Ivan Vulev

No difference in intra-arterial and intramuscular delivery of autologous bone marrow cells in patients with advanced critical limb ischemia.

Stem cell therapy has been proposed to be an alternative therapy in patients with critical limb ischemia (CLI), not eligible for endovascular or surgical revascularization. We compared the therapeutic effects of intramuscular (IM) and intra-arterial (IA) delivery of bone marrow cells (BMCs) and investigated the factors associated with therapeutic benefits. Forty-one patients (mean age, 66 ± 10 years; 35 males) with advanced CLI (Rutherford category, 5 and 6) not eligible for revascularization were randomized to treatment with 40 ml BMCs using local IM (n = 21) or selective IA infusion (n = 20). Primary endpoints were limb salvage and wound healing. Secondary endpoints were changes in transcutaneous oxygen pressure (tcpO2), quality-of-life questionnaire (EQ5D), ankle–brachial index (ABI), and pain scale (0–10). Patients with limb salvage and wound healing were considered to be responders to BMC therapy. At 6-month follow-up, overall limb salvage was 73% (27/37) and 10 subjects underwent major amputation. Four patients died unrelated to stem cell therapy. There was significant improvement in tcpO2 (15 ± 10 to 29 ± 13 mmHg, p < 0.001), pain scale (4.4 ± 2.6 to 0.9 ± 1.4, p < 0.001), and EQ5D (51 ± 15 to 70 ± 13, p < 0.001) and a significant decrease in the Rutherford category of CLI (5.0 ± 0.2 to 4.3 ± 1.6, p < 0.01). There were no differences among functional parameters in patients undergoing IM versus IA delivery. Responders (n = 27) were characterized by higher CD34+ cell counts in the bone marrow concentrate (CD34+ 29 ± 15×106 vs. 17 ± 12×106, p < 0.05) despite a similar number of total nucleated cells (4.3 ± 1.4×109 vs. 4.1 ± 1.2×109, p = 0.66) and by a lower level of C-reactive protein (18 ± 28 vs. 100 ± 96 mg/L, p < 0.05) as well as serum leukocytes (8.3 ± 2.1×109/L vs. 12.3 ± 4.5×109/L, p < 0.05) as compared with nonresponders (10 patients). Both IM and IA delivery of autologous stem cells are effective therapeutic strategies in patients with CLI. A higher concentration of CD34+ cells and a lower degree of inflammation are associated with better clinical therapeutic responses.

Characterization of Mesenchymal Stem Cells of “No-Options” Patients with Critical Limb Ischemia Treated by Autologous Bone Marrow Mononuclear Cells

Background Application of autologous bone marrow mononuclear cells to “no option” patients with advanced critical limb ischemia (CLI) prevented major limb amputation in 73% patients during the 6-month follow-up. We examined which properties of bone marrow stromal cells also known as bone-marrow derived mesenchymal stem cells of responding and non-responding patients are important for amputation-free survival. Methods and Findings Mesenchymal stem cells of 41 patients with CLI unsuitable for revascularisation were isolated from mononuclear bone marrow concentrate used for their treatment. Based on the clinical outcome of the treatment, we divided patients into two groups: responders and non-responders. Biological properties of responders’ and non-responders’ mesenchymal stem cells were characterized according to their ability to multiply, to differentiate in vitro, quantitative expression of cell surface markers, secretion of 27 cytokines, chemokines and growth factors, and to the relative expression of 15 mesenchymal stem cells important genes. Secretome comparison between responders (n=27) and non-responders (n=14) revealed significantly higher secretion values of IL-4, IL-6 and MIP-1b in the group of responders. The expression of cell markers CD44 and CD90 in mesenchymal stem cells from responders was significantly higher compared to non-responders (p<0.01). The expression of mesenchymal stem cells surface markers that was analyzed in 22 patients did not differ between diabetic (n=13) and non-diabetic (n=9) patient groups. Statistically significant higher expression of E-cadherin and PDX-1/IPF1 genes was found in non-responders, while expression of Snail was higher in responders. Conclusions The quality of mesenchymal stem cells shown in the expression of cell surface markers, secreted factors and stem cell genes plays an important role in therapeutic outcome. Paracrine mechanisms are main drivers in the induction of reparatory processes in CLI patients. Differences in mesenchymal stem cells properties are discussed in relation to their involvement in the reparatory process.

The recurrence of iatrogenic femoral artery pseudoaneurysm after occlusion by ultrasound guided percutaneous thrombin injection.

AIMS To evaluate efficacy of percutaneous ultrasound-guided thrombin injection (UGTI) of iatrogenic femoral artery pseudoaneurysm (PSA) and to identify the risk factors associated with PSA recurrence. METHODS AND RESULTS We treated 140 patients aged 76 years (range 49-83) presented with femoral artery PSA after cardiac catheterisation by percutaneous UGTI (500 IU/ml solution of activated human thrombin). Factors associated with the recurrence of PSA were analysed. One hundred nineteen patients were successfully treated by one injection of thrombin (immediate success rate 85%). In 19 patients (13.6%), short local compression following injection was needed for complete occlusion (overall success rate 98.6%, 138/140). In one case, progression of PSA required conversion to surgery (0.7%). In one patient with pre-existing stenosis of superficial femoral artery, acute limb ischaemia developed after UGTI (0.7%). The recurrence of PSA in 30-days follow-up (10 patients, 7%) was associated with obesity (BMI>30, OR=1.39, 95% CI 1.09-1.78, p<0.05), and with extensive combination of anti-aggregation and anti-coagulation therapy (OR=2.11, 95% CI 1.23-3.62, p<0.0001) as revealed by both univariate and multivariate analysis. CONCLUSIONS The UGTI is a safe and effective treatment of iatrogenic femoral artery PSA. Recurrence is low and associated with obesity and extensive use of combined anti-aggregation and anti-coagulation therapy.

