Studying the response of tissues of laboratory animals to implantation of vascular endoprostheses
Aim: The paper looks at one of pressing problems of angiosurgery, the choice of plastic material to be used in reconstructive interventions and focuses on the response of biological tissues to implantation of vascular endoprostheses. Methods: To do research on the study material, use was made of vascular dacron implant & a woven double velour vascular endoprosthesis of polyester fibers and impregnated with modified gelatin. 60 Vistar rats (males) weighing 200-250 g were chosen as study objects. The animals were assigned to 4 groups according to the number of firms-manufacturers and the time of removing from the experiment (at 15 and 30 days). Under general anesthesia in the operating room, the rats' skin and subcutaneous fat were dissected along the paravertebral line. Two pouches 3.5 cm deep were formed in the subcutaneous fat by blunt dissection. A 2x2 cm sample of the vascular patch was introduced into each pouch. The surgical wound was closed completely and treated with antiseptics. Histological preparations were stained by using a hematoxylin-eosin/Mallory technique. The obtained microphotographs enabled us to evaluate the structure of the connective-tissue capsule, as well as the content of its cellular layer. A cellular index, the relationship between fibroblast cells and inflammatory infiltrate cells, was calculated in each group. The indicator exceeding 1 demonstrated the predominance of reparative tendencies, if it was below 1, inflammatory changes prevailed. Statistical processing of the data obtained was performed by means of descriptive and variation statistical methods. Results: Changes of inflammatory reaction phases proceed faster in the zone of implantation of dacron patches, which manifest themselves by a reliable increase in the quantity of resident cells from 62.4% to 80.5% and a decrease in nonresident cells by 1.7 times on the same terms respectively. The reaction of fabrics is more expressed to a polyester implant, which is confirmed by an insignificant decrease from 53.5% to 43.7% of the quantity of inflammatory infiltrate cells and a growth of fibroblast cells from 46.5% (at 15 days) to 56.3% (at 30 days). Conclusion: The reaction of tissues of laboratory animals is less expressed to a dacron implant.