Transcatheter heart valve implantation is an emerging technology and an alternative to surgical valve replacement. Most existing systems consist of valves sewn into balloon-expandable stents with a delivery catheter functioning with the specific valve only. The aim of this study was to develop a universally applicable delivery system (DS) for plane stents, valves sewn into both balloon-expandable and self-expandable stents and feasible for use with different access routes. A DS was designed and manufactured in five different diameters. The requirements were derived from the implants, the implantation technique and the cardiovascular geometry of the experimental sheep. The combination of a self-expandable Nitinol stent and a jugular access point represented the major challenge as both flexibility and rigidity of the DS were required. To fulfill these contradicting mechanical properties the sheaths were comprised of a soft outer polymer tube with a stainless steel coiled spring inside. Tissue-engineered and pericardial pulmonary valves were implanted. Also polymeric and balloon-expandable stents were delivered to various positions in the vascular system. The initial success rate was 70.5%. After refinement of the DS, a success rate of 83.3% was achieved with the remaining failed implantations resulting from inadequate sizes of the prostheses.
Keywords: Pulmonary valve implantation; Stent implantation; TAVI; TPVI; Tissue engineered heart valve implantation; Transcatheter implantation.