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Introduction: In many countries, hemodialysis is still the most common method of renal replacement. Significant regional variations exist in creating and maintaining vascular access for hemodialysis. Therefore, analyzing national registries with vascular access data is essential for developing effective national treatment strategies. The Serbian national vascular surgery registry was established as part of the VascuNet collaboration network in 2019. The registry comprehensively records vascular procedures across Serbia, including those related to vascular access for hemodialysis., Objectives: This study aims to evaluate the prevalence of different vascular access methods for hemodialysis in Serbia, focusing on both new and prevalent patients and examining demographic differences and risk factors., Patients and Methods: The data were collected from the vascular accesses section of the SerbVasc registry over a 3-year observational period, focusing on the following aspects: number of incident and prevalent patients with types of vascular access, as well as comparison of patients with arteriovenous fistulas (AVF), arteriovenous grafts (AVG), central venous catheters (CVC), and tCVC based on age, gender, smoking, and comorbidities., Results: There were total of 1024 incident hemodialysis patients. AVF was created in 219 patients (21.4%), AVG in 5 patients (0.5%), and tCVC in 150 patients (14.6%), while hemodialysis via CVC was initiated in 650 (63.5%) patients. The total number of permanent vascular accesses for HD was 1402, comprising 686 (48.9%) distal AFVs, 220 (15.7%) proximal AVFs, 91 (6.4%) AVGs, and 405 (28.8%) tCVCs. The prevalence of current smoking was highest in the tCVC (48.3%) and lowest in the dAVF group (18.40%)., Conclusion: The percentage of patients starting hemodialysis with AVF remains suboptimal. tCVC is used substantially as first and permanent access, particularly among older patients., Competing Interests: Declaration of conflicting interestsThe author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

We investigated serum concentrations of specific inflammatory parameters in patients with significant carotid artery stenosis (CAS) of 50-99%, with an additional focus on patients with moderate stenosis (50-69%), in terms of both symptomatic status and plaque morphology, to determine whether there are certain parameters that can be associated with plaque instability before the progression of CAS to a high degree. The study included 119 CAS patients, 29 of whom had moderate stenosis, and 46 controls. Ultrasonography of the carotid arteries was performed using color flow Doppler and B-mode duplex ultrasound, and serum inflammatory parameters were measured using commercially available enzyme immunoassays. When comparing patients with 50-99% stenosis, only serum amyloid A (SAA) was higher in symptomatic patients, while in the group of patients with 50-69% stenosis, myeloperoxidase (MPO) was higher and pentraxin-3 (PTX-3) was lower in symptomatic compared to asymptomatic patients, and soluble urokinase plasminogen activator receptor (suPAR) was higher in patients with carotid plaque of unstable compared to stable morphology. Our results suggest that the importance of different inflammatory parameters in patients with moderate CAS is not the same as in CAS patients in general, and therefore their separate investigation in patients with high and moderate stenosis may be beneficial. SAA has the potential to be further considered in research to predict CAS symptom risk. There is a possibility that MPO and PTX-3 play a role in the development of CAS symptoms originating from less stenotic plaques and that suPAR is involved in the destabilisation of such plaques.

Endovascular repair has significantly improved the treatment of aortic aneurysms, particularly in older and high-risk patients. However, many studies have not found significant differences in long-term outcomes when comparing open and endovascular repair methods. Additionally, endovascular repair is associated with a higher rate of aortic-related reinterventions compared to open repair (OR), sometimes necessitating late open surgical conversion (LOSC). The increasing number of endovascular aortic aneurysm repairs exposes vascular surgeons to a growing number of patients requiring late open surgical conversion (LOSC) after previous endovascular aneurysm repair (EVAR) or thoracic endovascular aortic repair (TEVAR). LOSC following endovascular procedures is associated with higher perioperative mortality and complication rates compared to primary open repair of aortic aneurysms. This review summarizes the current knowledge, indications, possibilities, and techniques for LOSC after initial endovascular procedures. While the incidence of complications requiring LOSC remains relatively low, the number of endovascular procedures performed has increased significantly over the last decade, suggesting a rise in LOSC procedures as well. Due to the complexity involved, LOSC procedures should be performed in high-volume centers by highly experienced vascular surgeons. This underlines the importance of educating the younger generation of vascular surgeons in both endovascular and open aortic surgery.

