[Molecular and Cellular Aspects of the Endothelial-Mesenchymal Transition in Cardiovascular Diseases]

Endothelial cells (ECs), which form the inner surface of the blood vessels, contact the blood, withstand mechanical pressure, and demonstrate heterogeneous reactions to exogenous and endogenous stimuli. ECs have unique properties in accordance with their niches and play an important role in regulating vascular homeostasis. Endothelial cells may undergo a dynamic phenotypic switch in terms of its heterogeneity, which may lead to endothelial dysfunction and a number of associated pathologies. Endothelial-mesenchymal transition (EndMT) is one of the possible molecular and cellular mechanisms of this kind. EndMT is characterized by phenotypic changes in ECs through which endothelial cells acquire new properties, i.e., start producing mesenchymal markers such as alpha-SMA and vimentin, change morphology, and become able to migrate. EndMT is a complex biological process that can be induced by inflammation, hypoxia, or oxidative stress and be involved in pathogenesis of cardiovascular disease. This review describes the key markers, inhibitors, and inducers of endothelial-mesenchymal transition and overall state-of-the-art of EndMT in cardiovascular diseases.

Fibrin Sealant TISSEEL Lyo as a haemostatic agent in vascular surgery: Results of randomized, controlled, patient-blinded, multicentre clinical study in the Russian population

BACKGROUND

This phase III, controlled, patient-blinded, multicentre study in two parallel, equal-sized treatment groups compared the efficacy and safety of TISSEEL Lyo, fibrin sealant versus Manual Compression (MC) with surgical gauze pads for use as a haemostatic agent in patients who underwent vascular surgery in Russia.

METHODS

Adult patients, both genders, who received peripheral vascular expanded polytetrafluoroethylene conduits and had suture line bleeding after surgical haemostasis were enrolled. Patients were randomized to be treated with TISSEEL Lyo or MC. The bleeding needed additional treatment and had to be assessed as grade 1 or 2 bleeding according to the Validated Intraoperative Bleeding scale. The primary efficacy endpoint was the proportion of patients achieving haemostasis at 4 min after treatment application (T4) at the study suture line, which was maintained until the closure of the surgical wound. The secondary efficacy endpoints included the proportion of patients achieving haemostasis at 6 min (T6) and 10 min (T10) after treatment application at the study suture line, which was maintained until closure of the surgical wound, as well as the proportion of patients with intraoperative and postoperative rebleeding. Safety outcomes included incidence of adverse events (AEs), surgical site infections and graft occlusions.

RESULTS

A total of 110 patients were screened; 104 patients were randomized: (TISSEEL Lyo: 51 [49%] patients; MC: 53 [51%] patients). T4 haemostasis was achieved in 43 (84.3%) patients in the TISSEEL Lyo group and in 11 (20.8%) patients in the MC group (p < 0.001). Significantly more patients in TISSEEL Lyo group achieved the haemostasis at T6 (relative risk (RR) of achieving haemostasis 1.74 [95% confidence interval (CI) 1.37; 2.35]) and T10 (RR 1.18 [95% CI 1.05; 1.38]) versus MC. No one had intraoperative rebleeding. Postoperative rebleeding was reported only in one patient in the MC group. No treatment-emergent serious AEs (TESAEs) related to TISSEEL Lyo/MC, TESAEs leading to withdrawal and TESAEs leading to death were reported in patients during the study.

CONCLUSIONS

Data demonstrated TISSEEL Lyo had clinically and statistically significant superiority to MC as a haemostatic agent in vascular surgery at all measured time points including 4, 6 and 10 min and had proven to be safe.

Variations in the Clinical Anatomy of the Femoral and Popliteal Vessels

Objective:

The aim of this study was to assess the topography of the femoral and popliteal vessels focusing mainly on the venous variants, in patients with chronic venous disease (CVD).

Materials and Methods:

Duplex ultrasonography (DUS) was performed on 200 patients with varicose veins (VVs) and 253 patients with postthrombotic syndrome (PTS). In addition, an anatomical dissection was performed on 30 amputated lower extremities, without signs of CVD.

