Venous thrombosis following endovenous laser ablation with and without thromboprophylaxis.

OBJECTIVE: Venous thromboembolism (VTE) occurs infrequently after endovenous laser ablation (EVLA). The purpose of this study was to assess the incidence of VTE after EVLA with and without pharmacologic prophylaxis. METHODS: From October 2019 to March 2020, a series of consecutive patients from the prospectively maintained VEINOVA (vein occlusion with various techniques) registry was retrospectively analyzed. All the patients underwent EVLA with and without postoperative thromboprophylaxis. A 1470-nm laser wavelength with a radial fiber was used for EVLA. Concomitant phlebectomy or sclerotherapy of insufficient tributaries was allowed. Perivenous tumescence was applied with 1% Rapidocaine (lidocaine hydrochloride monohydrate; Sintetica SA). Ablation of varicose veins was performed by continuously drawing back the laser fiber at a power of 10 W, aiming for a linear endovenous energy delivery of 60 to 90 J/cm. Compression stockings were applied postoperatively, and the patients were advised to wear them for 1 week. Duplex ultrasound was performed at the 1- and 4-week follow-up visits to determine the occlusion rate and the occurrence of EHIT and VTE. RESULTS: Overall, 249 patients were identified from the registry. Of the 249 patients, 26 were omitted because of treatment of recurrent varicose veins. Finally, 223 consecutive patients with 223 legs and 227 saphenous veins (159 great saphenous veins, 49 small saphenous veins, and 19 anterior accessory saphenous veins) were included in the final analysis. Their mean age was 58.1 ± 13.8 years, and 167 patients (73.1%) were women. The clinical CEAP (clinical, etiology, anatomy, pathophysiology) classification was C2 for 11 legs (4.9%), C3 for 123 legs (55.2%), C4a or C4b for 86 legs (38.6%), and C5 to C6 for 3 legs (1.4%). Thromboprophylaxis was given to 132 patients (59.2%) for 3 days (rivaroxaban 10 mg once daily to 130 patients [98.5%] and low-molecular-weight heparin to 2 patients [1.5%]). No thromboprophylaxis was administered to 91 patients (40.8%) after EVLA. The average treatment length was 34.2 ± 19.3 cm and the average diameter was 5.0 ± 1.3 mm. At 1 week of follow-up, no thrombotic event had occurred in either group. At 4 weeks of follow-up, one case of EHIT class 2 (1.1%) and one case of pulmonary embolism (1.1%) had occurred in the group without thromboprophylaxis. In the thromboprophylaxis group, one deep vein thrombosis (0.8%) event had occurred (adjusted P = .135). At 1 and 4 weeks of follow-up, the treated varicose veins remained occluded in both groups. CONCLUSIONS: Endovenous ablation of truncal varicose veins appears to be safe with a low thrombotic event rate with or without pharmacologic thromboprophylaxis. However, more data are needed before a final recommendation regarding the best thromboprophylaxis treatment option can be given.

Men with erectile dysfunction (ED) should be screened for cardiovascular risk factors - Cost-benefit considerations in Swiss men.

Background: Current evidence indicates that erectile dysfunction (ED) is an independent risk factor for future cardiovascular events. This study aimed to estimate the cost-effectiveness of screening and subsequent preventive treatment for cardiovascular risk factors among men newly diagnosed with ED from the Swiss healthcare system perspective. Methods: Based on known data on ED and cardiovascular disease (CVD) prevalence and incidence costs and effects of a screening intervention for cardiovascular risk including corresponding cardiovascular prevention in men with ED were calculated for the Swiss population over a period of 10 years. Results: Screening and cardiovascular prevention over a period of 10 years in Swiss men with ED of all seriousness degrees, moderate and severe ED only, or severe ED only can probably avoid 41,564, 35,627, or 21,206 acute CVD events, respectively. Number needed to screen (NNS) to prevent one acute CVD event is 30, 23, and 10, respectively. Costs for the screening intervention are expected to be covered at the seventh, the fifth, and the first year, respectively. Conclusion: Screening and intervention for cardiovascular risk factors in men suffering from ED is a cost-effective tool not only to strengthen prevention and early detection of cardiovascular diseases but also to avoid future cardiovascular events.

