MORPHOLOGICAL CHANGES OF THE COSTAL PART OF THE DIAPHRAGM ARE CAUSED BY PNEUMOPERITONEUM OF MODERATE PRESSURE IN THE EXPERIMENT

Laparoscopy, one of the minimally invasive procedures, is a widely used procedure for the diagnosis and treatment of various types of clinical problems. Pneumoperitoneum during laparoscopy causes a displacement of the diaphragm by 1-3 cm. towards the pleural cavity and can cause problems in organs and tissues after surgery. Does the morphological structure of the diaphragm change? Aim. To investigate the histological structure of the costal part of the diaphragm after intra-abdominal pressure created by carbon dioxide for different times. Material and methods. The experimental study was performed on 40 animals, which were divided into 4 groups of 10 rats each as follows. Group I - an intact group, which was not modeled with any pathology, was used as an indicator of the norm of the morphological picture. Group II – created PP for 1 hour, Group III – created PP for 3 hours and Group IV – created PP for 5 hours. After which the required part of the diaphragm was selected. Results. The obtained data on the morphology of the intact group indicated the signs characteristic of this group of muscles. In Group II, muscle fibers with clear transverse striation were detected, located compactly, variability in thickness was observed, and they took a wavy arrangement. In Group IIІ animals, transverse striation is visualized fragmentarily, the nuclei are located unevenly with dislocation to the center. Signs of venous congestion were observed. The connective tissue is loosened by edema, there are low-intensity cellular infiltrates in the composition of which lymphocytes and histiocytes predominated. When studying the materials of Group IV animals, a deepening of destructive changes was observed. Muscle fibers are compactly arranged, but the boundaries are not clear. Eosinophilic areas alternate with hypochromic, in places there is sarcoplasmic decay and myocytolysis. Venous and capillary engorgement, there is a distribution leukocytosis. Conclusion. It was established that pneumoperitoneum at a level of 5 mm Hg. leads to the appearance of destructive changes in the costal part of the diaphragm and is comparable to the intact group. The severity of these changes depends on the duration of intra-abdominal pressure created in this experimental model.