Browsing by Author "Koncar, Igor B. (19337386500)"

The scope of this paper is to present the novel risk stratification framework for carotid artery disease which is under development in the TAXINOMISIS study. The study is implementing a multimodal strategy, integrating big data and advanced modeling approaches, in order to improve the stratification and management of patients with carotid artery disease, who are at risk for manifesting cerebrovascular events such as stroke. Advanced image processing tools for 3D reconstruction of the carotid artery bifurcation together with hybrid computational models of plaque growth, based on fluid dynamics and agent based modeling, are under development. Model predictions on plaque growth, rupture or erosion combined with big data from unique longitudinal cohorts and biobanks, including multi-omics, will be utilized as inputs to machine learning and data mining algorithms in order to develop a new risk stratification platform able to identify patients at high risk for cerebrovascular events, in a precise and personalized manner. Successful completion of the TAXINOMISIS platform will lead to advances beyond the state of the art in risk stratification of carotid artery disease and rationally reduce unnecessary operations, refine medical treatment and open new directions for therapeutic interventions, with high socioeconomic impact. © 2019 IEEE.

The scope of this paper is to present the novel risk stratification framework for carotid artery disease which is under development in the TAXINOMISIS study. The study is implementing a multimodal strategy, integrating big data and advanced modeling approaches, in order to improve the stratification and management of patients with carotid artery disease, who are at risk for manifesting cerebrovascular events such as stroke. Advanced image processing tools for 3D reconstruction of the carotid artery bifurcation together with hybrid computational models of plaque growth, based on fluid dynamics and agent based modeling, are under development. Model predictions on plaque growth, rupture or erosion combined with big data from unique longitudinal cohorts and biobanks, including multi-omics, will be utilized as inputs to machine learning and data mining algorithms in order to develop a new risk stratification platform able to identify patients at high risk for cerebrovascular events, in a precise and personalized manner. Successful completion of the TAXINOMISIS platform will lead to advances beyond the state of the art in risk stratification of carotid artery disease and rationally reduce unnecessary operations, refine medical treatment and open new directions for therapeutic interventions, with high socioeconomic impact. © 2019 IEEE.

Background: The purpose of this paper is to examine and assess the outcomes following open repair in 39 patients who experienced aorto-caval fistula (ACF) resulting from the spontaneous rupture of an abdominal aortic aneurysm (AAA). Methods: We reviewed the clinical records of all patients surgically treated with open repair for ACF at the Clinic for Vascular and Endovascular Surgery of the Serbian Clinical Center in Belgrade, Serbia, from January 2012 to February 2023. All of the patients in this series were consecutive and had aorto-caval fistula from AAA. No patients were excluded from the procedure due to the life-threatening nature of the state. A follow-up assessment was performed during the follow-up examination or by telephone interview with the patient or a family member. Results: All patients were male, with mean age 67.4±8.3 years (range: 52-83 years). The 30-day mortality rate in our cohort was 35.9%, with three (7.7%) intraoperative deaths, and 11 deaths in the postoperative period (28.2%). A total of 25 patients out of 39 (64.1%) in the original cohort have survived the surgery and the postoperative period and were followed-up for a total of 67.1 person-years. The mean follow-up was 3.7±2.2 years (range 0.25-8.4 years). Two patients (8.0%) died during the follow-up, 16 patients (64.0%) survived, and seven (28.0%) were lost to follow-up. The long-term mortality rate in the cohort that survived the postoperative period was 3.0/100 person-years. Conclusions: ACF caused by spontaneous AAA rupture into the inferior caval vein or iliac veins is a relatively rare, life-threatening condition which requires prompt treatment. An exact preoperative diagnosis is essential for perioperative strategy. As the comparison of our results with the results from contemporary literature indicates, wherever possible endovascular repair should be considered since it results might be superior to open repair. © 2024 EDIZIONI MINERVA MEDICA.

