Innovative technologies in vascular surgery

Abstract

The aim — to search for new diagnostic and therapeutic directions in vascular surgery and study their technologies via experimental and clinical researches.Materials and methods. 1) The temperature during electric welding of biological tissues ranged from 4 to 146 °C, the average operating temperature during the welding process was 88.4 0C. The noise filtering was performed using noise filter functions and a LowPass FIR filter with the 20 Hz frequency. Histological specimens were studied using the Olympus BX 51 microscope, the Olympus C5050 Z digital camera, and the Olympus DP­Soft software. 2) MRI was performed in order to determine the actual shape of the vessels. For the reconstruction of their spatial shape, 3D image reconstruction software MRI Invesalins was used. The solid model of the artery was created using a laser 3D printer. Graph­analytical methods were used to describe the shape of the compressed artery. 3) The polymorphism of the NOS3 gene (the single nucleotide genetic polymorphism (SNP) in the human reference sequence — rs1799983) and the polymorphism of the CRAT gene (SNP in the reference human sequence — rs2296771) were identified by real­time polymerase chain reaction. The amplification of a corresponding region of DNA with a standard set of primers using the phenomenon of energy transfer using fluorescence resonance (FRET) was conducted in order to identify the polymorphic alleles.Results and discussion. 1) The electrowelding of the artery wall between the electrodes formed a seam, which consisted of a dense semitransparent tissue of light brown color with a clear boundary along the edge of the electrodes location. Microscopically, the substance of the electrowelding seam was represented by a homogeneous dense substance, which consisted of coagulated and strongly interconnected protein structures of vessel wall collagen fibers. 2) 3D reconstruction of the cervical arteries was performed using the 3D image reconstruction program MRI Invesalins, which objectively displayed the condition of the vertebral artery at the site of its narrowing. Reconstruction of the spatial shape of the artery made it possible to create the artery solid model using a laser 3D printer. 3) Based on the results of the genetic studies, a group of patients with a predisposition to develop endothelial and mitochondrial dysfunction was identified, where Tivorel (4.2 g arginine hydrochloride + 2.0 g L­carnitine) was used. Endothelial function in this group of patients was assessed by the magnitude of flow mediated vasodilatation (FMD), which reflects the ability of the brachial artery to dilatate in response to ischemia induced hyperaemia. The use of L­arginine resulted in a statistically significant increase in the flow mediated vasodilatation (FMD), which indicated the restoration of impaired endothelial function.Conclusions. 1) The strength of the tissue connection in electric welding seam depends on the degree of the tissue homogenization. 2) Graphical 3D modeling of pathologically narrowed arteries and computer data processing of MRI of the vessels allows determining the localization, character and spatial characteristics of the artery extravasal compression. Graph­analytical methods for describing the arterial shape became the theoretical basis for a new method of the artery extravasal compression studying. 3) The basis of personalized treatment in patients with ischemic tissue lesions is the conduction of genetic studies. Especially the determination of single nucleotide genetic polymorphisms (SNP) of the NOS3 gene, that is responsible for the synthesis of the protein «endothelial nitric oxide synthase» (rs1799983), and gene CRAT, that is responsible for the synthesis of the protein «carnitine­O­acetyltransferase» (rs2296771), is needed. Identification of mutant homozygotes determines predisposition to endothelial and mitochondrial dysfunction of the vessels, the development of atherosclerosis, arterial hypertension, diabetes mellitus, and heart failure.