Aortic root prosthesis with pericardial cusps "Russian conduit": a hydrodynamic experiment

Aim. The study aimed to compare the hydrodynamic characteristics and durability of the aortic root prosthesis with pericardial cusps with various options for the formation of commissures. Methods. Nine conduits with pericardial valves were formed according to the technique described by Ozaki. The prostheses were divided into 3 groups of 3 specimens each: group 1 - without additional reinforcing seams on the top of the commissure; group 2 - with an additional U-shaped seam without gasket; and group 3 - with an additional suture with an opposite pericardial gasket. The prostheses were fixed on a stand for hydrodynamic testing of artificial heart valves. The hydrodynamic characteristics of the prostheses were evaluated. The hydrodynamics of the frame biological prosthesis was used for comparison. After assessing the hydrodynamic parameters of the aortic root prostheses, their work durability was tested. Defects of the pericardial cusps were studied macroscopically. Results. Two samples from group 2 were withdrawn from testing ahead of schedule at around 11 х 106 cycles, which is approximately 3.5 months of normal heart function. The other prostheses remained competent and were removed for an examination at 32 х 106 cycles, which is approximately 9.6 months of normal heart function. Conclusion. The hydrodynamics of the aortic root prosthesis with pericardial valves was comparable to the hydrodynamics of the frame biological prosthesis. Additional U-shaped sutures in the commissure area of the pericardial cusps did not increase the functional durability of the aortic root prosthesis with pericardial leaflets and served as additional risk factors for leaflet perforation. Implantation of pericardial leaflets into a vascular graft resulted in a different distribution of dynamic stress compared to the original aortic valve neocuspidisation, which preserved the aortic root.