Cardi-O-Fix VSD Occluder:

The StarwayCardi-O-Fix VSD 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 VSD. 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 VSD 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 (V1) has double ends (Fig.1) and type two (V2) has single end only (Fig.2).

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

Intended Use:
The Starway Cardi-O-Fix VSD Occluder is a percutaneous, transcatheter, permanent implant device intended for the occlusion of ventricular septal defects (VSD).
The Starway Cardi-O-Fix VSD Occluderis single-use device which is sterilized via ethylene oxide (EO).

Indications:

The Starway Cardi-O-Fix VSD Occluder is indicated for use in patients with complex ventricular septal defects of significant size to warrant closure who are considered to be at high risk for standard transatrial or transarterial surgical closure based on anatomical conditions and/or based on overall medical conditions.

1. Patients with demonstrated muscular or membranous ventricular septal defects (VSD) .
2. Size of VSD: It should be 3-15mm from left ventricle. If it is multi-hole from right

ventricle, the largest hole should be ¡Ý 2mm. In children, it should be < 10mm.

1. Margin of VSD from aortic valve > 2mm, no significant aortic valvular prolapse or regurgitation.
2. Margin of VSD from tricuspic valve ¡Ý1.5mm, no significant congenital anormaly or more than moderate regurgitation of tricuspid valve.
3. Patients who underwent surgical closure of ventricular septal defects and have a residual left-to-right shunt.
4. Patients with LV dilatation.
5. Patients with no other anormalies that require surgical correction.
6. Patients with age > 3 years old.

Contraindications:

1. Patients associated with other congenital cardiac anomalies which require cardiac surgery.
2. Patients with aortic valve prolapse or regurgitation.
3. Patients with severe pulmonary hypertention, ¡®Eisenmanger¡¯s Syndrome¡¯.
4. Patients with 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 within 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:

Starway 180¡ãCardi-O-Fix Delivery System was designed specifically to facilitate attachment, loading, delivery and deployment of the Cardi-O-Fix VSD, PDA and Plug Occluderand it is comprised of a delivery sheath, loader, dilator, hemostasis valve, delivery cable with plastic vise.
Starway Cardi-O-Fix Delivery Systemis a single-use device which is sterilized via ethylene oxide (EO).
The size of the delivery system for VSD Occluder: 7F, 8F and 9F.
The tip of delivery sheath: 180¡ã.

Fig. 3 Delivery System for VSD, PDA & Plug Occluders

Procedure:

1. A standard left and right heart catheterization are performed following puncture of femoral artery and vein.
   
2. Left ventricular angiography is perform in long axis view using pigtail catheter to assess the size, location and shape of VSD, and its relation to aortic valve.
3. A right coronary curve catheter or other specific catheter is used to cross the VSD from left ventricle (Note: tender manipulation to avoid ventricular arrhythmia). A 260mm long floppy exchange wire (hydrophilic or noodle) is easily introduced into right ventricle and to right atrium.
4. A right heart catheter is introduced to right atrium. The noodle guidewire is snared out to femoral vein with the snare-shaped foreign body forceps, so a continuous arteriovenous loop of aorta-left ventricle-VSD-right ventricle-right atrium-inferior vena cava is established.
5. The right heart catheter is removed with the vessel sheath. A delivery sheath is passed over the wire via the pathway of inferior vena cava-right atrium-right ventricle-VSD-left ventricle. Note: tip of the sheath should reach the apex of left ventricle.
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 apex of left ventricle.
9. With fluoroscopic and echocardiographic guidance, the sheath is withdrawn to the left ventricular outflow tract far from the mitral valve apparatus. Then the left disk is deployed and pulled back gently against the septum. Under gentle tension on the sheath the right disk is deployed by advancing the delivery catheter.
10. A left ventriculargraphy is repeated to assess if there is any residual shunt or encroachment of aortic valve.
11. Careful observation using echocardiography if there is impingement of tricuspid valve.
12. Monitor if any cardiac arrhythmia exists on electrocardiography.
13. The device is released only when its position is optimal and interference with the aortic valve and tricuspid valve structures has been excluded.
14. When it is misplaced, the device should be retracted, removed and redeployed.
15. The device is released by turning the delivery cable counterclockwise using the plastic vise, as indicated by the arrow on the delivery cable.

Complications & Solutions:

There would be several complications during or after the procedure: thrombosis, occluder dislodgement, cardiac tamponade, hemolysis, cardiac arrhythmia, residual shunt, etc.

1. 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 differentiated from intracranial hemorrhage, especially in senior or hypertensive patients.
2. Device dislodgement: If it happens, the device must be taken out by interventional method or surgery at once.
3. 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.
4. Hemolysis: Mechanic damage of red blood cell when insufficient occlusion occurs, that is attributed to improper device size or position, large residual shunt before occluder release and patent coagulation deficiency. If hemolysis happens, give some medicines to promote thrombogenicity, while monitoring hemoglobin or red cell count, renal function, and urine color. Some patients can get better with the treatment when delayed thrombosis gradually stops the abnormal shunt. However, if no signs of improvement show after medical therapy or renal function damage occurs, a surgical operation or another intervention should be attempted at once.
5. Arrhythmia: There are many conduction fibers passing through interventricular septum, so severe arrhythmia may be evoked during or after the procedure due to surrounding tissue edema, eg. third-degree AVB. 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 of a few days. If it persists and cannot be controlled by the drugs, it must be attempted to take the device out by surgery or/and implant a permanent pacemaker.