Explantation of Patent Foramen Ovale Closure Devices

Some Practical Points About Patent Foramen Ovale Conditions that May Not Be Covered in the Rest of the Book

This introductory article provides many key lessons that I have learned in my 23 years of studying patent foramen ovale (PFO). It discusses issues related to the diagnosis, clinical presentation, and treatment of PFO.

Petechial Rash and Glomerulonephritis: First Presentation of Endocarditis on a Patent Foramen Ovale Closure Device

Patent foramen ovale device closure is rarely associated with complications. This case report is believed to be the first description of a patient with infective endocarditis of a patent foramen ovale closure device presenting as glomerulonephritis. This article serves to educate as to this rare device complication and its unusual presentation. (Level of Difficulty: Intermediate.).

Patent Foramen Ovale and Cryptogenic Stroke: Integrated Management

Patent foramen ovale (PFO) is a common cardiac abnormality with a prevalence of 25% in the general population. PFO has been associated with the paradoxical embolism causing cryptogenic stroke and systemic embolization. Results from clinical trials, meta-analyses, and position papers support percutaneous PFO device closure (PPFOC), especially if interatrial septal aneurysms coexist and in the presence of large shunts in young patients. Remarkably, accurately evaluating patients to refer to the closure strategy is extremely important. However, the selection of patients for PFO closure is still not so clear. The aim of this review is to update and clarify which patients should be considered for closure treatment.

Outcomes of Patent Foramen Ovale Transcatheter Closure: Should a Short Aortic Rim Preclude Closure?

Background

The risk of erosion of an atrial septal closure device, in particular the Amplatzer Septal Occluder, has been described as higher in patients with a short aortic rim. Similar concern has been applied to patent foramen ovale (PFO) closure devices, but there are only rare reported cases of erosion. It may be that smaller devices are chosen due to fear of device erosion in PFO patients when this is not necessarily an issue.

Objectives

The authors aimed to assess outcomes after PFO closure with the Amplatzer PFO device in patients with a short (<9 mm) aortic rim.

Methods

We performed a retrospective analysis of PFO closure for any indication, between 2006 and 2017 at a quaternary center. Preprocedural transesophageal echocardiographic parameters including the aortic rim were remeasured. Long-term outcomes were obtained by linkage to provincial administrative databases.

Results

Over the study period, 324 patients underwent PFO closure with the Amplatzer PFO device, with a mean age of 49.8 years; 61% had a short aortic rim (<9 mm). The most common indication was cryptogenic stroke (72%); those with longer aortic distance were more likely to have a non-stroke indication for closure, diabetes (15% vs 6.5%, P = 0.04), and heart failure (15.7% vs 4%, P < 0.001). Over a median 7 years of follow-up, there were no cases of device erosion or embolization requiring cardiac surgery.

Conclusions

In a large cohort with long-term administrative follow-up (1,394 patient-years), implantation of an Amplatzer PFO device was performed safely even in patients with a short aortic rim.

Patent foramen ovale occlusion with the Cocoon PFO Occluder. The PROS-IT collaborative project

Background

The Cocoon patent foramen ovale (PFO) Occluder is a new generation nitinol alloy double-disk device coated with nanoplatinum, likely useful in patients with nickel hypersensitivity. Early results and mid-term outcomes of this device in percutaneous PFO closure are missing.

Aims

To assess the preliminary efficacy and safety profile of PFO closure with Cocoon device in an Italian multi-center registry.

Methods

This is a prospective registry of 189 consecutive adult patients treated with the Cocoon PFO Occluder at 15 Italian centers from May 2017 till May 2020. Patients were followed up for 2 years.

Results

Closure of the PFO with Cocoon Occluder was carried out successfully in all patients, with complete closure without residual shunt in 94.7% of the patients and minimal shunt in 5.3%. Except from a case of paroxysmal supraventricular tachycardia and a major vascular bleeding, no procedural and in-hospital device-related complications occurred. No patient developed cardiac erosions, allergic reactions to nickel, or any other major complications during the follow-up. During the follow-up period, 2 cases of new-onset atrial fibrillation occurred within thirty-day.

