Development and approbation of a mobile test bench for mechanical uniaxial compression testing of biological tissues

A technique and a prototype of a mobile test bench for conducting experiments on uniaxial compression of biological tissue samples have been developed. The test bench consists of high-precision scales, an electronic caliper with modified grips, and a video camera. With the help of the test bench, a series of experiments (120 in total) was carried out to determine Young's modulus of atherosclerotic plaques and vascular walls removed from the human body no later than a few hours. A database of plaques and artery walls' mechanical characteristics, as close as possible to their real strength properties, has been formed. In addition, regression dependencies linking Hounsfield units and Young’s moduli of atherosclerotic plaques were constructed. The uniaxial compression technique has been verified on the Instron 3342 universal testing machine. Also, to demonstrate the applicability of the developed technique and test bench for uniaxial compression of hard tissues, experiments were conducted with 14 samples of bovine spongy bone

ВЗАИМОСВЯЗЬ ОБЪЕМНОЙ СКОРОСТИ КРОВОТОКА ПО ПЕЧЕНОЧНОЙ АРТЕРИИ И СОСТОЯНИЯ МИКРОЦИРКУЛЯТОРНОГО РУСЛА ТРАНСПЛАНТИРОВАННОЙ ПЕЧЕНИ ПОСЛЕ ЕЕ РЕВАСКУЛЯРИЗАЦИИ

Aim: optimization of the surgical treatment policy with orthotopic liver transplantation (OLT) depending on the results of intraoperative fl owmetry and the state of intrahepatic microcirculatory bloodstream according to immunohistochemical (IHC) study of microspecimens of the donor’s liver.Materials and methods. 60 patients are included in the study. Group I (n = 30) comprised of patients for whom it was not necessary to perform any additional interventions on the bloodstream in the hepatopancreatobiliary area during OLT. Group II (n = 30) had patients with insuffi cient arterial blood supply for the graft in the intraoperative stage where it was needed to perform additional and/or repeated interventions in the arteries of the hepatopancreatobilliary area. Intraoperative fl owmetry with assessment of the volume blood circulation (VBC) in the hepatic artery (HA) was carried out in the both studied groups. Reference value of VBC was 100 ml/min and higher. Before and after reperfusion in the liver biopsy material we performed immunohistochemical study with the use of endothelial marker CD 31 with subsequent morphometric estimation of the specifi c square of the microvascular bloodstream.Results. In both groups there was no change in the specifi c square in the areas of portal tract and central vein before and after restoring blood fl ow. In the second group, an 8 times increase of the specifi c square of sinusoids was observed after restoring blood fl ow (р < 0,01).Conclusion. Intraoperative fl owmetric control of the blood fl ow allows in due time to perform surgical correction of the graft arterial blood supply during OLT, and it reduces the risk of thrombosis up to 0%. The value of VBC in the hepatic artery (HA) has reliable dependence upon the state of microcirculatory bloodstream of cadaveric donor’s liver after reperfusion.Цель: оптимизация тактики хирургического лечения при ортотопической трансплантации печени (ОТП) в зависимости от данных интраоперационной флоуметрии и состояния внутрипеченочного микроциркуляторного русла, по данным иммуногистохимического исследования (ИГХ) микропрепаратовдонорской печени. Материалы и методы. В исследование включены 60 пациентов. Первая группа (n = 30) – пациенты, не требовавшие дополнительных вмешательств на сосудистом русле гепатопанкреатобилиарной зоны во время ОТП. Вторая группа (n = 30) – с недостаточным артериальным кровоснабжением трансплантата на интраоперационном этапе, где потребовалось выполнение дополнительных и/или повторных вмешательств на артериях гепатопанкреатобилиарной зоны. В группах исследования проводилась интраоперационная флоуметрия с оценкой объемной скорости кровотока (ОСК) по печеночной артерии (ПА). Референтное значение ОСК – 100 мл/мин и более. В биоптатах печени до и после реперфузии проводилось ИГХ-исследование с использованием эндотелиального маркера CD 31 с последующим морфометрическим определением удельной площади микрососудистого русла.Результаты. В обеих группах изменения удельной площади в зоне портального тракта и центральной вены до и после запуска кровотока не было. Во второй группе отмечалось увеличение удельной площади синусоидов после запуска кровотока в 8 раз (р < 0,01).Заключение. Интраоперационный флоуметрический контроль кровотока позволяет своевременно выполнить хирургическую коррекцию артериального кровоснабжения трансплантата во время ОТП и снижает риск тромбоза ПА до 0%. Величина ОСК по ПА имеет достоверную зависимость от состояния микроциркуляторного русла трупной донорской печени после реперфузии

