HELEX Septal Occluder Research Articles

Abstract 102: Consistency of Efficacy of PFO Closure in the Gore Reduce Trial

Background: The Gore REDUCE Clinical Study (REDUCE) demonstrated superiority of PFO closure in conjunction with antiplatelet therapy over antiplatelet therapy alone in reducing the risk of recurrent clinical ischemic stroke or new silent brain infarct in patients with cryptogenic stroke. Methods: We randomized 664 subjects with cryptogenic stroke at 63 multinational sites in a 2:1 ratio to either antiplatelet therapy plus PFO closure (with Gore HELEX Septal Occluder or Gore CARDIOFORM Septal Occluder) or antiplatelet therapy alone. Co-primary endpoints were freedom from recurrent clinical ischemic stroke through ≥2 years and incidence of new brain infarct (defined as the composite of clinical ischemic stroke and silent brain infarct) at 2 years. Primary analyses were performed on the intention-to-treat (ITT) population. Per-protocol (PP) analysis included only subjects randomized and treated according to critical protocol requirements (excluding those who violated key eligibility criteria, did not receive the therapy to which they were randomized, or did not comply with protocol-required medical regimen). As-treated (AT) analysis assessed all subjects based on treatment received, regardless of study assignment. Results: PFO closure was associated with a highly consistent reduction in risk compared to medical therapy alone in all three analytic cohorts (Table). Conclusions: Among selected patients with cryptogenic stroke and PFO, closure of the PFO plus antiplatelet therapy was superior to antiplatelet therapy alone for reducing the risk of subsequent ischemic stroke.

Patent foramen ovale closure with GORE HELEX or CARDIOFORM Septal Occluder vs. antiplatelet therapy for reduction of recurrent stroke or new brain infarct in patients with prior cryptogenic stroke: Design of the randomized Gore REDUCE Clinical Study.

Rationale The utility of patent foramen ovale (PFO) closure for secondary prevention in patients with prior cryptogenic stroke is uncertain despite multiple randomized trials completed to date. Aims The Gore REDUCE Clinical Study (REDUCE) aims to establish superiority of patent foramen ovale closure in conjunction with antiplatelet therapy over antiplatelet therapy alone in reducing the risk of recurrent clinical ischemic stroke or new silent brain infarct in patients who have had a cryptogenic stroke. Methods and design This controlled, open-label trial randomized 664 subjects with cryptogenic stroke at 63 multinational sites in a 2:1 ratio to either antiplatelet therapy plus patent foramen ovale closure (with GORE® HELEX® Septal Occluder or GORE® CARDIOFORM Septal Occluder) or antiplatelet therapy alone. Subjects will be prospectively followed for up to five years. Neuroimaging is required for all subjects at baseline and at two years or study exit. Study outcomes The two co-primary endpoints for the study are freedom from recurrent clinical ischemic stroke through at least 24 months post-randomization and incidence of new brain infarct (defined as clinical ischemic stroke or silent brain infarct) through 24 months. The primary analyses are an unadjusted log-rank test and a binomial test of subject-based proportions, respectively, both on the intent-to-treat population, with adjustment for testing multiplicity. Discussion The REDUCE trial aims to target a patient population with truly cryptogenic strokes. Medical therapy is limited to antiplatelet agents in both arms thereby reducing confounding. The trial should determine whether patent foramen ovale closure with the Gore septal occluders is safe and more effective than medical therapy alone for the prevention of recurrent clinical ischemic stroke or new silent brain infarct; the neuroimaging data will provide an opportunity to further support the proof of concept. The main results are anticipated in 2017. Registration Clinical trial registration-URL: http://clinicaltrials.gov/show/NCT00738894.

An alien in the heart

We report a case of a 38-year-old-man who presented with altered mental status. The patient was diagnosed with infective endocarditis (IE) originating from the GORE HELEX septal occluder device, which was placed 15months earlier for symptomatic atrial septal defect. Brain imaging revealed shower emboli phenomena from the known IE. The patient developed hydrocephalus for which external ventriculostomy was performed. Improved neurological status warranted open heart surgery. The patient was later confirmed to be an intravenous drugs abuser, prejudicing IE. This case highlights the importance of meticulously monitoring patients with suspected high-risk behavior with an implanted intracardiac prosthetic device.

Device therapy for atrial septal defects in a multicenter cohort: acute outcomes and adverse events.

