Patent foramen ovale closure with the Intrasept occluder: Complete 6-56 months follow-up of 247 patients after presumed paradoxical embolism

Patent foramen ovale: Unanswered questions

The foramen ovale is a remnant of the fetal circulation that remains patent in 20-25% of the adult population. Although long overlooked as a potential pathway that could produce pathologic conditions, the presence of a patent foramen ovale (PFO) has been associated with a higher than expected frequency in a variety of clinical syndromes including cryptogenic stroke, migraines, sleep apnea, platypnea-orthodeoxia, deep sea diving associated decompression illness, and high altitude pulmonary edema. A unifying hypothesis is that a chemical or particulate matter from the venous circulation crosses the PFO conduit between the right and left atria to produce a variety of clinical syndromes. Although observational studies suggest a therapeutic benefit of PFO closure compared to medical therapy alone in patients with cryptogenic stroke, 3 randomized controlled trials (RCTs) did not confirm the superiority of PFO closure for the secondary prevention of stroke. However, meta-analyses of these RCTs demonstrate a significant benefit of PFO closure over medical therapy alone. Similarly, observational studies provide support for PFO closure for symptomatic relief of migraines. But one controversial randomized study failed to replicate the results of the observational studies while another two demonstrated a partial benefit. The goal of this review is to discuss the clinical conditions associated with PFO and provide internists and primary care physicians with current data on PFO trials, and clinical insight to help guide their patients who are found to have a PFO on echocardiographic testing.

Patent foramen ovale closure and medical treatments for secondary stroke prevention: a systematic review of observational and randomized evidence

BACKGROUND AND PURPOSE

Patients discovered to have a patent foramen ovale in the setting of a cryptogenic stroke may be treated with percutaneous closure, antiplatelet therapy, or anticoagulants. A recent randomized trial (CLOSURE I) did not detect any benefit of closure over medical treatment alone; the optimal medical therapy is also unknown. We synthesized the available evidence on secondary stroke prevention in patients with patent foramen ovale and cryptogenic stroke.

METHODS

A MEDLINE search was performed for finding longitudinal studies investigating medical treatment or closure, meta-analysis of incidence rates (IR), and IR ratios of recurrent cerebrovascular events.

RESULTS

Fifty-two single-arm studies and 7 comparative nonrandomized studies and the CLOSURE I trial were reviewed. The summary IR of recurrent stroke was 0.36 events (95% confidence interval [CI], 0.24-0.56) per 100 person-years with closure versus 2.53 events (95% CI, 1.91-3.35) per 100 person-years with medical therapy. In comparative observational studies, closure was superior to medical therapy (IR ratio=0.19; 95% CI, 0.07-0.54). The IR for the closure arm of the CLOSURE I trial was higher than the summary estimate from observational studies; there was no significant benefit of closure over medical treatment (P=0.002 comparing efficacy estimates between observational studies and the trial). Observational and randomized data (9 studies) comparing medical therapies were consistent and suggested that anticoagulants are superior to antiplatelets for preventing stroke recurrence (IR ratio=0.42; 95% CI, 0.18-0.98).

CONCLUSIONS

Although further randomized trial data are needed to precisely determine the effects of closure on stroke recurrence, the results of CLOSURE I challenge the credibility of a substantial body of observational evidence strongly favoring mechanical closure over medical therapy.

Patent foramen ovale: a comprehensive review for pulmonologists

PURPOSE OF REVIEW

A comprehensive review of the main concepts about patent foramen ovale (PFO) management is offered.

