Biomechanical Characteristics of Light Synthetic Materials for Hernioplasty (Experimental Study)

Abstract

Importance of the topic. One of the directions of improving hernioplasty efficiency with the use of light synthetic materials is including the strengthening zones in their structure.
 Purpose. To compare functional effectiveness of the light and the light strengthened polypropylene endoprostheses for hernioplasty on the base of studying biomechanical characteristics of anterior abdominal wall tissues after their implantation in experiment.
 Materials and methods. Experimental studies were conducted on 36 rabbits of “chinchilla” breed. All animals were divided into 2 series of experiments. In the first (control) series the light polypropylene endoprosthesis was implanted, while in the second (experimental) series there was used a new cancellated endoprosthesis from monofilamentous polypropylene, consisting of the basic and strengthened zones in the form of horizontally located, alternating with each other monothreads of the higher thickness. Pathomorphological changes and biomechanical properties of the abdominal wall tissues were studied macroscopically in the experiment by implantation of endoprostheses in onlay position on the 7th, 30th and 90th days.
 Results and their discussion. There was proved that in direction of the loop column as well as in the loop row after implantation of the studied materials breaking load increased from the 7th to the 90th day of experiment, that was related to the formation of the connective tissue capsule around materials. The light strengthened endoprosthesis was more durable and stronger in 1,6 times compare to the light analog at all stages of observation. Along the loop column there was no significant difference detected. In both series of experiment in the direction of the loop column as well as in loop row the reduction of sample lengthening took place. Along the loop column indicators of lengthening, characterizing elasticity of the prosthesis aponeurosis, in the series of the light strengthened endoprosthesis were 1,4-1,6 times lower than in its light analog. Along the loop row there was no significant difference of indicators.
 Conclusion. Introduction of the strengthened zones in a light endoprosthesis increases its durability with preservation of the material’s elasticity.

"Some Indicators of Intoxication and Leukocyte Response in Rodent Fecal Peritonitis"

“…The breath rate in rats with EP increased after half a day -by 50,0 % (p<0.01), after 1 day -by 58,0 % (p<0,01), after 3 days -by 37,2 % (p<0.01), with the most pronounced tachypnea after 1 day of inflammation, while the respiratory rate was greater than after 0,5 days and 3 days by 5,7 % (p<0,05) and 15,5 % (p<0.05) respectively. The occurrence of tachypnea in rats with EP is due to the development of hypoxia and acidosis [15]. The development of fever in rats with EP was manifested by an increase in rectal temperature after half a day -by 2,6 (2,6; 2,7) °C, p<0,01, after 1 day -by 3,3 (3,3; 3,5) °C, p<0,01, after 3 days -by 1,6 (1,6; 1.8) °C, p<0,01, compared with the value in the «control» group, characterizing the development of pyretic fever on the first day and febrile -after 3 days of peritonitis.…”