Manchenko A. Effect of low temperatures and electron beam on tissues of pericardium and heart valve leaflets in their preservation (experimental study).

Object of research was the influence of low temperatures, irradiation of electron flow and their combined effect on morphological, immune biological and biomechanical characteristics of pig`s pericardium (Pr) and aortic valve leaflets (AVL) to create the tissue implants. The research aim was a comprehensive evaluation of the efficiency of devitalizing treatment of the pig’s Pr and AVL by means of low temperatures and ionizing radiation of electron flow to create the tissue implants. The methods used were as follows: light, electron and fluorescence microscopy; immune histochemical method; study of biomechanical properties of tissues by deformation of stretching; ultrasound diagnostics; two experimental models in vivo, i.e. a subcutaneous tissue implantation and bladder defect plastic; statistical analysis of results. Theoretical and practical results, scientific novelty consist in the fact that for the first time, to create the implants from pigs Pr and AVL tissues were obtained by the method of devitalisation, based on a a combined preimplantation treatment with low temperatures and irradiation of the electron flow. The feasibility of its use has been justified. It has been shown that the extracellular matrix of the devitilized by combined effect tissues maintained an integrity, its elastic properties were enhanced, which provided structural stabilization and the possibility of implants preservation; while the xenoimplants maintain a durability margin, carcass, elasticity, tensile strength, resistance to breakage and twisting. First, it has been shown that the combined effect provides damage to cellular elements and reduces xenogenogenic expression of the α-1,3-Gal epitope by 3 times. The Pr tissues after the combined effect showed during the year of observation the absence of signs of implant rejection, maintenance of operating loads in conditions of aggressive environment, performance of the carcass function in the resected area, and ensuring reliable restoration of the anatomical integrity and functional parameters of the urinary bladder. Practical significance covers a new type of tissue xenomembranes has been obtained that characterized by a high degree of tissue devitalisation, the preservation of their biomechanical properties, the reduction of antigenicity. These results indicate the feasibility of pre-clinical and clinical studies, the results of which will allow the certification of tissue implants for subsequent use in clinical practice. Area of application is foreseen in reconstructive surgery in: cardiac surgery, urology, gynecology, abdominal surgery, herniology, otolaryngology, ophthalmology, stomatology and other areas.