Erectile dysfunction: role of computed tomography cavernosography in the diagnosis and treatment planning of venous leak.

BACKGROUND: Venous leak appears to be the most common cause of vasculogenic erectile dysfunction (ED), which can be treated with venous embolization. Traditionally, conventional cavernosography was used for the diagnosis and treatment planning of venous leak. Recently, computed tomography (CT) cavernosography was introduced as a novel cross-sectional imaging method proposed to be advantageous over conventional cavernosography. We created a novel management algorithm for diagnosing venous leak including CT cavernosography as an imaging modality. In order to provide a broader basis for our management algorithm, a systematic literature review was conducted. MAIN BODY: In this article we systematically review relevant literature on using CT cavernosography for the diagnosis and treatment planning in ED patients with venous leak following the PRISMA selection process. Nine full-text articles were included in the review and assigned a level of evidence grade (all grade II). Two studies (2/9) compared the results of conventional cavernosography with those of CT cavernosography which was superior for site-specific venous leak identification (19.4% vs. 100%, respectively). CT cavernosography is a more detailed imaging method that is faster to perform, exposes the patient to less radiation, and requires less contrast material. In one study (1/9), CT cavernosography was used for diagnostic purposes only. Eight studies (8/9) cover both, diagnostic imaging and treatment planning including embolization (1/9) and sclerotherapy (2/9) of venous leak in patients with venogenic ED. Three studies (3/9) describe anatomical venous leak classifications that were established based on CT cavernosography findings for accurate mapping of superficial and/or deep venous leak and identification of mixed or more complex forms of venous leak present in up to 84% of patients. In addition to treatment planning, one study (1/9) used CT cavernosography also for follow-up imaging post treatment. CONCLUSION: CT cavernosography is superior to conventional cavernosography for diagnosis and treatment planning in patients with ED caused by venous leak (grade II levels of evidence). Consequently, CT cavernosography should be included in management algorithms for ED patients with suspected venous leak.

Long-Term Outcomes of Drug-Eluting Stent Implantation for Patients With Atherosclerotic Erectile Dysfunction not Responding to PDE-5-Inhibitors.

PURPOSE: Endovascular therapy of erection-related arteries was shown to be a promising treatment option for patients with severe erectile dysfunction. Purpose of this study was to assess the longer-term safety and clinical success rate of endovascular revascularization of erection-related arteries with the Angiolite BTK stent in patients with arteriogenic erectile dysfunction. MATERIALS AND METHODS: A total of 147 consecutive men (63.5±9.3 years) with erectile dysfunction due to 345 atherosclerotic lesions underwent endovascular revascularization. Patients received an International Index of Erectile Function (IIEF)-15 questionnaire at 30.3±7.2 months (follow-up [FU] period no less than 18 months) after stenting. An improvement by 4 points in the erectile function domain consisting of 6 questions (IIEF-6) was defined as minimal clinically important difference (MCID). RESULTS: Technical success was achieved in 99% of lesions. One major adverse event occurred after endovascular revascularization. Sixty-eight (46%) patients completed their latest FU at least 18 months following the last intervention. Minimal clinically important difference was achieved in 54% (37/68) of patients. CONCLUSIONS: In patients with arteriogenic erectile dysfunction not responding to phosphodiesterase-5-inhibitors (PDE-5-Is), endovascular therapy with a novel thin-strut sirolimus-eluting stent is a safe and effective treatment option during short- and longer-term FU. CLINICAL IMPACT: Patients with severe erectile dysfunction profit greatly from endovascular therapy of erection-related arteries. Stable clinical outcomes are seen beyond a 1-year timeframe. It is proven that, the drug-eluting stent therapy for atherosclerotic ED in patients who have not responded to PDE-5-I therapy is safe and effective during longer-term follow-up.

Role of Lp(a) in patients with erectile dysfunction undergoing angioplasty for symptomatic pelvic artery disease.

