Eustachian valve, interatrial shunt, and paradoxical embolism

Abstract

Randomized clinical trials demonstrate that percutaneous closure of the patent oval foramen is a safe and effective treatment for secondary prevention of cryptogenic stroke in selected patients. The Eustachian valve is generally considered an incidental finding without any significant pathophysiological consequences in adults. However, a persistent Eustachian valve, particularly a prominent one, is significantly more prevalent in patients with patent oval foramen and cryptogenic stroke, and is associated with adverse outcomes following percutaneous closure. Therefore, the Eustachian valve may not be an incidental finding or an innocent bystander. By directing the blood flow from the inferior caval vein to the interatrial septum, the persistence of a Eustachian valve may prevent spontaneous closure of the oval foramen, and predispose to paradoxical embolism during adulthood. The Eustachian valve should be considered an adjunctive risk factor for paradoxical embolism in patients with patent oval foramen. Furthermore, the Eustachian valve has been included in several risk prediction models to identify patients at the highest risk of paradoxical embolism and such patients may benefit the most from an intervention.

Advances in the management of cardioembolic stroke associated with patent foramen ovale

“…For instance, exploratory analyses of existing trial data suggest that PFO closure may not be efficacious in patients with very small shunts, 160 and whether features of the eustachian valve can be used to inform clinical decision making and the risk of future stroke remains unknown. 51 An individual participant meta-analysis of the recent major RCTs is under way and will examine associations between morphological PFO biomarkers (including shunt size and presence of an ASA) and benefit of treatment. 132 Additionally, as PFO closure is a relatively modern therapy, the very long term stability of PFO closure devices remains unknown.…”

“…In the presence of a right-to-left shunt, these thrombi may pass directly from the right to the left side of the heart and enter the arterial system 4849. A large residual Eustachian valve may potentiate paradoxical embolism by directing a jet of blood toward the PFO, thereby increasing the likelihood of right-to-left passage as opposed to filtration through the pulmonary circulation 5051…”

“…The relation between other morphologic features (large residual Eustachian valve,51 biomarkers of left atrial dysfunction7475) and PFO pathogenicity or risk of recurrence after PFO associated stroke is unclear.…”

“…Further studies are also needed to determine which patients are most likely to benefit from PFO closure on the basis of individual patient level biomarkers. For instance, exploratory analyses of existing trial data suggest that PFO closure may not be efficacious in patients with very small shunts,160 and whether features of the eustachian valve can be used to inform clinical decision making and the risk of future stroke remains unknown 51. An individual participant meta-analysis of the recent major RCTs is under way and will examine associations between morphological PFO biomarkers (including shunt size and presence of an ASA) and benefit of treatment 132.…”

Pitfalls of Using Imaging Technique in the Presence of Eustachian Valve or Chiari Network: Effects on Right-to-Left Shunt and Related Influencing Factors

“…The prominent Eustachian valve or Chiari network (EV/CN) is one of the high-risk anatomic factors for PFO. It is not only associated with the cryptogenic stroke but also independently related to residual shunt and recurrent ischemic stroke even after PFO closure [ 2 , 3 ]. Therefore, accurate identification of PFO with prominent EV/CN is of great significance in decision-making in the management of the cryptogenic stroke.…”