Isolated left pulmonary artery: interventional stenting of a persistent fifth aortic arch. 
A few cases of isolated pulmonary artery have been successfully palliated by stenting the arterial duct using coronary stents.  However, progressive luminal narrowing within the stent due to neointimal proliferation and peal formation is a considerable problem.  We report the successful interventional palliation in a 7-week-old infant with isolated left pulmonary artery using sirolimus-eluting stents.  In this unusual case, the isolated pulmonary artery was supplied by a duct-like remnant of a persistent fifth aortic arch, whereby the distal part of this vessel showed severe constriction.  Implantation of two sirolimus-eluting coronary stents re-established good perfusion of the left pulmonary artery.  Seven months after the procedure, echocardiography revealed that perfusion of the stented vessel and the left pulmonary artery was still very good.  Stents eluting antimitotic agents also help to preserve the patency of small vessels in infants, and may be useful for ductal stenting.