Pediatric and Congenital Heart Disease Session 6: Pediatric and Congenital Cases
4 - Right superior vena cava obstruction with “normal” drainage via left superior vena cava: a case of the Warden procedure, demonstrated by 4D flow
Saturday, February 15, 2020
8:29 AM – 8:36 AM
Location: Salon J2
Description of Clinical Presentation: A 17-year-old male with right-sided partial anomalous pulmonary venous return (PAPVR) presented to the clinic after being lost to follow-up for 11 years. He had undergone the Warden operation with placement of intracardiac baffle and translocation of right superior vena cava (RSVC) at 3 years of age. No surgical sequelae was reported. He is asymptomatic and plans to enlist into the military. An echocardiogram demonstrated normal biventricular size and function. The anastomosis of the RSVC to the right atrial appendage could not be visualized. Images from the suprasternal notch also suggested the presence of a previously unrecognized left superior vena cava (LSVC). Cardiac magnetic resonance (CMR) was thus performed to clarify his systemic and pulmonary venous anatomy.
Diagnostic Techniques and Their Most Important Findings: CMR was performed using a Siemens 1.5T scanner assisted by respiratory compensation and ECG-gating. The following image sequences were obtained: cine, 2D phase contrast, contrast enhanced MR angiography (MRA), self-navigated 3D steady-state free precession (3D SSFP), and four-dimensional (4D) flow. Gadolinium-based contrast was administered intravenously at 0.1 mmol/kg for MRA. Cine imaging demonstrated normal right ventricular size and function. The pulmonary to systemic flow ratio was 1:1 by the 2D phase contrast. 3D SSFP (Figure 1) and MRA demonstrated severe stenosis across the RSVC anastomosis to the right atrial appendage. Several venous collateral vessels were also noted. Additionally, an LSVC with intact bridging vein was noted draining into the coronary sinus (Figure 2). 4D flow imaging was performed following contrast administration with FOV = 380 x 180 mm2, matrix = 160 x 77, slice thickness = 2.75 mm, TE = 2.19 ms, TR = 37.9 ms, VENC = 200 cm/sec, flip angle = 15°, and PAT = 2. Total acquisition time was just under 8 minutes. Arterys (Arterys Inc., San Francisco, CA) provided cloud-based post-processing of 4D flow data. Visualization of the vasculature with dynamic flow imaging (Figure 3) clearly demonstrated the “functionally normal” systemic venous drainage. Minimal flow was noted across the RSVC anastomosis; instead, systemic venous flow was routed across the bridging vein into the LSVC, through the coronary sinus into the right atrium. The pulmonary venous drainage was normal with no evidence of obstruction.
Learning Points from this
Case: The Warden procedure is a potential surgical option for right-sided PAPVR, with RSVC obstruction being a known complication. Clinical manifestations of RSVC obstruction may be offset by decompressing veins such as LSVC connecting into the coronary sinus. This case demonstrates how the routine use of 4D flow CMR can serve as an important diagnostic tool in visualization of systemic and pulmonary venous flow, for both preoperative and postoperative evaluation.