Posterior Urethral Valves (PUV) – from prenatal ultrasound features to postnatal outcomes

后尿道瓣膜（PUV）是男性下尿路梗阻（LUTO）的最常见原因，1-2/10000受影响的分娩。PUV的典型产前超声特征包括巨大膀胱、双侧输尿管肾积水、锁孔征和羊水过少。尽管结合这些超声特征的预测准确性增加，但产前检测具有挑战性，并且不是100%可靠。如果检查结果提示LUTO，则应告知父母LUTO是终身慢性疾病，在产前和新生儿期可能具有显著的发病率和死亡率。如果发现严重的结果（羊水过少），可能会提供胎儿干预措施，如膀胱羊膜分流术（VAS），以防止出生后肺部问题。大多数患有PUV的男孩会出现一定程度的膀胱功能障碍，据估计，三分之一的人会发展为终末期肾病（ESRD），最终需要透析或肾移植。因此，在高危中心进行早期和多学科护理至关重要。及时的产后超声检查、膀胱减压、持续的抗生素预防性治疗和随后的尿量监测是初始管理的关键点。在稳定和基于VCUG的诊断确认后，可以考虑进一步治疗，如瓣膜消融或低/高分流，这取决于患者的病情和个人偏好。虽然最近发表的指南和治疗建议是基于专家共识和现有文献的指导，但证据支持水平有限，供应商和机构之间的管理差异很大。鉴于PUV基于超声特征的产前表现各不相同，提供者有责任提供知情和全面的产前咨询以及可能漏诊的后果，因此了解特定的产前超声特征如何转化为PUV儿童的结局非常重要。 该项目的目的是与高风险三级胎儿中心（加拿大多伦多西奈山医院）合作，将携带疑似LUTO胎儿的孕妇与SickKids跟踪的LUTO儿童进行匹配，以了解产前超声检查结果与已知的产后结果之间的关系。第二个目的是审查由于可能的LUTO诊断而终止妊娠的妇女的产前超声特征以及尸检的胎儿，并将其与具有类似结果但继续妊娠的妇女相匹配。该项目使我们有机会改善这些家庭的产前咨询，因为我们将能够告诉他们“如果”他们继续怀孕或决定潜在的治疗（监测与产前干预），因为他们的孩子的早期和长期结果（例如ESRD）具有特定的超声特征。

Posterior urethral valves (PUV) are the most common cause of lower urinary tract obstruction (LUTO) in males with 1-2/10000 affected births. Prenatal ultrasound features typical of PUV include megacystis, bilateral hydroureteronephrosis, keyhole sign and oligohydramnios. Despite an increased predictive accuracy of combining these ultrasound features, prenatal detection is challenging and not 100% reliable. If the findings are suggestive of LUTO, parents should be told that LUTOs are life-long chronic conditions which may have significant morbidity and mortality rates in the prenatal and neonatal periods. In case of severe findings (anhydramnios), fetal interventions such as vesicoamniotic shunting (VAS) may be offered in an attempt to prevent pulmonary issues postnatally. Most boys with PUV will develop some degree of bladder dysfunction and it is estimated that one-third will develop end-stage renal disease (ESRD) and requires eventual dialysis or renal transplant. Hence, delivery at a high-risk center for early and multidisciplinary care is essential. Prompt postnatal ultrasound, bladder decompression, continuous antibiotic prophylaxis initiation and consequent monitoring of urine output are key points of initial management. After stabilization and VCUG-based confirmation of diagnosis, further treatments like valve ablation or lower/higher diversion can be considered, dependent on the patient’s condition and individual preferences. Although, there exist recently published guidelines and treatment recommendations based on expert consensus and guided by the available literature, the supporting level of evidence is limited and management between providers and institutions varies widely. Given the varied prenatal presentations of PUV based on ultrasound features, the responsibility of providers to give informed and thorough prenatal consultations and the consequences of a possible missed diagnosis, it is important to understand how specific prenatal ultrasound features translate into outcomes for children with PUV. The aim of this project is to partner with a high-risk tertiary fetal center (Mount Sinai Hospital, Toronto, Canada) to match pregnant females carrying fetuses with suspected LUTO to children with LUTO being followed at SickKids to understand how the prenatal ultrasound findings relate to the known postnatal outcomes. A secondary objective will be to review the prenatal ultrasound features of women who terminated their pregnancies due to a possible LUTO diagnosis as well as fetuses with autopsies, and match those to women with similar findings but continued their pregnancies. This project allows us the opportunity to improve prenatal counseling for these families as we will be able to tell them “what if” they continue the pregnancy or decide on potential treatment (surveillance vs. prenatal intervention) given specific ultrasound features with respect to early and long term outcomes (e.g. ESRD) in their child.