Background: Peripheral arterial disease (PAD) and diabetes are the major causes of lower extremity amputations (LEAs) worldwide. Morbidity and mortality in patients with LEAs are high with an associated significant burden on the global health system. The aim of this article is to report the overall morbidity and mortality rates after major and minor LEAs from the Serbian Vascular Registry (SerbVasc), with an analysis of predictive factors that influenced adverse outcomes., Materials and Methods: SerbVasc was created in 2019 as a part of the Vascunet collaboration that is aiming to include all vascular procedures from 21 hospitals in Serbia. Prevalence of diabetes among patients with LEAs, previous revascularization procedures, the degree and the type of foot infection and tissue loss, and overall morbidity and mortality rates were analyzed, with a special reference to mortality predictors., Results: In the period from January 2020 to December 2022, data on 702 patients with LEAs were extracted from the SerbVasc registry, mean age of 69.06±10.63 years. Major LEAs were performed in 59%, while minor LEAs in 41% of patients. Diabetes was seen in 65.1% of the patients, with 44% of them being on insulin therapy. Before LEA, only 20.3% of patients had previous peripheral revascularization. Soft tissue infection, irreversible acute ischemia, and Fontaine III and IV grade ischemia were the most common causes of above-the-knee amputations while diabetic foot was the most common cause of transphalangeal and toe amputations. The infection rate was 3.7%, the re-amputation rate was 5.7%, and the overall mortality rate was 6.9%, with intrahospital mortality in patients with above-the-knee amputation of 11.1%. The most significant intrahospital mortality predictors were age >65 years (p<0.001), chronic kidney disease (CKD) (p<0.001), ischemic heart disease (IHD) (p=0.001), previous myocardial revascularization (p=0.017), emergency type of admission (p<0.001), not using aspirin (p=0.041), using previous anticoagulation therapy (p=0.003), and postoperative complications (p<0.001)., Conclusions: The main predictors of increased mortality after LEAs from the SerbVasc registry are age >65 years, CKD, IHD, previous myocardial revascularization, emergency type of admission, not using aspirin, using previous anticoagulation therapy, and postoperative complications. Taking into account high mortality rates after LEAs and a small proportion of previous peripheral revascularization, the work should be done on early diagnosis and timely treatment of PAD hopefully leading to decreased number of LEAs and overall mortality., Clinical Impact: Mortality after lower limb amputation from the SerbVasc register is high. A small number of previously revascularized patients is of particular clinical importance, bearing in mind that the main reasons for above-the-knee amputations were irreversible ischemia, Fontaine III and Fontaine IV grade ischemia. Lack of diagnostics procedures and late recognition of patients with PAD, led to subsequent threating limb ischemia and increased amputation rates. The work should be done on early diagnosis and timely treatment of PAD in Serbia, hopefully leading to an increased number of PAD procedures, decreased number of LEAs, and lower overall mortality.

Background: The purpose of this study was to assess the clinical presentation and contemporary management of arterial thoracic outlet syndrome (TOS) in high-volume referral center., Methods: We conducted a retrospective review of a prospectively maintained database of patients with TOS of any etiology between January 1 st 1990 and 2021. Supra-, or combined supra-/infraclavicular approaches have been used for decompression/vascular reconstructions. The group was divided into two equal time periods: period 1 (1990-2006, N.=27) and period 2 (2006-2021, N.=36)., Results: Sixty-three consecutive patients underwent surgical treatment due to arterial TOS. Period 2 had more patients who were asymptomatic (N.=16, 44.4% vs. N.=0, 0%, P<0.001) and those presenting with critical hand ischemia (N.=12, 33.3% vs. N.=0, 0%, P=0.01), while acute limb ischemia was more common in period 1 (N.=16, 59.2% vs. N.=5, 13.9%, P<0.001). SA compression without lesion was more common in period 2 (N.=16, 44.4% vs. N.=0, 0%, P<0.001), while SA intimal damage with mural thrombus formation was more common in the period 1 (N.=12, 44.4% vs. N.=1, 2.7%, P<0.001). Decompression as an isolated procedure was performed in 25.4% (N.=16) of all asymptomatic patients, while combined decompressive and vascular procedure in 71.4% (N.=45) of patients. The most common postoperative complication was pneumothorax (N.=7, 11.1%)., Conclusions: The supraclavicular approach with its modifications provides adequate decompression and allows also repair or reconstruction of the SA, as well as complete additional revascularization of the upper extremity without the need for further patient repositioning. While treatment methods and early outcomes have not changed significantly over time, there has been a trend towards different clinical and SA pathomorphological presentation.