Carotid atherosclerotic plaque growth leads to the progressive luminal stenosis of the vessel, which may erode or rupture causing thromboembolism and cerebral infarction, manifested as stroke. Carotid atherosclerosis is considered the major cause of ischemic stroke in Europe and thus new imaging-based computational tools that can improve risk stratification and management of carotid artery disease patients are needed. In this work, we present a new computational approach for modeling atherosclerotic plaque progression in real patient-carotid lesions, with moderate to severe degree of stenosis (>50%). The model incorporates for the first time, the baseline 3D geometry of the plaque tissue components (e.g. Lipid Core) identified by MR imaging, in which the major biological processes of atherosclerosis are simulated in time. The simulated plaque tissue production results in the inward remodeling of the vessel wall promoting luminal stenosis which in turn predicts the region of the actual stenosis progression observed at the follow-up visit. The model aims to support clinical decision making, by identifying regions prone to plaque formation, predict carotid stenosis and plaque burden progression, and provide advice on the optimal time for patient follow-up screening. © 2021 IEEE.

Carotid atherosclerotic plaque growth leads to the progressive luminal stenosis of the vessel, which may erode or rupture causing thromboembolism and cerebral infarction, manifested as stroke. Carotid atherosclerosis is considered the major cause of ischemic stroke in Europe and thus new imaging-based computational tools that can improve risk stratification and management of carotid artery disease patients are needed. In this work, we present a new computational approach for modeling atherosclerotic plaque progression in real patient-carotid lesions, with moderate to severe degree of stenosis (>50%). The model incorporates for the first time, the baseline 3D geometry of the plaque tissue components (e.g. Lipid Core) identified by MR imaging, in which the major biological processes of atherosclerosis are simulated in time. The simulated plaque tissue production results in the inward remodeling of the vessel wall promoting luminal stenosis which in turn predicts the region of the actual stenosis progression observed at the follow-up visit. The model aims to support clinical decision making, by identifying regions prone to plaque formation, predict carotid stenosis and plaque burden progression, and provide advice on the optimal time for patient follow-up screening. © 2021 IEEE.

[No abstract available]

BaCKgrouNd: accumulated endovascular aneurysm repair (eVar) procedures will increase number of patients requiring conversion to open repair of abdominal aortic aneurysms (aaa). in most cases, patients undergo late open surgical conversion (losC), many months, or years, after initial eVar. The aim of this study is to analyze results of losC after eVar in elective and urgent setting, including presenting features, surgical techniques, as well as to review the clinical outcomes and their predictors. MeThods: retrospective review of all consecutive patients undergoing losC after eVar was performed at three distinct, high volume, vascular centers. Patients that required primary conversion within 30 days after eVar have not been included in this study. Between January 1st 2010 and January 1st 2017 total of 31 consecutive patients were treated. losC were performed either in elective or in urgent setting, thus dividing patients in two groups. Primary outcome was 30-day mortality and secondary postoperative complications resulTs: losC rate after eVar was 4.51%. Most common indication for losC was type i endoleak (N.=20, 64.51%). all patients that presented with ruptured AAA had some form of endoleak (type I endoleak was present in five from six cases). Most common site for aortic cross-clamping was infrarenal (51.61%). stent-graft was removed completely in 18 patients (58.06%) and partially in 13 (41.93%). 30-day mortality rate was 16.12% (5 patients) and most common cause of death was myocardial infarction (60%). following univariate factors were isolated as predictors for 30-day mortality: preoperative coronary artery disease, chronic obstructive pulmonary disease, urgent losC, prolonged time until losC, ruptured aaa, supraceliac clamp, higher number of red blood cell transfusion, postoperative myocardial infarction, and prolonged intubation (more than 48 hours). CoNClusioNs: losC seems to be safe and effective procedure when preformed in elective manner. on the other side, urgent losC after eVar is associated with very high postoperative mortality and morbidity. endoleak remains the main indication for open conversion. further studies are necessary to standardize timing and treatment options for failing eVar. © 2018 EDIZIONI MINERVA MEDICA.

