The closure of a patent foramen ovale (PFO) is a catheter-based intervention to prevent PFO-associated stroke. The PFO-occlusion device is advanced through the femoral vein and deployed across the interatrial septum using transesophageal echocardiography (TEE) and fluoroscopic guidance. The following protocol provides a step-by-step guide for the PFO-closure intervention using a double-disc device.
A patent foramen ovale (PFO) persists in about one-quarter of people and is the source of up to 25% of all ischemic strokes, especially strokes in young adults. PFO can be easily diagnosed by transthoracic contrast and/or transesophageal echocardiography. Interventional closure of the PFO via the femoral vein is a commonly used cardiological procedure since several trials have demonstrated the superiority of PFO closure over standard medical therapy in patients with PFO and who have experienced post ischemic, cardioembolic, or cryptogenic stroke. The current paper and video show the procedure of PFO closure in a step-by-step manner.
The foramen ovale is a remnant from embryologic heart development that usually closes within a few years after birth1. Previously, a patent foramen ovale (PFO) was found in 27.3% of cases in an autopsy study of 965 normal hearts2 and in 25.6% of the 581 subjects in a transesophageal echocardiography (TEE) study3. There are no significant differences with respect to sex or race/ethnicity2,3,4, and autopsy data show that the PFO diameter in adults varies from 1 mm to 19 mm (average: 4.9 mm) and increases with age5.
In up to 25% of all ischemic stroke cases, the cause cannot be attributed to clear factors such as the atherosclerosis of large vessels, small artery disease, or cardiac embolism despite extensive vascular, serological, and cardiac evaluation, hence the designation "cryptogenic stroke"6,7. Venous thrombus migration, through a PFO into the arterial circulation, has been shown as a possible cause of stroke in several studies and also by the imaging of the thrombus in transit8,9. PFO can be diagnosed with transthoracic contrast echocardiography when a contrast appears in the left atrium of the heart after filling the right atrium or within three heartbeat cycles after the Valsalva maneuver is terminated. Here, the shunt can be graded using the number of bubbles appearing in the left atrium: Grade 1 (fewer than 5 bubbles), Grade 2 (6-25 bubbles), Grade 3 (25 or more bubbles), and Grade 4 (visualization of the bubbles in the entire heart chamber)10. Further, transesophageal echocardiography (TEE) is necessary to evaluate the specific PFO morphology (see Figure 1). Certain findings are associated with a higher rate of thromboembolic events. These high-risk PFOs may have a large size, the presence of an atrial aneurysm (defined as an excursion of the septal tissue of more than 10 mm from the plane of the atrial septum into the right or left atrium), a large eustachian valve, spontaneous left-to-right shunts, and hypermobility of the septum during the Valsalva maneuver11. A number of scores, such as the RoPE score12, have been established to determine the probability that a discovered PFO is pathogenic. Finally, the PFO closure procedure is recommended by current guidelines for patients with cryptogenic stroke at 16 years to 60 years of age13. A further indication of this procedure is drug-resistant migraines.
Transesophageal echocardiography is regarded as the gold standard for the diagnosis of PFO and is utilized for the procedural planning of PFO closure. This procedure is performed percutaneously in a minimally invasive fashion in a standard cardiac catheterization laboratory using fluoroscopy, TEE guidance, and physiological monitoring. Intracardiac echocardiography (ICE) may be considered as an alternative to TEE by experienced operators14.
We describe the PFO-closure procedure under TEE and fluoroscopic guidance using a double-disc device made from a Nitinol (nickel titanium) wire mesh (i.e., the PFO occluder)15, as depicted in Figure 2.
The protocol and video publication were approved by the ethics committee of the University Hospital Jena. The patient gave his agreement for his anonymized data to be published for article purposes.
1. Physiological monitoring
2. Preparation of the sterile equipments
3. Venous puncture, catheter introduction, and invasive arterial pressure measurement
4. Local oropharyngeal anesthesia and introduction of the TEE probe
5. Wire passage through the PFO
6. Heparin application and measurement of the left atrial pressure (LAP)
7. Advancing into the LA
8. TEE-guided balloon sizing of the PFO
NOTE: Although balloon sizing is discussed critically by some experts, it is recommended to use a sizing balloon to determine the size of the PFO according to the instructions for use.
9. Occluder selection
10. Introduction of the device delivery system
11. Deployment of the PFO occluder
12. Evaluation of the correct device position
13. Sealing of the puncture and pressure bandage
14. Check-up and post-intervention care
In this study, the closure of a PFO was successfully performed. The Live echo was able to show the closure of the interatrial septum without residual shunt with the utilized device (see the Table of Materials). The control of the placement of the interatrial septum between the left and the right discs of the device is important to guarantee the stability of the device, and this is checked by TEE in several planes before the release of the device. The device lays smoothly on the interatrial septum without touching the roof of the atria. Due to the smooth device structure, the spreading of the device around the aortic root that is sometimes observed is acceptable. Within the following months, the endothelialization of the device closes the septum completely.
The results of trials that investigated the efficacy of PFO closure are depicted in Figure 3. Here, it can be seen that, in patients with cryptogenic stroke and relevant PFO, young patients (i.e., <65 years old) after interventional PFO closure had lower risk for recurrent strokes and mortality compared to the medical therapy only.
