Abstract 4622: Percutaneous Implantation of a Low Profile, Dry Membrane, Heart Valve in an Integrated Delivery System in the Aortic and Pulmonary Positions: One-month Animal Results
Background. Percutaneous heart valve (PHV) implantation is an emerging therapy for valve disease. Typically, like surgical valves, PHV are transported in solution and then mounted by the operator onto a delivery catheter. Such hydrated “wet” valves have thick tissue layers requiring large (18–26Fr) caliber delivery catheters, limiting insertion into the femoral artery. We developed a low profile, dehydrated (“dry”), folded pericardial stent-mounted PHV that is pre-assembled and pre-packaged within its delivery catheter for ready insertion and deliverable with 14 Fr catheter for 25 mm and 16Fr for 35 mm valves. One month animal data is described.
Methods. Four dogs weighing 30 to 40 kg underwent transcatheter implantation of a PHV. A customized delivery system integrating the valve and delivery catheter in pre-assembled form was inserted directly from the package into the femoral artery, and positioned and deployed by balloon expansion under flouroscopic guidance. Transthoracic echo-Doppler assessment was used. Scanning electron-microscopy (SEM) was performed to assess the surface of the valve leaflets.
Results. PHV were implanted in the orthotopic pulmonary valve (3 animals) and aortic valve positions (1). There were no post procedure complications and all animals were in good clinical condition before euthanasia. Procedural and follow-up angiographic studies showed forward flow without evidence of regurgitation of the valves. Pathological examination of the implantation site showed no evidence of infection, perforation or dissection. Pulmonary implant animals were followed for 4 weeks and the orthotopic aortic animal was examined 24 hours after PHV implantation. Histology of the valves showed fibrosis that attached the stented valve to the vascular wall, but no evidence of rejection. SEM showed a homogeneous surface without attachment of fibrin or thrombus.
Conclusion. Percutaneous implantation of this new integrated, pre-packaged, low profile, dry membrane PHV is feasible and well tolerated in dogs showing normally competent hemodynamic behavior. One month histology showed a favorable tissue response. Such a PHV system facilitates transfemoral delivery and should reduce the time and difficulty of the procedures.