Conclusions

Percutaneous closure of PFO with Cocoon Occluder provided satisfactory procedural and mid-term clinical follow-up results in a real-world registry.

A new era in patent foramen ovale closure - a percutaneous suture-based 'deviceless' technique (NobleStitch®): Experience of a Portuguese center

INTRODUCTION

In patients with cryptogenic stroke, one of the most frequently found abnormalities is patent foramen ovale (PFO). Percutaneous 'deviceless' systems based on surgical suture-mediated PFO closure have recently been introduced and show a favorable efficacy and safety profile with clear advantages.

OBJECTIVES

To present procedural details of the technique and baseline characteristics of patients who underwent the procedure in our center.

METHODS

A single-center prospective observational registry was established between February 2020 and February 2021, to assess the safety, efficacy and possible advantages of a novel percutaneous PFO closure system (NobleStitch® EL). Patient and PFO characteristics as well as technical features were collected for analysis.

RESULTS

Twenty-three patients were considered suitable for this technique after transesophageal echocardiography. Their mean age was 51 years and 69.5% were women. Most patients (91.3%) had a history of cryptogenic stroke. PFO closure with the NobleStitch® system was successfully performed in all patients. All procedures were performed under local anesthesia and fluoroscopic monitoring. The mean duration of the procedure was 52 min and median contrast dose used was 187 ml. Median radiation dose absorbed per patient was 61.5 Gy cm². All patients were discharged asymptomatic 24 hours after the procedure with no peri- or postprocedural complications recorded.

CONCLUSION

Suture-mediated PFO closure represents a valid and safe alternative to traditional umbrella-like devices, and is feasible in the majority of PFO anatomies. Follow-up information, results of larger series and clinical trials may possibly validate this technique as the first choice for PFO closure.

Platypnea Orthodeoxia Syndrome and Patent Foramen Ovale Closure: Single-Centre Experience and Long-Term Follow-Up

INTRODUCTION

Platypnea orthodeoxia syndrome (POS) is an uncommon condition characterised by dyspnoea and arterial desaturation induced by an upright position and relieved in the supine position, usually due to a patent foramen ovale (PFO). Percutaneous closure of a PFO is the preferred treatment to cure POS. This study aimed to evaluate the clinical and gasometrical characteristics and to describe the long-term outcomes of percutaneous PFO closure in a group of patients with POS.

METHODS

Patients with POS and a PFO treated by percutaneous intervention from 2010-2020 were reviewed. The primary efficacy outcome was the arterial oxygen pressure to fraction of inspired oxygen (PaO2/FiO2) ratio before and 24 hours after the procedure. Total clinical success was considered if the arterial oxygen saturation measured by pulse oximetry (SpO2) improved to >94% in the supine and sitting positions without supplemental oxygen, while partial success was considered if SpO2 improved from baseline but still required oxygen to achieve >94%. Secondary outcomes were an absolute improvement in SpO2 and sense of dyspnoea, without significant residual shunt on transthoracic echocardiography (TTE) at follow-up.

RESULTS

Of 168 patients undergoing PFO or atrial septal defect closure, 14 had POS (8.3%). Percutaneous PFO closure was successfully performed in all patients with a single device. Twelve of 14 patients had total clinical success (86%) and one patient had partial success. The PaO2/FiO2 ratio increased from 155.9±50.6 to 318.3±73.4 after PFO closure (p=0.002). All patients with total clinical success had a successful secondary efficacy outcome with an absolute improvement in SpO2 and complete resolution of dyspnoea, which was maintained at follow-up (37±20 months; range, 11 months to 6 years). None had a significant residual shunt between 12 and 24 months of follow-up.

CONCLUSION

The PFO percutaneous closure was a successful, durable and safe method for patients presenting with POS; it achieved major improvements in both gasometrical parameters and quality of life.

The management of patent foramen ovale in divers: where do we stand?