RECENT FINDINGS

PFO is a common, usually benign, anatomical variant that in the presence of a discrete right-to-left shunt and other predisposing factors (Eustachian valve/Chiari network, atrial septal aneurysm, and coagulation cascade abnormalities) may play an important role in the patho-physiology of paradoxical embolism at different levels (cryptogenic stroke, peripheral embolism, coronary embolism, etc.). Therapy is a controversial issue, since data on these patients are variable and accepted guidelines are missing. Recurrent strokes are the most diffuse and accepted indication for transcatheter closure of PFO, but severe refractory migraine with aura, unexplained oxygen desaturation, orthodeoxia-platypnea, and other conditions have been suggested to benefit from PFO closure. Different devices and techniques have been proposed for this procedure, mainly depending on operator experience and preferences, which have contributed to this intervention becoming a well tolerated and effective procedure with very low morbidity and virtually absent mortality.

SUMMARY

PFO management is still a debated field: indications, pathophysiology and ideal closure techniques remain to be fully clarified and investigated before considering PFO closure a routine procedure.

Biodisk: a new device for closure of patent foramen ovale: a feasibility study in swine

PURPOSE

To evaluate the feasibility, effectiveness, and safety of a porcine small intestinal submucosa (SIS)-covered Biodisk (BD) for the closure of patent foramen ovale (PFO) in swine.

METHODS

Twelve piglets (9-30 kg) with PFO ranging in size from 6 to 12 mm were used for the in vivo testing. The BD device consisted of two basic nitinol wire components covered with platinum coil, a flexible SIS-covered ring, and an anchor. The BD was advanced through an 8-Fr sheath from the femoral vein. Nine acute animals were used to test the BD for deployment, stability, immediate shunt closure, and device repositioning before or after its detachment. To assess retrievability, four devices were deployed and intentionally embolized into the RA (n = 2) and LA (n = 2). The effectiveness of the device was evaluated by angiocardiography. EKG was recorded before and after PFO closure for 3 hr. From the 12 animals, nine were acute and three were followed; one for 6 weeks, one for 12 weeks, and one for 16 weeks.

RESULTS

Successful device implantation was achieved in all animals with no shunting of contrast media observed during follow-up in. One animal needed to have device repositioned for complete PFO occlusion because of suboptimal placement at the first attempt. The device was easily placed and retrieved before detachment in all nine animals in the acute study. None of the BDs spontaneously embolized during release or on follow-up. EKG did not demonstrate arrhythmias during or after treatment. Four intentionally embolized BDs were easily retrieved with an Amplatz goose neck snare. Macroscopic and histologic evaluation of the three long-term animals showed that devices were well incorporated in the atrial septum with complete shunt closure. The SIS showed progressive remodeling with the host cells. There was also progressive endothelization of the BD device.

CONCLUSION

The BD device deployment is feasible, safe, and effective. Long-term studies are needed to evaluate its long-term effectiveness.

Patent foramen ovale and stroke

The presence of a patent foramen ovale has been found to be associated with an increased risk of ischemic stroke of otherwise unknown origin (cryptogenic stroke). The present article will review the evidence regarding this association, the technical aspects of PFO detection, and the preventive options to decrease the risk of recurrent cerebral events.

Patent foramen ovale and stroke: what should be done?

PURPOSE OF REVIEW

The role of a patent foramen ovale (PFO) as a risk factor for ischemic stroke has been established in recent years. However, the best therapeutic option to prevent recurrent events is still controversial, with antithrombotic treatment or transcatheter PFO closure being favored by different clinicians. Also, associated conditions that may guide the therapeutic choices are being investigated.

RECENT FINDINGS

The stroke risk associated with a PFO, mainly considered of importance in younger patients, has also been recognized and better defined in patients over the age of 55 years. The study of potential cofactors that may increase the possibility of paradoxical embolization through the PFO has made some progress and holds promises of allowing more informed and rational treatment choices in the future. More data have become available on the efficacy of transcatheter PFO closure.

SUMMARY

The approach to patients with PFO and ischemic stroke has been better defined in recent years. However, a better understanding of factors that increase the stroke risk in individuals with a PFO and the results from randomized treatment trials comparing medical treatment with PFO closure are needed to further advance the field.