Background: The aim of this study was to examine the influence of intraluminal thrombus (ILT) volume on the level of proteolytic activity and the content of abdominal aortic aneurysm (AAA) wall., Methods: The research was designed as a cross-sectional study at the Clinic for Vascular and Endovascular Surgery, Clinical Center of Serbia in the period from April 2017 to February 2018. During this period, a total of 155 patients with asymptomatic AAA underwent open surgical treatment and 50 were included in the study based on inclusion and exclusion criteria. Before surgery, patients included in the study were examined by MRI. During the operation, samples of ILT and AAA wall were taken for biochemical analysis., Results: A statistically significant correlation was found between the volume of the ILT and largest AAA diameter (ρ = 0.56; P < 0.001). The correlation of the ILT volume on the anterior wall and the concentration of MMP-9, MMP-2 and NE/ELA in the wall did not find statistical significance. Also, no statistically significant association was found between the volume of ILT and the concentration of ECM proteins (collagen type 3, elastin, proteoglycan) in the corresponding part of the wall. The association of ILT volume with MDA was also of no statistical significance. There was a positive statistical significance found in correlation of volume of ILT and catalase activity in the wall of AAA (ρ = 0.28, P = 0.049)., Conclusions: The volume of ILT in the aneurysmal sac seemed not to affect the level of proteolytic activity and the content of the aneurysm wall. However, a positive correlation was found between the ILT and the catalase activity. The effect of ILT on the aneurysm wall and its role in the progression of aneurysmal disease should be examined in future studies., (Copyright © 2022 Elsevier Inc. All rights reserved.)

Background and Objectives: Despite the relatively large number of publications concerning the validation of these models, there is currently no solid evidence that they can be used with absolute precision to predict survival. The goal of this study is to identify preoperative factors that influenced 30-day mortality and to create a predictive model after open ruptured abdominal aortic aneurysm (RAAA) repair. Materials and Methods: This was a retrospective single-center cohort study derived from a prospective collected database, between 1 January 2009 and 2016. Multivariate logistic regression analysis was used to identify all significant predictive factors. Variables that were identified in the multivariate analysis were dichotomized at standard levels, and logistic regression was used for the analysis. To ensure that dichotomized variables were not overly simplistic, the C statistic was evaluated for both dichotomized and continuous models. Results: There were 500 patients with complete medical data included in the analysis during the study period. Of them, 37.6% were older than 74 years, and 83.8% were males. Multivariable logistic regression showed five variables that were predictive of mortality: age > 74 years (OR = 4.01, 95%CI 2.43−6.26), loss of consciousness (OR = 2.21, 95%CI 1.11−4.40), previous myocardial infarction (OR = 2.35, 95%CI 1.19−4.63), development of ventricular arrhythmia (OR = 4.54, 95%CI 1.75−11.78), and DAP < 60 mmHg (OR = 2.32, 95%CI 1.17−4.62). Assigning 1 point for each variable, patients were stratified according to the preoperative RAAA mortality risk score (range 0−5). Patients with 1 point suffered 15.3% mortality and 3 points 68.2% mortality, while all patients with 5 points died. Conclusions: This preoperative RAAA score identified risk factors readily assessed at the bedside and provides an accurate prediction of 30-day mortality after open repair of RAAA.

In a recent study we described an increase of elastic tissue fibres in blood vessel walls of placental stem villi during pre-eclampsia when compared to uncomplicated pregnancies. Furthermore, the thickness of these blood vessel walls was enhanced in pre-eclampsia. Since it is known that elastic tissue fibres increase in systemic hypertension, it may be assumed that the enhancement of elastic tissue fibres in placental stem villi during pre-eclampsia may be induced by the hypertension. To get further insight into this assumption, we examined the amount of elastic tissue fibres in stem villus blood vessels of placentae of pregnancies complicated by intrauterine growth retardation (isolated IUGR, fourteen cases), a disease without hypertension of the mother and such with pre-eclampsia and concomitant IUGR (IUGR+PE, nine cases). Each study group was compared with uncomplicated pregnancies (twenty-six cases). Unfixed cryostat serial sections were processed for conventional orcein staining and for the demonstration of alpha-actin-immunoreactivity. The intensity of orcein staining of stem villus blood vessel walls was evaluated by a semiquantitative score method. Significant lower intensities of orcein staining were calculated for blood vessel walls of placentae of isolated IUGR (P=0.0007) and IUGR+PE (P=0.0039) when compared to uncomplicated pregnancies each. Additionally, the blood vessel wall thickness of stem villi of isolated IUGR (P=0.0081) and IUGR+PE (P=0.0007) was significantly reduced. In comparison to the above mentioned investigation, our results show that, in contrast to isolated pre-eclampsia, elastic tissue fibres are decreased during pregnancies complicated by IUGR, independently of the occurrence of concomitant pre-eclampsia when compared to uncomplicated pregnancies. From our studies it may be considered that the increase of elastic tissue fibres in placentae of patients with isolated pre-eclampsia may be induced by systemic hypertension. Furthermore, our study underline arguments that IUGR may be an independent disease of the fetus.

