PDA Occluder System

Cardi-O-Fix PDA Occluder:

Starway Cardi-O-Fix PDA Occluderis a self-expandable, mushroom shaped implant device made from a Nitinol wire mesh. A 2-millimeter retention skirt assures secure positioning in the mouth of the patent ductus arteriosus (PDA). The communication is closed by the induction of thrombosis which is accomplished by polyester patches sewn securely into the device.
Starway PDA 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 (P1) has double ends (Fig.1) and type two (P2) has single end only (Fig.2).

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

Intended Use:

Starway Cardi-O-Fix PDA Occluder is a percutaneous, transcatheter, permanent implant device intended for the occlusion of patent ductus arteriosus (PDA).
The Cardi-O-Fix PDA Occluderis a single-use device which is sterilized via ethylene oxide (EO).

Indications:

Patients who are diagnosed to suffer from the patent ductus arteriosus (PDA).

Contraindications:

1. Patients with ¡®Silent¡¯ PDA only diagnosized by echocardiography,but without any significant hemodynamic alteration or clinical symptom.
2. Associated with other congenital cardiac anomalies, which require cardiac surgery.

General Exclusion Criteria:

1. Sepsis (local/ generalized).
2. Any type of serious infection within 1 month prior to procedure.
3. Malignancy where life expectancy is less than 5 years.
4. Demonstrated venous thrombosis in lower limbs.
5. Severe pulmonary hypertension, ¡®Eisenmenger¡¯s Syndrome¡¯.
6. Inability to obtain informed consent.

Cardi-O-Fix Delivery System:

Starway 180degree Cardi-O-Fix Delivery System was designed specifically to facilitate attachment, loading, delivery and deployment of Cardi-O-Fix PDA, VSD and Plug Occluder and it is comprised of a delivery sheath, dilator, loader, hemostasis valve, delivery cable with plastic vise.
The Cardi-O-Fix Delivery System is a single-use device which is sterilized via ethylene oxide (EO).
The size of delivery system for PDA Occluder: 6F, 7F, 8F, 9F and 10F.
The tip of the delivery sheath is: 180¡ã.

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

Procedure:

1. A standard right heart catheterization is performed following puncture of femoral artery and femoral vein.
2. A aortography is performed to demonstrate PDA by passing a pigtail catheter into descending aorta near the arch. Its anatomy, size and length are assessed.
3. A right heart catheter is introduced with the exchange wire retrogradely through the PDA to descending aorta, then the right heart catheter is removed together with vessel sheath. The delivery sheath is introduced over the wire and positioned in descending aorta.
4. According to the angiogram of PDA, a device of 2-4mm bigger than its narrowest diameter is chosen for loading.
5. 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.
6. 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.
7. The loader is introduced into the delivery sheath, and without rotation the occluder device is advanced into the descending aorta.
8. The delivery sheath is retracted until the retention disc is opened, then the sheath with the delivery cable in it is pulled back as one unit until the disc against the aortic side of the ductus (it can be felt and by fluroscopic or echocardiographic observation). The sheath is further retracted with constant tension on the delivery cable, the round waist is deployed in the PDA.
9. Aortography is performed once more to confirm a correct placement or detect a residual shunt.
10. If it is misplaced, the device can be retrieved into the delivery sheath and redeployed, or replaced by another device.

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 three major kinds of complications: mild left to right shunt, hemolysis and device dislodgement.

1. Residual shunt: It is considered normal if mild left to right shunt seen in a few patients just after the procedure, but it disappears as time goes by, usually in 2-3 months. While if the shunt persists half a year later, another interventional procedure should be considered one year after the first.
2. 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 sign of improvement show after medical therapy or renal function damage occurs, a surgical operation or another intervention should be attempted at once.
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 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.
4. Device dislodgement: If it happens, the device must be taken out at once by either surgery or interventional method.