Number 10-27: MR Angiography Revealing a Giant Systemic Venous Collateral
Case from: Bonello, B and Fraisse, A
CHU Timone Children's Hospital , Marseille , France
Case: Magnetic resonance imaging (MRI) is an imaging modality increasingly employed in the follow up of patients with congenital heart disease1. Contrast enhanced 3-D magnetic resonance angiography (MRA) can be useful to reveal undiagnosed lesions. We report the case of a systemic venous collateral channel revealed by MRA.
A 26 year old woman complained of worsening cyanosis in the setting of complex congenital heart disease: dextrocardia with situs inversus, interrupted inferior vena cava with hemiazygos continuation, right and left superior vena cava, double outlet right ventricle with unbalanced atrioventricular septal defect and pulmonary stenosis. A bidirectional bicavo pulmonary connection had been performed when she was 12 years old with the aim of connecting the majority of venous flow to the pulmonary arteries. Following this last palliative surgery, she remained stable with a transcutaneous oxygen saturation in the mid 90's for the next 10 years before developing progressive hypoxemia. Her transcutaneous oxygen saturation was 80 to 83% at presentation.
A cardiac MRI was performed. Systemic single ventricle and atrioventricular valve functions were normal (Movie 1). Pulmonary arteries were well developed. MRA was performed after injection at right foot vein level. It demonstrated enhancement of giant systemic venous collaterals originating from the infra-renal vena cava going thru the mesenteric venous system with a tortuous course and ultimately draining into the portal trunk (Figure 1). Cardiac output was within normal range with a net aortic anterograde flow at 2.6 l/min/m² (Figures 2 and 3).
Movie 1 Figure 1
Figure 2 Figure 3
Conclusion: To our knowledge, this is the first case reported with contrast enhanced 3-D MRA diagnosing systemic venous collaterals. The development of systemic venous collaterals is a well known complication after Fontan palliation causing cyanosis and ventricular dysfunction. Diagnosis is difficult and prediction sites must be carefully evaluated. Cardiac catheterization is typically the first line imaging modality to be used to look for venous collaterals and, if found, can be treated by embolization2. Nevertheless MRI is a non-ionizing method which plays an increasingly important role in the evaluation of complex congenital heart disease. It provides assessments of anatomic repair, ventricular function, and measurements of flow with good accuracy. As previously reported, MRA is useful for venous system and aorto-pulmonary collateral vessel evaluation3,4. Leg injection might be preferable for pulmonary arterial evaluation in patients with Fontan circulation1. In cases of an interrupted inferior vena cava, contrast injection from the upper extremity will be diluted by non-opacified (SVC) flow and will not allow sufficient pulmonary arterial enhancement. Our case demonstrates the usefulness of MRA in the detection of inferior vena cava collaterals in those patients.
The optimal timing of the contrast bolus should be considered because of the reduced blood circulation within the collateral system. In our case, first pass venous enhancement was optimized by observing enhancement on images reconstructed real time. Dynamic imaging was performed after enhancement of the portal trunk. MRI is an essential tool for the determination of cyanosis and also for guiding therapeutic management.
Following the MRI, a completion of cavo-pulmonary anastomosis with connection of the supra hepatic veins to the pulmonary arteries had been scheduled for the patient.
References: 1. Kilner PJ, Geva T, Kaemmerer H, Trindade PT, Schwitter J, Webb GD. Recommendations for cardiovascular magnetic resonance in adults with congenital heart disease from the respective working groups of the European Society of Cardiology.Eur Heart J. 2010;31(7):794-805.
2. Sugiyama H, Yoo SJ, Benson LN. Characterization and treatment of systemic venous to pulmonary venous collaterals seen after Fontan operation.Cardiol Young. 2003;13(5):424-30. 3. Mac Donald S, Emmanuel Y, Myerson S, Prendregast B, Neubauer S and Leeson P. Absent right superior vena cava.Multimodality imaging of upper body venous drainage via left-sided superior vena cava and azygos venous system.Circ Cardiovasc Imaging 2009;2 :34-e36. 4. Prasad SK, Soukias N, Hornung T, Khan M, Pennell DJ, Gatzoulis MA, Mohiaddin RH. Role of magnetic resonance imaging angiography in the diagnosis of major aortopulmonary collateral arteries and partial anomalous pulmonary venous drainage.Circ 2004;20;109(2):207-14.