Superior Vena Cava Syndrome Associated with Right-to-Left Shunt through Systemic-to-Pulmonary Venous Collaterals
A 54-year-old woman presented with intermittent swelling of the face and arms. Her past surgical and medical history included pleurodesis for recurrent left-sided pleural effusions and Factor V Leiden deficiency disorder, for which she was taking warfarin. This was further complicated by recurrent hypercoagulable events including deep venous thrombosis and pulmonary embolisms. On examination, her body temperature was 36.8℃, heart rate was 94 beats per minute, blood pressure was 132/68 mm Hg, and respiratory rate was 18 breaths per minute. Clinical examination also revealed bilateral lung basal crackles, and prominent engorged vasculature in the neck and anterior chest wall.\nMultidetector computed tomographic (MDCT) venography of the chest was performed. Coronal reformation images (), maximum-intensity-projection images (), and volume-rendered images () demonstrated complete chronic SVC obstruction () with numerous resultant paravertebral and chest wall venous collaterals (), representing the involvement of lateral thoracic and paravertebral collateral pathways. In addition, a few patent left-sided pleuro-pulmonary venous collaterals () extending from the chest wall, crossing the pleura and lingular lobe, and finally draining into the left superior pulmonary vein were seen, and this finding was consistent with the presence of systemic-to-pulmonary venous collateral pathway (SPVC) and bridging subpleural pulmonary veins.\nSince our patient had complete chronic SVC occlusion resulting in the formation of right-to-left systemic-to-pulmonary venous collaterals, a coexisting hypercoagulable state, and deep vein thrombosis, subsequent lifelong anticoagulation with warfarin was initiated to reduce the risk of stroke. Angioplasty or stenting of the SVC was not recommended, because the SVC occlusion was secondary to a hypercoagulable state, rather than due to external compression, which in most cases, is due to malignancy. Due to the presence of extensive collaterals, embolization of the venous collaterals was not performed, and the patient was discharged after symptomatic improvement.