Hospital and long-term results of carotid endarterectomy in patients with different severity of coronary artery lesion according to syntax score.

AIM: Analysis of in-hospital and long-term results of carotid endarterectomy (CEE) in patients with different severity of coronary atherosclerosis. MATERIAL AND METHODS: This comparative, retrospective, open study for the period from January 2013 to April 2020 included 1719 patients operated on for occlusive-stenotic lesions of the internal carotid arteries (ICA). Classical and eversion CEA were used as revascularization strategies. The criteria for inclusion in the study were: 1. Presence of coronary angiography within six months before the present CEE; 2. A history of myocardial revascularization in patients with severe coronary lesions. Depending on the severity of coronary atherosclerosis, all patients were divided into 3 groups: Group 1-871 (50.7 %) patients - with the presence of hemodynamically significant stenosis of the coronary arteries (CA) with a history of myocardial revascularization; Group 2-496 (28.8 %) patients - with the presence of hemodynamically insignificant lesions of the coronary artery (up to 70 %, not inclusive, and the trunk of the left coronary artery, up to 50 %, not inclusive); Group 3-352 (20.5 %) patients - without signs of atherosclerotic lesions of the coronary artery. In group 1, the observation period was 56.8±23.2 months, in group 2-62.0±15.6 months, in group 3-58.1±20.4 months. RESULTS: During the hospital observation period, there were no significant intergroup differences in the number of complications. All cardiovascular events were detected in isolated cases. The most common injury was damage to the cranial nerves, diagnosed in every fifth patient in the total sample. The combined endpoint (CET), including death + myocardial infarction (MI) + acute cerebrovascular accident/transient ischemic attack (stroke/TIA), was 0.75 % (n=13). In the long-term follow-up period, when comparing survival curves, group 3 revealed the largest number of ischemic strokes (p = 0.007), myocardial infarction (p = 0.03), and CCT (p = 0.005). There were no intergroup differences in the number of deaths (p=0.62). CONCLUSION: The results of the study showed that there was no significant intergroup difference in the development of complications at the hospital postoperative stage. However, in the long-term follow-up period, a group of patients with isolated lesions of the ICA demonstrated a rapid increase in the number of MI, stroke/TIA, and a combined endpoint, which was apparently associated with low compliance and progression of atherosclerosis in previously unaffected arteries.

Vertebral triangle of doctor A.N. Kazantsev - double vertebral artery in V3 segment.

We have described a variant of the structure of the vertebral artery. In the V3 segment, the vertebral artery bifurcated and then joined again. This building looks like a triangle. Such anatomy has not been previously described in the world literature. By the right of the first description, this anatomical formation was called the «vertebral triangle of Dr A.N. Kazantsev¼. This discovery was made during stenting of the V4 segment of the left vertebral artery in the most acute period of stroke.

The results of thrombectomy from the arteries of the lower extremities in patients infected with SARS-CoV-2 Omicron variant with different severity of respiratory failure.

GOAL: Analysis of the results of thrombectomy from the arteries of the lower extremities in patients with COVID-19 against the background of different severity of respiratory failure. MATERIALS AND METHODS: This retrospective, cohort, comparative study for the period from 05/01/2022 to 20/07/2022 included 305 patients with acute thrombosis of the arteries of the lower extremities against the background of the course of COVID-19 (SARS-CoV-2 Omicron variant). Depending on the type of oxygen support, 3 groups of patients were formed: group 1 (n = 168) - oxygen insufflation through nasal cannulas; group 2 (n = 92) - non-invasive lung ventilation; and group 3 (n = 45) - artificial lung ventilation. RESULTS: Myocardial infarction and ischemic stroke were not detected in the total sample. The highest number of deaths (group 1: 5.3%, n = 9; group 2: 72.8%, n = 67; group 3: 100%, n = 45; p < 0.0001), rethrombosis (group 1 : 18.4%, n = 31; group 2: 69.5%, n = 64; group 3: 91.1%, n = 41; p < 0.0001), and limb amputations (group 1: 9.5%, n = 16; group 2: 56.5%, n = 52; group 3: 91.1%, n = 41; p < 0.0001) was recorded in group 3 (ventilated) patients. CONCLUSION: In patients infected with COVID-19 and on artificial lung ventilation, a more aggressive course of the disease is noted, expressed in an increase in laboratory parameters (C-reactive protein, ferritin, interleukin-6, and D-dimer) of the degree of pneumonia (CT-4 in overwhelming number) and localization of thrombosis of the arteries of the lower extremities, mainly in the tibial arteries.