Hyaluronan (HA), a high molecular weight polysaccharide, is a major component of connective tissue and is thus present in the extracellular matrix of most tissues. Increased serum concentrations have been reported in association with pre-eclampsia and liver malfunction, amongst other disorders. We have performed histochemical investigations with a HA-specific hyaluronic acid binding protein in placentas from uncomplicated pregnancies and from patients with pre-eclampsia. Staining for HA was found in the stroma and blood vessel walls of stem villi in all the placentas investigated. The syncytiotrophoblast and cytotrophoblast cells usually remained unstained. In addition, reactivity for HA was found within and on the surface of intervillous and perivillous fibrinoid deposits. Since fibrinoid deposits are increased in pre-eclampsia, our findings suggest that the increased HA serum concentrations in cases of pre-eclampsia could result from the stroma of the infarcted villi and from the fibrinoid deposits. HA may reach the maternal blood through fibrinoid gaps., (Copyright 2001 S. Karger AG, Basel)

Although pre-eclampsia (PE) is often associated with fetal hypoxia, hypertension and/or disturbed function of the fetal circulation, the effect of these altered hemodynamic parameters on the structure and composition of umbilical vessels has not been systematically investigated before. Therefore, this study focuses on PE-associated changes of the elastic fibre system in umbilical cord vessels investigated by light and electron microscopy, immunocytochemistry and biochemistry. In umbilical cord veins, no changes in thickness of the vessel wall or of any sublayer were observed. However, the internal elastic lamina of the veins was split in 80% of the PE-group in contrast to 20% in uncomplicated pregnancies. This effect was significant (alpha <0.01) from 36 weeks of gestation onwards. In umbilical cord arteries, the entire arterial vessel wall was found to be 15% thicker in PE than in uncomplicated pregnancies. The enlargement was caused by an increase of both the tunica intima and tunica media. The thickening of the tunica intima was attributed to a migration of smooth muscle cells towards the endothelium, accompanied by a splitting of the internal elastic lamina. Compared to uncomplicated pregnancies, smooth muscle cells of arteries and veins in PE showed a metabolic activation demonstrated by highly dilated endoplasmic reticulum. A semiquantitative score method as well as a quantitative dot blot assay indicated a PE-associated reduction of elastin expression in the arterial vessel walls. In summary, PE obviously induces a decrease of the elastin content accompanied by a thickening of the vessel wall in umbilical cord arteries. This remodeling of the elastic fibre system, together with an increased migration of smooth muscle cells, might represent part of the functional adaptation system of the umbilical cord arteries on the altered hemodynamic conditions in PE.

Background: Pre-eclampsia is associated with serum factors which can activate blood vessel endothelial cells. Hyaluronan (HYA) and its specific receptor CD44 play a central role in cell activation processes. Our study focussed on the behavior of serum concentrations of HYA and the soluble standard form of CD44 (sCD44std) in the maternal serum from normotensive and pre-eclamptic pregnancies., Patients and Methods: Serum was collected from normotensive pregnant women (n = 10) and from pregnant women with a severe pre-eclampsia (n = 10). HYA-serum concentrations were measured with a radioimmunoassay while sCD44std were measured with an ELISA., Results: The pre-eclampsia group shows a significant (p < 0.001, Mann and Whitney u-test) increased HYA serum concentration (median 79 ng/ml, range 53-165 ng/ml) when compared to the normotensive group (n = 10, median 32 ng/ml, range 19-59 ng/ml). sCD44std-serumconcentration in the pre-eclampsia group (328.3 +/- 68.3 ng/ml) was weakly higher but not statistically significant (p > 0.05) when compared to the normotensive group (292.9 +/- 74.0 ng/ml). There exist no correlations between the HYA and sCD44std serum concentrations in both pre-eclamptic and normotensive groups., Conclusion: The increased HYA-serumconcentration may indicate a pathophysiological role of the HYA/CD44-signal transduction system in pre-eclampsia. The existing overlap of HYA serum levels in the pre-eclampsia group with HYA serum levels in the normotensive control group limits the diagnostic precision of HYA serum concentration as a diagnostic parameter in pre-eclampsia. According CD44 it is not excluded that serum concentration of other soluble CD44-isoforms is increased in pre-eclampsia.