Results:

Duplication of the femoral vein (FV) was found in 14% of patients with VVs. Multiple FV trunks were identified in 42% of patients with PTS. One patient had a developmental anomaly with a hypoplastic FV and dilated deep FV. Two trunks of the popliteal vein (PV) below the knee level were detected in 83.3% of cases during anatomical dissection, in 87.5% of cases in patients with VVs, and in 90.1% of cases in PTS subjects during DUS. In 98.2% of cases, popliteal artery (PA) had a typical bifurcation. One patient was presented with a duplication of PA above the level of the knee. In 1.8% of cases, the PA was divided into an anterior tibial and peroneal artery.

Conclusion:

This study found variant anatomy in the FV and PV, which is frequent, with major changes occurring in patients with PTS. Variant anatomy of the PA was also found and is considered uncommon, occurring in less than 2% of cases.

Coagulation Factor Activity and Hemostatic Markers of Endothelial Dysfunction in Patients with Peripheral Arterial Disease

Purpose

We aimed to evaluate the impact of intrinsic coagulation factors and hemostatic markers of endothelial dysfunction on complications in patients with atherosclerotic peripheral arterial disease (PAD).

Methods

Materials and This prospective study enrolled 120 PAD patients at Fontaine stages 2b to 3 who underwent open surgical, endovascular, or conservative treatment. Coagulation factors (FVIII, FIX, and FXI) and endothelial hemostatic markers, including von Willebrand factor (vWF) activity and level, soluble endothelial protein C receptor, and plasminogen activator inhibitor-1 (PAI-1) levels, were assessed.

Results

At 3 months after open bypass grafting, activity of FVIII significantly increased from a median of 175% to 233% (P<0.001). At 3 months after endovascular treatment, the activities of FVIII, FIX, and FXI significantly increased from medians of 157%, 180%, and 156% to 184%, 218%, and 181%, respectively (P<0.05). Six patients with increased FVIII activity developed bypass graft thrombosis. Four patients in the endovascular group and three patients in the conservative treatment group with increased activity of vWF developed myocardial infarction (P=0.049). The subjects who developed restenosis had increased vWF activity (P=0.023) and decreased nitric oxide metabolite levels (P=0.003). Three subjects who received conservative treatment and developed PAD progression at 12 months had increased PAI-1 activity (P=0.028).

Conclusion

Patients with advanced PAD had a hypercoagulable status, and performance of open or endovascular revascularization was associated with further hypercoagulability. Increased activity of coagulation factors and altered levels of hemostatic markers of endothelial dysfunction were associated with PAD complications such as graft thrombosis, myocardial infarction, disease progression, and restenosis.

[Study of gene expression in patients with peripheral artery disease]

Currently, there are no widely used available techniques for reliable prognosis of the onset and course of peripheral artery disease. Working out of optimal test systems including genetic ones for assessment of risks for the development of the disease, its progression or development of complications in patients with peripheral atherosclerosis is an important mission of modern medicine. This article deals with a promising technique of genetic studies in patients with peripheral artery disease, i. e., study of gene expression. Also provided herein is a literature review devoted to the main techniques used for the analysis of the profile of gene expression. This is followed by evaluating the possibility of using DNA chips, as well as describing the state of the art and unsolved problems of studying gene expression in patients with peripheral artery disease.

[Duration of treatment with phlebotonics in patients with chronic venous disease]

Lower extremity chronic venous disease is a highly prevalent vascular pathology. Progression of the disease exerts a negative impact on the patients' quality of life and imposes a large economic burden on the healthcare systems. Conventional methods of conservative treatment of chronic venous disease include wearing compression knitwear and pharmacological therapy. Although highly effective, compression therapy appears to be associated with lower compliance due to difficulties putting on and taking off the compression stockings. Therefore, the majority of patients prefer pharmacological therapy with phlebotonic drugs. There are many phlebotropic agents possessing particular indications and recommendations regarding the duration of administration. This article presents a review of the available literature addressing the problems related to prescription of pharmacotherapy to patients with lower limb chronic venous disease, also describing the results of published clinical studies evaluating efficacy and safety of phlebotropic drugs, as well as those concerning the duration of the course administration of drugs depending on the severity of the disease, invasive nature of a surgical intervention performed, or sclerotherapy. Besides, analysed is the role of phleboactive agents in correction of pathophysiological mechanisms of the development and progression of venous disease. This is followed by a review of clinical trials studying the influence of phlebotonics on such links of pathogenesis as leukocyte activation, vein-specific inflammation, endothelial dysfunction, and activation of proteolytic enzymes promoting destruction of the extracellular matrix. Based on the above data, proposed herein are appropriate approaches to determining the duration of the courses of phlebotropic therapy with due regard for the patients' status, underlying once again the importance and necessity of a personalized approach to selection of the optimal duration of venotonic therapy.