Background: Atherosclerotic disease of erection-related arteries is a major reason for erectile dysfunction (ED). Lp(a) has been implied in the pathophysiology of atherosclerosis in the coronary and lower limb arteries. Here, we investigated if Lp(a) plays a specific role in ED due with symptomatic pelvic artery atherosclerosis. Patients and methods: Out of 276 consecutive patients treated for ED with angioplasties on proximal (69%) and distal (31%, distal to Alcock channel) erection-related arteries, 236 patients (age: 62±10 years) of which Lp(a) values were available were retrospectively analyzed. Results: The baseline International Index of Erectile Function-15 (IIEF-15) score was 29±15 and significantly increased to 43±20 (increase: 14±21) after treatment at average follow up of 286±201 days. In 25%, Lp(a) values were elevated to more than 30 mg/dL. Hypercholesterolemia, coronary, lower extremity peripheral, and polyvascular disease were more common in patients with Lp(a) ≥60 mg/dl. Anatomic arterial lesion distribution (proximal/distal), improvement in IIEF-15 and clinically driven re-intervention rate (overall 7%) did not differ between patients with <30, 30-59, and ≥60 mg/dL Lp(a). Conclusions: While angioplasty is an effective therapy for ED of arterial origin in patients with obstruction of erection-related arteries, Lp(a) does not seem to play a major role for clinical outcomes in these patients.

Frequency and anatomic distribution of arterial obstructions in patients with vasculogenic erectile dysfunction not responding to intracavernous prostaglandin.

Background: The extent of arterial disease in patients with erectile dysfunction (ED) non-responsive to intracavernosal injection of Alprostadil is of importance for therapeutic options. However, published evidence, in particular angiographically validated is scarce. Here we investigated arterial lesion patterns in this specific patient cohort by selective angiography. Patients and methods: A cohort of 239 patients received a clinical and duplex-sonographic workup for ED of suspected vascular origin. Duplex ultrasound of the cavernosal arteries was performed after intracavernosal injection of 10 µg Alprostadil. Consequently, standardized workup included grading of the erectile and determination of peak systolic velocity (PSV) and end-diastolic velocity (EDV) in both cavernosal arteries. PSV-values below 30 cm/sec indicated reduced arterial flow, whereas EDV-values above 15 cm/sec indicated a venous leak of the pudendal veins. All patients with suspected arterial ED based on duplex sonography underwent contrast-enhanced computed tomography. Endovascular therapy was carried out in ED patients not responsive or with significant side effects to PDE-5-inhibitors or Alprostadil by selective angiographic depiction of erection-related arteries. Results: 54 patients with a mean age of 61.2 (±9.8) years underwent angioplasty of erectionr elated arteries. Out of these 48/54 (89%) patients presented with an erection considered insufficient for penetration (E0-E3) subsequent to intracavernous application of 10 µg Alprostadil. 14/48 (29%) patients had bilateral arterial obstructions and 34/48 (71%) had unilateral disease. Commonly affected was the internal pudendal artery (n = 31, 65%), followed closely by the common penile artery (n = 30, 64%). The least affected arteries were the dorsal penile (n = 6, 13%), hypogastric (n = 4, 8%), common iliac (n = 4, 8%), cavernosal (n = 4, 8%), and inferior gluteal (n = 1, 2%) arteries. Conclusions: Arterial obstructions amenable to endovascular revascularization are frequent in patients non-responsive to intracavernosal prostaglandin administration. Therapeutic strategies in ED patients non-responsive to conservative measures should therefore consider endovascular treatment opportunities.

Demographic and procedural characteristics in the RECording COurses of vasculaR Diseases (RECCORD) registry - the first 1000 patients.

