Secondary embolization of a Helex occluder implanted into a secundum atrial septal defect

Chronic embolization of an atrial septal occluder device: percutaneous or surgical retrieval? A case report

Percutaneous closure of secundum atrial septal defects may be complicated by immediate or late device embolization. Percutaneous retrieval techniques are usually successful even if sometimes surgery is required. The optimal selection of an atrial septal defect and the choice of appropriate device sizes are fundamental to reduce the incidence of embolization. We describe a case of late device embolization occurring two years after transcatheter atrial septal defect closure and for which percutaneous retrieval was unsuccessfully attempted.

First experience with the 2005 modified Gore Helex ASD occluder system

We report about our initial experience for the in 2005 modified Helex (Gore) device for closure of atrial septal defects (ASD) and persistent foramen ovale (PFO). Major changes were made at the delivery system for simplifying the Helex implantation procedure. We treated 11 patients, 8 children and 3 adults, with ages between 3 and 62 years. In 10 patients the diagnosis was a relevant ASD with volume overload of the right heart (Left to right shunts between 30 and 50%). One adult (age 58 years) have had a small left to right shunt with a PFO-like defect and the history of 2 neurologic embolic events. In 3 patients we found 2 defects. In all patients a Helex occluder was implanted successfully. The mean fluoroscopy time was 8,4 minutes. The immediate occlusion rate after 24 hours was 91%. In all cases there was a very good adaptation of the device to the anatomical structures. In this small series, the Helex occluder appears to offer a reliable system of occlusion for small and moderate ASDs and for PFO with minimal risk of major complications.

Analysis of factors related to successful transcatheter closure of secundum atrial septal defects using the HELEX septal occluder

BACKGROUND

The HELEX septal occluder is a new transcatheter atrial septal defect occlusion device. This study analyzes the data collected from the first US clinical trials with this device to determine the most significant factors in successful use of the device.

METHODS

Tables of subsets of data were constructed in categories of possibly significant patient and device variables compared with important outcomes. Chi2 analysis was used to determine which variables had significant impact on outcomes.

RESULTS

The device was successfully implanted in 87% of patients (298/342). A major adverse event occurred in 5.8% (mostly device removal for various reasons). A significant residual leak persisted at 1 year in 2.6%. A fracture of the wire frame occurred in 8%--all were asymptomatic and only 1 required treatment. Overall composite success (no significant leak and no major adverse event) was seen in 91.5%. Patient age, body surface area, and device size had no significant influence on outcomes, except that wire frame fractures were more likely with the 35-mm device. Defect stretch diameter had the largest influence on outcomes, and implantation was possible in only 67% if the stretched diameter of the defect was >20 mm. Device-defect ratio also had a significant effect on delivery success and composite success.

CONCLUSIONS

The HELEX septal occluder is best suited for small to moderate atrial septal defects with a stretch diameter <20 mm. Although composite success was achieved in 80% of patients when a device-defect ratio <1.6 was necessitated or elected, use of a device that provided a ratio >2 resulted in 95% composite success, and is recommended when possible.

Embolization and transcatheter retrieval of coils and devices

Embolizations of coils and devices are well-known complications of transcatheter procedures performed in order to occlude extracardiac or intracardiac shunts. A review of the literature and of our experience was performed to provide a succinct review of existing transcatheter retrieval techniques. After embolization of a coil or device, the appropriate initial procedure involves repositioning of the coil or device using a snare or bioptome to a location where harm to the patient is minimized. The subsequent retrieval technique depends on the characteristics of the coil or device involved. Coils may be retrieved using a bioptome or a snare. Devices must be snared, often in specific places. Both may be pulled into long or short, appropriately sized retrieval sheaths. To minimize potential morbidities associated with these retrievals and to maximize efficacy of retrieval, operators performing transcatheter coil or device occlusions must be familiar with retrieval techniques.