Computer Modeling of Carotid Endarterectomy With the Different Shape Patches and Prediction of the Atherosclerotic Plaque Formation Zones.

The article describes a method for constructing geometric models of the carotid bifurcation and computer simulation of endarterectomy surgery with the patches of various configurations. The purpose of this work is to identify the areas of the greatest risk of restenosis in the constructed models and to conduct a comparative analysis of risk factors when using the patches of different widths and shapes. The method is demonstrated on a reconstructed model of a healthy vessel. Its building is based on a preoperative computed tomography study of a particular patient's affected vessel. The flow in the vessel is simulated by computational fluid dynamics using data from the patient's ultrasound Doppler velocimetry. Risk factors are assessed through the hemodynamic indices on the vessel wall associated with Wall Shear Stress. The distribution of risk zones in the healthy vessel, presumably leading to its observed lesion (plaque), is analyzed. Comparative evaluation of 10 various patches implantation results is carried out and the optimal variant is determined. The proposed method can be used to predict the hemodynamic results of surgery using patches of various sizes and shapes.

Mathematical Model for the Choice of Tactics of Revascularization in Case of Combined Lesions of the Carotid and Coronary Arteries.

Based on the assessment of the long-term results of various surgical treatment strategies for patients with combined hemodynamically significant lesions of the coronary basin and internal carotid arteries, to develop a model for choosing the optimal revascularization strategy for patients with multifocal atherosclerosis. In 391 patients with combined hemodynamically significant atherosclerotic lesions of the coronary bed and internal carotid arteries, various options for reconstructive operations were performed. 1 - Staged surgery in the volume of coronary artery bypass grafting followed by carotid endarterectomy (n = 151, 38.6%); 2 - Combined coronary bypass surgery and carotid endarterectomy (n=141, 36%); 3 - Hybrid revascularization in the volume of percutaneous coronary intervention and carotidal endarterectomy (n = 28, 7.2%); 4 - Phased surgery in the volume of carotidal endarterectomyand subsequent coronary bypass surgery (n = 71, 18.2%). The study analyzed the frequency and structure of complications in the remote postoperative period (33.95±12.05 months - for of the total sample of patients). To select the optimal tactics of revascularization, the prognostic coefficients of all levels of risk factors for each tactic were evaluated and, on their basis, integral indicators characterizing a comprehensive assessment of risk factors for the corresponding surgical tactics were calculated. The developed model of personalized choice of the optimal surgical strategy, based on a comprehensive assessment of risk factors for an unfavorable outcome (clinical-demographic, coronary and cerebrovascular), makes it possible to predict the likelihood of developing unfavorable cardiovascular ones.

Effects of different types of carotid endarterectomy on the course of resistant arterial hypertension.

