This protocol helps to learn all the steps for the standardized procedure for interventional closure of the PFO. We show a standardized technique that is safe and feasible and allows to close nearly every PFO. To begin, establish a peripheral venous access line and connect to 500 CC of sodium chloride, then fix the arms and legs of the patient.
Initiate the ECG, peripheral oxygen saturation and pulse measurements. Perform sterilization of the right groin using an iodine-based solution. Prepare sterile equipment with the materials required by the catheter assistant or nurse.
Cover the sterilized femoral access site with a transparent foil plaster. Apply local anesthesia to the oropharyngeal region five to 10 times, then apply bite protection. Prepare ultrasound guidance under sterile conditions.
Access the right femoral vein through palpation, fluoroscopic, or ultrasound guidance. Provide subcutaneous anesthesia. Perform the venous puncture of the groin.
Then introduce a standard wire with a J-Tip and a five French multipurpose catheter into the superior vena cava. Perform an arterial puncture of the femoral artery and introduce a four French sheath for pressure monitoring. Many interventional cardiologists may find non-invasive blood pressure monitoring reliable in stable patients or use a radial access.
Once the arterial blood pressure measurement is established, start the conscious sedation of the patient with midazolam and propofol as described in the text manuscript. Measure the pressure in the right atrium. The CVP should be in a normal range of around six to 12 millimeters of mercury.
If the main CVP is lower, give a sodium chloride infusion until the CVP reaches a minimum of six millimeters of mercury to avoid air embolism during the procedure. Introduce the TEE probe and assess possible preexisting pericardial effusion in a four-chamber view and set the bicaval view to include the PFO. Advance, a J-Tip standard wire and the multipurpose catheter into the left atrium by slightly pushing forward the wire and placing it in the left upper pulmonary vein under fluoroscopy and TEE guidance.
Obtain optimal TEE imaging by sweeping from 30 degree to 110 degree. Obtain a 45-degree left anterior oblique view as this may be helpful. Once the catheter is introduced into the left atrium, administer a bolus injection of 100 IU heparin per kilogram body weight to reach an activated clotting time of around 250 seconds.
The activated clotting time should be controlled after around five minutes by a point-of-care ACT analyzer. Measure the left atrial pressure via the multipurpose catheter. If it is below five millimeters of mercury, administer IV fluid to reach a mean left atrial pressure of five to 10 millimeters of mercury.
Advance a stiff, long guide wire with a soft tip along the catheter into the left atrium, targeting the upper pulmonary vein. Then deair the balloon carefully with one-fourth to two-fourth contrast dye and saline mix outside the patient. Exchange the multipurpose catheter for a 24-millimeter sizing balloon.
Position the balloon across the PFO and inflate it with a 0.9%sodium chloride in the contrast agent solution in a three-to-one ratio. Use two perpendicular TEE projections for the PFO measurement. Confirm the dimensions by angiography images.
In both cases, the measurement of the smallest balloon tail is crucial. Use a sizing chart to select the size and type of the PFO-occluded device using the PFO size and total septum length assessed by TEE or TTE according to the manufacturer's instructions. Prepare an adequately-sized closure device as described in the text manuscript.
And flush properly to eliminate air bubbles. Deflate the sizing balloon and exchange it for the delivery sheath. Introduce the delivery sheath via the stiff guide wire.
Then remove the introducer and wire. After the aspiration of blood, ensure a wet-to-wet connection between the sheath and the PFO closure device to guarantee air bubble-free advancement of the device. Introduce the closure device through the sheath via a wet-to-wet connection by flushing saline through the side port and ensuring back bleeding from the sheath.
Then push the device forward into the sheath. Once the device is visible within the sheath, observe if there is no air bubble in front of the device. Then pull the device back approximately two centimeters to confirm the attachment of the device to the delivery cable.
Push the device forward into the left atrium and carefully retract the sheath into the mid-left atrium in a push and pull movement and the echocardiographic guidance, which allows the left-sided disc to unfold. Here, TEE guidance, instead of angiography, is sufficient and recommended to reduce the radiation dose. We draw the left-sided disc toward the interatrial septum until a subtle resistance is felt and the left-sided disc is seen on the septum by TEE.
Under discreet tension, pull the sheath back into the right atrium, expanding the right-sided disc. Push the device gently against the interatrial septum until the discs attach. Assess the correct position of the closure device with TEE and angiography.
With the latter, the Pacman sign indicates the correct device placement. Inspect the edges of the device thoroughly for any misalignments concerning the aorta or the roof of the left atrium, which may lead to localized compression damage. A push-pull tug test can help to show the stability of the device.
Once the position of the device is correct, disconnect the delivery cable and remove the sheath. Close the femoral vein with the resorbing suture using a figure of eight stitch of the subcutaneous tissue material or a vessel closure device. Use a tight-sitting pressure bandage to prevent local bleeding.
After removing the arterial blood pressure monitoring device, perform manual compression of the common femoral artery or use a closure device followed by applying a tight bandage. Continue non-invasive monitoring of the blood pressure and heart rate for 24 hours. Provide heparin for 24 hours as described in the text manuscript.
In young patients, less than 65 years old, a lower risk for recurrent strokes and mortality was observed after interventional PFO closure compared to medical therapy only. Peri-interventional complications in PFO closure were rare. Pericardial tamponade rarely occurred in the RESPECT and REDUCE trials at a rate of 0.4 and 0.2%respectively.
Cardiac perforation was a severe complication that occurred in 0.25%of patients in the CLOSURE-I trial and 0.2%in the RESPECT trial. It is crucial that the device opening and positioning is done under TEE control to obtain the best possible result. If TEE is unavailable, the device position can also be checked by contrast dye injection.
