Medical Care
Most patients with a patent foramen ovale (PFO) as an isolated finding receive no special treatment. No consensus exists on treatment of PFO in patients with transient ischemic attack (TIA) or stroke.
When PFO is associated with an otherwise unexplained neurologic event, traditional treatment has been antiplatelet (ie, aspirin) therapy alone in low-risk patients or combined with warfarin in high-risk individuals to prevent cryptogenic stroke. [9, 17] With administration of warfarin, the international normalized ratio (INR) is maintained at 2-3. Consultation with a neurologist is mandatory to direct this treatment.
The recurrence rate of stroke or TIA has been reported to be as high as 3.4-3.9% per year.
In patients with atrial septal aneurysm and PFO, the risk of first recurrent stroke within 2 years has been reported to be as high as 9%, whereas the rate of subsequent stroke or TIA recurrence within 2 years increases to 22%.
In a study that evaluated the antiplatelet effects of clopidogrel and aspirin in 140 patients who underwent interventional PFO/atrial septal defect (ASD) closure, Polzin et al reported a 71% incidence of high on-treatment platelet reactivity (HTPR) to clopidogrel but only a 4% HTPR for aspirin. [18] Of the 12 complications noted, 9 were bleeding events (including 3 major bleeding events) and the remaining 3 were TIAs. The investigators noted that despite the high incidence of HTPR to clopidogrel in this patient population, there were no reports of stroke or thrombus formation on the occluder. [18]
Surgical Care
Surgical closure
Surgical closure of patent foramen ovale (PFO) with double continuous suture has resulted in elimination of residual shunt across the PFO.
Indications include the following:
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PFO more than 25 mm in size
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Inadequate rim of tissue around the defect
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Percutaneous device failure
Advantages include the following:
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Permanent closure of the defect
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Prevents future paradoxical emboli
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No long-term anticoagulation and its risks
Disadvantages include the following:
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Open-heart surgery
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Hospital stay for a few days
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The usual risks of cardiac surgery
Percutaneous care
Percutaneous closure of PFO during cardiac catheterization is an emerging therapeutic option.
Indications
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Recurrent cryptogenic stroke due to presumed paradoxical embolism through PFO failure of conventional drug therapy
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Contraindications to anticoagulant treatment
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Alternative to medical therapy or surgical closure - Cryptogenic transient ischemic attack (TIA) due to presumed paradoxical embolism through a PFO
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Presumed paradoxical peripheral or coronary embolism through PFO
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Cryptogenic stroke, TIA, or peripheral or coronary embolism due to presumed paradoxical embolism through a PFO that is associated with hypercoagulability state, [19] such as (1) divers with a PFO who are at risk of clinical events that are related to paradoxical embolism through a PFO during decompression, (2) those with systemic deoxygenation due to right-to-left shunting through a PFO in the absence of severe pulmonary hypertension (eg, platypnea orthodeoxia, right ventricular infarction), (3) those with migraine headache accompanied by aura, and (4) those with posttraumatic fat embolism syndrome with cerebral embolism by way of PFO.
Long-term follow-up (40.2 ± 11.0 y) in 301 patients who underwent percutaneous PFO closure following cryptogenic stroke or TIA demonstrated the procedure to be safe and effective, with a low incidence of procedural complications and recurrent neurovascular events. [19]
The Federal Drug Administration (FDA) has approved 2 percutaneous devices for PFO closure. The CardioSEAL Septal Occlusion System is a double umbrella-shaped permanent implant. It is made up of metal framework to which polyester fabric is attached. The CardioSEAL implant is available in sizes 17 mm, 23 mm, 28 mm, and 33 mm.
The Amplatzer PFO Occluder is a self-expanding wire mesh with double discs. It contains inner polyester fabric patches that, along with the wire mesh, cause the formation and accumulation of a blood clot, which seals the opening. After the device is in place, tissue will grow over it, and the device then becomes a part of the atrial septum.
The procedure requires a hospital stay of 24-48 hours and prophylactic aspirin or warfarin for 6 months following the procedure. After more than 5 years of follow-up observation, the results are promising.
Although hypertrophy and lipomatosis of the interatrial septum have been considered contraindications for transcatheter PFO closures, a study by Rigatelli et al suggests that this is not always the case. [20] The authors investigated outcomes in 10 patients with PFO who, owing to multiple recurrent stroke events (9 patients) or to the need for a posterior cerebral operation (1 patient), underwent transcatheter PFO closure, despite the presence of hypertrophy or lipomatosis of the rim of the fossa ovalis.
Following intracardiac echocardiography assessment and measurements, a 25-mm Amplatzer device was implanted in 2 patients in the Rigatelli study, and a 25-mm Premere Occlusion System device was implanted in 8 patients. On mean follow-up (36.6 months), 2 patients were found to have a small residual shunt. During this period, however, none of the patients experienced stroke recurrence, aortic erosion, or device thrombosis. The investigators concluded that in patients with hypertrophy or lipomatosis of the fossa ovalis rim, safe and effective PFO closure may be attainable, at least in the absence of severe atrial septal aneurysm, if rim thickness is carefully evaluated with intracardiac echocardiography, and if soft and asymmetrical opening devices are used.
Midterm results of interventional closure of patent foramen ovale with the third-generation Occlutech Figulla Flex II Occluder in patients who suffered from cryptogenic stroke, TIA, or paradoxical peripheral embolism appear to show the device and its delivery system to be safe. [21] Of 57 patients who had suffered from a thromboembolic event of unknown cause and underwent transcatheter PFO closure with the device, over 94% had sufficient closure without residual right-to-left shunt at 6 months follow-up and 3 patients had only minimal residual shunt. There were no major periprocedural or inpatient complications, nor any thrombotic formations related to the device, although one patient each had atrial fibrillation or a recurrent cerebral ischemic event (TIA). [21]
In a single-center study of 201 patients who underwent transcatheter closure of interatrial communications (IAC) using the Cera and the CeraFlex Occluder, occlusion was successful in 183 patients (94.3%), with no reports of death, embolization, or major complications. [22] Although immediate postimplantation occurrence of small residual shunts was noted in 8 patients, these resolved after 3 months.
Complications
Complications of catheter-based closure of patent foramen ovale (PFO), such as embolism of device, device entrapment within the Chiari network, frame fracture, vessel damage, or perforation of atrial wall, may require further surgery. Other possible complications include air embolism during device delivery, thrombus formation around the device, and infective endocarditis.
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This 2-dimensional echocardiogram in an infant (subcostal long-axis view) shows a patent foramen ovale. Right atrium (RA) and left atrium (LA
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Color Doppler of the patent foramen ovale (PFO) seen in the previous image. A small amount of left-to-right flow is present. This left-to-right flow pattern is typical for PFO seen in newborn infants
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Color Doppler of the patent foramen ovale (PFO) seen in the previous image. A small amount of left-to-right flow is present. This left-to-right flow pattern is typical for PFO seen in newborn infants
