be designed to validate whether the UTD-A system can predict postnatal events related to UTD morbidity such as need for UT-related surgery or UTI.
尿路扩张（UTD）是一种常见的产前诊断疾病；然而，目前尚不清楚哪些特征会导致良性且可缓解的异常或病理性异常。Nguyen等人于2014年创建了一种共识性UTD分类系统（产前UTD分类，UTD-A）[1]，但尚未得到验证。
评估UTD-A系统识别肾脏和尿路（KUT）异常的能力，评估UTD-A是否能够预测KUT疾病的严重程度，并对筛查超声（US）进行成本分析。
在一家学术医疗中心进行了一项回顾性单中心研究。纳入标准为：2011年1月1日至2013年12月31日期间在出生后前30天内接受了完整腹部超声或有限肾脏超声检查的健康或患病新生儿重症监护室的新生儿。收集产前超声特征数据，据此回顾性应用UTD-A分类，收集出生后至2岁的产后数据。
共识别出203例患者。在36例产后KUT异常诊断中，90%在产前被诊断为UTD A1或UTD A2-3。其余10%因脊髓脊膜膨出导致产后KUT异常，如膀胱输尿管反流（VUR）或UTD，这些在产前并不明显。当将已缓解的UTD视为正常诊断时，UTD-A系统的总体敏感性和特异性分别为0.767（95%CI 0.577，0.901）和0.836（95%CI 0.758，0.897）。如汇总图所示，产后诊断因UTD-A分类而异。在所有梗阻性尿路疾病中，90.9%发生在UTD A2-3类，UTD-A正常类中无一例发生。UTD A1组产后UTD缓解率（78%）显著高于UTD A2-3组（31%）或UTD-A正常组（12%，所有P<0.001）。UTD A2-3患者中UT手术、UTI和VUR阳性的趋势较为明显，但由于患者数量较少，统计学意义有限。
本研究发现UTD-A分类系统揭示了UTD异常严重程度的重要差异。通过在更大队列中反复验证，UTD-A分类可用于为父母提供关于产前诊断的KUT疾病的预后信息。应设计更大规模的前瞻性研究，以验证UTD-A系统是否能够预测与UTD发病率相关的产后事件，如UT相关手术或UTI需求。