ОРТОТОПИЧЕСКАЯ ТРАНСПЛАНТАЦИЯ ПЕЧЕНИ: РОЛЬ ИНТЕРВЕНЦИОННОЙ РАДИОЛОГИИ

To study therapeutic modalities of interventional radiology in patients (pts) before and after orthotopic liver trans- plantation (OLT). OLT was performed in 53 pts between 1998 and 2008. Endovascular treatments were performed in 20 pts. Pre-OLT interventional procedures included transcatheter arterial chemoembolization (5 patients) and TIPS (8 patients). Post-OLT procedures were: dilatation or/and stenting of biliary strictures (4), stenting of IVC (2), balloon dilatation of cava-caval anastomosis (1), partial splenic embolization (PSE) in steel syndrome (1). All IR procedures were technically successful. There was no mortality or serious complication. After chemoemboliza- tion, there was partial tumor response in all 5 patients with HCC; two successfully transplanted are alive without recurrence in 11 and 15 months. After TIPS, 3 pts underwent OLT. Satisfactory biliary passage was achieved in all pts with strictures. Clinical symptoms and liver function improved in three pts with venous strictures. After PSE, steal syndrome regressed rapidly. All pts are asymptomatic and well in 5–24 mo after IR treatment. IR procedures prolong long-term patient survival before OLT and may improve outcomes in pts after OLT. В работе обсуждается эффективность интервенционных радиологических процедур у больных перед и после ортотопической трансплантации печени (ОТП). За период 1998–2008 гг. ОТП выполнена 53 паци- ентам. Лечебные эндоваскулярные вмешательства осуществлены у 20 из этих больных. Предоперацион- ные процедуры выполнены у 13 пациентов: масляная химиоэмболизация печеночной артерии (МХЭПА, n = 5), наложение внутрипеченочного портокавального шунта (TIPS, n = 8). У 7 больных произведены 8 послеоперационных вмешательств: дренирование и/или стентирование желчных протоков (n = 4), ре- канализация и стентирование стеноза/окклюзии нижней полой вены (НПВ, n = 2), баллонная дилатация кава-кавального анастомоза (n = 1), эмболизация селезеночной артерии (n = 1). После МХЭПА отмечено уменьшение злокачественной опухоли или замедление ее роста у всех 5 пациентов, ОТП к настоящему времени осуществлена у 3 из них. В результате TIPS снижение портальной гипертензии произошло у всех больных, ОТП выполнена в 3 наблюдениях. Все послеоперационные процедуры были также технически и клинически успешны. Методы интервенционной радиологии позволяют продлить время ожидания до- норской печени у больных, которым требуется ОТП. Рентгеноэндоваскулярные вмешательства позволяют устранить послеоперационные билиарные и сосудистые стриктуры, а также другие осложнения ОТП.

Clinical Guidelines of the Russian Society of Surgeons, the Russian Gastroenterological Association, the Association of Surgeons-Hepatologists and the Endoscopic Society “REndO” on Diagnostics and Treatment of Chronic Pancreatitis

Aim: to present modern methods of diagnosis and treatment of chronic pancreatitis for gastroenterologists, general practitioners and physicians.Chronic pancreatitis (CP) is a long-term inflammatory disease of the pancreas, manifested by irreversible morphological changes in the parenchyma and pancreatic ducts, which cause pain and/or persistent impairment of function. Current concept on the etiology of CP is reflected by the TIGAR-O classification. The criteria for establishing the diagnosis of CP include typical attacks of abdominal pain and/or clinical and laboratory signs of exocrine, endocrine insufficiency with the mandatory detection of characteristic morphological changes (calcifications in the parenchyma and pancreatic ductal stones, dilatation of the main pancreatic duct and its branches). CT, MRCP, and pancreatobiliary endosonography are recommended as the methods of choice to verify the diagnosis of CP. Conservative treatment of patients with CP is provided for symptom relief and prevention of complications. Individual cases with severe non-interactable abdominal pain, as well as a complicated course of the disease (development of ductal hypertension due to main pancreatic duct stones or strictures, obstructive jaundice caused by compression of the common bile duct, symptomatic postnecrotic cysts, portal hypertension due to compression of the portal vein or thrombosis of the splenic vein, persistent duodenal obstruction, pseudoaneurysm of the celiac trunk basin and the superior mesenteric artery) serve as an indication for endoscopic or surgical treatment. The Guidelines set out modern approaches to the diagnosis, conservative, endoscopic and surgical treatment of CP, and the prevention of its complications.Conclusion. The implementation of clinical guidelines can contribute to the timely diagnosis and improve the quality of medical care for patients with chronic pancreatitis