OBJECTIVE: Analysis of the dynamics of systolic blood pressure (SBP) and the results of various types of carotid endarterectomy (СЕЕ) (classical with plasty of the reconstruction zone with a patch, eversion, formation of a new bifurcation, autoarterial reconstruction, glomus-saving techniques) in patients with resistant arterial hypertension (RAH). MATERIALS AND METHODS: The actual cohort, comparative, retrospective, open research for the period from January 2013 to December 2021 includes 1577 patients with significant hemodynamic stenosis of the internal carotid artery Depending on revascularization strategy five groups were formed: Group 1: 18.3% (n = 289) - classical Carotid endarterectomy with plasty of the reconstruction zone with a patch (from diepoxy-treated xenopericardium or synthetic); Group 2: 29.9% (n = 472) - eversional CEE with cut-off of carotid gloomus (CG); Group 3: 6.9% (n = 109) - the formation of a new bifurcation; Group 4: 7.4% (n = 117) - autoarterial reconstruction; Group 5: 37.4% (n = 590) - glomus-saving CEE (1 technique - according to A.N. Kazantsev; two technicians - according to R.A. Vinogradov; three technicians - according to K.A.Antsupov). According to the 24-h blood pressure monitor in the preoperative period, the following degrees of AH were identified: 1° - 5.7% (n = 89); 2° - 64.2% (n = 1013); and 3° - 30.1% (n = 475). RESULTS: In the postoperative period, no significant differences were obtained in the frequency of deaths, myocardial infarction, stroke, hemorrhagic transformation. However, according to the frequency of the combined endpoint (death + myocardial infarction + ischemic stroke + hemorrhagic transformation), the lowest rates were observed in the group of classical carotid endarterectomy with plasty of the reconstruction zone with a patch and glomus-sparing CEE (group 1: 1.03% (n = 3); group 2: 3.6% (n = 17); group 3: 3.67% (n = 4); group 4: 2.56% (n = 3); group 5: 0.5% (n = 3); p = 0.10). This is due to the absence of cases of labile AH and hypertensive crises among patients of groups 1 and 5, which was ensured by the preservation of carotid glomus (CG). As a result, the number of patients with 2 and 3 degrees of hypertension in these groups decreased statistically significantly. The vast majority of patients after these operations achieved a stable target SBP. In groups 2, 3, and 4, there was a statistically significant increase in the number of patients with 2 and 3 degrees of AH, which is associated with excision of the CG. CONCLUSION: Classical CEE and glomus-sparing CEE techniques make it possible to achieve a stable target SBP level in patients with RAH as a result of CG preservation. Removal or traumatization of the latter during eversional CEE, the formation of a new bifurcation, autoarterial reconstruction is accompanied by the development of labile hypertension, an increase in the degree of hypertension and a high risk of hemorrhagic transformation in the brain. Thus, the most effective and safe types of CEE in the presence of RAH are classical CEE with plasty of the reconstruction zone with a patch and glomus-sparing CEE, accompanied by the lowest incidence of adverse cardiovascular events caused by postoperative hypertensive crisis and hyperperfusion syndrome.

Changes in Electrical Conductance of Polymer Composites Melts Due to Carbon Nanofiller Particles Migration.

In this work, the results of investigation of the effect of polymer composite melts electrical conductance increase with time are presented. The conductance time dependencies were obtained for composites based on polypropylene filled with carbon nanoparticles of different types. The dependencies were analyzed to demonstrate the possibility of correlation of the conductance kinetics with different composite parameters, such as the filler geometry. Additional studies were carried out, such as electron microscopy study, conductance measurements after consecutive surface layer removal, and composite melt conductance measurements using a three-electrode scheme. The results showed that the increased electrical conductance of the composite materials can be attributed to the formation of an enriched with the filler particles surface layer, which happens during the stay of the composite in a melt state. Analysis of the experimental data, along with the results of numerical modeling, allowed to suggest a possible filler distribution transformation scheme. The physical premises behind the investigated effect are discussed.

Multiscale Numerical Modeling for Prediction of Piezoresistive Effect for Polymer Composites with a Highly Segregated Structure.

In this work, the piezoresistive effect for a polymer nanocomposite with a highly segregated distribution of conductive filler was investigated. As a base polymer for the investigated nanocomposites, ultrahigh-molecular-weight polyethylene, processed in a solid state (below melting point), was used. Multiwalled carbon nanotubes (MWCNTs) were used as a nanofiller forming a highly segregated structure in between polymer particles. A numerical multiscale approach based on the finite element method was proposed to predict changes in the conductive structure composed of MWCNTs in response to uniaxial deformation of the material. At the nanoscale, numerical simulations were conducted for uniformly distributed MWCNTs providing confinement of the filler to a two-dimensional layer with a high volume fraction of the filler in between two polymer particles. At the microscale, the piezoresistive response to uniaxial deformation for the three-dimensional highly segregated structure reconstructed from experimental data was investigated numerically. The embedded element method was implemented to conduct a realistic and computationally efficient simulation of MWCNT behavior during deformation of the nanocomposite. The results of numerical simulations were compared with the experimental data to prove the correctness of assumptions used in the modeling.