Secundum atrial septal defect (ASD) closure devices were granted approval based on industry-sponsored, prospective, nonrandomized, single device studies, demonstrating acceptable efficacy and safety in selected patients. We sought to report community practice and outcomes. Procedure specific data was collected on cases considered for ASD closure in the congenital cardiac catheterization project on outcomes (C3PO) between February 1, 2007 and June 31, 2010. Eight centers contributed data during this time period. All adverse events (AE) were independently reviewed and classified by a five level severity scale. In 40 months (2/07-6/10), 653 of 688 ASDs were occluded with a single device using an AMPLATZER(®) Septal Occluder (ASO) in 566 (87%), GORE(®) HELEX(®) Septal Occluder (HSO) in 33 (5%), and a CardioSEAL(®) or STARFlex™ device (CSD) in 54 (8%). Most patients had an isolated ASD (93%). 85% were >2 years of age. The ASD median diameter was 12 mm [8,16] for ASO, with smaller diameters in HSO 8 mm [7,10] and CSD 8 mm [5,10] (P < 0.001). AE (n = 82) were recorded in 76 cases, 11.5% (95% CI 9.2%, 14.1%) and classified as high severity in 4.7% (95% CI 3.2%, 6.5%), with no mortality. A new conduction abnormality was detected during 15 cases and did not resolve in one. Transcatheter device retrieval was possible in 7 of 10 device embolizations. Device erosion occurred in 3 of 566, 0.5% (95% CI 0.1%, 1.5%), ASO implants. Although device closure of ASDs is associated with low morbidity and rare mortality, ongoing assessment of device safety profiles are warranted, and registries offer opportunities to facilitate the required surveillance.

Results of the U.S. Food and Drug Administration Continued Access Clinical Trial of the GORE HELEX Septal Occluder for Secundum Atrial Septal Defect

ObjectivesThis report describes the immediate, 1-, and 5-year follow-up results of the U.S. Food and Drug Administration Continued Access clinical trial of the GORE HELEX Septal Occluder (W. L. Gore & Associates, Inc., Flagstaff, Arizona) for closure of secundum atrial septal defect. BackgroundThe trial was conducted between May 2003 and August 2006 to allow continued enrollment in a trial of the investigational device during review of data from the Pivotal Trial. Devices with hydrophilic coating on the expanded polytetrafluoroethylene to improve echocardiographic visualization were first used in this trial. MethodsA total of 137 devices were implanted in 137 patients at 13 US institutions. Evaluations were scheduled at 1, 6, and 12 months for the initial trial and at 36 and 60 months for a later extension of the trial in those who consented to longer term evaluations. ResultsTwelve-month follow-up was completed on 122 of 126 patients with implantations, and 5-year follow-up on 83 of 95 patients who agreed to the trial extension. The overall clinical success rate was 96.7%, and the major adverse event rate 3.6%. Wire frame fractures were seen in 11.7% of patients with no clinical symptoms. A trivial, clinically insignificant leak was seen, or could not be ruled out, in 26.6% of patients at the 5-year evaluation, but no clinically significant leaks were seen. No patient experienced an erosion or sudden catastrophic event. ConclusionsThe immediate, 1-, and 5-year follow-up outcomes of the Continued Access clinical trial continue to demonstrate that the GORE HELEX Septal Occluder is a safe and effective transcatheter occluder for repair of ostium secundum atrial septal defect.

Helex device closure of multiple atrial septal defects

To describe the effectiveness of the Helex Septal Occluder (HSO) to close multiple atrial septal defects (mASDs). Background : Limited information is available describing closure of mASDs with the HSO. A total of 28 patients who underwent closure of mASDs with the HSO were identified by retrospective review of our catheterization database between 2001 and 2012. Procedural details and follow up information were collected. Median age was 19.2 years, median weight 48 kg, with 10 (36%) patients weighing <25 kg. Indication for closure was RV enlargement (RVE) in all patients and additionally neurologic events occurred in 3/28 (11%). Median stop-flow diameter for the largest ASD was 14 (4-23) mm. One HSO was implanted in 21/28 (75%), 2 in 6/28 (21%), and 3 in 1/28 (4%). One embolization and one transient arrhythmia occurred with no sequelae. Immediate residual shunt was absent in 5/28 (18%), trivial in 15/28 (54%), small in 6/28 (21%), and moderate in 2/28 (7%). Of the 25 patients with ≥6 months follow-up (median 53 months), residual shunt was absent in 13/25 (52%), trivial in 5/25 (20%), and small in 7/25 (28%). RVE resolved in all but one patient with no other associated lesions and ≥6 months of follow-up. No patient with prior neurological event had recurrence at last follow-up. We conclude that closure of mASDs with ≥1 HSO is effective with a low complication rate. The ability of HSO devices to overlap or sandwich each other may facilitate safe implantation of multiple devices in smaller patients.

