Forces at single point attached commissures (SPAC) in pericardial aortic valve prosthesis.

Objective: New pericardial aortic bioprostheses (3F Therapeutics and temporarily stented autologous pericardial valve prosthesis) were developed recently. These valves are designed with commissures connected to the aortic wall at only three single points (single point attached commissures (SPAC)). The aim of this study was to investigate the forces acting on SPAC during varying pressure load. Methods: Aortic roots with diameters 19,25, and29 mm were madeusing siliconepolymer. A bovinepericardial SPACaorticvalve prosthesis was constructed usinga 3D-mold and was implanted in thesilicone aorticroot. The baseof the valvewas sutured ontothe aortic annuluswith 4-0 polypropylene running sutureand each commissure was sutured to a miniaturized force transducer with only one 3-0 polypropylene U-stitch. Three silicon aortic roots of each size were pressurized up to 200 mmHg and forces on SPAC were measured. Results: All valves remained competent at a pressure of 200 mmHg. Recordings showed a linear correlation between applied pressure and forces measured at SPAC. At a pressure of 80 mmHg (equivalent to diastolic pressure), the forces were 0.44 0.22 N, 1.15 0.18 N, and 2.00 0.35 N in annular diameters 19 mm, 25 mm, and 29 mm, respectively. It was observed, that the main forces were acting along the axial direction and not along the radial direction. Conclusions: Forces on ‘‘single point attached commissures’’ in pericardial aortic valves were measured. These forces were acting mainly in axial direction and not in radial direction. This knowledge is important for the implantation technique of SPAC pericardial aortic valves. # 2005 Elsevier B.V. All rights reserved.