Cardi-O-Fix ASD Occluder:

The StarwayCardi-O-Fix ASD Occluder is a self-expandable, double disc implant device made from a Nitinol wire mesh. The two discs are linked together by a short connecting waist corresponding to the size of the ASD. In order to increase its closing ability, the discs and the waist are filled with polyester fabric. The polyester fabric is securely sewn to each disc by surgical sutures.

Starway ASD Occluders have been designed with two types, the traditional type and the improved type. The traditional type has double ends, and the improved type only has single end. Both types can be used for the intended patients.

Type one (A1) has double ends (Fig.1) and type two (A2) has single end only (Fig.2).

a. Distal end
b. Wire mesh
c. Polyester
d. Proximal end
D. Device size in diameter

Intended Use:

The StarwayCardi-O-Fix ASD Occluder is a percutaneous, transcatheter, permanent implant device intended for the occlusion of atrial septal defects (ASD) in secundum position.
The StarwayCardi-O-Fix ASD Occluderis a single-use device, which is sterilized via ethylene oxide (EO).

Indications:

1. Patients have echocardiographic evidence of ostium Secundum atrial septal defect (ASD) with diameter ¡Ü 36 mm.
2. A distance of ¡Ý 5mm from the margins of the defect to the coronary sinus, AV valves and right upper lobe pulmonary vein.

Contraindications:

1. Patients associated with other congenital cardiac anomalies which require cardiac surgery.
2. Ostium primum atrial septal defect.
3. Severe pulmonary hypertension, ¡®Eisenmenger¡¯s Syndrome¡¯.
4. Total occlusion of inferior vena cava due to thrombosis.

General Exclusion Criteria:

1. Sepsis (local/generalized) .
2. History of repeated pulmonary infection.
3. Any type of serious infection < 1 month prior to procedure.
4. Malignancy where life expectancy is < 3 years.
5. Demonstrated intracardiac thrombi on echocardiography.
6. Inability to obtain informed consent.

Cardi-O-Fix Delivery System:

The Cardi-O-Fix Delivery System is comprised of a delivery sheath, dilator, loader, hemostasis valve, delivery cable with plastic vise.
Starway 45¡ãCardi-O-Fix Delivery System was designed specifically to facilitate attachment, loading, delivery and deployment of Cardi-O-Fix ASD and PFO Occluders.
The Cardi-O-Fix Delivery Systemis a single-use device which is sterilized via ethylene oxide (EO).

Sizes of the Delivery System for ASD Occluder are:
7F, 8F, 9F, 10, 12F and 14F (in French size)
The Tip of Delivery Sheath is: 45¡ã.
Delivery Sheath with Hemostasis Valve - used to deliver the occluder device.
Dilator ¨C used to prevent from penetration of tissue.
Loader ¨C used to introduce the occluder into the delivery sheath.
Delivery Cable ¨C the device is screwed onto the distal tip of the delivery cable, which allows for placement (and if necessary, retrieval) of the device.
Plastic Vise ¨C facilitates directional control and serves as the ¡°handle¡± for disconnecting (unscrewing) the delivery cable from the device.
(Fig. 1 Assembled Delivery System & Fig. 2 Parts of Delivery System)
A. Delivery Sheath
B. Dilator
C. Hemostasis Valve
D. Loader
E. Delivery Cable with Plastic Vise

Fig. 1 Assembled Delivery System for ASD & PFO Occluders

Fig. 2 Delivery System for ASD & PFO Occluders

Procedure:

