Sonography of renal venous thrombosis in neonates and infants: can we predict outcome?

The relationship between sonographic features of renal venous thrombosis (RVT) and outcome has not been described in a large series of patients. To analyze sonographic findings of RVT and their evolution in a large series of patients and to attempt to identify features that might predict outcome. Retrospective analysis of sonograms and medical records of neonates and infants diagnosed with RVT during the period 1998-2007. Of 22 children (mean age: 3 days; age range: 0–107 days), RVT was bilateral in 12. Of 34 affected kidneys, thrombus in the main renal vein was seen in 17 and typical RVT sonographic findings without main renal vein thrombus were seen in the remaining 17. All children had US follow-up (range: 0.6–97.2 months). Three children with bilateral RVT died. Nine kidneys atrophied. Imaging findings associated with subsequent kidney atrophy included markedly reduced perfusion at diagnosis, subcapsular collections, patchy cortical echotexture and profoundly hypoechoic and irregular renal pyramids. Six patients (eight kidneys) presented with renal calcifications on initial sonogram before 7 days of life, suggesting antenatal RVT. Sonography is useful in neonatal and early infant RVT and might help predict renal atrophy. Antenatal RVT appears to be relatively common.