The experimental production of a persistent ductus arteriosus for testing catheter closure devices

An experimental model was constructed to simulate a persistent ductus arteriosus (PDA) in infants. In 21 beagles (mean weight, 8.2 kg), a piece of subclavian artery was interposed between the main pulmonary artery and the aorta, thereby creating a large left-to-right shunt across the short, straight arterial pathway. There were no intraoperative complications. Three animals died postoperatively of stenosing tracheitis, pneumothorax, or bronchopneumonia. The model proved suitable for the serial testing of a new transvenous catheter closure procedure. Occlusion of the shunt was mandatory within a day after placement or severe heart failure would occur. Twelve animals with a released silicone double-balloon plug inside the vascular connection had a long-term follow-up of up to three years. Autopsy findings after the death of the animals at specified intervals revealed smooth ingrowth of the anastomoses and occlusion, by endothelialized fibrous tissue, of the pulmonary and aortic sides of the plugged experimental PDA within a month.