Diving is a fascinating activity, but it does not come without any cost; decompression illness (DCI) is one of the most frequent diseases occurring in divers. Rapid surfacing after diving causes alveolar rupture and bubbles release, which enter in the systemic circulation and could embolize numerous organs and tissues. The presence of patent foramen ovale (PFO) contributes to the passage of venous gas bubbles into the arterial circulation, increasing the risk of complications related to DCI. The diagnosis is established with a detailed medical history, a comprehensive clinical evaluation, and a multimodal imaging approach. Although the percutaneous closure of PFO is ambiguous for divers, as a primary prevention strategy, transcatheter management is considered as beneficial for DCI recurrence prevention. The aim of this study is to introduce the basic principles of DCI, to review the pathophysiological connection between DCI and PFO, to highlight the risk factors and the optimal treatment, and, last but not least, to shed light on the role of closure as primary and secondary prevention.

SCAI Guidelines for the Management of Patent Foramen Ovale

Background

Patent foramen ovale (PFO) is a vestigial congenital cardiovascular structure present in around 25% of adults. In most cases, PFO is entirely benign and requires no treatment. However, it may cause serious complications under certain circumstances.

Objective

These evidence-based guidelines from the Society for Cardiovascular Angiography and Interventions (SCAI) aim to support patients, clinicians, and other stakeholders in decisions about management of PFO.

Methods

SCAI convened a multidisciplinary guideline panel balanced to minimize potential bias from conflicts of interest. The Evidence Foundation, a registered 501(c)(3) nonprofit organization, provided methodological support for the guideline-development process. Following the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach, the guideline panel formulated and prioritized clinical questions in population, intervention, comparison, outcome (PICO) format. A separate technical review team of clinical and methodological experts conducted systematic reviews of the evidence, synthesized data, and graded the certainty of the evidence across outcomes. The guideline panel then reconvened to formulate recommendations and supporting remarks informed by the results of the technical review and additional contextual factors described in the GRADE evidence-to-decision framework.

Results

The panel agreed on 13 recommendations to address variations on 5 clinical scenarios.

Conclusions

Key recommendations address patient selection for PFO closure in the prevention of recurrent PFO-associated stroke, including populations not commonly included in randomized studies, and scenarios where the PFO closure might serve a role in the prevention of other outcomes such as migraine headaches and decompression illness. The panel has also identified future research priorities to advance the field.

Nickel Hypersensitivity to Atrial Septal Occluders: Smoke Without Fire?

Nickel is one of the most common contact allergens worldwide; it is used as the main component of the devices used for atrial septal defects (ASDs) and patent foramen ovale (PFO) closure. Developing nickel hypersensitivity after PFO/ASD occlusion is significantly rarer described in medical literature than typical nickel contact sensitization. The exact pathophysiological mechanism of this "device syndrome" remains unknown, and many question the real incidence or even the existence of this clinical entity. Nevertheless, it has been associated with a wide spectrum of symptoms, including chest pain, migraines, palpitation, and dyspnea. Skin patch tests are the first-line approach to diagnose nickel hypersensitivity. However, diagnostic criteria for the device syndrome have not been developed, and diagnosis in reported cases is established by a process of elimination. Management-drug therapy (corticosteroids, clopidogrel, etc.) or even surgical explantation in severe cases-of patients developing such clinical manifestations after percutaneous PFO/ASD occlusion is empirical. Undoubtedly, endocardiac device-related nickel hypersensitivity requires more focused research to discover the underlying mechanism as well as to develop reliable prognostic tests for detecting high-risk patients and preventing severe nickel hypersensitivity reactions.

Pooled Analysis of PFO Occluder Device Trials in Patients With PFO and Migraine

BACKGROUND

Although observational studies have shown percutaneous patent foramen ovale (PFO) closure to be a safe means of reducing the frequency and duration of migraine, randomized clinical trials have not met their primary efficacy endpoints.

OBJECTIVES

The authors report the results of a pooled analysis of individual participant data from the 2 randomized trials using the Amplatzer PFO Occluder to assess the efficacy and safety of percutaneous device closure as a therapy for episodic migraine with or without aura.