Varicose Veins: A Local or Systemic Hemodynamic Disorder?

Objective:

To determine the capabilities of a sonographic examination to evaluate local and systemic hemodynamic disorders in patients with varicose disease.

Materials and Methods:

This study included 583 patients with varicose veins, among whom 348 had trophic disorders. All subjects underwent lower limb duplex sonography and superficial, perforator, and deep venous diameter measurements, as well as had a calculated velocity for antegrade and reflux flow. Peripheral resistive index (RI) in the arteries, accompanying perforator veins (PVs), was analyzed. In addition, echocardiography was performed on 46 of the participants.

Results:

A statistically significant difference in the diameter of the great saphenous vein was obtained between class C2 and C4 varicose veins ( P < .05). Similar findings were obtained for the diameter of the PVs and the velocity reflux flow through PVs. Arteries in the perforator bundles demonstrated low RI, which may be attributed to the presence of arteriovenous shunts. Varicose veins were associated with an increased incidence of nonrestrictive type of blood flow through the tricuspid valve.

Conclusions:

Sonography demonstrated that additional factors rather than hemodynamics may be attributable to the development of venous ulcers. The most informative parameters of cardiac function, in a patient with varicose veins, are the indicators of diastolic function in both ventricles.

[Review of the proceedings of the 68th International Congress of the European Society of Cardiovascular and Endovascular Surgery (May 22-25, 2019)]

This article covers the main trends of the work of the 68th International Congress of the European Society of Cardiovascular and Endovascular Surgery, reviewing the papers encompassing current problems in not only vascular but also cardiac surgery.

[Current aspects of performing treadmill test in patients with peripheral artery disease]

The protocols of performing treadmill tests (TMT) in patients presenting with peripheral artery disease have over the last decades undergone significant changes, with the alterations concerning not only the speed and time values of the load, but also the parameters measured. Currently, there is no unified generally accepted method of TMT, hence the need for an optimal protocol for carrying out this type of examination, which would help obtain reliable results in assessment of everyday life functional activity of patients and efficacy of various methods of treatment for peripheral atherosclerosis. The choice of an optimal methodology of performing a TMT in patients with intermittent claudication is extremely important because studying the haemodynamic parameters alone not always clearly reflect functional peculiarities of the course of the disease, since they depend not only on the presence of arterial stenoses or occlusions, but also on the activity of oxidative enzymes, endothelial and mitochondrial dysfunction, taking therapeutic agents, concomitant pathology and a series of other factors. The article is a review of the related literature contained in such databases as the Medline, PubMed, Russian Science Citation Index (RSCI) and Scopus and concerning TMT in patients with peripheral artery disease. The authors summarized the information from a total of 63 literature sources over the period from the 1970s to 2018.

[Effect of genetic polymorphisms on functioning of a permanent vascular access in patients on dialysis]

Thromboses and stenoses of permanent vascular access appear to be a serious hazard for patients with end-stage kidney disease on programmed haemodialysis. Relapses of these pathological conditions are the cause of repeated hospitalization, secondary surgical interventions and may eventually lead to impossibility of carrying out procedures of haemodialysis. Often, vascular access dysfunction occurs for no apparent reason, thus underlying the importance of studies aimed at revealing additional factors of intravascular thrombogenesis and neointimal formation in a vascular access, including the works dedicated to studying genetic predictors of the development of the above-mentioned complications. The authors examined herein the role of polymorphisms of the genes of endothelin-1 (END-1), nitric oxide synthase-3 (NOS-3), angiotensinogen-2 (AGT-2), angiotensinogen-1 (AGT-1), angiotensinogen 2 receptor type 1 (AGTR1), mitochondrial superoxide dismutase-2 (SOD-2), catalase (CAT) superoxide dismutase-1 (SOD-1) and angiotensin converting enzyme (ACE) in the functional state of permanent vascular access in patients on dialysis. The obtained results demonstrated direct cause-and-effect relationships between polymorphisms lys-198 asn in the END-1 gene, C60T, T58C in the SOD-2 gene and the function of vascular access. The presence of END-1 gene lys-198 asn polymorphism in a homozygous state (allele 1) was associated with a high risk of an unsatisfactory condition of permanent vascular access (p=0.019).

