Evaluation of Hybrid Surgical Access Approaches for Pulmonary Valve Implantation in an Acute Swine Model

Percutaneous implantation of the pulmonary valve through peripheral vascular access can be limited due to poor venous access, low patient weight, hemodynamic or rhythmic instability, and size constraints related to the valve. In such cases, hybrid procedures may provide alternatives. Because the most commonly used median sternotomy is unsuitable for chronic trials in large animals, we evaluated several hybrid approaches for pulmonary valve replacement in a swine model. We tested the feasibility of hybrid pulmonary valve implantation in pigs by using inhouse-generated valves containing bare-metal or nitinol stents. Valves consisted of bovine jugular veins, bovine pericardial valves, or sprayed polyurethane valves. Access was achieved through median sternotomy, lower partial sternotomy, transverse sternotomy, or right lateral thoracotomy. The delivery device was introduced in a transventricular manner. Implantation took place under fluoroscopic and epicardial echocardiographic guidance. We achieved implantation of the stented valve in 12 (92.3%) pigs, of which 5 (41.7%) of the implanted valves were in an optimal position. Paravalvular leakage occurred in 2 trials (16.7%). Lower partial sternotomy provided the best trade-off between feasibility and minimized trauma for long-term animal trials. Here we describe our experience with hybrid pulmonary valve implantation in an acute large-animal (swine) model. We demonstrate the feasibility of the procedure in terms of surgical technique and the perioperative management and preparation of the field for a chronic trial.