Steering clear of the Chiari network pitfall in the transoesophageal echocardiography-guided transcatheter closure of patent foramen ovale

A 47-year-old woman with cryptogenic stroke was diagnosed with a patent foramen ovale (PFO), with grade III shunting on agitated saline study by transthoracic echocardiography. Transcatheter PFO closure was performed exclusively under transoesophageal echocardiography (TEE) guidance. Preprocedural TEE confirmed the PFO and incidentally observed the Chiari network (CN) traversing the PFO into the left atrium (LA). (Panel A, arrow = Chiari network). A 6F angiographic catheter (Cordis) and a 0.035-inch stiff guidewire were introduced into the right atrium through the femoral access. A 9F delivery sheath was advanced and exchange the catheter over the wire. The sheath’s blunt tip was aligned and pushed towards the right atrial side of the CN to retrieve the LA segment back to the right atrium (Panel B, arrowhead = delivery sheath). Following in situ repositioning of the sheath’s tip to align with the PFO, the guidewire and delivery sheath were successively advanced through the PFO into the LA (Panel C). An 18/25-sized PFO occluder (Abbott Medical) was then deployed, while maintaining the integrity of the CN within the right atrium (Panel D, Supplementary data online, Video S1–S4).