[Hemostatic changes in patients with peripheral artery disease before and after bypass surgery]

AIM

To assess intrinsic coagulation pathway factors activity and hemostatic markers of endothelial dysfunction in patients with peripheral artery disease (PAD) before and after lower extremity bypass surgery.

MATERIAL AND METHODS

80 patients with PAD Fontaine grade IIB-III were enrolled. 40 patients underwent open aorto-femoral-popliteal repair (group A) and 40 patients - medication (group B). Before and in 3 months after surgery peripheral venous blood samples were collected to assess the activity of factors VIII, IX, XI, von Willebrand factor (VWF), protein C (PrC), and metabolites of nitric oxide II (NO).

RESULTS

Increased preoperative activity of VIII, IX, XI, and VWF factors compared with normal values was observed in group A. After 3 months there was an additional increase of VIII and VWF factors' activity. Activity of IX and XI factors remained increased on background of reduced level of NO metabolites. In group B increased activity of IX, XI, and VWF factors was revealed while levels of NO metabolites and PrC were normal.

CONCLUSION

Thus, PAD is followed by prothrombotic state especially in patients after surgery. Surgical procedures are associated with more severe hypercoagulation.

[Gene-mediated induction of angiogenesis in inoperable patients with atherosclerosis and diabetes mellitus]

Analysed in the article are the results of a comprehensive approach to treatment of patients presenting with lower limb critical ischaemia and diabetes mellitus by means of gene-induced angiogenesis. The study comprised a total of 65 patients found to have an ill-suited for surgical reconstruction peripheral arterial bed and undergoing conservative therapy. The patients were divided into two groups. The Study Group patients additionally to the conventional conservative therapy received 2 intramuscular injections of therapeutic agent Neovasculgen at a course dose of 2.4 mg. The active period of follow up amounted to 6 months followed by evaluating limb salvage and lethal outcomes at a further 6 months thereafter. Efficacy of treatment was determined both by primary criteria (lethality rate, amputations, dynamics of necrosis healing, clinical relief of critical ischaemia) and secondary criteria (pain-free walking distance, ankle-brachial index, transcutaneous oxygen tension, linear velocity of blood flow, the Michigan Neuropathy Screening Instrument (MNSI) and Neurological Symptom Score (NSS) scale). After 6 months of follow up, the statistical significance in the intragroup and intergroup comparisons was reached for the pain-free walking distance (increment up to 72.9±9.2 m, p=0.032), transcutaneous oxygen tension (increment by 34.4%, p=0.028), linear velocity of blood flow (increment by 65.3%, p=0.047). Induction of angiogenesis also made it possible to statistically significantly decrease the manifestations of diabetic neuropathy, as was evidenced by the data of the MSNI (p=0.009) and the NSS scale (p=0.044). The findings of the study also demonstrated the best value of the limb salvage rate (p=0.049) and a lower number of lethal complications at 1 year of follow up.

[Promising methods of studying perfusion in patients with atherosclerosis of peripheral arteries]

