Cerebrovascular emboli related to pulmonary venous thrombosis after lung transplantation

Transesophageal Echocardiographically-Confirmed Pulmonary Vein Thrombosis in Association with Posterior Circulation Infarction

Pulmonary venous thromboembolism has only been identified as a cause of stroke with pulmonary arteriovenous malformations/fistulae, pulmonary neoplasia, transplantation or lobectomy, and following percutaneous radiofrequency ablation of pulmonary vein ostia in patients with atrial fibrillation. A 59-year-old man presented with a posterior circulation ischemic stroke. ‘Unheralded’ pulmonary vein thrombosis was identified on transesophageal echocardiography as the likely etiology. He had no further cerebrovascular events after intensifying antithrombotic therapy. Twenty-eight months after initial presentation, he was diagnosed with metastatic pancreatic adenocarcinoma and died 3 months later. This report illustrates the importance of doing transesophageal echocardiography in presumed ‘cardioembolic’ stroke, and that potential ‘pulmonary venous thromboembolic’ stroke may occur in patients without traditional risk factors for venous thromboembolism. Consideration should be given to screening such patients for occult malignancy.

Lack of evidence for pulmonary venous thrombosis in cryptogenic stroke: a magnetic resonance angiography study

BACKGROUND

Even after extensive evaluation, the etiology of ischemic stroke remains undefined in a considerable proportion of cases, suggesting that causes of stroke may exist that have not yet been established. We tested the hypothesis that pulmonary venous thrombosis (PVT) is a potential source of brain embolism in patients with cryptogenic stroke.

SUMMARY OF REPORT

Within 7 days after mild to moderately severe ischemic stroke or transient ischemic attack, 18 patients (9 women, 9 men; mean age, 48 years) were studied in whom the etiology remained undefined despite complete workup. All patients received high-resolution pulmonary venography with the use of multiple-bolus, multiphase, 3-dimensional, gadolinium-enhanced MR angiography (MRA). Overall quality of the MRA was good in 14 and insufficient in 4 patients, mainly as a result of breathing artifacts. Visualization of the main and segmental veins and evaluability of their patency were good for most right pulmonary veins but often inadequate for left pulmonary veins, particularly for those in the left lower lobe. There was no evidence for PVT in any of the sufficiently visualized pulmonary veins.

CONCLUSIONS

The results do not support the hypothesis of PVT as a contributor to the etiology of ischemic stroke. However, the study was limited regarding scan volume, spatial discrimination, patient selection, and delay between ischemia and MRA. Therefore, further investigations, including postmortem studies, are needed to resolve the question of whether PVT may contribute to ischemic stroke.