Device closure of secundum atrial septal defects in infants weighing less than 8 kg.

This study aimed to assess the technical aspects of atrial septal defect (ASD) closure using the Amplatzer septal occluder (ASO) and the Gore Helex septal occluder (GHSO) for infants weighing less than 8 kg and to determine the safety, effectiveness, and near-to-intermediate-term outcome of the closure. The Mid-Atlantic Group of Interventional Cardiology Registry of percutaneous, transcatheter ASD closure procedures was reviewed for this analysis. Patients from 10 hospitals in the United States were included. The cohort for this report consisted of 68 patients weighing less than 8 kg (range, 2.3-7.8 kg; mean, 5.5 ± 1.6 kg) and ranging in age from 1 to 24 months (mean, 8.6 ± 4.7 months). The indications for ASD closure were failure to thrive, significant right heart enlargement, shunts otherwise thought to be hemodynamically significant, and poor overall clinical status. Devices were successfully implanted in 66 of the 68 infants (97.1 % procedural success rate). Five minor procedure-related complications occurred. At follow-up assessment, clinical status had improved significantly as measured by improved weight gain and decreased ventilator or oxygen dependence. All residual shunts spontaneously closed during the follow-up period. Six late deaths occurred, none of which were clearly device related. The ASO and GHSO can be safely and effectively implanted for ASD closure in infants weighing less than 8 kg. These procedures usually are successful and seldom complicated, resulting in significant clinical improvement.

Combined prospective United States clinical study data for the GORE® HELEX® septal occluder device

Our goal was to summarize the outcome for all subjects evaluated during a prospective clinical study in the United States with the GORE(®) HELEX(®) Septal Occluder for transcatheter repair of secundum atrial septal defects (ASD). The GORE(®) HELEX(®) Septal Occluder is currently utilized for repair of secundum ASD. No previous reports are available that summarize the combined clinical trial outcomes for this device. In the United States between 1999 and 2009, 435 subjects were enrolled through the Feasibility, Pivotal, Continued Access, and Post-Approval Studies. All subjects enrolled through these studies were collectively reviewed as the "study cohort." Clinical success, defined as a composite evaluation of safety and efficacy, is reported for subjects at the 12-month follow-up period. Of the 435 device subjects enrolled in the four clinical studies, 412 subjects were eligible for follow-up. Device efficacy, as represented by clinical closure at 12 months, was achieved in 98.3% of subjects, and in 99.5% of those receiving a device whose nominal diameter was greater or equal to twice the balloon sized defect diameter. Through 12 months following implantation, freedom from major adverse events was 95.2%. Together, these results yield a 93.0% composite clinical success at 12 months following the index procedure. The combined clinical study cohort represents the largest prospective, controlled clinical trial data set available for the GORE(®) HELEX(®) Septal Occluder. The clinical data presented in this report reaffirm the safety and efficacy of the GORE(®) HELEX(®) Septal Occluder when utilized for secundum atrial septal defect repair.

Clinical Practice, Resource Utilization, and Outcomes of Device Closure of Patent Foramen Ovale in Pediatrics

BackgroundThere are few data on patent foramen ovale closure and its outcome in children. In this study, we evaluated the current clinical practice, resource utilization, and outcome of device closure of patent foramen ovale in children. We hypothesized that patent foramen ovale closure would not result in a demonstrated benefit in children. MethodsWe undertook a prospective survey of all consecutive patients (<20 years) who underwent patent foramen ovale closure in our metropolitan area between 1995 and 2010. Differences in proportions were tested using the chi-square test or Fisher's exact test where appropriate. Differences in group medians were tested using Wilcoxon signed-rank test. ResultsA total of 153 patients (104 girls), median age 16 years (range 7-19) were studied. Indications for patent foramen ovale closure included: (1) migraine headache (104; 68%), (2) nonmigraine headache (24; 16%), (3) visual symptoms (110; 72%), (4) transient ischemic attack symptoms (42; 28%), and (5) stroke-like symptom (24; 16%). Patent foramen ovale was closed with an Amplatzer septal occluder in 115 (75%) and a Helex septal occluder in 47 (30%). The mean length of hospital stay was 18 ± 11 hours; the mean hospital charge was $24,126 ± $5808. The median duration of follow-up was 12 months, and 80 patients responded to the study survey. On follow-up, symptoms improved in 143 (93%), of which 29 (19%) had a residual shunt. None of the patient or treatment parameters predicted lack of improvement on follow-up. ConclusionsDespite the lack of proven benefit, children undergo closure of the patent foramen ovale for a variety of reasons, with the vast majority (92%) of patients reporting significant improvement in their symptoms. However, patent foramen ovale closure is an expensive procedure with serious potential complications. Symptomatic improvement even in the presence of a residual shunt suggests a strong placebo effect.