1. A standard right heart catheterization is performed following puncture of femoral vein.
2. The right heart catheter is introduced to left atrium, and to left upper pulmonary vein.
3. The stiff J tip guidewire is introduced to the left pulmonary vein through the right heart catheter, then the right heart catheter is removed together with vessel sheath. Meanwhile heparin is administered routinely via IV infusion route.
4. Before being advanced into the heart, the measure balloon is inflated with contrast medium to drive the air out, then deflated and kept in negative pressure by drawing the medium out. Balloon catheter is exchanged over the wire and positioned in the left atrium, inflated with contrast and pulled back across the defect under fluoroscopic and echocardiographic guidance. The size of the balloon just prior to its popping through the defect is the stretched diameter of the defect, where a slight deformity of the sizing balloon can be seen. The balloon catheter is removed, reinflated with the same amount of contrast, and pushed through holes on a sizing plate to determine the stretched diameter of the defect. Compare readings of the three different methods, and choose a proper device.
5. The delivery sheath is exchanged to left atrium over the wire. At this moment, pay more attention not to bring air into the body, otherwise air embolism in coronary arteries would happen.
6. The delivery cable is passed through the loader, and the occluder is screwed clockwise into the tip of the delivery cable. Screwed and unscrewed for 3-4 times, but not over-tightened when screwed on.
7. The device and the loader are immersed in saline solution as the device is pulled into the loader to remove the air. Flush via the side arm of the loader.
8. The loader is introduced into the delivery sheath, and without rotation the device is advanced into the left atrium.
9. With fluoroscopic and echocardiographic guidance, the sheath is retracted until the left atrial disc is opened in the middle of the left atrium. The sheath with the delivery cable in it is pulled back as one unit till the left atrial disc against the interatrial septum (it can be felt and also detected by echocardiography). The sheath is retracted further with constant tension on the delivery sheath and cable, and the right atrial disc is deployed in the right atrium.
10. With echocardiographic observation, the delivery cable is pushed forward and pulled backward repeatedly with a proper tension, to confirm a stable position of the device. If misplacement occurs, the device can be retrieved into the delivery sheath and redeployed, or replaced by another device.
11. The device is released by turning the delivery cable counterclockwise using the plastic vise, as indicated by the arrow on the delivery cable.
12. Heparin is given during 3 days following the procedure, and an antiplatelet medicine (eg. Aspirin) for half a year.

Complications & Solutions:
There would be several complications during or after the procedure:

1. Air embolism in coronary arteries: It may happen if air is brought into the body due to improper manipulation, in that it can get reach to coronary arteries via left atrium-left ventricle-aorta route when patient kept in supine position. Symptoms and signs of acute myocardial infarction will be shown, which need immediate treatment such as sublingual nitroglycerin, oxygen, and intravenous vasodilators. If symptoms are relieved and electrocardiogram is returned to normal in a short time, the procedure can be continued. Otherwise stop the operation.
2. Thrombosis: Usually, it is caused by improper use of anticoagulatants during or after the procedure, and should be treated symptomatically in most cases. However, thromboembolism must be differenciated from intracranial hemorrhage, especially in senior or hypertensive patients.
3. Arrhythmia: If severe arrhythmia occurs before the device released, the procedure should be stopped immediately. Retrieve the device and remove it out of the body. Then refer the patient to cardiac surgeon. If it happens after the procedure, drugs to diminish edema, protect myocardium or treat arrhythmia should be given. When necessary, temporary pacing lead should be advanced during the observation period within a few days. If arrhythmia persists and cannot be controlled by the drugs, it must be attempted to take the device out by surgery or/and implant a permenant pacemaker.
4. Device dislodgement: If it happens, the device must be taken out by interventional method or surgery at once.
5. Cardiac tamponade: Usually caused by improper operation. It is a severe adverse event and may be life-threatening if in delayed awareness and treatment. The clinical symptoms and signs include: sudden cardiac pain (at the moment of rupture), dropping blood pressure, increased heart rate, disappeared pulsing of cardiac edge and enlarged heart shadow on x-ray. Blood volume in pericardial cavity can be assessed by echocardiography. If it happens, pericardial puncture must be performed immediately. However, it can be prevented if it is assured to introduce over the guidewire and manipulate tenderly. When it is misplaced, the device should be retracted, removed and redeployed.