The Impact of Blood Pressure on Carotid Artery Stiffness and Wave Intensity inPatients with Resistant Hypertension after Renal Sympathetic Denervation

Objective: The study investigated the impact of renal sympathetic denervation on office blood pressure and ambulatory blood pressure monitoring in patients with resistant hypertension. We evaluated whether a decrease in blood pressure may improve local carotid stiffness and parameters of wave intensity. Methods: Renal sympathetic denervation was performed in 17 patients (age 55 ± 9 years) with true resistant hypertension. Measurements of carotid stiffness and wave intensity were performed using ultrasound combined with echo-tracking. Results: We found significantly improved office systolic blood pressure changes 1 month (p=0.023) and together with pulse pressure changes at the 6 month follow up (p=0.041; p=0.016). Changes in systolic blood pressure during the daytime were significantly decreased at 1 month and diastolic blood pressure changes during the daytime were significantly reduced at 1 and 3 months. Stiffness parameters beta stiffness and pressure-strain elastic modulus were significantly reduced (p=0.04; p=0.03) and arterial compliance was increased (p=0.03), especially 1 and 3 months. The changes in negative area were significantly reduced after 1 month (p=0.041) and the ejection period was significantly increased at the 6 month follow-up (p=0.011). According to linear regression analysis systolic blood pressure correlated positively with the beta stiffness, pressure-strain elastic modulus, pulse wave velocity, and negatively with arterial compliance. Conclusions: We found significantly lower office blood pressure as well as blood pressure from ambulatory blood pressure monitoring in patients with resistant hypertension 6 months after renal sympathetic denervation. The decrease in blood pressure was followed by improvement of carotid stiffness and wave intensity. That may be reflected in enhancement of ventricular-arterial coupling.

Improvement in asymmetric dimethylarginine and oxidative stress in patients with limb salvage after autologous mononuclear stem cell application for critical limb ischemia

BackgroundAsymmetric dimethylarginine (ADMA), an endogenous inhibitor of nitric oxide synthase, acts as an inhibitor of angiogenesis and is associated with an increased risk of cardiovascular mortality. Administration of stem cells may affect endogenous mechanisms that regulate ADMA production and metabolism. The aim of the present study was to analyze ADMA concentration and changes in oxidative stress in patients with advanced critical limb ischemia (CLI) after bone marrow-derived mononuclear cell (BM-MNC) therapy.MethodsFifty patients (age 64 ± 11 years, 44 males, 6 females) with advanced CLI (Rutherford category 5 or 6) not eligible for revascularization were treated by intramuscular (n = 25) or intra-arterial (n = 25) injection of 40 ml BM-MNC concentrate. Patients with limb salvage and improved wound healing after 6 months were considered responders to cell therapy. The concentrations of markers of oxidative stress and angiogenesis were analyzed before, and at 3 and 6 months after BM-MNC delivery.ResultsAt 6-month follow-up, four patients died of reasons unrelated to stem cell therapy. Among the survivors, 80% (37/46) showed limb salvage and improved wound healing. At 6 months follow-up, ADMA concentration significantly decreased in patients with limb salvage (1.74 ± 0.66 to 0.90 ± 0.49 μmol/L, p < 0.001), in parallel with decreased tumor necrosis factor (TNF)-α (2.22 ± 0.16 to 1.94 ± 0.38 pg/ml, p < 0.001), and increased reduced glutathione (6.96 ± 3.1 to 8.67 ± 4.2 μmol/L, p = 0.02), superoxide dismutase activity (168 ± 50 to 218 ± 37 U/L, p = 0.002), and coenzyme Q10 concentration (468 ± 182 to 598 ± 283 μg/L, p = 0.02). The number of delivered BM-MNCs significantly correlated with the decrease in ADMA concentration at 3 months (p = 0.004, r = −0.48) and the decrease in TNF-α concentration at 6 months (p = 0.03, r = −0.44) after cell delivery. ADMA or TNF-α improvement did not correlate with the number of applied CD34+ cells, C-reactive protein concentration, leukocyte count, or the dose of atorvastatin.ConclusionsThe therapeutic benefit of BM-MNC therapy is associated with reduced ADMA levels and oxidative stress. Regulation of the ADMA-nitric oxide axis and improved antioxidant status may be involved in the beneficial effects of stem cell therapy.Trial registrationThe study was approved and retrospectively registered by ISRCTN registry, ISRCTN16096154. Registered on 26 July 2016.

Intra-arterial Autologous Bone Marrow Cell Transplantation in a Patient with Upper-extremity Critical Limb Ischemia

Induction of therapeutic angiogenesis by autologous bone marrow mononuclear cell transplantation has been identified as a potential new option in patients with advanced lower-limb ischemia. There is little evidence of the benefit of intra-arterial cell application in upper-limb critical ischemia. We describe a patient with upper-extremity critical limb ischemia with digital gangrene resulting from hypothenar hammer syndrome successfully treated by intra-arterial autologous bone marrow mononuclear cell transplantation.

Endovascular Treatment of Internal Carotid and Vertebral Artery Aneurysms Using Covered Stents

© 2012 Vulev and Klepanec, licensee InTech. This is an open access chapter distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Endovascular Treatment of Internal Carotid and Vertebral Artery Aneurysms Using Covered Stents

TCT-120 The Policy Of Total Percutaneous Abdominal Aortic Aneurysm Repair: One-year Follow-up

Endovascular abdominal aortic aneurysm repair (EVAR) is accepted therapeutic strategy. The use of a total percutaneous approach to endovascular repair of aortic pathology is becoming more common and further extends the EVAR indications. The aim of our retrospective analysis was assessment of safety