Support for Use of PFO in Selected Cases to Access the Left Atrium During LAA Device Implantation

Benjamin Leis, MD,1 Jeff Booker, MD,2 and Payam Dehghani, MD2,,1 Division of Cardiology, Department of Medicine, University of Saskatchewan, Saskatoon, Canada;,,2 Prairie Vascular Health Network, University of Saskatchewan, Regina, Canada

EP Tips & Techniques

Support for Use of PFO in Selected Cases to Access the Left Atrium During LAA Device Implantation

Benjamin Leis, MD,¹ Jeff Booker, MD,² and Payam Dehghani, MD²

¹ Division of Cardiology, Department of Medicine, University of Saskatchewan, Saskatoon, Canada;

² Prairie Vascular Health Network, University of Saskatchewan, Regina, Canada

March 2019

Case Description

A 79-year-old male with paroxysmal atrial fibrillation, a high CHADS₂ score, and a history of intracranial hemorrhage on anticoagulation was referred to our center for left atrial appendage (LAA) closure with the WATCHMAN device (Boston Scientific). Pre-procedural transesophageal echocardiogram (TEE) showed significant lipomatous hypertrophy of the interatrial septum with maximal measurement of 26 mm and a 3 mm wide membranous portion of the septum as a potential target for transseptal puncture (Figure 1, Panel A).

After general anesthesia, standard techniques for performing transseptal puncture were deployed using a HeartSpan^® transseptal needle (Merit Medical). However, the desired membranous portion of the interatrial septum could not be targeted using TEE guidance. As the TEE identified a patent foramen ovale (PFO) periprocedure, a decision was made to use the PFO to access the LAA, which in this case was inferiorly directed. The double curve WATCHMAN access sheath and dilator were advanced over an extra-stiff wire to the LAA. The WATCHMAN delivery sheath and device were inserted with successful deployment into the LAA. Post insertion, the WATCHMAN device had an excellent sealing effect of the appendage with good positioning on anchor test (Figure 1, Panel C). There was no thrombus visualized or evidence of residual leak (Figure 1, Panel D).

Discussion

The WATCHMAN device is the only FDA-approved LAA closure device available for stroke prevention in Canada and the United States. Ways to troubleshoot unique anatomical variations during this procedure are worth describing to help maximize accessibility of this beneficial procedure to all patients.

Patent foramen ovale arise due to failure of septum primum flap closure over the fossa ovalis at birth; it is widely accepted that they occur in up to 25% of the general population. Given that PFO is typically located too cranial and anterior for optimal orientation of the delivery sheath into the LAA, accessing the left atrium through a PFO has historically been discouraged.¹ Nonetheless, success with this approach has been described with the PLAATO (percutaneous left atrial appendage transcatheter occlusion) device and Amplatzer Cardiac Plug (Abbott) on multiple occasions, most robustly in a recent single-center case series.² Our patient represents a rare reported case of LAA closure through a PFO with a WATCHMAN device.

We were successful given that our patient’s dominant lobe was inferiorly directed. This allowed us to intubate the os from a superior approach and remain aligned with the long axis of the main lobe (Figure 2, Panel B). Second, we used a double curve delivery sheath that allowed us to compensate for the anteriorly located PFO to arrive at the posteriorly located appendage (Figure 2, Panel A). Third, our patient’s primarily windsock appendage morphology allowed deeper intubation of the delivery sheath, which maintained long axis alignment. Indeed, a chicken wing appendage, particularly if retroflexed (superiorly-anteriorly directed), probably would have made deployment more challenging. The above anatomical complexities would help argue for more rigorous spatial imaging in the pre-operative phase, like computed tomography or magnetic resonance imaging, to help plan left atrial access when a PFO is present.

Although modern techniques have rendered life-threatening complications of interatrial septal puncture an uncommon occurrence, there remains a non-negligible risk of tamponade, aortic puncture, and paradoxical embolism during the procedure.³ Furthermore, although the majority of residual shunts close with time, up to 20% of septal punctures remain open after many months of follow-up.⁴ This is especially problematic in WATCHMAN patients who are not anticoagulated long term and in whom there may be a significant risk of ischemic stroke compared to warfarin.⁴

The prevalence of lipomatous hypertrophy of the interatrial septum is greater than 2%, and it is more prevalent with age and obesity.⁵ In the absence of a PFO, this LAA closure procedure would have been higher risk given the abnormal anatomy. However, in carefully selected patients, using the PFO can be a reasonable alternative to transseptal puncture in patients receiving a WATCHMAN device.

Disclosures: The authors have no conflicts of interest to report regarding the content herein.

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