Patent ductus arteriosus (PDA) is a when a vessel connecting the two major cardiac vessels (the aorta and the pulmonary artery) fails to close at birth as it should (see www.heartydog.co.uk). It’s effects are like a “hole in the heart”. Uncorrected, a PDA leads to progressive heart enlargement and heart failure. If left untreated, approximately 50% of dogs with a PDA die in the first year of life.

PDA closure involves passing catheters via the artery in the hind leg (‘keyhole’ surgery) and ‘plugging’ the vessel with devices to stop or minimise flow through it. The success rate is proving to be very high and the hospitalisation time is very short - currently averaging 1 or 2 days. There is minimal pain compared to traditional surgery (which involves cutting open the chest between the ribs) and your pet can play and exercise normally within 24 hours.

Martin Referrals is currently one of the few centres in the UK performing interventional closure of PDAs in dogs and cats. We have considerable expertise in this area, averaging around 10 – 15 of these procedures each year.

Overall, closure of the PDA is a successful procedure with an excellent prognosis. However if there is already heart enlargement or lung congestion before the procedure is performed, a return to normal heart function is not always seen, and whilst heart failure is often slowed, it does progress in some dogs.

Ligation of the PDA via traditional surgery (thoracotomy) may occasionally have to be performed, for instance in very small breeds of dogs (<3kg). Following traditional surgery patients are hospitalised for 3 - 5 days to provide pain relief and to monitor for complications that can arise following open chest surgery. After discharge dogs must be rested for 3 or 4 weeks so as not to pull any of the sutures, especially those between the ribs. After that, exercise can be gradually introduced over a period of a couple of weeks.

Some important requirements for successful PDA closure

• For best results, the procedure should be performed by a cardiologist experienced in interventional cardiac procedures.
• A thorough ultrasound scan by a cardiologist, to check for signs of heart enlargement or congestion, to assess heart function and to double check for any other concurrent defects. Chest x-rays are beneficial to assess heart size or check for early signs of heart failure.
• Measurement of the size and shape of the PDA prior to closure (to indicate the size of device required tp plug the hole).