In previous studies, we have shown that smooth muscle cells and myofibroblast subpopulations of the perivascular stem villous sheath of the human placenta contain focal adhesion plaques and talin immunoreactivity. The close association of these cells to elastic and collagen fibres have led to the assumption of a functional myofibroelastic unit within the perivascular stem villous sheath. Interactions between the extracellular matrix and smooth muscle cells depend on a variety of structural protein assemblies. In the present study, we examined, by immunocytochemistry, whether the molecular assembly of extracellular matrix proteins and molecules of focal adhesions, known to be essential for signal transduction in smooth muscle cells, are also found in smooth muscle cells of the perivascular stem villous sheath of the human placenta. Vascular and extravascular smooth muscle cells were immunoreactive for alpha-actinin, vinculin, paxillin and tensin, the integrin chains alpha1 and beta1, and the basement membrane components laminin and heparan/-chondroitin sulfate proteoglycan perlecan. pp125(FAK) did not react. In the extracellular matrix of blood vessel walls and the perivascular stem villous sheath, we found immunoreactivity of fibronectin and collagen types I, VI and undulin (collagen type XIV). From our data we conclude that within the perivascular stem villous sheath, there exists a system of signal transduction molecules, indicating a cross talk between the smooth muscle cells of this sheath and their surrounding extracellular matrix.

In the course of our studies on the local blood flow modulation in the NMRI-mouse placenta we have focussed on regulatory pathways involving recently appreciated gaseous messenger molecules nitric oxide (NO) and carbon monoxide (CO), which are generated by NO synthase (NOS) and heme oxygenase (HO)-2, respectively. The distribution of NOS was investigated by immunohistochemistry using an antiserum to the neuronal isoform (NOS-I) and by NADPH diaphorase (NADPHd) histochemistry, supplemented with procedures (permanganate and formaldehyde method) serving to enhance the specificity of the enzyme histochemical method for NOS visualization. HO-2 was demonstrated immunohistochemically. In addition, cyclic guanosine monophosphate (cGMP)-forming soluble guanylate cyclase (sGC) and dehydrogenases generating the NOS co-substrate NADPH were analysed either by immunohistochemistry or enzyme histochemistry. NOS-I immunostaining was observed in the intraplacental visceral yolk sac epithelial cells but not in the placenta and extraplacental visceral epithelial yolk sac cells. Co-localization of NOS-I immunolabeling and NOS-associated NADPHd was exclusively found in the intraplacental visceral epithelial cells, while NADPHd activity not associated to NOS was present in other placental and extraplacental cells additionally analysed for control reasons. HO-2 and sGC immunoreactivity could not be detected in the placenta including the intraplacental visceral epithelial cells but were expressed in several extraplacental cells. Dehydrogenases producing the NOS co-substrate NADPH were present in the intraplacental visceral epithelium as well as in other placental and extraplacental cells. Since the intraplacental visceral epithelial yolk sac layer closely accompanies large fetal blood vessels entering the placental labyrinth from the chorionic plate it may be assumed that NO, generated by the NADPH-consuming NOS-I in the intraplacental yolk sac epithelium, acts to regulate the blood flow by relaxing smooth muscle cells in the wall of these fetal vessels. The lack of immunoreactivity to the NO-effector molecule sGC may be due to methodological reasons. The absence of the HO-2/CO system suggests its insignificant role as a potential gas signaling pathway in the vascular smooth muscle system of the intraplacental visceral yolk sac of mice.

Antitoxinum viperinum was tested for its ability to prevent alteration of the myocardium induced by Vipera ammodytes ammodytes venom. Antivenom was injected intraperitoneally either immediately, 30 min or 2 hr after the intraperitoneal injection of venom. The light microscopic examination showed that the antiserum neutralized the effects of venom and antivenom might be useful in treating V.a. ammodytes venom poisoning.