Persistent pathology of the patent foramen ovale: a review of the literature

A patent foramen ovale (PFO) is an interatrial shunt, with a prevalence of 20-34% in the general population. While most people do not have secondary manifestations of a PFO, some reported sequelae include ischaemic stroke, migraine, platypnoea-orthodeoxia syndrome and decompression illness. Furthermore, in some cases, PFO closure should be considered for patients before neurosurgery and for patients with concomitant carcinoid syndrome. Recent trials support PFO closure for ischaemic stroke patients with high risk PFOs and absence of other identified stroke mechanisms. While PFOs can be associated with migraine with auras, with some patients reporting symptomatic improvement after closure, the evidence from randomised controlled trials is less clear in supporting the use of PFO closure for migraine treatment. PFO closure for other indications such as platypnoea-orthodeoxia syndrome, decompression illness and paradoxical embolism are based largely on case series with good clinical outcomes. PFO closure can be performed as a day surgical intervention with high procedural success and low risk of complications.

Interatrial shunts: technical approaches to percutaneous closure

INTRODUCTION

Interatrial shunt closure is considered the first-line therapy for congenital simple communications such as patent forame ovale (PFO), atrial septal defect (ASD), and post surgical interatrial communications.

AREAS COVERED

Anatomical, functional, and technical details useful for planning a transcatheter-based closure procedure are discussed as well as the available equipments and their use and the procedural routes and the specific closure techniques.

EXPERT COMMENTARY

Anatomical and functional details, appreciated at both pre-procedural and intraprocedural steps, are of paramount importance for planning interatrial shunts transcatheter - based closure procedures. Rims of the defects, borders of the fossa ovalis, presence and relevance of atrial septal aneurysm, persistence of Eustachian valve or cor triatriatum dexter, and interatrial septum hypertrophy or lipomatosis are all factors to be investigated when planning the procedure and selecting the device. Routes for interventions should include femoral, and eventually the jugular and hepatic vein approaches. Intraprocedural transoesophageal echocardiography (TTE) or intracardiac echocardiography (ICE) should be used at least in most complex cases to have the exact definition of the anatomy of the defects. Future developments of device material and imaging tools are expected to improve safety and long-term efficacy even in the most complex cases.

Transcatheters for closure of patent foramen ovales

INTRODUCTION

Nowadays patent foramen ovale (PFO) closure is considered clinically beneficial and even cost-effective over medical therapy in secondary prevention of stroke due to paradoxical embolism.

AREAS COVERED

In this review, the authors discuss both anatomical and technical details and constructive concepts of current devices used for PFO closure.

EXPERT COMMENTARY

Right atrial and interatrial septum anatomy is more complex than usually thought and a unique prosthesis that fits properly to all the possible morphologies is far from being designed. Existing devices can be classified into suture-like devices, metal disk occluders and mixed metal/tissue occluders depending on the mechanism of closure and the amount of metal/tissue components. Moreover, during recent years, nothing-behind technology has been introduced and will be closely watched as a future option.

Long-Term Contrast Echocardiography and Clinical Follow-Up after Percutaneous Closure of Patent Foramen Ovale Using Two Different Atrial Septal Occluder Devices

INTRODUCTION

Percutaneous patent foramen ovale (PFO) closure by means of a septal occluder device (SOD) is a well-known therapeutic strategy for the secondary prevention of paradoxical embolic neurological events. The aim of this study was to provide long-term echocardiographic and clinical follow-up data on patients who had undergone percutaneous PFO closure with 2 different SOD.

METHODS

We selected 2 groups of patients treated with 2 different SOD: Group A: 52 patients with an Amplatzer(®) PFO Occluder and Group B: 49 patients with a Figulla Flex(®) device. All patients underwent follow-up Bubble Test Transthoracic Echocardiography (BTTE) and clinical examination. The results were compared with those recently reported in a group of patients with similar characteristics, but that had been treated conservatively, which acted as a control group.

RESULTS

The mean follow-up after PFO closure was 53 months. The Amplatzer(®) PFO Occluder and the Figulla Flex were used in 52 (51.5%) and 49 (48.5%) of patients, respectively. We found no significant difference in the rate of effective PFO closure between the devices: Amplatzer 91.4%, Figulla 93.9% (P = 0.71). One patient (1.0%) suffered a recurrent neurologic event. BTTE was positive (BTTE+) in 8 patients (8%), 5 with an Amplatzer, and 3 with a Figulla device (P = 0.516). Only 1 patient with BTTE+ had a recurrent TIA (12.5%). No significant relationship was found between device dimensions and BTTE+ (P = 0.062). In the control group (163 patients), the recurrence of neurologic events was 9.2% (15 events), that was significantly higher in respect to the patients who had undergone percutaneous closure of the PFO.

CONCLUSIONS

Percutaneous PFO closure was associated with a remarkably low risk of recurrent embolic neurological events, and no long-term device-related major complications. No statistically significant difference emerged between the 2 different SODs regarding BTTE positivity. Long-term follow-up showed that the recurrence of neurological events has been significantly higher in the group treated in a conservative way.

Percutaneous implantation of a second device in patients with residual right-to-left shunt after patent foramen ovale closure

INTRODUCTION

The management of patients with residual right-to-left shunt (rRLS) after percutaneous patent foramen ovale (PFO) closure is debated. The aim of this study was to define the incidence of moderate-to-large rRLS and to report the feasibility, safety and long-term clinical outcome of transcatheter closure of rRLS.

METHODS AND RESULTS

From June 2000 to March 2013, 322 subjects underwent percutaneous PFO closure. In 39 patients (12.1%) with moderate-to-large rRLS on transcranial Doppler (TCD) and/or transesophageal echocardiogram a second cardiac catheterization was performed with the aim of completing the closure. A second closure device was implanted in 21 patients (53.8%). In the remaining 18 (46.2%), a second device was not delivered for the following reasons: in 13 (72.2%) no residual passage could be crossed, in 5 (27.8%) the residual shunt was deemed to be negligible. No complications occurred. After the second procedure, complete closure was proved by TCD in 16/21 (76.2%) subjects. One patient received a third device. During follow-up (41 ± 19 months), no cerebrovascular ischemic accidents occurred.

CONCLUSION

A second percutaneous PFO occlusion device can be safely implanted in patients with significant rRLS. However, a moderate-to-large rRLS on TCD and/or TEE may not necessarily represent a significant risk of further paradoxical embolization.