The Covert Impact of Chiari Network and Eustachian Valves on Stroke

Background: The role of Chiari network (CN) and Eustachian valves (EVs) in cardioembolic strokes is still unclear. There is inconsistency in the literature regarding clinical approach to these lesions to reduce stroke risk. We aimed to describe clinical presentation, neuroimaging and cardioimaging features, as well as management approaches for CN and EV in stroke context. Review Summary: A systemic search was carried out using PubMed and Web of Science following PRISMA guidelines, Supplemental Digital Content 1 (http://links.lww.com/NRL/A123). We retrieved 4 case-control studies, 2 cross sectional studies as well 8 case reports, with a total of 883 patients with a mean age of 44.6 years (+/- 13.8). The combined prevalence of EV/CN in stroke-related patent foramen ovale (PFO) patients was 50% (95% CI: 31-68). With isolated prevalence for EV and CN of 43% (95% CI: 25-63), 18% (95% CI: 12-25), respectively. Patients with history of stroke had higher prevalence of EV/CN compared with controls odds ratio=2.45 (95% CI: 1.2-5, P<0.01). All case-control and cross-sectional studies defined EV/CN by transesophageal echocardiography or intracardiac cardiography. In the 8 case reports, 7 cases were diagnosed by transesophageal echocardiography, while only 1 case was diagnosed postmortem. Conclusion: EV/CN are relatively common findings in stroke patients with PFO. While it appears that presence of EV/CN with a PFO increases the risk of cardioembolic stroke, they remain underrecognized. EV/CN should be considered as high-risk PFO features. There is a scarcity of research emphasizing their role in clinical decision making, especially PFO closure and antithrombotic therapy choice.