Biophysical parameters of the greater omentum after experimental extended liver resection

Abstract

Bioimpedance parameters of the large omentum after performing extensive liver resection in an experiment were evaluated. The study was performed on 20 Wistar rats that underwent median laparotomy under anesthesia, followed by liver resection with the removal of 70% of the organ. Invasive bioimpedance measurement of the liver and large omentum was performed before and immediately after extensive liver resection on days 3 and 14 after surgery using an original device for measuring the electrical impedance of biological tissues BIM-II at frequencies of 2 and 20 kHz with the calculation of the average impedance values at each frequency and measurement zone. Liver tissue was subjected to histological examination. The minimum values of the impedance of the large omentum were recorded on day 3 after extensive liver resection. By day 14, in both zones of the large omentum, the electrical impedance increased relative to day 3 of the postoperative period and did not differ significantly from the indicators before extensive liver resection. Immediately after extensive liver resection, the bioimpedance index in all animals decreased significantly at a frequency of 2 kHz. On day 3 after surgery, the electrical impedance of the liver parenchyma at a frequency of 2 kHz increased significantly. On day 14, the electrical impedance of the liver parenchyma did not differ from the indicators before extensive resection at frequencies of 2 and 20 kHz. A strong significant correlation was found between the electrical impedance of the large omentum and liver parenchyma. At a frequency of 2 kHz, the correlation coefficient of the liver parenchyma and the proximal part of the large omentum was 0.82 and that of the distal part was 0.87 (p 0.05). A strong correlation was detected at a frequency of 20 kHz, with r = 0.93 and 0.74, respectively, in both parts of the gland. Thus, the electrical impedance of the liver parenchyma by day 3 of the experiment increased compared with values before extensive liver resection, whereas the large omentum decreased. We believe that studying the dynamics of the electrical impedance of the large omentum after extensive liver resection is promising in the development of diagnostic criteria for the severity of liver failure.