Prevalence of atherosclerotic peripheral artery disease (PAD) has steadily been increasing all over the world, affecting approximately 10% of the population. PAD dramatically decreases the patients' quality of life and is accompanied by high risks of limb amputation and death. Reconstructive and restorative interventions make it possible to achieve the highest success in treatment of PAD. Their results largely depend on the state of the patient's peripheral bed. Currently, the periphery is objectively assessed by means of ultrasonographic duplex examination, digital subtraction angiography, roentgen computed tomographic angiography (CTA), and in a series of cases magnetic resonance tomographic angiography (MRA). Widely known are the scale of assessing peripheral vascular resistance, suggested by R. Rutherford and the Bollinger scoring system. All these methods study predominantly the major blood flow, only slightly touching the microcirculatory bed. Promising methods in this area are radionuclide methods - single-photon emission computed tomography (SPECT) and positron-emission tomography (PET). Used singly, they possess high sensitivity but low spatial resolution, therefore they are supplemented by CTA or MRA. It is supposed that the use of radionuclide methods would make it possible to accurately assess the state of an atherosclerotic plaque and angiogenesis in conditions of ischaemia. Yet another method of diagnosis of microperfusion is contrast-enhanced ultrasonography (CEUS). CEUS reveals deficit of perfusion of the gastrocnemius muscles of patients with PAD in accordance with severity of the disease and degree of the development of collaterals. It is also used for determining the results of therapy with agents improving microcirculation. The degree of blood supply to tissues may be evaluated with the help of perfusion computed tomography (PCT). The main area of its application is diagnosis of impairments of cerebral circulation. Under study is a possibility of using PCT in atherosclerosis of lower-limb arteries, as well as assessing the efficacy of the reconstructive and restorative procedures performed.

[Venous thromboembolic complications in patients with cardiovascular implantable electronic devices]

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.

[Oxidative carbonylation of proteins in experimental hind-limb ischaemia-reperfusion injury]

Formation of carbonylated protein derivatives is one of the key signalling pathways in cellular damage and may be regarded as a reliable marker in cellular injury. It allows evaluating both direct effects of reactive oxygen species and indirect interrelations with the secondary by-products of oxidation. The present study was undertaken to investigate the activity of lysosomal cysteine proteinases (cathepsins B and L) in blood serum and the arterial wall in an experimental model of ischaemia and ischaemia-reperfusion injury. To this was added comprehensive assessment of oxidative modification of proteins derived from blood serum and the arterial wall, namely, calculating the area under the curve of the absorption spectrum of the products of protein carbonylation, the proportion of the primary and secondary markers of oxidative stress, as well as the reserve and adaptation potential. The obtained findings were indicative of the development of oxidative stress in the model of ischaemia-reperfusion injury from day 1 to day 7, and in the ischaemia model on day 3 and day 5 in both the vascular wall and blood serum, which was accompanied by activation of cathepsins B and L. Reversible oxidation of proteins was observed on days 3 and 5 in the experimental ischaemia model and on days 1 and 7 in the ischaemia-reperfusion injury model, which was confirmed by the predominance of the primary markers of oxidative stress. Irreversible oxidation of proteins, i. e., the predominance of the secondary markers, was suggestive of the enhancement of oxidative stress, its transition to the late stage, leading to the loss of biological properties of proteins and eventually followed by their aggregation and degradation as seen in the ischaemia-reperfusion injury model on days 3 and 5. Analysing the obtained findings revealed direct correlation between the total area under the curve of oxidative modification of proteins and overall activity of cathepsin L in the ischaemia model: in blood serum on days 3 and 5, in the vascular wall for cathepsins B and L on day 5; in the ischaemia-reperfusion injury model: the activity of cathepsin L in blood serum on day 3, in the vascular wall on day 5 for cathepsins B and L.

[Concentration of matrix metalloproteinases and magnesium ions in patients with varicose veins of lower limbs]

The study was aimed at investigating alterations in the concentration of matrix metalloproteinases (MMP-1, MMP-9) and the tissue inhibitor of metalloproteinase-1 (TIMP-1), as well as the level of magnesium ions (Mg²⁺) as an indicator of connective tissue dysplasia (CTD) in patients presenting with lower limb varicose veins. The study included a total of 110 people. Of these, the Study Group comprised 90 patients with lower limb varicose veins of clinical class C2-C6 (according to the CEAP classification) and the Control Group was composed of 20 apparently healthy volunteers. Samples of peripheral blood were examined. The content of MMP-9, MMP-1 and TIMP-1 in blood serum was determined by means of the quantitative solid-phase immunoenzymatic assay. The concentration of Mg²⁺ was determined by the colorimetric method. We revealed a statistically significant interrelationship between the concentrations of matrix metalloproteinases and severity of varicose transformation of lower-limb veins, with the highest level of matrix metalloproteinases being observed in patients with cutaneous alterations and trophic ulcers. Determination of the level of matrix metalloproteinases and magnesium ions, characterizing connective tissue dysplasia, makes it possible to predict the development of lower limb chronic venous insufficiency and to evaluate the degree of its severity.

