The other three indicators (calcium content, inorganic phosphorus, total bilirubin) did not undergo significant changes in either group throughout the entire postoperative period.
The biochemical analysis of serum samples in rabbits from the experimental and control groups indicates the development of changes in their metabolic transformations of the main classes of organic substances and significant stress in the functioning of internal organs (liver, kidneys, heart), which was noted at all stages of observation. Moreover, the molecular mechanisms of the development of these changes in the intermediate metabolism of proteins, carbohydrates, and enzyme activities in the bodies of rabbits in the mentioned groups have significant differences in both qualitative and quantitative indicators.
According to the results of the histological study, it was found that in rabbits of the experimental group undergoing gastrotomy, who were treated with infiltration of the suture with platelet-rich autologous plasma, on the first day after the surgery, the site of the simulated wound, as in the control group rabbits, was closed due to the contraction of the muscle layer of the stomach wall. As a result, in the area of the created wound, the muscle layer formed numerous folds during this period of the study. However, unlike the rabbits treated with the classical treatment scheme, no changes in the histological structure were observed on the serous membrane side of the stomach wall. In the muscle layer, unlike the control group rabbits, there was no disintegration and lysis of smooth muscle cells and necrosis of muscle tissue foci. Fragments of other layers of the wall were also not detected between the folds of the muscle layer of the stomach wall. In our opinion, this may indicate that the use of platelet-rich autologous plasma accelerated the intensity of muscle layer contraction with faster closure of the experimentally modeled wound. This is also confirmed by a less pronounced inflammatory reaction in this layer and the absence of eosinophils among the inflammatory cells, which negates the effect of gastric juice on the muscle layer. It should be emphasized that when using platelet-rich autologous plasma in the muscle layer in the area of the simulated wound during this period of the study, unlike the control group rabbits, expanded, blood-filled blood vessels were observed. This indicates that the platelet mass stimulates blood supply to the site of the stomach wall defect.
It is worth noting that in rabbits of the experimental group, who were administered platelet-rich autologous plasma in the suture area during gastrotomy, unlike the control group rabbits, hemorrhages into the muscle layer near the simulated wound site were not recorded on the first day of the study. In these animals, small foci of lysis in the submucosal base were observed on the first day in the area of the simulated wound, which is probably caused by the aggressive action of gastric juice on it. At the same time, lysis of many fibroblasts and part of the collagen fiber bundles was recorded in the submucosal base, which was accompanied by infiltration of this area with leukocytes, mainly monocytes. In contrast, rabbits in the control group that were not administered platelet-rich autologous plasma showed stromal edema of the gastric pits, microhemorrhages, and granular dystrophy of epithelial cells of all types. In the gastric mucosa, in the area of the simulated wound, small fragments of necrotized mucosa were also observed. Near these fragments, destruction of the apices of the gastric pits and hemorrhages in the mucosa were noted. Slightly distant from the simulated wound, minor destruction of the apices of the gastric glands and hemorrhages, primarily in the upper region of the gastric glands, were also noted. In the experimental group rabbits, unlike the control group animals, there were no massive destructions of epithelial cells, shedding of chief and parietal cells into the lumen of the fundic glands, and loosening and partial lysis of the basal membrane of the gastric pit epithelium.
Thus, in the experimental group rabbits that received platelet-rich autologous plasma in the suture area, complete regeneration of all layers of the stomach wall was registered on the 14th day. In contrast, in the rabbits that did not receive this plasma in the suture area, complete restoration of the stomach wall occurred on the 21st day.
The developed method of administering platelet-rich autologous plasma has been tested in clinical practice during gastrotomy in dogs and cats. It is simple to perform, does not affect the duration of the operation, and reduces blood loss. Infiltration of the suture area on the animals' stomachs with this plasma to stimulate wound regeneration did not cause an inflammatory reaction in the postoperative period and did not lead to complications.
