Systemic to pulmonary venous collaterals in adults with single ventricle physiology after cavopulmonary palliation

ObjectivesTo assess the frequency, anatomic characteristics, and associations of systemic to pulmonary venous collaterals in adult patients undergoing cardiac catheterization after a Fontan operation. Additionally, the embryologic basis for the presence of venous collaterals is reviewed.MethodsCardiac catheterization data was reviewed for 66 adults with single ventricle physiology and a Fontan palliation.ResultsThere were a total of 66 patients that underwent catheterization between 2004 and 2014 at the Ahmanson/UCLA Adult Congenital Heart Disease Center. There were 24 males and 42 females. Systemic venous to pulmonary venous collaterals were present in 38 patients (58%), most commonly originating from the right brachiocephalic vein (35%), azygous vein (20%) and superior vena cava (13%). Trans-catheter interventional closure was performed in 27/38 (71%) of patients with venous collaterals. At baseline these patients had lower oxygen saturation when compared to those not requiring intervention, 85.6% ± 6.1% vs 89.9% ± 5.4%, p < 0.05. At 6 months, the ambulatory systemic saturation improved from 85.6% ± 6.1% to 91.8% ± 6.4%, p < 0.05. At two years follow-up, the ambulatory systemic saturation had decreased to 90.5% ± 4.1% (p < 0.05).ConclusionIn adults with single ventricle physiology and prior Fontan surgery, systemic venous collaterals are common and can be percutaneously occluded at minimal risk with resultant improvement in systemic oxygen saturation on long term follow up. When evaluated from a developmental standpoint, 85% of collaterals are above the diaphragm and could be secondary to recanalization of the collateral veins, an embryological connection between systemic and pulmonary veins.