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

后尿道瓣膜（PUV）是下尿路梗阻（LUTO）最常见的原因，在1 / 2/10000的男性中。产前超声特征包括巨囊、双侧输尿管肾盂积水、锁孔征和羊水过少。尽管结合这些超声特征的预测准确性有所提高，但产前检测具有挑战性，并且不是100%可靠。如果调查结果提示LUTO，应告知父母LUTO是终身慢性疾病，在产前和新生儿时期可能有很高的发病率和死亡率。在严重的情况下（羊水无），胎儿干预，如膀胱羊水分流（VAS）可能会提供，以防止出生后的肺部问题。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，三分之一的男孩会发展为终末期肾病（ESRD），最终需要透析或肾移植。因此，在高风险中心进行早期和多学科护理是必不可少的。产后及时超声、膀胱减压、持续的抗生素预防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vug的诊断确认后，根据患者的病情和个人偏好，可以考虑进一步的治疗，如瓣膜消融或低/高转移。尽管最近有基于专家共识和现有文献指导的指南和治疗建议，但支持证据的水平有限，提供者和机构之间的管理差异很大。鉴于基于超声特征的PUV的各种产前表现，提供者有责任提供知情和彻底的产前咨询，以及可能漏诊的后果，了解特定的产前超声特征如何转化为PUV患儿的预后是很重要的。该项目的目的是与一家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胎儿的孕妇与在SickKids医院随访的LUTO患儿进行匹配，以了解产前超声检查结果与已知的产后结局之间的关系。第二个目标将是审查因可能的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，并将其与有类似发现但继续妊娠的妇女进行匹配。这个项目让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”继续怀孕，或者根据孩子早期和长期结果（如ESRD）的特定超声特征，决定潜在的治疗方法（监测与产前干预）。

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.