A total of 127 consecutive patients (mean age 46.6±12.2years; 71% female) were referred to our center for percutaneous closure of defects of the atrial septum between January 2008 and December 2010. In accordance with the department's protocol, all patients were assessed by TEE prior to the procedure. Inclusion criteria for ASD closure were QP/QS >1.5, right chamber dilatation, and previous cryptogenic stroke or transient ischemic attack (TIA). Indications for PFO closure were a history suggestive of paradoxical embolism in patients with imaging evidence of multiple ischemic foci or previous cryptogenic stroke or TIA.

All patients with cryptogenic stroke or TIA and suspicion of paradoxical embolism underwent prior neurological assessment.

TEE was performed on a GE Vivid 7 scanner (General Electric Corp., Norfolk, VA, USA) with the microbubble test and Valsalva maneuver under local anesthesia. A diagnosis of PFO was established if microbubbles were observed passing into the left chambers in the three cardiac cycles following opacification of the right chambers. The following anatomical criteria indicating high risk for paradoxical embolism were also assessed: atrial septal aneurysm (defined as excursion of at least 10mm beyond the septal plane), prominent Eustachian valve, wide or long tunnel (length≥12mm) and the presence of spontaneous shunt.

ICE studies were performed using an 8F AcuNav catheter (manufactured by Siemens Medical Solutions and distributed by Biosense Webster). This has a 64-element transducer (5.5–10MHz) with tissue penetration of 1–15cm and all Doppler functions (tissue, continuous, pulsed and color). ICE study began by advancing the catheter under fluoroscopic guidance up to the mid right atrium with a 15–30° clockwise rotation (termed ‘home view’), which enables visualization of the tricuspid valve, atrium and right ventricle (Figure 1.1). The Eustachian valve can be observed by slightly withdrawing the catheter to the inferior right atrium (Figure 1.2). In the home view, and with the catheter directed towards the tricuspid valve, a 30–45° clockwise rotation enables visualization of the right ventricular outflow tract and the aortic valve (Figure 1.3). The anterior septum can be observed in this view with a further slight clockwise rotation (Figure 1.4). The transducer is directed towards the interatrial septum (IAS) by tilting the catheter posteriorly (Figure 1.5), in order to visualize the septum, coronary sinus and pulmonary veins, depending on the precise location of the transducer (septal view). After locking the distal tip of the catheter in this position, other views are possible by anterior-posterior and left-right rotation. The superior vena cava and its relation to the IAS can be visualized by advancing the catheter superiorly and the superior and inferior extension of the IAS can be observed, corresponding to long-axis view in TEE. The catheter is locked in this position, and then rotated clockwise until it is located proximally to the tricuspid annulus and inferior to the aortic valve. In this view, tilting the transducer to the right enables visualization of the aortic valve in short-axis view and the anterior IAS (Figure 1.6).

Figure 1.

Views obtained by intracardiac echocardiography in a patient with patent foramen ovale. AD: right atrium; AE: left atrium; VD: right ventricle; VT: tricuspid valve; AO: aorta; TSVD: right ventricular outflow tract.

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ASD diameter, IAS length and rim dimensions were measured in various planes. Rims were defined as deficient when measuring less than 5mm (for the aortic rim) and less than 7mm for the remainder.

Prophylactic antibiotic therapy (cefuroxime 750mg) was administered intravenously 1hour before the procedure and unfractionated heparin (70U/kg) during the intervention. All patients began dual antiplatelet therapy (aspirin 100mg and clopidogrel 75mg) the evening before, clopidogrel being continued for one month and aspirin for six months in patients with ASD. In the case of PFO, aspirin was prescribed according to the neurologist's recommendation (usually for an indefinite period).

ICE was the only imaging technique used to guide device positioning and implantation. The procedure began with puncture of both femoral veins, an 8F introducer being inserted in the right femoral vein for right catheterization, replaced when necessary by a 10F or 12F introducer for device implantation. A 24-cm 8F introducer was inserted in the left femoral vein for the ICE transducer.

Based on ICE findings, the operators selected one of the following: an Amplatzer PFO occluder, Cribriform occluder, or ASD occluder (AGA Medical Corporation), Occlutech Figulla PFO and ASD occluder, Solysafe septal occluder (Swissimplant AG), or Premere Closure System (St. Jude Medical). After passing a 0.35-in.×260-cm guidewire and positioning a 6F multipurpose catheter at the ASD, it was replaced by an Amplatzer Super Stiff guidewire, which was introduced up to the left superior pulmonary vein. The selected device's delivery sheath was then positioned and the guidewire withdrawn. After advancing the device up to the ASD, the distal disc was released in the left atrium and the sheath withdrawn. Under simultaneous fluoroscopic and ICE guidance, the entire device was positioned by releasing the proximal disc in the right atrium. Once good apposition and absence of residual shunt or additional defects had been confirmed, the device was finally deployed. Any devices seen to be malpositioned were withdrawn and repositioned.

Procedure and fluoroscopy times and length of hospital stay were analyzed.

Figure 2 shows a case of ASD closure with a 22-mm Amplatzer ASD® device.

Figure 2.

Atrial septal defect closure guided by intracardiac echocardiography: (1) visualization of defect; (2) color Doppler showing left-to-right shunt at the level of the defect; (3) balloon measurement estimating diameter of 19mm; (4) device delivery sheath with guidewire in the left superior pulmonary vein; (5) initial positioning of the device and release of the distal disc in the left atrium; (6) release of the proximal disc in the right atrium; (7) color Doppler showing absence of residual shunt; (8) deployment of device. AE: left atrium; AD: right atrium; AO: aorta; AP: pulmonary artery; CIA: atrial septal defect; VPSE: left superior pulmonary vein. Filled arrow: Amplatzer® device; unfilled arrow: measuring balloon; dashed arrow: device delivery sheath.

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All patients underwent clinical, electrocardiographic and transthoracic echocardiographic reevaluation at discharge, one month, three, six and twelve months after implantation to exclude residual shunt (defined as very mild if the color Doppler jet width was <1mm, mild if 1–2mm, moderate if 2–4mm and severe if >4mm),10 device malposition or other complications. TEE was also performed in patients with residual shunt or large ASDs (>25mm).

There was one case of right femoral hematoma in the immediate postprocedural period, resolved by compression and monitoring, which prolonged hospital stay by 24hours.

During a mean follow-up of 16±10months, three patients presented mild residual shunt (confirmed by TEE). There was one case of transient cardiac rhythm disturbance in a 28-year-old woman who developed junctional rhythm in the third month following the procedure; subsequent 24hour Holter monitoring showed no recurrence of arrhythmias and the patient remains asymptomatic. Another patient had a stroke six months after PFO closure, but there was no evidence of residual shunt, confirmed by TEE after injection of agitated saline. There was no case of device embolization, aortic erosion or device thrombosis.