Purpose: Renal vein thrombosis (RVT) is a rare cause for pediatric surgical consultation. The purpose of this study is to review the Montreal experience in the 1990s with RVT.
Methods: A retrospective chart review was conducted from 1990 through 1999.
Results: Twenty-three cases were identified by Duplex ultrasound scan. Mean length of follow-up was 42 months. Eighty-three percent (83%) of cases were diagnosed within the first month of life. In utero thrombosis was suspected in 22% and was associated with caval thrombosis and factor V Leiden. Known risk factors were present in 87%. The "diagnostic triad" of flank mass, gross hematuria, and thrombocytopenia was present in only 13% at the time of diagnosis. Long-term renal function impairment was detected in 100% of those who did not receive heparin, and in 33% of those who did receive heparin. No patient required dialysis. One patient required nephrectomy for recurrent pyelonephritis.
Conclusions: RVT occurs more commonly than anticipated. Because the "classic" triad of signs usually is absent at presentation, the presence of either a flank mass, hematuria, or thrombocytopenia in a patient with risk factors should prompt investigation for RVT. Factor V Leiden is a risk factor for in utero RVT. Anticoagulation improves renal outcome. Patients with RVT require long-term follow-up.