Systemic to pulmonary venous shunt in superior vena cava obstruction: MDCT angiography findings

Abstract

Occlusion of the superior vena cava (SVC) is a complication of malignant and benign diseases that compress, occlude, or invade the SVC, subsequently directing blood flow into collateral veins. SVC obstruction is associated with multiple venous collaterals. These include the azygos-hemiazygos, internal and lateral thoracic veins, intercostal veins and the vertebral venous plexus which all drain systemic veins from the upper extremities, head and neck into the right heart. Systemic-to-pulmonary venous shunts (SPVS) may occur in rare cases (1-9). These shunts drain systemic veins from the upper extremities, head and neck into the left heart. SPVS have been described as unusual collateral pathways that appear in SVC obstruction, and occasionaly have been detected in patients with lung cancer that obstructed the SVC (2). To the best of our knowledge, this is the second reported case of Budd-Chiari syndrome associated with SVC obstruction (10). Our case is interesting because it features two points that have not been previously emphasized: First, the majority of cases in this issue have lung cancer occluding the SVC; our patient had thrombus in the SVC due to coagulopathy. Second, systemic to pulmonary venous communication was illustrated using multidetector computed tomography (CT) angiography. Case reportA 43-year-old man was admitted to the hospital because of swelling of his face, neck and upper extremities which had started a month before. The patient also complained of progressive dyspnea and cough. He had been diagnosed with Budd-Chiari syndrome due to coagulopathy (protein C and S deficiency and homozygous factor V Leiden mutation) three months earlier. Physical examination revealed that the patient had a heart rate of 78/min, respiratory rate of 28/min, and blood pressure of 120/70 mmHg. Venous distension of the neck and upper thorax was recognized. Left jugular vein thrombosis was demonstrated by Doppler ultrasonography of the upper extremities. CT angiography was performed using a 16-row system (Lightspeed 16, GE Medical Systems, Milwaukee, Wisconsin, USA) to evaluate the possibility of pulmonary emboli. The exam was performed after the intravenous injection of 110 mL of ioversol (350 mgI/mL, Optiray; Tyco Healthcare, Pointe Claire, Quebec, Canada) through the right antecubital vein with a power injector at a rate of 4 mL/s. The scan was obtained 30 s after the start of injection. The scanning protocol was as follows: 1.25-mm slice thickness, a pitch of 1.375, reconstruction interval of 0.8 mm, 120 kV, 380 mA. Initially, there was no visible opacification of the main pulmonary artery and its branches (Fig. 1). The pulmonary veins, the left heart and aorta were intensely opacified before opacification of the right heart and the pulmonary artery. There were numerous strongly enhanced collaterals, abundant peripheral bridging veins and pleural enhancement in the right hemith- ABSTRACT Superior vena cava obstruction is associated with multiple venous collaterals. There is an unusual pathway involving pulmonary ...

Hypoxemia and Right-to-Left-Shunt in Patient with Antiphospholipid Syndrome: A Case Report with Multimodality Imaging Findings and Literature Review

“…The third interesting point is that this patient had a successful IVC and SVC dilatation and stenting with significant clinical improvement similar to one previous reported case [ 6 ]. The fourth point is that this case shows predominately central multiple mediastinal venous plexus collaterals around the bronchi, pulmonary arteries, and pulmonary veins resulting in early filling of central pulmonary veins with paucity of contrast in peripheral pulmonary veins unlike the other two reported cases [ 5 , 6 ]. Combinations of these diagnostic and therapeutic findings have not been reported in the previous two cases.…”

“…SVC obstruction associated with SPVS is usually caused by primary or secondary malignant processes [ 1 , 7 , 8 ]. However, it has been reported with other rare benign entities [ 5 , 6 , 9 ].…”

“…We present a case of antiphospholipid syndrome causing BCS with IVC and SVC thrombosis with progressive shortness of breath and hypoxemia due to SVC syndrome and SPVS. Upon extensive literature review, we found that this is the fourth reported case of BCS associated with SVC obstruction [ 5 , 6 , 10 ]. Two of these cases were associated with SPVS [ 5 , 6 ] and one was known to have antiphospholipid syndrome similar to our case [ 6 ].…”

“…Collateral venous channels are usually formed to restore venous return [ 1 – 4 ]. Systemic-to-pulmonary venous shunts (SPVS) might be developed in case of severe and long-standing SVC obstruction [ 5 – 9 ].…”