Background: The RECcording COurses of vasculaR Diseases (RECCORD) registry established by the German Society of Angiology - Society for Vascular Medicine aimed to address the lack in contemporary real-world data regarding current practice of medical and interventional care in vascular patients. We herein report the demographic and procedural characteristics of the first 1000 patients undergoing endovascular revascularization (EVR) for symptomatic peripheral artery disease (PAD). Patients and methods: RECCORD is an observational, prospective, multicenter, all-comers registry. Only patients undergoing EVR for symptomatic PAD are included and followed up for at least 1 year. Demographic characteristics, comorbidities, previous peripheral vascular interventions, medication, clinical stage of lower extremity artery disease (Rutherford category), hemodynamic parameters, and procedural data including complications are recorded via an entirely web-based platform. Results: Of the first 1000 patients (mean age 70 ± 10 years, 35% female) with 1096 EVR at 1477 vascular segments of the lower extremities, 25.0% were at the stage of chronic limb threatening ischemia (CLTI) and 75.0% at non-CLTI. The femoropopliteal segment was the dominant target lesion site (61.0%), followed by iliac (26.4%) and below-the-knee EVR (10.3%). Only angioplasty was performed in 130 EVR (11.9%), adjunctive drug coated balloons (DCB) in 498 (45.4%), additional stenting in 633 (57.8%). Debulking devices were used in 106 (9.7%) EVR. Clinical (Rutherford categories) and hemodynamic parameters (ankle-brachial-index) as well as secondary preventive medication were significantly improved post EVR. Periprocedural complications occurred in 63 (5.7%) EVR with pseudoaneurysm as the leading complication type in 26 (2.4%) EVR. Conclusions: The baseline data of the first 1000 patients from the RECCORD registry representing the real-world setting illustrate that the majority of EVR are performed in patients with claudication. Adjunctive use of DCB and stenting are the dominant types of EVR, while periprocedural complications are at an acceptable low rate.

Incidental findings during computed tomographic angiography diagnostic work-up in patients with arteriogenic erectile dysfunction.

AIM: To analyse the incidental findings during computed tomographic angiography (CTA) diagnostic work-up in patients with arteriogenic erectile dysfunction (ED). PATIENTS AND METHODS: The medical records of all patients with suspected arteriogenic ED were entered into a database. Risk factors and underlying comorbidities were also collected. Pathological CTA findings were extracted from the CT readings and entered into the database. Incidental findings on CTA were classified as those requiring immediate medical treatment, requiring deferred medical treatment or of no clinical importance. RESULTS: A total of 200 patients underwent CTA for suspected arteriogenic ED. Mean patient age was 59.6 ± 11.7 years. Of these, 181 patients (90.5%) had obstructions of erection-related arteries. In 168 patients (84.0%), CTA showed multiple incidental pathological findings. Eighty-five of 200 patients (42.5%) exhibited incidental findings requiring immediate further medical workup and/or treatment: coronary artery calcification was diagnosed in 75/200 (37.5%), aorto-iliac aneurysms in 8/200 (4%) of patients and incidentally detected embolism in 1/200 patient. Pancreatic and liver tumours were less frequent (incidence 1.5% and 1%, respectively). Incidental findings requiring deferred medical workup and/or treatment were detected in 175/200 patients (87.5%). The findings with the highest prevalence were liver steatosis followed by colon diverticulosis and prostate hyperplasia. Findings of little to no clinical importance were reported in 117 (58.5%) patients. These included uncomplicated renal cysts, spinal degeneration and renal vascular anomalies. Almost every second patient presenting with ED had an incidental finding which required immediate treatment. CONCLUSIONS: Incidental findings not directly related to ED were common among patients undergoing CTA scans for suspected arterial obstructions. Coronary artery calcification was the leading finding requiring further medical workup and/or treatment. Thus, the benefit of CTA investigations extends beyond the anatomic description of arterial obstructions of erection-related arteries.

Treatment of the antiphospholipid syndrome with direct oral anticoagulantsPosition statement of German societies.