METHODS

The authors analyzed individual patient-level data from 2 randomized migraine trials (the PRIMA [Percutaneous Closure of Patent Foramen Ovale in Migraine With Aura] and PREMIUM [Prospective Randomized Investigation to Evaluate Incidence of Headache Reduction in Subjects with Migraine and PFO Using the Amplatzer PFO Occluder Compared to Medical Management] studies). Efficacy endpoints were mean reduction in monthly migraine days, responder rate (defined as ≥50% reduction in monthly migraine attacks), mean reduction in monthly migraine attacks, and percentage of patients who experienced complete cessation of migraine. The safety endpoint was major procedure- and device-related adverse events.

RESULTS

Among 337 subjects, 176 were randomized by blocks to device closure and 161 to medical treatment only. At 12-month follow-up, the analysis met 3 of the 4 efficacy endpoints: mean reduction of monthly migraine days (-3.1 days vs. -1.9 days; p = 0.02), mean reduction of monthly migraine attacks (-2.0 vs. -1.4; p = 0.01), and number of subjects who experienced complete cessation of migraine (14 [9%] vs. 1 [0.7%]; p < 0.001). For the safety analysis, 9 procedure-related and 4 device-related adverse events occurred in 245 subjects who eventually received devices. All events were transient and resolved.

CONCLUSIONS

This pooled analysis of patient-level data demonstrates that PFO closure was safe and significantly reduced the mean number of monthly migraine days and monthly migraine attacks, and resulted in a greater number of subjects who experienced complete migraine cessation.

International experience with the use of Cocoon septal occluder for closure of atrial septal defects

BACKGROUND

The Cocoon septal occluder (CSO) is a new generation double disk occluder device for catheter closure of the secundum atrial septal defect (ASD). Initial clinical evaluations with the use of this device have shown quite satisfactory results but large follow-up studies are missing. In this international multicenter study, we present procedural and follow-up data from 4008 patients with secundum ASD who underwent catheter closure with the use of CSO.

METHODS

The study cohort consisted of 1853 pediatric and 2155 adult patients with secundum ASD treated with the CSO. Patients were enrolled retrospectively from 11 international centers and were followed for a mean period of 43 months (range 12-84 months), postprocedural. Clinical, electrocardiographic, echocardiographic, procedural, and follow-up data were collected from each collaborating hospital.

RESULTS

The CSO was permanently implanted in 3983 patients (99.4%). Echocardiographic evaluation at one month follow-up revealed complete closure in 99.6% of those patients who had a device implanted. Thrombus formation in one adult patient was the only major device related to procedural complication. During the follow-up period, no patient developed cardiac erosions, allergic reactions to nickel, or other major complications.

CONCLUSIONS

Implantation of CSO provided satisfactory procedural and follow-up results with high success and no device-related cardiac erosions and nickel allergy.

Systemic Allergic Contact Dermatitis Due to a GORE CARDIOFORM Septal Occluder Device: A Case Report and Literature Review

Nickel hypersensitivity is a rarely reported complication of percutaneous patent foramen ovale/atrial septal defect closure. Herein, we report a case of systemic allergic contact dermatitis to nickel present in a GORE CARDIOFORM (W.L. Gore, Flagstaff, Arizona) septal occluder that resolved following explanation. To our knowledge this is the first published case of nickel hypersensitivity associated with this device. (Level of Difficulty: Beginner.)

Comparison of Two Percutaneous Atrial Septal Defect Occluders for Device Healing and Nickel Release in a Chronic Porcine Model

Aims

To investigate the healing process and nickel release of the Hyperion occluder (Comed BV, Netherlands), as compared to the Amplatzer septal occluder (ASO) (St. Jude Medical Inc., St. Paul, MN, USA) in a chronic swine model.

Background

Some long-term complications occurring after percutaneous atrial septal defect (ASD) closure may be partially associated with an inappropriate healing of the device and increased nickel release. There is no direct comparative study of different occluders for healing and nickel release.

Methods

After percutaneous ASD creation, 12 pigs were implanted with 15 mm Hyperion (n = 6) and 15 mm ASO (n = 6) devices. After 1 month (n = 3 for each device) and 3 months (n = 3 for each device) of follow-up, device explantation was performed and healing was assessed using histopathological workup. Systemic and tissular nickel release was performed.