ЭВОЛЮЦИЯ ПРОГРАММЫ ТРАНСПЛАНТАЦИИ ПЕЧЕНИ В РОССИЙСКОМ НАУЧНОМ ЦЕНТРЕ РАДИОЛОГИИ И ХИРУРГИЧЕСКИХ ТЕХНОЛОГИЙ

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Features of image formation of higher education institutions to increase the rating in the market of educational services

The article identifies a significant deformation of education, which led to the opening of new educational institutions. The authors noted the change of priorities in the state regarding the image of knowledge and education. This article examines the problem of creating a positive image for higher education institutions; orientation of modern educational institutions on search, development, and application of managerial cognitive and artistic means of creating a positive image of educational institution, reflection in this image of internal, essential meanings, maintenance and tasks, features of its activity. The authors investigated certain shifts in the market of educational services, namely: increasing society’s requirements for the quality of vocational education, constant updates of teaching technology, rapidly changing economic conditions of universities, intensification of competition in the market of educational services. All this causes the urgent problem of finding new sources of increasing the competitiveness of higher education, the basic indicator of which is the image. The authors consider approaches to rating higher education institutions. The most famous international university rankings are analyzed. The theoretical and methodological approaches and the basic principles of university rankings are compared. Using cluster analysis to enhance the competitiveness of higher education institutions, expand their capabilities and take them to the next level. The cluster analysis was conducted to determine the activity of students, graduates, employees, employers in the life of the university, their awareness of the symbolism of the university. As the students are not part of the university, their answers were not taken into account. The technological chain of formation of public attitude to the HEA through event measures was also forme

EVALUATION OF LEFT VENTRICULAR REMODELING AFTER SURGICAL RECONSTRUCTION OF POSTINFARCTION ANEURYSM

Objective: To assess the effect of left ventricle reconstruction in patients with postinfarction aneurysm on remodeling and heart failure dynamics in the immediate and long-term postoperative period. Material and methods: 162 patients with IHD who underwent myocardial infarction and chronic left aneurysm were included in the study. All the patients underwent myocardial revascularization and reconstructive intervention in the LV cavity at the National Medical Research Center named after V.А. Almazov. Two groups of patients were formed, depending on the type of surgical intervention performed. Group 1 (n = 116) included patients who underwent linear plastic surgery of the left ventricle aneurysm. Group 2 (n = 46) identified patients who underwent an intraventricular plastic aneurysm of V. Dor. Results: In the early postoperative period, a statistically significant decrease in the volume of the LV cavity was observed and the global ejection fraction changed in both study groups. In patients with a significant degree of mitral insufficiency additionally did the plastic fibrous ring. The conducted single-factor analysis showed a statistically significant effect of correction of mitral insufficiency on CDD, DAC, and global ejection fraction. The majority of patients in both groups experienced a decrease in LV volumes in the long-term period. Predictors of unfavorable clinical course of heart failure in the long-term period were revealed: violation of contractility at the level of basal parts of the left ventricle with a decrease in the index of violation of local contractility more than 3, ejection fraction less than 35%, uncorrected mitral insufficiency II and more, increased level of natriuretic peptide 4 times from the upper limit of the norm. Conclusions: Combined operation makes it possible to improve the contractive function of left ventricular, to reduce the degree of mitral insufficiency, the functional class of heart failure

Study of the harmful factors influence on the occupational risk level: the example of the Ukrainian mining industry

Purpose: The choice of preventive measures and labour protection equipment should be justified taking into account the occupational risk. For objective reasons, existing approaches do not provide an opportunity to justify the choice of the necessary measures, which best reduce the occupational risk level. Consequently, an effective methodological approach to justify preventive measures is required, since the level of risk in mining enterprises is still high, especially in developing countries and countries with weak economies. The current research is devoted to solving this urgent scientific problem. Design/methodology/approach: Construction of mathematical models based on accumulated statistical data on the values of production factors using polynomial regression, which is justified by the simplicity of computational algorithms and the clarity of the results obtained. Findings: On the example of the Ukrainian mining industry, it was found that to reduce occupational risk; the most effective is to change the operating mode of the equipment and rational planning of working hours, but not measures to reduce the dust concentration. Research limitations/implications: The study is focused on the mining industry; a methodological approach and a mathematical model are proposed for specific working conditions at Ukrainian mining industry. Practical implications: The proposed approach makes it possible, based on statistical data, to quickly and reliably select the most effective measures to reduce the industrial risk level. Originality/value: A feature of the proposed approach to reducing industrial risk is a comprehensive accounting of data on factors affecting occupational risk, the construction of mathematical models and the use of modelling results when planning measures to improve working conditions