[FORMATION OF BILIODIGESTIVE ANASTOMOSES BY THE METHOD OF HIGH-FREQUENCY ELECTRIC WELDING].

The aim of the study was to develop a new method of formation of biliodigestive anastomoses, which would make it possible to form anastomoses both on unchanged bile ducts and in conditions of their inflammation. An experimental study was carried out on 50 rabbits of the "Chinshila" breed, which formed biliodigestive and interintestinal anastomoses by the method of high-frequency (HF) electric welding using the "Patonmed EKVZ-300" coagulator. Anastomoses were formed both on non-inflamed tissues and under conditions of biliary peritonitis. In different terms after the operation macro- and microscopic examination of the formed anastomoses was carried out, their patency, tightness and strength were determined. With HF-electric welding the connection of biological tissues is achieved due to thermal adhesion, the mucous and serous layers in the area of the anastomosis are almost completely destroyed under the influence of electricity and the connection occurs due to the submucosal layer. The suture is well-established, hermetically sealed, the anastomoses have sufficient strength (40-100 mm Hg). The coagulation scar is narrow, thermal damage to the membranes is local (within 2700-3000 microns), the epithelialization of the suture was completed after 3 months and the maturation of the scar after 6 months. The method of HF-electric welding equally allows the formation of reliable biliodigestive and interintestinal anastomoses, both in conditions of unchanged and inflamed tissues. The everting weld connection prevents the occurrence of anastomotic strictures in the future.

[Analysis of tension-distraction state in the shin bones fractures in conditions of external fixation with application of apparatuses with different spatially oriented supports].

In Autodesk Inventor 11 program, using method of end-capping elements, a three- dimensional computeric modelling of biomechanical systems of two models was conducted: I - "tibia - Ilizarov's apparatus with concentric location of supports"; II - "tibia - Ilizarov's apparatus with excentric location of supports". The loading, which was applied towards distal fragment in 6 standard degrees of freedom, was modelled for studying of the fixation rigidity of tibial fragments in these systems. Determination of the loading value in various directions, in which the fragment have had shifted by 1 mm, have constituted the main task of the investigation. In a model II a rigidity of the fragments fixation, in comparison with such in a model I, is bigger by 631.43% - while applying a compression loading, by 8.35 - 31.75% - the transversal one and by 19.72% - the rotation loading. While choosing the method of transosteal osteosynthesis of the shin bones the advantage, have the apparatuses with excentric location of supports, what secures the enhanced rigidity of the fragments fixation in comparison with such in apparatuses with concentric location of supports. Although, even in excentric location of supports in the apparatus the fixation rigidity is insufficient for early full loading of the traumatized extremity while walking. It is necessary to elaborate such apparatus, the form of which may be adopted toanatomic configuration of segment.

[Experimental substantiation of the construction peculiarities of the universal apparatus, applied for transosseal osteosynthesis based on three-dimensional modelling].

Comparative analysis of constructive peculiarities was done for Ilizarov's apparatus and elaborated universal apparatus, which is applied in transosseal ostheosynthesis in fractures of the shin bones, basing on results of the three-dimensional computeric modelling. The universal apparatus due to its unification done secures possibility to conduct the individual selection of a support, using adaptation of their form to anatomic configuration of the injured segment. This permits to lower by 19 - 49.3% the dimensions and by 15.4% a metal consumption of external construction in comparison with such of Ilizarov's apparatus and, accordingly, to rise significantly the patients treatment comfort.