Renal vascular thrombosis in the newborn

Abstract

Neonatal renal vascular thrombosis is rare but has devastating sequelae. The renal vein is more commonly affected than the renal artery. Most neonates with renal vein thrombosis present with at least one of the three cardinal signs, namely, abdominal mass, macroscopic hematuria and thrombocytopenia, while unilateral renal artery thrombosis presents with transient hypertension. Contrast angiography is the gold standard for diagnosis but because of exposure to radiation and contrast agents, Doppler ultrasound scan is widely used instead. Baseline laboratory tests for platelet count, prothrombin time, activated partial thromboplastin time and fibrinogen concentration are essential before therapy is initiated. Maternal blood is tested for lupus anticoagulant and anticardiolipin antibody. Evaluation for prothrombotic disorders is warranted when thrombosis is clinically significant, recurrent or spontaneous. Management should involve a multidisciplinary team that includes neonatologists, radiologists, pediatric hematologists and nephrologists. In addition to supportive therapy, recent guidelines recommend at least prophylactic heparin therapy in the majority of cases to prevent thrombus extension. Thrombolytic therapy is reserved for bilateral thrombosis compromising kidney function. Long-term sequelae, such as kidney atrophy, systemic hypertension and chronic kidney disease, are common, and follow-up by pediatric nephrologists is recommended for monitoring of kidney function, early detection and management of hypertension and chronic kidney disease.

Sequential sonographic features in neonatal renal vein thrombosis

“…At this stage gray-scale ultrasound may demonstrate a thrombus within the renal vein and the IVC because the clotting process originates in the small renal vein and progresses into the main renal vein, ultimately reaching the inferior vena cava. The thrombus extends to the inferior vena cava in about 50% of cases and adrenal hemorrhage is a complication in 15% of cases [1,8]. Adrenal hemorrhage occurs occasionally as a result of an occlusion of the adrenal vein and may be recognized ultrasonically [4].…”

“…Renal vein occlusion due to thrombosis is a potentially fatal condition in neonates [1,2]. It is responsible for 10 to 20 percent of all thrombotic manifestations in the neonatal period [3][4][5].…”

“…It is responsible for 10 to 20 percent of all thrombotic manifestations in the neonatal period [3][4][5]. Neonates are more susceptible to renal vein thrombosis (RVT) due to immaturity of the hemostatic system, small vessel diameter and underlying diseases [1,6,7].…”

Arterial hypertension and unusual ascending aortic dilatation in a neonate with acute kidney injury: mechanistic computer modelling

“…The patient developed acute kidney injury with oligoanuria and hematuria needing peritoneal dialysis by day 5 of life, which was continued for 9 days. This treatment was based on sudden onset anuria, macrohematuria, hypertension, bilaterally large kidneys on ultrasound with high resistive indices exceeding 1 (normal 0.7-0.8, (Bude et al, 1992)) and low blood flow in the apparent patent renal veins, as well as transient thrombocytopenia, the diagnosis of bilateral renal vein thrombosis was assumed, although no thrombus was seen in the vena cava (Resontoc & Yap, 2016). Dialysis was stopped because the patient regained sufficient urinary output.…”

Thrombosis of Bilateral Renal Veins, Inferior Vena Cava, and Superior Sagittal Sinus with Adrenal Hemorrhage in a Neonate

“…N eonates are more predisposed to thrombosis than older children because of low levels of anticoagulants (antithrombin III, protein C and S) and fibrinolytic component (plasminogen). 1,2 Risk factors for thrombosis in neonates include vascular catheters, birth asphyxia, dehydration, sepsis, acidosis, polycythemia, gestational diabetes mellitus (GDM), cyanotic heart diseases, inherited thrombophilia (deficiency of protein C, protein S, and antithrombin III), and acquired thrombophilia [placental transfer of antiphospholipid antibodies (APLA) and maternal autoimmune disorders. 1,3,4 Renal vein thrombosis (RVT) is the commonest noncatheter related thrombosis in neonates 2,3 and can lead to longterm renal impairment.…”