A left-right shunt can nowadays be closed minimally invasive without surgery using a catheter intervention. Therefore special wire spirals (coils) or a wire braid (duct occluder) are pushed through the artery at the inner side of the femur to the heart, where they are implanted in the ductus arteriosus botalli. This procedure has a lower complication rate compared to the previous operation methods on the open thorax and is therefore recommended.
In the case of right-left shunt, the possibilities of therapy are unfortunately only very limited. Since the pulmonary hypertension cannot be influenced, a closure of the ductus arteriosus botalli is unfortunately not possible with this type of PDA. The resultant massive pressure increase in the pulmonary circulation would directly lead to the death of the patient. The only way to help patients with right-left-shunt is to reduce the red blood cells with medicaments or phlebotomy (bloodletting).
Also regarding prognosis the PDA with left-right shunt and a PDA with right-left shunt are strongly different.
The sooner a left-right shunt is diagnosed, the better the chances are that no – or only minor – changes have been caused as a result of heart failure. And this in turn also greatly improves the prognosis. In most cases, the animals have a normal heart function after a catheter has been applied, and thus also a normal life expectancy. Animals, which have the first signs of congestion as a result of the PDA, must first be stabilized by means of medication prior to the procedure.
Without a treatment, 65% of the affected animals develop left heart failure, which usually leads to death within the first year of life.
The prognosis for a PDA with right-left shunt is, however, unfortunately bad, since only the over-supply with red blood cells can be counteracted, but the cause itself cannot be fixed.