Mid-term Outcomes of the Helex Septal Occluder for Percutaneous Closure of Secundum Atrial Septal Defects

The HELEX Septal Occluder (HSO) was approved by the Food and Drug Administration for closure of secundum atrial septal defects (ASD) in 2006. However, little mid-term follow-up information is available. The object of this study was to examine mid-term outcomes after HSO implantation A retrospective chart review was performed on the first 74 patients who underwent ASD closure with the HSO between 4/00-10/04. Only patients who left the catheterization laboratory after successful implantation and had a minimum follow-up of 5 years were selected for analysis. Thirty-three patients met entry criteria. At implantation the mean age was 10.9 years and the median ASD size was 15.1 mm. At a median follow-up of 88 months, 26 patients had complete ASD closure, 6 had trivial left-right shunts, and 1 had a significant residual shunt having a reintervention. Fluoroscopy, performed in 27 patients revealed a frame fracture in 3 patients (9%), all of whom were asymptomatic and had effective ASD closure. All 3 devices were 30 mm or 35 mm HSO and were left in place. One patient developed first-degree heart block and remained asymptomatic with no progression. There were no instances of late device embolization, cardiac perforation, erosion, or death. Following successful implantation, HSO results in effective closure of secundum ASD in mid-term follow-up. Late complications appear to be rare with the exception of frame fracture, which in this series did not result in clinical sequelae.

A strategy for atrial septal defect closure in small children that eliminates long‐term wall erosion risk

To evaluate feasibility, efficacy, and safety of an approach to atrial septal defect (ASD) occlusion in children ≤20 kg that eliminates cardiac wall erosion risk. Cardiac wall erosion is a potentially catastrophic complication of ASD device closure. The HELEX Septal Occluder (HSO) is a compliant device with no reports of erosion. The HSO is technically difficult to deploy in smaller children and cannot be used to close larger defects. To eliminate wall erosion risk, we use the HSO when feasible and surgery for larger defects. Retrospective review of ASD procedures performed in children ≤20 kg. Between January 2006 and January 2011, 60 children underwent ASD closure. HSO placement was successful in 32 of 34 patients, and surgical closure was successful in all of 28 patients. Surgical patients were younger (35.1 ± 12.6 vs. 47.4 ± 15.3 months, P < 0.01) and smaller (15.3 ± 3.2 vs. 12.6 ± 4.3 kg; P < 0.01) with larger ASDs (15.8 ± 4.5 vs. 9.8 ± 3.0 mm; P < 0.01). No surgical patients demonstrated residual leak. Residual leak was seen in 14 of 32 (44%) HSO patients on postprocedure day #1 and in 1 of 26 (3.8%) with ≥6 months follow-up. Indications for surgery included: deficient inferior/superior rims (n = 17), provider preference (n = 2), and HSO device not feasible (n = 9). Serious adverse events included device embolization with percutaneous retrieval (n = 1) and postpericardiotomy syndrome without intervention (n = 1). The HSO can be safely used in most children ≤20 kg. Our approach to ASD closure is associated with minimal morbidity and good short-term results. This approach requires no more than a 15% increase in surgical referrals and eliminates risk of cardiac wall erosion.

Ring Array Transducers for Real-Time 3-D Imaging of an Atrial Septal Occluder

We developed new miniature ring array transducers integrated into interventional device catheters such as used to deploy atrial septal occluders. Each ring array consisted of 55 elements operating near 5 MHz with interelement spacing of 0.20 mm. It was constructed on a flat piece of copper-clad polyimide and then wrapped around an 11 French O.D. catheter. We used a braided cabling technology from Tyco Electronics Corporation to connect the elements to the Volumetric Medical Imaging (VMI) real-time 3-D ultrasound scanner. Transducer performance yielded a –6 dB fractional bandwidth of 20% centered at 4.7 MHz without a matching layer vs. average bandwidth of 60% centered at 4.4 MHz with a matching layer. Real-time 3-D rendered images of an en face view of a Gore Helex septal occluder in a water tank showed a finer texture of the device surface from the ring array with the matching layer.