Background Both, open and endovascular, procedures are related to higher complication rate in abdominal aortic aneurysm (AAA) with shorter neck. Previous study showed that long-neck AAA might have lower risk of rupture. Estimation of biomechanical forces in AAA improves rupture risk assessment. The aim of this study was to compare morphological features and biomechanical forces in the short- and long-neck AAA with threshold of 15 mm. Methods Digital Imaging and Communication in Medicine images of 64 aneurysms were prospectively collected and analyzed in a case-control study. Using commercially available software, Peak wall Stress (PWS) and Rupture Risk Equivalent Diameter (RRED) were determined. Difference between the maximal aneurysm diameter (MAD) and RRED was calculated and expressed as an absolute and relative (percentage of the MAD) value. In addition, volume of intraluminal thrombus (ILT) was calculated and expressed relative to AAA volume. Results Study included 64 AAA divided in group with long (36, 56.25%), and short (28, 43.75%) neck. There was no correlation between neck length and MAD, PWS, and RRED (P = 0.646, P = 0.421, and P = 0.405, respectively). Relative ILT volume was greater in the short-neck aneurysms (P = 0.033). Relative difference between RRED and MAD was −4% and −14.8% in short- and long-neck aneurysms, respectively (P = 0.029). The difference between RRED and MAD was positive in 14/28 patients (50%) with short neck and in 6/35 patients (17.14%) with long neck (P = 0.011). Conclusions Based on our biomechanical analysis, in AAA with neck longer than 15 mm rupture risk might be lower than the risk estimated by its diameter. It might be explained with lower relative volume of ILT. © 2017 Elsevier Inc.

[No abstract available]

Objective: Screening for abdominal aortic aneurysm (AAA) is recommended in high risk populations based on local conditions. Differences in lifestyle and risk factors between countries with different income status make risk stratification based on geographic location necessary. The majority of epidemiological studies on AAA have reported data from high income countries. The aim of this study was to explore the prevalence and risk factors for AAA in an upper middle income country in Eastern Europe. Methods: A pilot screening project for AAA, supported by a mass media campaign, was conducted in 2023 in seven cities in Serbia. Ultrasound evaluation of the abdominal aorta was performed by a registered vascular surgeon on individuals who agreed to participate. Participants who attended screening completed a questionnaire on demographic and clinical information. To assess risk factors for AAA, univariable logistic regression analysis was performed to compute the odds ratio (OR) with 95% confidence interval (CI). Multivariable logistic regression was subsequently performed with adjustments for sex, age, family history of AAA, and other relevant factors. Results: A total of 4 046 participants (51.2% male and 48.8% female; mean age 68.8 ± 7.6 years) responded to the campaign. An aneurysm was found in 195 (4.8%) screened individuals (8.2% of men and 1.3% of women). In males aged 50 – 64 years, the prevalence of AAA was 5.4%. Male sex, older age, family history of AAA, being a smoker or ex-smoker, being overweight, and alcohol consumption were predictors of AAA in the univariable analysis. After adjustments in the multivariable analysis, male sex (OR 8.04, 95% CI 4.87 – 13.28), older age (OR 1.04, 95% CI 1.02 – 1.07), positive family history (OR 2.47, 95% CI 1.61 – 3.78), smoker status (OR 3.10, 95% CI 2.10 – 4.59), ex-smoker status (OR 2.13, 95% CI 1.39 – 3.27), and being overweight (OR 1.85, 95% CI 1.25 – 2.74) were independent risk factors for AAA. Conclusion: The prevalence of AAA has not been reduced in all countries, and screening strategies might be changed based on local epidemiological data. The results of this pilot study underline the importance of exploring the prevalence of AAA in populations with a high prevalence of smoking. © 2024

