Michel B Walsdorff MD,BA, Presenter: Nothing to Disclose

Fred E. Avni MD, PhD, Abstract Co-Author: Nothing to Disclose

Aniq Rumy, Abstract Co-Author: Nothing to Disclose

Renal vein thrombosis (RVT) is a well documented illness in children. It is the most common, non catheter induced thrombosis in neonates. However, previous case reports suggest that RVT may also occur in utero. RVT can be found both in an acute or a sequelar form in the antenatal or early postnatal period. The aim of this study was to clarify the predisposing factors, diagnostic criteria, and prognosis of fetal RVT (fRVT) in a large series of patients.

Cases of possible fRVT detected during antenatal or early postnatal ultrasound were identified retrospectively from multiple centres from 1991 to 2007. Diagnosis was confirmed on basis of ultrasound and computed tomography features as classically described. Clinical outcome and long term imaging findings were analyzed.

Eleven subjects were diagnosed with fRVT: 7 during the antenatal and 4 in the postnatal period. 64% had at least one predisposing factor. Typical imaging features (direct visualisation of thrombus, increased renal volume, and hyperechoic streaks) were found in 64% of cases. Associated findings included adrenal hemorrhage and vena cava thrombosis. Acute signs included renal enlargement, increased echogenicity, and loss of corticomedullary differentiation. Sequelar forms showed thin, well defined, and calcified-like interlobular streaks.Outcome was favorable in all but 1 patient.

Ultrasound enables to diagnose fRVT and differentiate the acute stage from the sequelar one. Our study suggests that patients with sequelar streaks tend to have a good prognosis.

To provide the most accurate imaging tools for identifying fRVT and analyze its outcome in a large series of patients.

Walsdorff, M, Avni, F, Rumy, A, Fetal Renal Vein Thrombosis: Diagnostic Criteria and Outcome.  Radiological Society of North America 2011 Scientific Assembly and Annual Meeting, November 26 - December 2, 2011 ,Chicago IL. http://archive.rsna.org/2011/11016096.html