Transcranial Doppler Quantification of Residual Shunt after Percutaneous Patent Foramen Ovale Closure: Correlation of Device Efficacy with Intracardiac Anatomic Measures

Percutaneous, mechanical closure of defects of the atrial septum fails to completely resolve shunting in up to 20% of cases. Little is known about the factors associated with device failure. We measured the left atrial opening (X), right atrial opening (Z), tunnel length (Y), septum secundum, device-septum primum separation, and tunnel compressibility of the patent foramen ovale (PFO) in 301 patients with cryptogenic neurological events, PFO anatomy, and severe Valsalva shunting (Spencer Grade 5-5+). All patients then underwent percutaneous closure with the GORE®HELEX Septal Occluder device and were evaluated at 3 months for residual shunt by transcranial Doppler (TCD). Severe residual Valsalva shunt (TCD Grade 5-5+) was found at 3 months in 21 of 301 (7%) patients. X, Y, and Z were associated with failure with a high degree of statistical significance, whereas the width of the septum secundum, device-septum primum separation, and tunnel compressibility were not. An unanticipated finding was that 14 of 35 (40%) patients sized with a large balloon failed compared with 9 of 280 (3%) sized with a small balloon (P < 0.0001). In the multivariate logistic regression model, X (P = < 0.0001) and balloon size (P < 0.0001) were both strong predictors of failure. In an intracardiac echocardiography-defined PFO population, characterized by severe baseline Valsalva shunt and a high incidence of persistent (rest) shunting, association of six intracardiac measurements to closure device failure by multivariate logistic regression showed that the width of the left atrial opening was a strong predictor of residual shunting. An unanticipated finding was that use of a large sizing balloon was also strongly associated with failure.

Abstract 17197: Closure of Multiple Atrial Septal Defects with the Helex Device

Background: The performance of the Helex Septal Occluder (HSO) for closure of fenestrated atrial septum/multiple ASDs (mASDs) has not been evaluated. We sought to review our experience with closure of mASDs with the HSO. Methods: We identified 48 patients with mASDs who underwent percutaneous closure between 6/2001 and 5/2011. Number and size of ASDs, number of implanted HSOs, residual shunt, and complications were recorded. Results: Of 48 patients, 27 had defect closure with ≥ 1 HSO. Indication for closure was RV enlargement (RVE) in 24 (89%) and cryptogenic neurologic event in 3 (11%). Median age was 9.1 (1.9-66.2) years, median weight 30.7 (12.2-99.5) kg. Six patients (22%) weighed &lt; 20 kg. Median number of ASDs was 2 (2-≥5). Median stop-flow diameter in 25/27 patients was 12 (6-24) mm. Two patients had multiple small defects that were not sized. One HSO was implanted in 21 patients (78%), and 2 HSOs in 6 patients (22%). Procedural complications included device embolization in 2 patients, and both were retrieved percutaneously with successful deployment of another HSO. Residual shunt immediately post-closure was absent in 5/27 (19%), trivial in 15/27 (55%), small in 6/27 (22%), and moderate in 1/27 (4%). The median length of follow-up was 2 (0-9) years. Residual shunt at last follow-up was absent in 13/27 (48%), trivial in 8/27 (30%), small in 5/27 (18%), and moderate in 1/27 (4%). No complication occurred during follow-up. Of the 24 patients with RVE before closure, 2 are recent without follow-up and 1 is lost to follow-up. RV size normalized in 20/21 (95%) patients. No patient with a prior neurological event had a recurrence. The patient with moderate residual shunt and RVE had 1 HSO, and placement of a second HSO is planned. Conclusions: We conclude that closure of mASDs with 1 or more HSOs is effective with a low complication rate. The complication observed, embolization, did not significantly affect outcome in this series, as percutaneous retrieval was successful. In addition, the low profile of the HSO may facilitate safe implantation of multiple devices in smaller patients.

Cor Triatriatum Dextro Iatrogenica: An Unusual Complication of Atrial Septal Defect Closure Device

We present a case of a rare complication of atrial septal defect (ASD) device closure causing cor triatriatum dextro iatrogenica. A 29-year-old female presented with sudden onset dysarthria and ataxia and was found to have basilar and thalamic infarcts. Further evaluation using transthoracic echocardiography revealed an ASD which was repaired using the Gore HELEX septal occluder. Transesophageal echocardiography done after 2 months of ASD closure revealed an interesting finding termed cor triatriatum dextro iatrogenica. We briefly describe the case and discuss the relevant literature.