Results

Implantation was successful in 100% without complications. Device coverage was observed as early as 1 month after implantation and was almost complete after 3 months. A granulation tissue with a predominantly mononuclear inflammatory reaction was observed in contact with nitinol wires while an inflammatory reaction was seen in contact with textile fibers. We found no statistically significant difference between the 2 devices whether for histological grading scores or systemic nickel release, regardless to follow-up duration.

Conclusions

In this preclinical study, we demonstrated that Amplatzer septal occluder and Hyperion occluder were not significantly different for device healing and nickel release processes.

Surgical explantation of atrial septal closure devices for refractory nickel allergy symptoms

OBJECTIVES

Systemic allergic reactions to nickel alloys in percutaneous atrial septal defect occlusion devices have a poorly defined natural history. We describe our experience of surgical removal of the offending device in a series of patients with nickel allergy and refractory symptoms.

METHODS

Patients with atrial septal defect device explants for nickel allergy were reviewed. Administered questionnaires focused on symptoms, quality of life, and satisfaction along with the 36-Item Short Form Health Survey to measure physical and mental health postsurgery.

RESULTS

Atrial septal defect devices were removed for nickel allergy in 58 patients during the past 10 years. The median age was 42 years (range, 24-71 years) and 95% were women. Explantation occurred at a median of 8 years (range, 6 months-18 years) after insertion. Symptoms included fatigue (82%), chest pain (78%), headache (73%), and palpitation (58%). Surveys were available for 45 patients: 58% rated their quality of life as poor and 69% were not at all satisfied with their device. Postexplant, all patients reported improvement in their symptoms, with 18 patients (42%) noting complete resolution. In 12 patients prospectively studied, the preoperative scores in physical and mental health domains were lower than the validation group, indicating significant disability. Similarly, there was marked improvement in each domain postremoval.

CONCLUSIONS

Patients with nickel allergy and severe refractory symptoms after atrial septal defect device implantation experience profound resolution of symptoms and improved quality of life after removal. Nickel allergy should be considered before device insertion, and a low threshold should exist for surgical removal for refractory symptoms.

Transcatheter Closure of Patent Foramen Ovale: Randomized Trial Update

A patent foramen ovale (PFO) is found in about one-quarter of all adults, but the prevalence increases to approximately half of those with a history of a so-called cryptogenic stroke. The true efficacy of PFO closure for prevention of recurrent paradoxical embolism has been debated for years, as the early 3 randomized trials did not show a statistically significant benefit of PFO closure over standard-of-care medical therapy. However, 3 recent randomized trials along with the long-term follow-up data from the largest early trial demonstrated superiority of device closure for secondary stroke prevention.

Cryptogenic Stroke and Patent Foramen Ovale

Nearly one-half of patients with cryptogenic stroke have a patent foramen ovale (PFO). The dilemma of whether to close these PFOs percutaneously, in an effort to reduce the risk of recurrent paradoxical embolism, has been a matter of ongoing debate for more than a decade. Early randomized clinical trials failed to demonstrate a significant benefit of percutaneous PFO closure for secondary prevention of cryptogenic stroke in an intention-to-treat analysis. The long-term follow-up data from the RESPECT trial and 2 new randomized trials (CLOSE and REDUCE) have clarified these findings. They showed that with good patient selection, transcatheter PFO closure significantly reduces the risk of recurrent stroke compared with medical therapy in patients with cryptogenic stroke, with no increased risk of serious adverse events or influence on major bleeding.

Acute Hypoxic and Refractory Respiratory Failure Induced by an Underlying PFO: An Unusual Case of Platypnea Orthodeoxia and Transient Complication after Transcatheter Closure

