Case Reports / Journal of Clinical Neuroscience 21 (2014) 1257–1258

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Successful endovascular repair of an unusual right-to-left shunt
presenting with cerebral ischemia q
Nicholas L. Zalewski a, Elizabeth A. Coon a, Frank Cetta Jr. b, Nathaniel W. Taggart b, Kelly D. Flemming a,⇑
a
b

Department of Neurology, Mayo Clinic, 200 First Street SW, Rochester, MN 55902, USA
Department of Pediatric Cardiology, Mayo Clinic, Rochester, MN, USA

a r t i c l e

i n f o

Article history:
Received 7 October 2013
Accepted 13 November 2013

Keywords:
Cardioembolic stroke
Pulmonary arteriovenous fistula
Right-to-left shunt
Vertical vein

a b s t r a c t
Ischemic stroke due to congenital cardiopulmonary vasculature anomalies is rare in adults. We report a
54-year-old man with a stroke due to a unique right-to-left shunt who underwent successful endovascular treatment. This patient developed acute onset of right arm weakness with facial droop and aphasia
which improved after intravenous thrombolysis. An MRI showed acute cerebral ischemia in the left middle cerebral artery and left posterior cerebral artery distribution. The patient developed recurrent stroke
symptoms during agitated saline injection while undergoing a transthoracic echocardiogram which
showed right-to-left shunting. Chest CT scan and conventional angiography revealed near occlusion of
the superior vena cava. Head and upper limb venous return drained via a large left vertical vein into
an anomalous left pulmonary vein into the left atrium. He underwent endovascular surgery to relieve
the superior vena cava obstruction and to occlude the source of right-to-left shunt. While rare, congenital
cardiopulmonary vascular anomalies may result in ischemic stroke in adults. CT angiography may be necessary to evaluate cardiopulmonary vasculature when right-to-left shunting is discovered on echocardiography in the setting of ischemic stroke. With large right-to-left shunts, agitated saline should be
avoided.
Ó 2014 The Authors. Published by Elsevier Ltd. All rights reserved.

1. Introduction
A cardioembolic source is present in approximately 30% of
ischemic strokes. In young adults, cardioembolic stroke may be
attributed to a right-to-left shunt, most commonly an atrial septal
defect (ASD) or patent foramen ovale (PFO) [1]. In adults, causes of
a right-to-left shunt other than a PFO include pulmonary arteriovenous fistulas and anomalous systemic venous return such as a
persistent left superior vena cava with connection to the left atrium [2–5]. We present an adult patient with an ischemic stroke
due to a unique cardiopulmonary vasculature anomaly which
was successfully repaired endovascularly.

2. Case presentation
A 54-year-old right-handed man with hypertension and a past
history of an atrial-septal defect repaired at age 5 developed
sudden onset of right-sided arm weakness with right facial droop,
dysarthria, and aphasia. Initial head CT scan was negative for hemorrhage. He was administered intravenous tissue plasminogen
activator 1 hour after symptom onset with near resolution of his
symptoms. The following morning he experienced immediate
worsening of his dysarthria with right face and arm weakness during injection of agitated saline for a transthoracic echocardiogram.
His symptoms resolved within 30 minutes.
MRI of the brain showed a linear area of restricted diffusion in
the left middle cerebral artery distribution and a small focus of restricted diffusion in the left posterior cerebral artery distribution.
With a cardioembolic mechanism suspected due to his symptoms
q
This is an open-access article distributed under the terms of the Creative
Commons Attribution-NonCommercial-No Derivative Works License, which permits non-commercial use, distribution, and reproduction in any medium, provided
the original author and source are credited.
⇑ Corresponding author. Tel.: +1 507 774 4741; fax: +1 507 266 4419.
E-mail address: flemming.kelly@mayo.edu (K.D. Flemming).

during agitated saline in echocardiogram, the radiographic stroke
appearance, and minimal vascular risk factors, unfractionated heparin was initiated for anticoagulation. He was then transferred to
our institution for further evaluation.
A chest CT angiogram and transesophageal echocardiogram
without agitated saline were obtained revealing several anomalies
(Fig. 1A, B). The right superior vena cava (SVC) was subtotally occluded. The right head and neck veins drained via a left innominate
vein drained into a large left-sided vertical vein, which also drained
an anomalous left upper pulmonary vein. The vertical vein entered
a dilated, tortuous fistula in the left lower lobe of the lung. The fistula primarily drained into the left atrium creating a significant
right-to-left shunt. Upper extremity ultrasound showed no evidence of a venous clot.
The patient underwent endovascular repair of his anomalous
circulation and right-to-left shunting. Balloon dilatation of the
stenotic right SVC was performed followed by placement of a
Transhepatic Biliary Stent (PALMAZ GENESIS; Cordis, Bridgewater,
NJ, USA). Once normal flow was re-established in the SVC, the left
innominate vein was entered and an occluder device (Amplatzer
Vascular Plug II; St Jude Medical, St Paul, MN, USA) was placed in
the left vertical vein just distal to the junction of the anomalous left
pulmonary vein. This resulted in a return of normal systemic
venous flow with only a small residual left-to-right shunt due to
the anomalous pulmonary vein (Fig. 1C). His arterial oxygen
saturation rose from a baseline of 88% to 95% at the end of the
procedure. He was discharged the following day on clopidogrel
and aspirin therapy.
At 6 weeks posthospitalization the patient had a National
Institutes of Health Stroke Scale score of 0 and was clinically doing
well.
3. Discussion
This case demonstrates an adult patient with an ischemic stroke
due to right-to-left shunting from an unusual cardiopulmonary

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Case Reports / Journal of Clinical Neuroscience 21 (2014) 1257–1258

Fig. 1. (A) Angiography of the cardiac and great vessels and (B) diagram demonstrating the preoperative configuration of the venous anomaly. Due to the superior vena cava
(SVC) occlusion, injection of dye into the SVC resulted in filling of the innominate and vertical vein to an anomalous pulmonary vein and fistula draining into the left atrium.
(C) Angiography demonstrating the stent after placement in the stenotic SVC and a normal flow of dye into the right atrium when injected into the SVC. LA = left atrium,
LV = left ventricle, RA = right atrium, RV = right ventricle.

vasculature anomaly. He had a subtotal occlusion of his SVC with
venous drainage from his head and upper extremities predominantly passing to the left atrium through a left vertical vein to an
anomalous pulmonary vein. The vertical vein and anomalous pulmonary vein were felt to be congenital; however, the SVC occlusion
and subsequent development of the fistula were likely acquired.
The patient was successfully treated with endovascular repair.
Other cardiopulmonary anomalies have been described in
adults associated with left-to-right shunt and stroke, not due to
an ASD or PFO. These include persistent left SVC and arteriovenous
fistulas [2–5].
While these are uncommon causes of stroke in adults, they
should be considered if right-to-left shunting is noted on echocardiography without obvious ASD or PFO. CT angiography and/or
conventional angiography should be considered. When a large
right-to-left shunt is noted, agitated saline should be avoided to
prevent paradoxical air emboli. In addition, intravenous lines
should be filtered [6].
Patients should be referred to centers where pediatric and adult
cardiology, pulmonary, and neurology expertise is available to
determine the best treatment options.
http://dx.doi.org/10.1016/j.jocn.2013.11.016

Conflicts of Interest/Disclosures
The authors declare that they have no financial or other conflicts of interest in relation to this research and its publication.

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