Patients undergoing carotid endarterectomy and carotid artery stenting are susceptible to the development of adverse cardiac events. Perioperative myocardial injury – an entity characterized by increased values of cardiac troponins – is strongly associated with the occurrence of both short- and long-term cardiac adverse events, non-cardiac complications, poor treatment outcomes, and increased mortality. The silent nature of this condition, in most cases, emphasizes the significance of perioperative troponin measurement, which is reflected in its diagnostic, prognostic, and risk stratification value. Thus, the possible benefits of troponin screening represent the main aim of numerous studies in non-cardiac surgery patients. Still, this issue has not been sufficiently explored in patients undergoing carotid revascularization. Questions regarding the superiority of routine/selective screening, one troponin essay over the other, preoperative/postoperative/perioperative evaluation, the appropriate timing and duration of troponin measurement, the predictors of its elevation and patient-specific risk factors, the impact of different anesthesia techniques and methods of carotid revascularization, the predictive role of perioperatively elevated troponin, secondary preventive strategies, therapeutic measures, and its cost-effectiveness mostly remain unanswered. The present review provides a comprehensive overview of the current knowledge regarding the value of troponin measurement in patients undergoing carotid revascularization, critically appraises the up-to-date literature, and marks directions for future research in this area. © 2024 EDIZIONI MINERVA MEDICA.

Background: Pediatric peripheral vascular trauma carries significant risk of complications including limb loss and long-term invalidity. Mechanisms and types of morphological lesions are very diverse. The objectives of this study are to present the experience of a single vascular center in the surgical approach to pediatric vascular injuries, and to analyze the main challenges related to this clinical entity. Methods: Over a period of 25 years, 17 pediatric peripheral vascular injuries were treated in our institution. Patient's age ranged between one day (newborn) and 15 years (mean: 10.7 years). There were five injuries of upper and 12 injuries of the lower extremity. Preoperative diagnosis was established by clinical examination (N.=4), ultrasonography (N.=1) and angiography (N.=12). Blunt trauma mainly caused arterial thrombosis while penetrating trauma caused arterial laceration or complete transection. Five patients had associated orthopedic injuries (29,4%). There were two posttraumatic pseudoaneurysms and two arterio-venous fistulas. Results: There was no perioperative mortality. Vascular reconstructions included arterial suture (N.=4), thrombectomy + patch angioplasty (N.=1), termino-terminal anastomosis (N.=3), venous anatomic bypass (N.=6), PTFE graft reconstruction (N.=2), and venous extra-anatomic reconstruction (N.=1). Two patients had associated venous injury demanding both arterial and venous reconstruction. In the only case of war trauma treatment ended with limb loss. Other reconstructions presented good early and long-term patency. Conclusions: Pediatric vascular injuries are extremely challenging issues. Treatment includes broad spectrum of different types of vascular reconstructions. It should be performed by vascular surgeon trained in open vascular treatment or pediatric surgeon with significant experience in vascular surgery. © 2019 EDIZIONI MINERVA MEDICA

BACKGROUND: The purpose of this study was to examine demographic and baseline characteristics of patients with vascular injuries of extremities and to define the most relevant factors which influenced an early outcome, as well as limb salvage after the management of vascular trauma. METHODS: This study used the database that included 395 patients with peripheral arterial injuries, who were treated in the tertiary vascular university center in the period between 2005-2020. Exclusion criteria were isolated thoracic, abdominal and neck injuries as well as iatrogenic injuries and injuries of intravenous addicts. Univariate binary logistic regression analysis and multiple logistic regression were used to determine risk factors for lomb loss (after vascular reconstruction) or mortality. Decision to perform primary amputation (without vascular reconstruction) was based on surgeons’ preference and experience. RESULTS: Out of 395 vascular injuries treated in the period 2005–2020, 210 (53.2%) presented with non-iatrogenic vascular injuries of upper and lower extremities were analyzed. According to the univariate regression analysis, hemorrhage as the main clinical manifestation on admission (P=0.035) and early reintervention (P=0.048) increased, while an early patency of repaired artery (0.010) significantly decreased a 30-day amputation rate. Multivariate logistic regression analysis of these three variables showed that only early patency of repaired artery significantly decreased the early amputation rate (P=0.009). CONCLUSIONS: Based on presented experience, the patency of vascular reconstruction plays a crucial role in limb salvage in patients with non-iatrogenic peripheral vascular injuries. All factors that might influence the patency should be in focus of improvement. © 2022 EDIZIONI MINERVA MEDICA.