Background: The surgical creation of an aortopulmonary shunt is an important tool in the therapy of complex congenital heart defects. We report on a transcatheter approach to establish an aortopulmonary shunt in piglets.
Material, methods and results: In 10 piglets with a median body weight of 10.5 kg (8-12 kg), a central aortopulmonary shunt was created by radiofrequency perforation from the aorta to the pulmonary trunk, followed by stent implantation. The procedures were performed via the femoral vessels through 5F sheaths under biplane fluoroscopy guidance. A total of six bare metal coronary stents and five polytetrafluoroethylene-covered coronary stents of 3-4 mm diameter were deployed. Four animals were sacrificed immediately after intervention; six pigs were reevaluated 4-5 weeks later for stent patency and measurement of shunt volume. The procedure was successful in all pigs. Median shunt volume was Qp:Qs = 2.4:1. At re-evaluation median body weight had increased to 18 kg (15.5-27.5 kg) P < 0.028. Four of six stents were completely obstructed due to tissue ingrowth in the bare metal stents (two cases) and thrombus formation in the covered stents (two cases). A third bare metal stent had a residual lumen, and a third covered stent was fully open without any thrombus formation or tissue ingrowth.
Conclusions: Transcatheter creation of an aortopulmonary shunt by radiofrequency perforation and stent implantation is feasible. The use of appropriate covered stents and an effective anticoagulatory regimen seem to be crucial to keep the shunts open.