pCMV-vegf165 Intramuscular Gene Transfer is an Effective Method of Treatment for Patients With Chronic Lower Limb Ischemia

Effective treatment of chronic lower limb ischemia is one of the most challenging issues confronting vascular surgeons. There are a number of choices available to the vascular surgeon. Open or endovascular revascularization is the treatment of choice when applicable. Current pharmacological therapies play an auxiliary role and cannot prevent disease progression. Therefore, new methods of treatment are needed. We conducted a phase 2b/3 multicenter randomized controlled clinical trial of the intramuscular transfer of a plasmid DNA encoding vascular endothelial growth factor (VEGF) 165 with cytomegalovirus promotor (CMV) in patients with atherosclerotic lower limb ischemia. A total of 100 patients were enrolled in the study, that is, 75 patients were randomized into the test group and received 2 intramuscular injections of 1.2 mg of pCMV-vegf165, 14 days apart together with standard pharmacological treatment. In all, 25 patients were randomized into the control group and received standard treatment only. The following end points were evaluated within the first 6 months of the study and during a 1.5-year additional follow-up period: pain-free walking distance (PWD), ankle-brachial index (ABI), and blood flow velocity (BFV). The pCMV-vegf165 therapy appeared to be significantly more effective than standard treatment. The PWD increased in the test group by 110.4%, 167.2%, and 190.8% at 6 months, 1 year, and 2 years after treatment, respectively. The pCMV-vegf165 intramuscular transfer caused a statistically significant increase in ABI and BFV. There were no positive results in the control group. Thus, pCMV-vegf165 intramuscular gene transfer is an effective method of treatment of moderate to severe claudication due to chronic lower limb ischemia.

[Possibilities of pharmacotherapy for chronic venous insufficiency with diosmin preparations from the position of the endothelial functional state]

Despite a high level of the development of modern angiology and vascular surgery, the problem of chronic venous insufficiency (CVI) complicating the course of various venous diseases seems to have no tendency towards being solved, thus calling forth permanent search for optimization of methods of treatment and rehabilitation of patients presenting with the above-mentioned syndrome. The article presents a review of contemporary studies dedicated to the problem of correcting CVI. Special attention is paid to the endothelial state in CVI and possibilities of correcting endothelial dysfunction with the use of bioflavonoids, in particular, diosmin. Also presented herein are the results of an original experimental study dedicated to peculiarities of the endothelial functional state, endothelial dysfunction, and correction thereof on the background of the existing CVI.

[Efficacy of using VEGF165 gene in comprehensive treatment of patients with stage 2A-3 lower limb chronic ischaemia]

The authors share their experience in treating a total of 100 patients presenting with stage 2A-3 chronic lower limb ischaemia according to the classification of Pokrovsky-Fontain (the clinical group was composed of 75 patients and the control group comprised 25 subjects), in whom it was impossible to perform surgical revascularization. The clinical group patients received in addition to the conventional vascular therapy local intramuscular injections of Neovasculogen (plasmid genetic construction containing human gene VEGF165) at a course dose of 2.4 mg. The results were assessed after 1 year. It was shown that administration of this gene therapeutic agent is safe with no local or systemic allergic reactions and free form neoplastic processes. Efficacy of treatment was assessed by registering the pain-free walking distance (PFWD), transcutaneous oxygen tension (TCPO2), linear velocity of blood flow, ankle-brachial index (ABI), angiography, and by means of SF-36 questionnaire. It was determined that after 12 months the statistical significance of intergroup and intragroup differences was reached for PFWD (increment 167.2%), TCPO2 (increment 20.4%). The highest clinical response for the PFWD was registered in patients with stage 3 of the disease (547.5%), as well as in those with multi-storey vascular lesions (269.1%). The obtained findings make it possible to consider gene therapy with Neovasculogen as an efficient component of comprehensive treatment of this cohort of patients.