Patent foramen ovale and cryptogenic stroke: a complex neuro-cardio-vascular problem

Patent foramen ovale has been suggested to be a risk factor for cryptogenic stroke by means of paradoxical embolism. The data, however, are complex, conflicting and largely unavailable. In this review, we attempt to summarize the existing data separately for the questions of whether patent foramen ovale is associated with cryptogenic stroke and whether it is a risk factor for a first ischemic stroke and for recurrent strokes. Treatment options will be discussed, and the different viewpoints from the two specialists mainly involved in the care of those complex patients (neurologists and cardiologists) will be provided.

Perforation of the aortic sinus after closure of atrial septal defects with the Atriasept occluder

Percutaneous atrial septal defect closure is routinely performed nowadays because of the ease of implantation as well as the low complication rate. The Atriasept ASD occluder is a low profile, double disc device; over the years several modifications have been made. We report two cases of aortic sinus perforation by the Atriasept ASD occluder (model 2007). Two asymptomatic patients, in whom the device was implanted, were noticed to have metal projecting into the aorta. Real-time fluoroscopy showed fractures of the outer metal ring with abnormal movement of one of the struts of the device. One patient is being conservatively managed and in the other the device was surgically removed due to the presence of a second ASD, which needed closure. Transesophageal echocardiography and fluoroscopy may be necessary to identify this potentially life-threatening complication of this device.

Late complications of transcatheter closure of patent foramen ovale: new technology and new outcomes

As a method to prevent recurrent paradoxical embolism and therefore cryptogenic stroke, catheter-based patent foramen ovale closure was first reported in 1992. Since then numerous different devices have been designed to prevent paradoxical embolism. The development of new devices has risen pretty rapidly. Currently, no device can be regarded as the gold standard. Prospective randomized trials comparing interventionalpatent foramen ovale closure with medical treatment are still lacking. The primary aim is to create a device which is easy to implant and able to prevent paradoxical embolism. Additional goals are to minimize early and late complications, such as thrombembolism, erosion of adjacent structures, thrombus formation or atrial arrhythmia. This review gives an overview of the data and the current literature regarding long-term complications (follow-up ≥ 1 month) after patent foramen ovale closure with current devices and presents the initial, midterm and late results after patent foramen ovale closure with newer devices.

Long-term outcome of transcatheter patent foramen ovale closure in patients with paradoxical embolism

BACKGROUND

Optimal management of patients with PFO and paradoxical embolic events is still debated. Moreover, data from long-term studies on large patient populations are lacking. Aim of the study is to assess immediate and long-term clinical outcome of patients with PFO and paradoxical thrombo-embolic events submitted to transcatheter PFO closure.

METHODS

Only patients with PFO-related transient ischemic attack or stroke underwent PFO closure. Patients were evaluated clinically and echocardiographically at 1, 6 and 12 months after the procedure and yearly thereafter. Primary endpoints were death, recurrent stroke or TIA. Residual right-to left shunt (RLS) was monitored by transthoracic echocardiography (TTE) or transcranial Doppler (TCD) at 6 months'follow-up.

RESULTS

202 consecutive patients underwent percutaneous PFO closure for secondary prevention of TE. Device migration was observed in one patient 24 h after the procedure. No cases of procedure-related death or stroke occurred during a median follow-up of 3+/-1.3 years. Three recurrent TIAs were observed within the first 6 months of follow-up. The cumulative estimated probability of recurrent TE-free survival rate after PFO closure was 99% in patients <or=55 years, 84% in patients >55 years (p<0.05) and 94% and 100% in patients with PFO, with or without atrial septal aneurysm (ASA), respectively (p<0.05). Of the 188 (93%) patients submitted to TTE or TCD at 6 months' follow-up, 8 (4%) presented a small RLS.

CONCLUSION

Transcatheter PFO closure is associated with low incidence of in-hospital complications and low frequency of recurrent TE at long-term follow-up.