Patent Ductus Arteriosus (PDA)
Patent ductus arteriosus (PDA) is a vessel connecting the two major cardiac vessels (the aorta and the pulmonary artery) which should have closed at birth. If left untreated, a PDA causes the heart to enlarge over time, eventually causing fluid to build up on the lungs ("heart failure"). Without treatment, about half of dogs with a PDA would die before their first birthday.
Heartvets is one of the few specialist centres in the UK to regularly perform PDA closure. Due to our considerable experience we have a high success rate and the long-term outcome is very good.
We close PDAs by passing catheters via the artery in the back leg and plugging the abnormal blood vessel with a metal plug (Amplatz Canine Duct Occluder) to stop flow through it. This device has been specifically designed for use in dogs. Part of the assessment we make is to measure the size of the PDA (with ultrasound, or "Echo") to make sure that we fit the right size of ACDO. In our hands the success rate is very high and usually only involves an overnight stay after the procedure. Importantly, there is minimal pain, compared to traditional surgery.
Owner information sheet on PDAs
This X-ray image shows an angiogram with dye inside the aorta and Ductus Arteriosus (blue arrow), to test the effectiveness and positioning of the ACDO before being released from the delivery catheter (red arrow). There is no contrast (‘dye’) escaping past the ACDO which indicates that it is in a good position and providing complete closure.
Once we have confirmed the ACDO (red arrow) is in a good position, it is then released from the delivery catheter and left in place in the heart, closing the vessel.
Following a successful PDA closure, the prognosis is excellent with a normal life expectancy, when there is no heart enlargement or evidence of congestive failure. If there were signs of heart enlargement or fluid build-up before closure then some dogs may need to stay on medication.
Before recommending PDA occlusion, one of our cardiologists will need to examine the patient and perform tests to confirm the diagnosis, measure the size of the heart and PDA and check for other heart defects which could affect the procedure.
Long term management
We always recommend a follow-up scan by a cardiologist 3 to 6 months after the operation, to check that everything stays in place and to monitor the heart size and function.
If your pet has been diagnosed with a PDA, ask your vet to contact us to discuss options for treatment.