| Popis: |
The investigation was based on the examinations of 85 aortal valves of man and swine after conservation in 1% betapropiolactone solution, 4% formaldehyde solution, 0.6% glutaraldehyde solution and after treatment with gamma-rays preceded by freezing. Besides, 38 allo- and xenotransplants of valves preserved by the above methods which had functioned in the mitral and tricuspidal positions in patients for 1 day to 9 years were examined. Implantation of the grafts was found to complete by 5-6 months. Irrespective of the period of functioning, no encapsulation and cusp formation occurred in the transplanted valves. The time course of destruction of cusp tissue of transplants after various periods of their functioning in the human heart was elucidated. The four main factors causing the development of destructive changes and insufficiency of transplanted valves were detected: biological, mechanical, hemodynamical, and septic. Moderate structural alterations slowly developing in transplanted valves previously preserved in glutaraldehyde and functioning for long periods in the tricuspidal position suggest that valve transplantation (with this method of preservation) in treatment of acquired valvular disease is encouraging. |