Platypnea orthodeoxia (PO) is an infrequent condition of dyspnea with hypoxemia, increased by adopting an upright position and is relieved in decubitus. This condition may occur in patients with hidden intracardiac shunts, usually across a persistent foramen ovale (PFO). The incidence of PFO in general population is quite common, around 27%; however, the concurrent presentation with PO, especially in acute refractory respiratory failure, is extremely rare. PFO closure in this setting is still the treatment of choice with significant improvement or complete resolution of symptoms after closure with an overall periprocedural complication in the first 24 hours of approximately less than 5%. A transient ST-segment elevation in the inferior leads is present in extremely rare occasions and most likely is induced by either an air embolism or a mechanically provoked spasm of coronary arteries. We report a case of an 83-year-old woman in acute hypoxic and refractory respiratory failure in whom PO was identified, most likely induced by a hidden PFO. The patient underwent percutaneous transcatheter closure and developed immediate chest pain, transient hemodynamic instability, and ST-segment elevation in the inferior leads; nevertheless, our patient recovered completely with rapid resolution of respiratory failure with no adverse clinical sequelae.

Mitral Ring Extraction due to Nickel Allergy

The incidence of allergic reactions due to mechanical prosthesis or rings is not well established. We report the case of a 56-year-old man who presented a persistent urticarial rash and anaphylactic shock after a mitral valve repair operation. Prick skin tests were positive for nickel. After the nucleus from the mitral annulus was removed, the urticarial rash disappeared.

Stroke prevention

Patients who have had a stroke are at high risk for recurrent stroke, myocardial infarction, and vascular death. Prevention of these events should be initiated promptly after stroke, because many recurrent events occur early, and should be tailored to the precise cause of stroke, which may require specific treatment. Lifestyle advice including abstinence from smoking, regular exercise, Mediterranean-style diet, and reduction of salt intake and alcohol consumption are recommended for all patients with stroke. For most patients with ischemic stroke or TIA, control of risk factors, including lowering blood pressure under 140/90mmHg and LDL cholesterol under 1g/L, together with antiplatelet or oral anticoagulant therapy, depending on the cause of stroke, have been shown to decrease the risk of recurrent stroke and cardiovascular events. Aspirin, clopidogrel, or the combination of aspirin and dipyridamole, are all acceptable options for secondary prevention in patients with ischemic stroke or TIA of arterial origin. Dual therapy with aspirin and clopidogrel might be considered for 3 weeks after a minor ischemic stroke or TIA and for 3 months in patients with stroke due to severe intracranial stenosis. Oral anticoagulants are very effective to prevent cardioembolic stroke. Non-VKA oral anticoagulants have a favorable risk-benefit profile compared with VKAs, with significant reductions in stroke, intracranial hemorrhage, mortality, with similar major bleeding, but increased gastrointestinal bleeding. Carotid endarterectomy reduces the risk of ipsilateral stroke in patients with recent (<6 months) non disabling ischemic stroke or TIA in the territory and severe carotid artery stenosis. Carotid stenting is a potential alternative to surgery in patients younger than ≈70 years or patients with greater risk of surgery due to anatomic or medical conditions or specific circumstances such as radiation-induced stenosis or restenosis after surgery. For patients with hemorrhagic stroke due to hypertension-associated small vessel disease or cerebral amyloid angiopathy, strict control of blood pressure is essential. Restarting oral anticoagulants in patients after intracranial hemorrhage is a difficult decision that should weigh the risks of recurrent ischemic and hemorrhage stroke with and without oral anticoagulants. Several areas of uncertainty persist including the optimal target of blood pressure in patients with cerebrovascular disease, the benefit of PFO closure in patients with PFO-associated stroke, of stenting procedures in patients with atherosclerotic intracranial artery or extracranial vertebral artery stenosis, and of interventional procedures in patients with brain arteriovenous or cavernous malformations.

Infective endocarditis after device closure of atrial septal defects: Case report and review of the literature

We report a case of late infective endocarditis in an 8-year-old boy 3 years after transcatheter closure of an atrial septal defect with the Amplatzer Atrial Septal Occluder Device. Echocardiography showed a very thick pannus lining the left atrial disc of the prosthesis, with some mobile elements. MRI showed several cerebral microemboli. The patient had dental caries and blood cultures found Staphylococcus aureus. Patient was treated with gentamicin and oxacillin before surgical removal of the prosthesis. Twenty-one cases of infective endocarditis after atrial defect device closure have been reported in the literature (13 ostium secundum ASD and 8 patent foramen ovale). Seven pediatric cases were reported. S. aureus was the most frequent bacterium. Antibiotics were administered in all cases and most patients (n = 18) underwent surgical removal of the device. Incomplete endothelialization of the prosthesis was a suggested mechanism. Two patients died after surgery. © 2016 Wiley Periodicals, Inc.

