title: Chiari network: a protective filter against pulmonary embolism in a case of polycythaemia.
abstract: The Chiari network, a net-like structure within the right atrium, has been described as an embryonic remnant of no clinical significance. Its role in facilitating paradoxical arterial embolic events and as a potential site for thrombus formation however, has been reported in the literature. This case illustrates the protective filter-effect of the Chiari network in a 79-year-old Caucasian man with an unknown diagnosis of polycythaemia rubra vera who presented with clinical signs and symptoms of deep vein thrombosis. Transoesophageal echocardiogram confirmed entrapment of a thrombus within the Chiari network, which was not visualised following treatment on repeat scanning 1 month later. Here the authors describe how the Chiari network may have prevented the occurrence of a fatal massive pulmonary embolism in a patient with a high pro-thrombotic tendency, and review the current literature regarding the action of this anatomic variant as risk factor or protector.
authors.affiliation: Department of Cardiology, Countess of Chester Hospital, Chester, UK.
authors.forename: Samya Gwen
authors.initials: SG
authors.lastname: Obaji
authors.forename: Robert
authors.initials: R
authors.lastname: Cooper
authors.forename: John
authors.initials: J
authors.lastname: Somauroo
mesh_terms: D000368:Aged; D000925:Anticoagulants / Q000627:therapeutic use; D015415:Biomarkers / Q000097:blood; D004452:Echocardiography; D004562:Electrocardiography; D006325:Heart Atria / Q000033:anatomy & histology*; D006801:Humans; D007866:Leg / Q000098:blood supply; D008297:Male; D011087:Polycythemia Vera / Q000150:complications* / Q000175:diagnosis; D011655:Pulmonary Embolism / Q000517:prevention & control*; D016306:Vena Cava Filters; D020246:Venous Thrombosis / Q000150:complications* / Q000175:diagnosis
chemical_list: D000925:Anticoagulants; D015415:Biomarkers