Russian Patient Travels to China for Medical Treatment: Large, Long-Tunnel PFO Treated with MemoSorb® Bioabsorbable Occluder

Patient Information

Gender: Female

Nationality: Russian

Age: 33

Chief Complaint: Recurrent headaches and dizziness for over ten years.

Present Illness History: The patient began experiencing dizziness and headaches without an obvious cause over ten years ago, accompanied by a sensation of vertigo. These episodes occurred paroxysmally, with frequencies ranging from every two days to once every few months, lasting several hours each time. Symptoms slightly improved after taking pain medication. There was no nausea, vomiting, chest tightness, chest pain, blurred vision, syncope, tinnitus, or other discomforts.

In November 2021, she experienced a sudden episode of left-sided limb weakness. In September 2023, she experienced left-sided hemianopia. No specific treatment was sought for either episode, and symptoms improved the next morning. In February 2024, due to severe dizziness and headache, she went to a local hospital where head MRI and cerebrovascular MRI were performed, showing no significant abnormalities.

Echocardiography Description

Contrast Transthoracic Echocardiography (cTTE):

The interatrial septum was intact, with no aneurysm seen. Color Doppler: No obvious shunt signal detected at the atrial level.

After agitated saline was injected via the antecubital vein, the right heart showed immediate dense opacification with microbubbles.

After 6-7 cardiac cycles, several microbubbles (approx. 5-8 bubbles in a single frame) appeared in the left heart.

After the Valsalva maneuver, numerous microbubbles appeared in the left heart within 2-3 cardiac cycles (approx. >30 bubbles in a single frame).

Microbubbles gradually disappeared from the heart approximately 4-5 minutes after stopping the injection.

Echocardiography Indication:

Contrast Transthoracic Echocardiography (cTTE)

Intracardiac Right-to-Left Shunt (Grade 3) combined with Extracardiac Shunt (Grade 1). Patent Foramen Ovale (PFO) combined with suspected pulmonary arteriovenous fistula shunt was considered.

Clinical Strategy

Defect Measurement:

Pre-procedure PFO width: 3.1 mm, Tunnel length: 5.9 mm.

Post-traversal entry PFO width: 7.9 mm, Exit width: 5.3 mm, Tunnel length: 9.8 mm.

Device Selection Considerations: This was a large, long-tunnel type PFO, classified as complex. After comprehensive consideration, the operator planned to select a symmetric occluder, model BDPFO-I 2424, using a 12F bioabsorbable sheath.

Pre-procedural Plan:

1.Perform angiography to exclude pulmonary arteriovenous fistula.

2.Perform PFO closure via femoral access. Radiopaque marker points would assist in positioning the device discs under DSA guidance. Intracardiac Echocardiography (ICE) would be used throughout the procedure to assist in judging the deployment and release of the occluder.

Procedure Details

1.Intraoperative Angiography:

Pulmonary artery angiography results ruled out pulmonary arteriovenous fistula.

2.PFO Traversal: Achieved using a guidewire and catheter technique.

3.Left Disc Deployment:

The cable was advanced, the sheath was retracted, and the shaping wire was pulled to form the left disc. The three marker points on the left disc converged.

The cable and sheath were retracted to allow the left disc to appose the interatrial septum.

ICE confirmed the left disc was formed and apposed to the septum.

4.Right Disc Deployment:

The sheath was retracted while the cable was supported forward, releasing the right disc. The shaping wire was gently pulled to form the occluder.

DSA showed the four marker points converging.

 The cable and sheath were pulled, confirming the two discs straddled the interatrial septum.

Gentle traction on the shaping wire confirmed both discs were well-apposed to the septum with appropriate morphology, ready for locking.

5.Shaping and Locking:

The sheath was advanced forward while the shaping wire was pulled, completing the lock.

ICE showed both discs tightly apposed to the septum.

DSA showed the four marker points converged together in a quadrilateral distribution.

6.Pull Test: 

The four marker points remained converged, their relative positions unchanged, moving together with cable manipulation.

Gentle traction on the cable showed the relative position of the two discs remained unchanged, still tightly apposed to the septum, confirming successful locking.

7.Device Release:

The shaping wire was pulled a second time to lock before final release.

The shaping wire was removed, the sheath was advanced, and the cable was rotated counterclockwise. The four marker points maintained their relative position, indicating successful device release.

ICE showed the bioabsorbable PFO occluder had good morphology.

8.Post-procedure Echocardiography:

ICE showed the occluder's left and right discs firmly apposed to the interatrial septum, with no residual shunt, indicating successful closure.

9.Procedure Images

Case Summary

Pulmonary arteriovenous malformation (PAVM), also known as pulmonary arteriovenous fistula, is a pathological connection between the pulmonary artery and pulmonary vein, often involving a thin-walled aneurysmal sac. It is a rare pulmonary vascular disease, typically diagnosed based on clinical presentation, imaging, and special examinations. Common imaging includes chest X-ray, CT scan, MRI, and pulmonary angiography.

In this patient, contrast transthoracic echocardiography (cTTE) revealed a late-appearing (6-7 cycles), small number (5-8 bubbles) of left heart microbubbles at rest, and an early-appearing (2-3 cycles after Valsalva), large number (>30 bubbles) of left heart microbubbles, indicating Intracardiac Right-to-Left Shunt (Grade 3) combined with Extracardiac Shunt (Grade 1). Therefore, PFO possibly combined with a pulmonary arteriovenous fistula shunt was considered. Pre-procedural pulmonary angiography showed no shunt, ruling out pulmonary arteriovenous fistula.

The patient's pre-procedure PFO measurements (width 3.1mm, tunnel length 5.9mm pre-traversal; entry width 7.9mm, exit width 5.3mm, tunnel length 9.8mm post-traversal) classified it as a large, long-tunnel PFO. When selecting the bioabsorbable PFO occluder, considerations included optimal apposition to both sides of the interatrial septum to stop the right-to-left shunt, while not interfering with heart valve function. Consequently, a size 2424 bioabsorbable PFO occluder was chosen for the procedure.

The procedure was performed percutaneously under DSA and ICE guidance. Post-procedure ultrasound confirmed the bioabsorbable PFO occluder had good morphology and position, complete closure with no residual shunt, no pericardial effusion, and no adverse reactions before or after closure, indicating successful closure.

Acknowledgement: Thanks to Dr. Lu Linxiang from Shanghai East Hospital (South Campus) for sharing this case.