Introduction

The ductus arteriosus is present in all fetuses allowing blood to bypass the non-functioning lungs. At birth or shortly after birth as the baby starts to breathe, the Ductus Arteriosus would normally close permanently. Failure to do so results in Patent Ductus Arteriosus (PDA) which is an open channel allowing blood to flow from the aorta (blood vessel carrying blood from the heart to the rest of the body) to the pulmonary artery (blood vessel supplying the lung). If the PDA is large, the heart will be volume loaded resulting in heart failure. The PDA also carries a risk of bacterial infection (Infective Endarteritis). PDA can be closed by inserting a device through the blood vessels in the groin (percutaneous transcatheter approach).

How is the procedure performed

This procedure is performed in the cardiac catheterisation lab. This procedure is performed under local anaesthetic (LA). You will lie on an X-ray table and an X-ray camera will move over your chest during the procedure. A plastic catheter (a long tube) will be inserted via a vein in the groin and navigated until it reaches the heart. Sometimes (depending on individual case), the catheter is position at different chambers of your heart to measure the pressure and oxygen content prior to device closure. In certain circumstances, balloon sizing of the PDA may be required. Once your doctor is satisfied with all the measurements, the appropriate size device is connected onto a cable, put into a special delivery tube, advanced through your PDA and carefully deployed. Your doctor will study the device’s position and stability before releasing the device. The catheter will be removed and the procedure is completed.

Is the procedure safe

The procedure usually takes between 1 to 2 hours and the success rate is about 95%. However, there are known risks involved. The risks and their estimated incidence of occurrence are:
• Device dislodgement (embolization) and the need for emergency heart surgery – <1%
• Death – <1% (usually from perforation of the heart chamber).
• Dislodgement of clot or air bubbles to the brain (causing stroke) and other organs –<1%
• Rhythm disturbance (arrhythmia) are usually transient -<1%
• Device distorting blood flow in the Pulmonary Artery <1%
• Other potential risks – Allergic dye reaction, anaesthetic reaction, bleeding and bruising around the sheaths in the groin, injury to the artery/vein/nerves in the groin, infection, fever, headache, migraine, allergic reaction to the nickel component of the device

Some of these complications if they occur, are of a serious nature and may require further treatment including surgery and prolonged hospitalisation. In the event of device dislodgement, you may require surgery for removal of the device and ligation of the PDA at the same time. As PDA device is relatively new, long term follow-up data are not available and there may be other risks which are not known at this time.

Who is it for

Adults with PDA and heart enlargement or elevated pressure in the lung (as long as pressure is not irreversibly elevated) should be offered closure. In adults, device rather than coils are used as the defect is usually > 4mm in size. If the lung pressure is already very high, careful measurement of the lung pressure and lung resistance need to be performed first to determine if it is still safe to close such a defect.