Peri-interventional complications in PFO closure are rare. Most complications are due to access site hematoma or, more rarely, AV shunt. The rate of bleeding as a complication ranges from 0% to 2.5%12,16,18,19,20. Central complications, including neurological complications such as transient ischemic attack (TIA) or stroke, which are mostly due to air embolism, are very rare. Additionally, pericardial effusion/tamponade are very rare complications. Pericardial tamponade occurred rarely in the RESPECT and REDUCE trials at a rate of 0.4% and 0.2%, respectively16,21. In other trials, no post-procedural pericardial effusion has been described. Cardiac perforation was a severe complication that occurred in 0.25% of patients in the CLOSURE-I trial and in 0.2% of patients in the RESPECT trial20,22. Device-associated atrial fibrillation occurs more often (in 0.5% to 5.4% of patients)23; this also depends on the device used and can occur either immediately or after several days16,18,19,20,21,24. Device-associated thrombus occurs in 0% to 1.1% of patients.
Figure 1: High-risk persistent foramen ovale. The arrow indicates prominent eustachian valves. The asterisk indicates an atrial septal aneurysm (ASA). The triangle indicates spontaneous right-to-left shunt. Please click here to view a larger version of this figure.
Figure 2: PFO occluder. The PFO occluder is a self-expandable, double-disc device made from a Nitinol wire mesh. Please click here to view a larger version of this figure.
Figure 3: Hazard ratios from representative randomized PFO trials. (A) RESPECT trial, (B) REDUCE trial, (C) CLOSURE-I trial. Please click here to view a larger version of this figure.
The interventional closure of a PFO is relatively simple compared to other procedures in interventional cardiology. It is important to perform it without complications since patients are mostly young and experience no short-term benefit from the procedure due to its prophylactic nature, in contrast to potentially life-saving therapies during acute myocardial infarction.
The critical steps of the procedure from our perspective are the safe puncture of the groin to avoid bleeding complications, the adequate flush of all the catheters and the device to avoid air embolization, and the selection of the right device size to assure a complete seal of the PFO. The balloon sizing of the PFO is controversial. We recommend performing balloon sizing on a routine basis to gather the most information possible for adequate device selection, since PFOs, and especially tunneled PFOs, vary significantly in size. The measurement is performed in two perpendicular TEE planes (e.g., 45° and 135°) and is confirmed by the angiographic assessment of the thinnest balloon tail. This helps in selecting the smallest device that closes the PFO completely.
There is ongoing controversy regarding whether TEE guidance is needed, since fluoroscopy alone may suffice for guidance in many cases, and TEE requires constant sedation throughout the procedure for better TEE tolerance. We recommend using a combination of both imaging methods to gather the best imaging information and to keep the radiation exposure as low as possible in these predominantly young patients. Furthermore, TEE allows for monitoring and documenting the complete closure of the PFO and the proper position of the device before its final release. Some small PFOs may be also very difficult to pass without TEE guidance. In such cases, a device that is stiffer than a routine wire (e.g., a transseptal sheath) is recommended.
TEE can be also helpful in the presence of anatomical variations. Some patients have a prominent eustachian valve and extensive Chiari network, which can hinder the passage of the wire and the device and lead to incomplete closure of the PFO or RA obstruction. By using imaging with TEE, this scenario can be avoided.
The method shown in this publication is the standard method for modern PFO closure, and it can be used in almost all patients. Limitations to this procedure occur when access to the PFO via the vena cava is not possible due to, for example, additional congenital heart defects.
There are several different devices available for PFO closure, but all of them are two-disc devices with a similar function. The current guidelines recommend the use of these disc devices. Newer devices aim to minimize the amount of foreign material. The NobleStitch system tries to close the PFO with a single suture via a catheter-based system. To date, there are no data available regarding the effectiveness of such a deviceless system compared to double-disc systems. Other systems with absorbable devices are in development. Early data from different devices show good safety profiles but improvable efficacy25,26.
The authors have nothing to disclose.
None.
50 ml syringe- Perfusor syringe Luer-Lock 50 cc | B. Braun | 8728844F | Flush syringe |
Amplatz Super stiff Guide wire 260 cm | Boston Scientific | M001465021 | exchange wire |
Amplatzer Sizing ballon II 24 mm | Abbott | 9-SB-024 | sizing |
catheter set- Angiodyn Set Uni Jena | B. Braun | 6010111-0 | cover set |
Figulla Flex II PFO Occluder Procedure Pack | Occlutech | 19PFO25DP | various sizes available |
Mullins Sheat 7-11 fr.- Check Flow Performer Introducer- 9F 75 cm | Cook Medical | RCFW-9.0-38-75-RB-MTS | delivery sheath |
Multi purpose catheter 5 F – Impulse MPA 1 | Boston scientific | H749163911171 | atrial septal passage |
Sheath 4 F- Radiofocus Introducer II 4 Fr. 10 cm | Terumo | RS*B40K10MR | arterial blood pressure measurement |
Sheath 7-11 Fr- Radiofucus Introducer II 9 F 10 cm | Terumo | RS*B90N10MRD | Device Loading |