Allergy to Surgical Implants

Surgical implants have a wide array of therapeutic uses, most commonly in joint replacements, but also in repair of pes excavatum and spinal disorders, in cardiac devices (stents, patches, pacers, valves), in gynecological implants, and in dentistry. Many of the metals used are immunologically active, as are the methacrylates and epoxies used in conjunction with several of these devices. Allergic responses to surgical components can present atypically as failure of the device, with nonspecific symptoms of localized pain, swelling, warmth, loosening, instability, itching, or burning; localized rash is infrequent. Identification of the specific metal and cement components used in a particular implant can be difficult, but is crucial to guide testing and interpretation of results. Nickel, cobalt, and chromium remain the most common metals implicated in implant failure due to metal sensitization; methacrylate-based cements are also important contributors. This review will provide a guide on how to assess and interpret the clinical history, identify the components used in surgery, test for sensitization, and provide advice on possible solutions. Data on the pathways of metal-induced immune stimulation are included. In this setting, the allergist, the dermatologist, or both have the potential to significantly improve surgical outcomes and patient care.

The relationship of patent foramen ovale location with severity of stroke: A new risk factor for paradoxical embolism

OBJECTIVE

Patent foramen ovale (PFO) is a common developmental anomaly and is well associated with paradoxical embolism and cryptogenic stroke. The aim of this study was to investigate the relationship of PFO location with severity of cryptogenic stroke.

MATERIALS AND METHODS

Fifty patients with cryptogenic stroke and echocardiographically proven PFO were classified according to the severity of stroke. In order to define the location of PFOs, an imaginary line dividing the length of interatrial septum vertically into two equal parts was drawn manually at axial plane on cardiac multidetector computed tomography. PFOs located at superior part of this imaginary line was defined as superiorly located PFO, while PFOs located at inferior part of this imaginary line was defined as inferiorly located PFO.

RESULTS

Fourteen patients (28%) revealed mild, 20 patients (40%) revealed moderate and 16 patients (32%) had severe stroke. Based on PFO location, there were 34 patients (68%) with superiorly (group 1), and 16 patients (32%) with inferiorly (group 2) located PFO. It was found that patients of group 1 had significantly higher frequency of moderate or severe stroke compared to those of group 2 (p < 0.005) CONCLUSION: In conclusion, the patients with superiorly located PFO had higher frequency of severe stroke compared to the patients with inferiorly located PFO. Since this is a preliminary study, clinical application and importance of this finding necessitates further large-scale interventional studies.

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.

Sleep Apnea in Patients with and without a Right-to-Left Shunt

OBJECTIVES

To assess the presence of right-to-left shunting (RLS) in patients with obstructive sleep apnea (OSA), and compare clinical characteristics and parameters of the sleep studies of patients with and without RLS.

BACKGROUND

The most common cause of RLS is due to intermittent flow through a patent foramen ovale (PFO). PFO occurs more frequently in patients with OSA and may be involved in the exacerbation of OSA.

METHODS

Patients with an abnormal polysomnogram seen at UCLA-Santa Monica Sleep Medicine Clinic were enrolled. A diagnosis of RLS was made using a transcranial Doppler (TCD) bubble study. Gender and age-matched controls were drawn from patients referred for cardiac catheterization who underwent a TCD. The frequency of RLS in OSA patients and the controls was evaluated. Clinical characteristics and polysomnogram parameters were compared between OSA patients with and without a RLS.

RESULTS

A total of 100 OSA patients and 200 controls participated in the study. The prevalence of RLS was higher in patients with OSA compared to the control group (42% versus 19%; p < 0.0001). Patients with OSA and a RLS had a lower apnea-hypopnea index (AHI), less obstructive apnea, and fewer hypopnea episodes than patients with OSA without a RLS. The baseline and nadir SpO2 were similar in both groups and did not correlate with the level of RLS assessed by TCD. The degree of desaturation for a given respiratory disturbance, as measured by oxygen desaturation index (ODI)/AHI ratio, was higher in OSA patients with RLS versus OSA patients without RLS (0.85 ± 0.07 versus 0.68 ± 0.04; p < 0.0001).

