Aleksandar Cvetkovic

Prediction models for estimation of survival rate and relapse for breast cancer patients

In this paper, we described the practical application of data mining methods for estimation of survival rate and disease relapse for breast cancer patients. A comparative study of prominent machine learning models was carried out and according to the achieved results we concluded that the classifiers obviously learn some of the concepts of breast cancer survivability and recurrence. These algorithms were successfully applied to a novel breast cancer data set of the Clinical Center of Kragujevac. The Naive Bayes classifier is selected as a model for prognosis of cancer survivability on the basis of the 5 years survival rate, while the Artificial Neural Network has achieved the best performance in prognosis of cancer recurrence. Selection of twenty attributes that are the most related to success of prognosis on survivability can give new insights into the set of prognostic factors which need to be observed by medical experts.

Numerical and experimental analysis of factors leading to suture dehiscence after Billroth II gastric resection

The main goal of this study was to numerically quantify risk of duodenal stump blowout after Billroth II (BII) gastric resection. Our hypothesis was that the geometry of the reconstructed tract after BII resection is one of the key factors that can lead to duodenal dehiscence. We used computational fluid dynamics (CFD) with finite element (FE) simulations of various models of BII reconstructed gastrointestinal (GI) tract, as well as non-perfused, ex vivo, porcine experimental models. As main geometrical parameters for FE postoperative models we have used duodenal stump length and inclination between gastric remnant and duodenal stump. Virtual gastric resection was performed on each of 3D FE models based on multislice Computer Tomography (CT) DICOM. According to our computer simulation the difference between maximal duodenal stump pressures for models with most and least preferable geometry of reconstructed GI tract is about 30%. We compared the resulting postoperative duodenal pressure from computer simulations with duodenal stump dehiscence pressure from the experiment. Pressure at duodenal stump after BII resection obtained by computer simulation is 4-5 times lower than the dehiscence pressure according to our experiment on isolated bowel segment. Our conclusion is that if the surgery is performed technically correct, geometry variations of the reconstructed GI tract by themselves are not sufficient to cause duodenal stump blowout. Pressure that develops in the duodenal stump after BII resection using omega loop, only in the conjunction with other risk factors can cause duodenal dehiscence. Increased duodenal pressure after BII resection is risk factor. Hence we recommend the routine use of Roux en Y anastomosis as a safer solution in terms of resulting intraluminal pressure. However, if the surgeon decides to perform BII reconstruction, results obtained with this methodology can be valuable.

Real-time monitoring of cytotoxic effects of electroporation on breast and colon cancer cell lines.

PURPOSE To study the effects of electroporation on different cell lines. MATERIAL The effects of electroporation on human breast cancer (MDA-MB-231), human colon cancer (SW-480 and HCT-116), human fibroblast cell line (MRC-5), primary human aortic smooth muscle cells (hAoSMC) and human umbilical vein endothelial cells (HUVEC) were studied. Real-time technology was used for cell viability monitoring. Acridine orange/ethidium bromide assay was applied for cell death type determination. A numerical model of electroporation has been proposed. RESULTS Electroporation induced inhibition of cell viability on dose (voltage) dependent way. The electroporation treatment 375-437.5Vcm-1 caused irreversible electroporation of cancer cells and reversible electroporation of healthy cells. The application of lower voltage rating (250Vcm-1) led to apoptosis as the predominant type of cell death, whereas the use of higher voltage (500Vcm-1) mainly caused necrosis. CONCLUSION Electroporation represents a promising method in cancer treatment. Different cancer cell lines had different response to the identical electroporation treatment. Electroporation 375-437.5Vcm-1 selectively caused permanent damage of cancer cells (SW-480), while healthy cells (MRC-5, hAoSM and HUVEC) recovered after 72h. The type of cell death is dependent of electroporation conditions. The proposed numerical model is useful for the analysis of phenomena related to electroporation treatment.

The impact of pain on functionality and health related quality of life in patients with knee osteoarthritis

Aleksandra Jurišić-Škevin1,2, Vesna Grbović1,2, Ivana Stanković3, Aleksandar Radunović4, Jasmin Nurković5, Bojan Milošević6,2, Aleksandar Cvetković6,2, Ana Divjak1, Maja Vulović7 1University of Kragujevac, Faculty of Medical Sciences, Department of Physical medicine and rehabilitation, Kragujevac, Serbia; 2Clinical center Kragujevac, Kragujevac, Serbia; 3University of Defence in Belgrade, Military Medical Academy, Institute for Medical Research, Belgrade, Serbia; 4Military medical academy, Clinic for orthopedic surgery and traumatology, Belgrade, Serbia; 5State University of Novi Pazar, Department of Biomedical Sciences, Novi Pazar, Serbia; 6University of Kragujevac, Faculty of Medical Sciences, Department of Surgery, Kragujevac, Serbia; 7University of Kragujevac, Faculty of Medical Sciences, Department of Anatomy, Kragujevac, Serbia;

Esophageal Mobilization in the Treatment of Short Esophagus

Abstract Short esophagus is well known complication of a long term gastroesophageal disease. There are several ways to solve this problem intraoperatively. One of the first steps is extensive esophageal mobilisation. In this review we emphasize different approaches and types of this procedure, with their advantages and disadvantages.

