Skoryi D. Experimental and clinical substantiation of methods of liver dissection for it resection.

The thesis focuses on the problem of prevention of intra- and post-operative complications and improvement of surgical treatment of patients with hepatic masses based on a comprehensive experimental and clinical study of the influence of different dissection techniques on liver parenchyma. An original technique and a device for gas-jet dissection have been designed based on hepatic tissue separation using gas jet under a pressure exceeding parenchyma strength but being less than stroma strength. Technological parameters of gas-jet dissection and device performance have been optimized based on mathematical modeling and on experiments on cadaveric human liver (n=12). The technology of gas-jet dissection was elaborated, the dynamics of reparative and regenerative processes in the resection region involving different dissection techniques was studied, and safety of the proposed gas-jet dissection technique was proved in experiments involving 32 rabbits and 36 pigs. It was established that gas-jet, water-jet, and ultrasound dissection techniques are the optimum, the least traumatic and the most prognostically favorable for healing. Within the clinical part of the research, surgical treatment of 200 patients with hepatic masses was analyzed. All parameters of liver parenchyma dissection techniques were assessed based on the analysis of efficacy, traumaticity and surgical treatment results in reference group patients (90 patients). It was proved that ultrasound and water-jet dissection techniques ensure preservation of liver functional activity after its resection and minimum rate of post-operative complications. Instrumental dissection technique is more traumatic though it does not influence functional activity and the rate of post-operative complications. A new tactical approach to the selection of dissection technique was proposed based on a comprehensive analysis of research results. This approach was employed for the treatment group (110 patients). It contributed to an over 1.5-fold decrease in post-operative complications - from 36.7 % to 20.9 %, and a decrease in the lethality rate from 8.9 % to 3.6 %.