Clinical case of successful thrombolysis in a newborn with thrombosis of the left renal vein

Thrombosis occurring in the neonatal period is a nosology with a large number of complications, often leading to disability and death. This article highlights the successful treatment of a newborn child with renal vein thrombosis using systemic thrombolysis. A clinical case of successful systemic thrombolysis in a full-term boy in the early neonatal period with thrombosis of the left renal vein and transition of the floating part of the thrombus to the inferior vena cava is presented. A child aged 3 days was admitted to the neonatal intensive care unit from a maternity hospital, where thrombosis was suspected. Gross hematuria was observed. Laboratory data revealed thrombocytopenia and increased levels of fibrinogen and D-dimer. Ultrasound showed a sharp increase in the volume of the left kidney, a diffuse change in its parenchyma, a sharp depletion of blood flow, and accumulation of fluid in the perinephric tissue on the left, and a thrombus was observed in the lumen of the left renal vein with the presence of a floating part extending into the inferior vena cava. Thrombolytic therapy with the drug alteplase was started in combination with an infusion of unfractionated heparin. Doses were selected based on coagulogram parameters. On day 2 of therapy, hematuria resolved. On day 4 of therapy, the alteplase infusion was completed, and heparin therapy was continued. On day 13, the child was switched to a low-molecular-weight-heparin therapy. Dynamic ultrasound revealed size reduction, recanalization and further thrombus lysis, and normalization of intrarenal blood flow and kidney size. No renal dysfunction was recorded during observation. The child was transferred to the further care unit at aged 14 days and was discharged home at the age of 25 days in satisfactory condition on ongoing anticoagulant therapy under outpatient supervision of a hematologist. During follow-up observation at aged 1.5 months of life, no clinical, laboratory, and ultrasound indicators of renal function disorders were noted. Currently, there are no approved recommendations and protocols for individual thrombosis in newborns, although this particular age group is due to the vulnerability of hemostasis to the development of a thrombotic process.