Subbiah Vivek, Parimi Prabhu
Department of Internal Medicine/Pediatrics, Case Western Reserve University School of Medicine, MetroHealth Medical Center, Cleveland, OH 44109, USA.
J Med Case Rep. 2008 Apr 10;2:106. doi: 10.1186/1752-1947-2-106.
Renal vein thrombosis, although rare in adults, is well recognized in neonates and is one of the most common manifestations of neonatal thromboembolic events. The etiology of renal vein thrombosis remains unidentified in the majority of cases. We report a case of renal vein thrombosis in a neonate associated with elevated maternal lipoprotein (a).
A full-term female infant, appropriate for gestational age, was born via spontaneous vaginal delivery to an 18-year-old primigravida. The infant's birth weight was 3680 g and the Apgar scores were eight and nine at 1 and 5 minutes respectively. Evaluation of the infant in the newborn nursery revealed a palpable mass in the right lumbar area. Tests revealed hematuria and a high serum creatinine level of 1.5 mg/dl. An abdominal ultrasound Doppler flow study demonstrated an enlarged right kidney, right renal vein thrombosis, and progression of the thrombosis to the inferior vena cava. There was no evidence of saggital sinus thrombosis. An extensive work-up of parents for hypercoagulable conditions was remarkable for a higher plasma lipoprotein (a) level of 73 mg/dl and an elevated fibrinogen level of 512 mg/dl in the mother. All paternal levels were normal. The plasma lipoprotein (a) level in the neonate was also normal. The neonate was treated with low molecular weight heparin (enoxaparin) at 1.5 mg/kg/day every 12 hours for 2 months, at which time a follow-up ultrasound Doppler flow study showed resolution of the thrombosis in both the renal vein and the inferior vena cava.
There have been no studies to date that have explored the effect of abnormal maternal risk factors on fetal hemostasis. A case-control study is required to investigate whether elevated levels of maternal lipoprotein (a) may be a risk factor for neonatal thrombotic processes. Although infants with this presentation are typically treated with anticoagulation, there is a lack of evidence-based guidelines. Treatment modalities vary between study and treatment centers which warrants the establishment of a national registry.
肾静脉血栓形成在成人中虽罕见，但在新生儿中却广为人知，是新生儿血栓栓塞事件最常见的表现之一。大多数情况下，肾静脉血栓形成的病因仍不明。我们报告一例与母亲脂蛋白（a）升高相关的新生儿肾静脉血栓形成病例。
一名足月女婴，适于胎龄，经自然阴道分娩出生，母亲为18岁初产妇。婴儿出生体重3680克，1分钟和5分钟时阿氏评分分别为8分和9分。在新生儿保育室对婴儿进行评估时，发现右腰区可触及肿块。检查显示血尿，血清肌酐水平高，为1.5毫克/分升。腹部超声多普勒血流研究显示右肾增大、右肾静脉血栓形成，且血栓蔓延至下腔静脉。无矢状窦血栓形成证据。对父母进行的广泛高凝状态检查显示，母亲血浆脂蛋白（a）水平较高，为73毫克/分升，纤维蛋白原水平升高，为512毫克/分升。父亲所有指标均正常。新生儿血浆脂蛋白（a）水平也正常。该新生儿接受低分子量肝素（依诺肝素）治疗，剂量为1.5毫克/千克/天，每12小时一次，持续2个月，此时超声多普勒血流随访研究显示肾静脉和下腔静脉血栓均已溶解。
迄今为止，尚无研究探讨母亲异常危险因素对胎儿止血的影响。需要进行病例对照研究，以调查母亲脂蛋白（a）水平升高是否可能是新生儿血栓形成过程的危险因素。尽管有这种表现的婴儿通常接受抗凝治疗，但缺乏循证指南。不同研究和治疗中心的治疗方式各异，这就需要建立一个全国性登记系统。