Transcranial Doppler Quantification of Residual Shunt After Percutaneous Patent Foramen Ovale Closure: Efficacy of the GORE® HELEX Septal Occluder

Ideally, percutaneous, mechanical closure of defects of the atrial septum should completely resolve shunt. To achieve this goal, more information is needed about the factors associated with device failure. Consecutive patients with cryptogenic neurological events who had severe baseline Valsalva shunt (Spencer Grade 5-5+) and intracardiac echocardiography (ICE) defined patent foramen ovale (PFO) who underwent percutaneous PFO closure with the GORE(®) HELEX Septal Occluder device were evaluated for residual 3-month shunt by transcranial Doppler (TCD). We closed 315 PFO patients with the HELEX devices: 15, 20, 25, 30 mm devices in 19, 138, 150, and 8 patients, respectively. Severe residual Valsalva shunt (TCD Grade 5-5+) at 3 months occurred in 23 of 315 (7%) of all patients and in 2 of 108 (2%), 5 of 86(6%), and 16 of 121 (13%) patients with none, Grade 4, and Grade 5-5+ baseline rest shunt, respectively (P = 0.002). At 3 months, rest shunting was essentially abolished by closure. The percent of patients with severe residual Valsalva shunt was also related to device size: 15 mm (0%), 20 mm (4%), 25 mm (10%), and 30 mm (25%) (P = 0.008) and to atrial septal aneurysm. All of these variables were independent predictors of failure by multivariate logistic regression. In an ICE-defined PFO population characterized by severe baseline Valsalva shunt and a high incidence of persistent (rest) shunting, the GORE(®) HELEX Septal Occluder device effectively reduces both provoked and persistent shunt. The causes of device failure are multifactorial. Larger devices perform less reliably suggesting the need for size-specific modifications to improve closure of more severe defects. (J Interven Cardiol 2011;24:366-372).

Percutaneous retrieval of the locked helex septal occluder

The HELEX device is approved for percutaneous closure of an atrial septal defect (ASD). It is also often used off-label to close patent foramen ovale (PFO). The device is well tolerated because it is very flexible, but this characteristic increases the likelihood of embolization of locked implants. While the company provides a mechanism to retrieve devices that do not lock correctly, retrieval of locked and released devices is much more difficult. A case of percutaneous retrieval of an embolized, locked HELEX device is reported. This device was successfully retrieved from the aorta by snaring the left atrial eyelet and unlocking the device. A variety of potential techniques for retrieval of these devices was explored on the bench top. Strategies which can be used to successfully retrieve embolized HELEX devices are described.

Fenestration of a Gore Helex Septal Occluder device in a patient with diastolic dysfunction of the left ventricle

We report successful deployment of a fenestrated Helex Septal Occluder in a 46-year-old lady with a moderate-sized secundum atrial septal defect and elevated left-ventricular end diastolic pressure secondary to renovascular hypertension. Initial balloon occlusion of the defect lead to significant rise in left atrial pressure. Creation of a 4-mm fenestration offered controlled decompression of the left atrium while reducing the atrial shunt considerably.

Failure of the GORE HELEX atrial septal defect occluder to treat membranous VSDs in swine

We tested the suitability of the GORE HELEX septal occluder for closure of membranous ventricular septal defect in three Yucatan minipigs that had naturally-occurring membranous ventricular septal defects. The animals were studied in the Gore Science Center Laboratory in Flagstaff, Arizona. In all of the device implantations, seating of the right disk along the right ventricular septum was problematic with resultant entanglement of one device in the chordae tendinae during attempted removal, implantation of one device onto the tricuspid valve papillary muscle and unlocking of one device occurring after implantation. A new occluder design appears to be needed to minimize the risk of disk entanglement with cardiac structures, particularly within the right ventricle. These studies did establish that the Yucatan mini swine are an acceptable and appropriate model for evaluating occluders intended for closure of membranous ventricular septal defects.

Late thrombus formation on the Helex septal occluder after double-lung transplant

Percutaneous device closure in patients with an atrial septal defect (ASD) or patent foramen ovale (PFO) has gained popularity because of the short learning curve, cosmetic advantage and relative safety compared with surgery. Device complications may include device embolism, erosion, pericardial tamponade or thrombus formation, and most complications occur early. Herein we describe the previously unreported finding of a late thrombus on a Helex device after PFO closure in a patient with cystic fibrosis and double-lung transplantation.