The Collis Procedure and the Acquired Short Esophagus

Abstract One of the most intriguing problems in modern esophageal surgery is the acquired short esophagus. While some authors recognize this entity, others deny its existence. There is a consensus about types of the short esophagus, its etiology and pathophysiology. Definitive diagnosis can be established only intraoperatively. There are a few surgical procedures for this problem, and most frequently is used Collis gastroplasty with fundoplication. In this review we emphasize recent literature data and further perspectives of the Collis procedure.

Length of Hospital Stay and Bed Occupancy Rates in Former Yugoslav Republics 1989–2015

Recent decades have been witnesses that developing world economies preceded global economic growth with all the consequences on healthcare systems of their countries. Complex and dynamic socioeconomic and technological evolution, primarily in free market of capitalist economies as well as in former socialist countries/economies with some postponement, provided significant advances and improvements in health outcomes (Jakovljevic and Ogura, 2016). Large differences in the quality of health systems are evident. Globalization among many changes led to the creation of so called emerging markets. The one with the most intensive development were marked by Goldman Sachs as BRICS European region offers great opportunities for studying variations in the magnitude of inequalities in health system quality because of the numerous intercountry varieties of political, cultural, economic, and epidemiologic nature (Arcaya et al., 2015). Eastern Europe and Balkans allow very good insight whether states with history of recent period of war, political instability, economic crisis, and different types of health care reforms have larger inequalities in health than countries elsewhere in Europe and worldwide (Mackenbach et al., 2008). We conducted a study within former Yugoslav republics, today independent countries and tried to identify some of the indicators determining these variations. A shortage of published data related to the consequences of SouthEastern European transition on healthcare is evident, especially regarding former Yugoslavia. The civil war events between 1989 and 1995 initiated a huge wave of socioeconomic changes in the whole region of the Balkans that inevitably influenced national health systems quality referring to health care provision, planning and financing. These reforms were significantly more prosperous in some states of former Yugoslavia compared to the others (Jakovljevic et al., 2015a). National health system of former Yugoslavia was actually something in between Western European and Eastern Soviet bloc financing pattern. Serbia is the largest Western Balkans medical equipment and pharmaceutical market in terms of population size as well as the value of sales among neighboring non-EU countries. Global recession caused serious problems in provision of sustainable financing and increased shortages of pharmaceuticals and medical equipment across the region of former Yugoslavia (Jakovljevic et al., 2015b). Health insurance systems are similar in all former Yugoslav republics. All employed citizens are insured and they use health care services in public health care institutions as well as in private institutions which have a signed contract with the Health Insurance Fund, a legal entity established by the Republic Ministry of Health. …

Role of computer analysis in prediction of surgical outcome after Billroth II gastric resection

This paper presents computer analysis of how geometry of reconstructed gastrointestinal tract can influence outcome of Billroth II gastric resection. We performed three-dimensional computer simulation in order to predict duodenal stump blowout. For creation of initial three dimensional FE models of preoperative gastroduodenal region we used data from Multi Slice Computer Tomography (MSCT). Using the initial model we performed virtual gastric surgery. All post operational models were examined separately in order to find correlation between post operational geometry and pressure in duodenal stump. Data acquired by methodology presented in this study can be valuable to surgeons for prediction of suture dehiscence after gastric surgery.

Hybrid SPECT/MSCT 3D computational preoperative simulation in breast cancer surgery

Hybrid imaging combining CT and SPECT is becoming a state of the art nuclear medicine technique. Advantages of hybrid imaging are improved quality of the images using CT data for attenuation correction based on true transmission density data in an individual patient, and CT and SPECT fusion images providing accurate localization of the tracer uptake. Accurate localization of increased tracer uptake is very important especially in the diagnostic of tumors. For this purpose a software developed for generating 3D models from standard DICOM images, obtained from CT and SPECT, and then merging these 3D objects, provides us with the exact location of sentinels nodes. This is certainly very helpful for a surgeon performing biopsy. The ability of SPECT/CT to improve diagnostic accuracy, especially specificity, has a great potential in further development of nuclear medicine techniques in evaluation of tumors.

Afferent loop syndrome CFD simulation after Billroth II gastric resection

In this paper a CFD study of afferent loop syndrome after Billroth II gastric resection is presented. Three-dimensional CFD simulation is used in this study in order to investigate conditions at the duodenal stump after Billroth II gastric resection which may cause duodenal stump blowout. We performed virtual gastric resection using the preoperative Finite Element (FE) model based on MSCT Dicom. Three models after Billroth II gastric resection were created. CFD calculation was performed employing these models with data from literature. We calculated pressure and velocity distribution, as well as saliva and pancreatic juice and bile concentrations. After CFD simulation we had better insight into the processes within the duodenal stump after surgical intervention. This study can be useful for predictions of surgical complications.