Right-to-left shunt secondary to duplicated superior vena cava as etiology of ischemic stroke
Imaging in Emergency and Critical Care Medicine

Right-to-left shunt secondary to duplicated superior vena cava as etiology of ischemic stroke

Ana Margarida Damas1, Gustavo Nobre de Jesus1,2, Paula Campos2,3, Isabel Moniz1, João Ribeiro1

1Serviço de Medicina Intensiva, Centro Hospitalar Universitário de Lisboa Norte, Lisboa, Portugal; 2Faculdade de Medicina de Lisboa, Lisboa, Portugal; 3Serviço de Imagiologia, Centro Hospitalar Universitário de Lisboa Norte, Lisboa, Portugal

Correspondence to: Gustavo Nobre de Jesus. Serviço de Medicina Intensiva, Centro Hospitalar Universitário de Lisboa Norte, Lisboa, Portugal. Email: Gustavo.jesus@chln.min-saude.pt.

Received: 19 September 2019; Accepted: 25 October 2019; Published: 13 December 2019.

doi: 10.21037/jeccm.2019.10.11


Duplication of superior vena cava (SVC) has an estimated prevalence of 0.3%. Incomplete regression of anterior cardinal vein can lead to persistent left superior vena cava (PLSVC) and is associated with chronic hypoxemia and predisposition to systemic embolization from right-to-left shunt. Blood drainage to the left atrium is extremely rare.

A 59-year-old male with type 4 pulmonary hypertension was admitted with diagnosis of ischemic stroke after withdrawal of systemic anticoagulation. Increased hypoxemia demanded invasive mechanical ventilation. Investigation confirmed embolization to the left medial cerebral artery and excluded conventional predisposing conditions to stroke. Deep vein thrombosis of lower limbs was excluded. CT scan after right side contrast injection showed pulmonary embolism (PE) and a duplication of SVC with filling of the four heart chambers and pulmonary arteries (Figure 1A,B). Left side upper body contrast injection confirmed a PLSVC, contrasting exclusively the left heart chambers (Figure 1C,D).

Figure 1 Coronal and axial views of CT scan. (A,B) Right side contrast injection showing pulmonary embolism (black arrow) and a duplication of SVC (white arrow) with filling of the four heart chambers and pulmonary arteries; (C,D) left side upper body contrast injection confirming a persistent left SVC (white arrow) with exclusive filling of the left heart chambers. SVC, superior vena cava.

We hypothesize that thrombus originating from the upper body migrated to cerebral arterial branches through the PLSVC and also to the pulmonary arteries, leading to the concurrent occurrence of stroke and PE. We believe that evidence of paradoxical embolization demands a search for PLSVC in cases where cardiac causes are excluded.


Acknowledgments

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Footnote

Conflicts of Interest: The authors have no conflicts of interest to declare.

Ethical Statement: The authors are accountable for all aspects of the work in ensuring that questions related to the accuracy or integrity of any part of the work are appropriately investigated and resolved. Written informed consent was obtained from the patient for publication of this manuscript and any accompanying images.

doi: 10.21037/jeccm.2019.10.11
Cite this article as: Damas AM, Nobre de Jesus G, Campos P, Moniz I, Ribeiro J. Right-to-left shunt secondary to duplicated superior vena cava as etiology of ischemic stroke. J Emerg Crit Care Med 2019;3:57.