CONCLUSION

RLS, most commonly due to a PFO, occurs 2.2 times more frequently in OSA patients compared to a control population that was matched for age and gender. The severity of sleep apnea is not greater in OSA patients who have a PFO. However, patients with OSA and a PFO are more likely to become symptomatic at a younger age with an equivalent decrease in nocturnal SpO2, and have greater arterial desaturation in proportion to the frequency of respiratory disturbances.

Stent thrombosis caused by metal allergy complicated by protein S deficiency and heparin-induced thrombocytopenia: a case report and review of the literature

A 43-year-old woman recipient of a bare metal coronary stent during an acute anterior myocardial infarction was repeatedly hospitalized with recurrent stent thrombosis (ST) over the following 3 years. Emergent coronary angiography showed a thrombus in the in-stent segment of the proximal left anterior descending artery. We repeatedly aspirated the thrombus, which immediately reformed multiple times. The discontinuation of heparin and administration of thrombolytics and argatroban, followed by repeated balloon dilatations, ended the formation of new thrombi. The patient was found to be allergic to nickel, protein S deficient and carrier of heparin-induced thrombocytopenia antibody. We discuss this case in the context of a) literature pertaining to acute coronary syndromes in the young, and b) the detailed investigations needed to identify thrombotic risk factors. Steroids may be effective to prevent recurrent ST caused by stent allergy.

"Migraine side effect" and stroke recurrence in late follow-up after transcatheter patent foramen ovale closure as secondary prevention of cryptogenic thromboembolism

INTRODUCTION

Patent foramen ovale (PFO) is associated with cryptogenic strokes, recurrent transient neurologic deficits, sleep apnea, decompression illness and migraines with aura.

AIM

We verify cryptogenic embolism recurrence after transcatheter PFO closure in patients younger than 55 years old, and determine the prevalence of migraine with aura before and after PFO closure.

MATERIAL AND METHODS

We sent a questionnaire concerning the recurrence of stroke or transient ischemic attack (TIA) and the presence of migraine symptoms before and after PFO closure to 224 consecutive patients (mean age 40.9 ±9 years; 103 men; 108 patients < 40 years old, 116 patients 40-55 years old) after successful PFO transcatheter closure as secondary prevention of cryptogenic embolism.

RESULTS

The mean follow-up period was 37.8 ±32.5 (median 27) months. Stroke or TIA recurred in 6 patients (2.6%), all of whom were over 40 years old at the time of closure. The median time of recurrence was 24 months. Two patients (0.89%) died, but the deaths were not related to the device nor to thromboembolism. Migraine occurred in the study group before closure in 68 (30.4%) patients. After the procedure 55 (80.9%) reported improvement or disappearance of migraine symptoms.

CONCLUSIONS

Recurrent strokes after PFO closure are rare, and they occur more often in patients over 40 years old at the time of closure. The PFO closure results in migraine subsiding or symptoms noticeably ameliorating.

Iatrogenic erosion of the septum primum resulting in an atrial septal defect with left-to-right shunt: a rare pitfall of patent foramen ovale percutaneous closure

Iatrogenic erosion of the septum primum after foramen ovale closure is an anecdotal event. We report the case of a 39-year-old woman admitted to our institution for multifocal cryptogenic cerebral ischemia and a patent foramen ovale (PFO) associated with an aneurysm of the septum primum. The patient underwent percutaneous closure of the PFO with an Amplatzer PFO Occluder device. At the 6-months follow up, the device was in the right position, but a jagged defect of the septum primum and evidence of significant left-to-right shunting was detected. The atrial septal defect was then repaired by a surgical approach. Although this event is not life-threatening, it should be considered as a therapeutic pitfall, resulting in a risk of paradoxical embolism recurrences and long-term hemodynamic impairment. © 2013 Wiley Periodicals, Inc.