Effect of Nitinol on Metabolic and Coagulation Activity of Endothelial Cells Culture.

We studied the effect of nitinol, the most prevalent material for endovascular stents, on metabolic and coagulation activity of a primary culture of human umbilical vein endothelial cells (HUVEC). Metabolic activity was evaluated using MTS-test and by the level of stable NO metabolites in the conditioned medium, coagulation activity was assessed by activity of von Willebrand factor (vWF) and levels of plasminogen activator inhibitor-1 (PAI-1) and soluble endothelial protein C receptors (sEPCR). Exposure to nitinol reduced metabolic activity of the cell culture by 11.1% in comparison with the control (p<0.001). Although absolute activity of vWF and absolute level of sEPCR were elevated, incubation with nitinol did not lead to a statistically significant elevation of these parameters in comparison with the control, which can indicate the absence of substantial hypercoagulation effects of nitinol.

[Venous thromboembolic complications in patients with cardiovascular implantable electronic devices]. / Venoznye tromboémbolicheskie oslozhneniia u patsientov s serdechno-sosudistymi implantiruemymi élektronnymi ustroistvami.

The problem of venous thromboembolic complications (VTECs) in patients with cardiovascular implantable electronic devices (CIEDs) is extremely important today because of an annually increasing number of surgical interventions for life-threatening arrhythmias and chronic heart failure. There are hitherto no clearly defined reliable risk factors for VTECs due to heterogeneity of the available literature data. Some sources point to elevated thrombus formation in patients with a large number of electrodes, in repeat operative interventions, in the presence of a temporary pacemaker, in implantation on the left side, silicon cover of an electrode, others refute these facts. Still undetermined remains the choice of antithrombotic therapy for prevention and treatment of VTECs in this cohort of patients. Implantation of a VTEC may be accompanied by thrombosis of deep veins of the upper extremities up to the development of total occlusion of veins. In rare cases, thrombosis extends proximally, there appears superior vena cava syndrome which may require surgical treatment. Diagnosis of these diseases is complicated by their symptom-free course in the majority of cases. The most dangerous VTEC is pulmonary thromboembolism very commonly not accompanied by clinical symptomatology or taking its course under the mask of other more frequent diseases. Despite the fact that pulmonary thromboembolism with a source in the system of the superior vena cava is rarely massive, it may lead to the development of chronic postembolic pulmonary hypertension and to decreased quality of life. The article contains a review of the present-day literature and a clinical case report concerning the development of VTECs in a patient with a CIED in the form of thrombosis of the right internal jugular, subclavian and brachiocephalic veins, pulmonary embolism of small branches of the right pulmonary artery, suppuration of the pacemaker's bed and sepsis. Therapy with antibiotics, low-molecular-weight heparins, antiplatelet drugs and anti-inflammatory agents with regular sanitation of the pacemaker's bed turned out effective.