Abstract 2614: Thirty Five Percent of Children with Single Ventricle have Deep Venous Thromboses as Detected by Magnetic Resonance Venography
INTRODUCTION: Thrombotic events are a frequent complication in children with congenital heart disease undergoing staged palliative surgery and may preclude further cavopulmonary shunts. However, their true prevalence is unknown. In our institution, children are evaluated by cardiac MRI prior to the Glenn or Fontan procedure. The objective of this study was to determine the prevalence of venous thrombosis detected by magnetic resonance venography (MRV).
METHOD: A retrospective study of children with single ventricle undergoing 3-D contrast enhanced MRV at time of MRI was performed. The MRV were reviewed to document patency of the hepatic, IVC, SVCs, innominate, internal jugular, and subclavian veins by a pediatric radiologist and a cardiologist. Veins were classified as patent, completely occluded, partially occluded, or not seen. Results were compared with conventional venography and Ultrasound (US) performed within 3 months of the MRI when available.
RESULTS: A total of 23 patients had 29 MRV studies. Of these studies, 15 (52%) had a concomitant US, 11 (38%) a venography, and 4 (14%) both studies. MRV found that 8/23 children, 35% (95% CI 16%–57%) had at least 1 completely occluded vein and 61% (95% CI 39%– 80%) had at least 1 partially or completely occluded vein. Of all the veins per patient, 7% were occluded, 6% partially occluded and 74% patent by MRV. When analyzed by vessel, the most commonly thrombosed was the right subclavian vein, being partially occluded in 30% patients and completely occluded in 17%. In vessels which were imaged by 2 modalities, there was an 88% agreement of MRV with venography and 73% with US. All children were asymptomatic at the time of assessment.
CONCLUSION: One third of children with single ventricle had asymptomatic thrombosis by MRV. In patients who are already undergoing cardiac MRI, a late phase MRV is a useful non invasive method to screen for deep venous thrombosis.