The antiphospholipid-syndrome (APS) is one of the most severe forms of thrombophilia, which may not only lead to recurrent venous but also to arterial thromboembolic events (TE), and to severe pregnancy complications, respectively. APS is defined by clinical symptoms and specific laboratory findings: 1. Lupus anticoagulant (LA), 2. anticardiolipin-antibodies (ACA), and 3. ß2-Glycoprotein I-antibodies (ß2GPI-Ab). All test results have to be confirmed after at least 12 weeks. The thrombotic risk is highest, if all 3 test groups are positive. It must be pointed out that the presence of UFH, VKA or DOACs may lead to false positive LA-test results; the addition of a specific absorber after blood sampling may provide reliable results in the presence of DOACs. A prospective randomized controlled trial comparing warfarin and rivaroxaban (TRAPS-trial) including only high-risk patients with triple positive APS was terminated early because of an increased rate of TE in patients treated with rivaroxaban [19 %, mostly arterial, compared to 3 % with warfarin (HR 7.4;1.7-32.9)]. Subsequently, a warning letter was issued by the pharmaceutical manufacturers of DOACs, including a warning of DOAC use in APS-patients, particularly in triple-positive high-risk patients. Conclusions: 1. Clinical suspicion of APS requires careful diagnostic testing. Because of inadequate diagnostic workup, many patients may not even have an APS, and these patients could be adequately treated with a DOAC. 2. Patients with single or double positive antiphospholipid antibodies but without positive LA may have a comparably low thrombotic risk and may also be treated with a DOAC in venous TE - sufficient evidence for that conclusion is not yet available but is suggested by the results of meta-analyses. 3. Triple positive patients or those with APS who suffered from arterial thromboembolism have a very high recurrence risk of thrombosis; the TRAPS-Study shows that these patients should be treated with VKA instead of a DOAC.

[Peripheral Arterial Disease: When is a PCSK9 Inhibitor Useful?] / Periphere arterielle Verschlusskrankheit: Wann ist ein PCSK9-Inhibitor sinnvoll?

The guideline of the European Society of Cardiology recommends an LDL-C target < 70 mg/dL or a 50 % reduction in patients with manifest peripheral arterial disease (PAD) as well as in CHD or cerebrovascular disease when the baseline LDL-C is between 70 and 135 mg/dL. Application of a PCSK9 inhibitor allows target attainment for those patients who do not achieve this under maximal conventional therapy with a statin in combination with ezetemib. In the Fourier study, patients with PAOD who had neither a myocardial infarction nor a stroke at admission of the study had a significant risk reduction (RR) of both cardiovascular (RR = 0.67, 0.47 - 0.96, p = 0.0283) as well as extremity endpoints (RR = 0.43 (0.19 - 0.99; p = 0.042). In Germany these patients are primarily seen by angiologists. This group of vascular specialists is specifically mentioned in the decision of the Federal Joint Committee as one of those who may indicate treatment with PCSK9 inhibitors.

Endothelial progenitor cells as a biological marker of peripheral artery disease.

The role of endothelial progenitor cells (EPCs) in peripheral artery disease (PAD) remains unclear. We hypothesized that EPC mobilization and function play a central role in the development of endothelial dysfunction and directly influence the degree of atherosclerotic burden in peripheral artery vessels. The number of circulating EPCs, defined as CD34(+)/KDR(+) cells, were assessed by flow cytometry in 91 subjects classified according to a predefined sample size of 31 non-diabetic PAD patients, 30 diabetic PAD patients, and 30 healthy volunteers. Both PAD groups had undergone endovascular treatment in the past. As a functional parameter, EPC colony-forming units were determined ex vivo. Apart from a broad laboratory analysis, a series of clinical measures using the ankle-brachial index (ABI), flow-mediated dilatation (FMD) and carotid intima-media thickness (cIMT) were investigated. A significant reduction of EPC counts and proliferation indices in both PAD groups compared to healthy subjects were observed. Low EPC number and pathological findings in the clinical assessment were strongly correlated to the group allocation. Multivariate statistical analysis revealed these findings to be independent predictors of disease appearance. Linear regression analysis showed the ABI to be a predictor of circulating EPC number (p=0.02). Moreover, the functionality of EPCs was correlated by linear regression (p=0.017) to cIMT. The influence of diabetes mellitus on EPCs in our study has to be considered marginal in already disease-affected patients. This study demonstrated that EPCs could predict the prevalence and severity of symptomatic PAD, with ABI as the determinant of the state of EPC populations in disease-affected groups.

Longitudinal Telomere Erosion in Lymphocyte Subsets of Patients with Atherosclerotic Peripheral Arterial Disease (PAD).

Telomere attrition has been linked to accelerate vascular ageing and seems to predispose for vascular disease. Our aim was to study the telomere length dynamics over time and in subsets of leukocytes from 15 patients with peripheral arterial disease (PAD). The mean telomere length in subsets of leukocytes of patients with PAD was in the normal range of age-related telomere length values from healthy individuals. However, we found significant higher telomere attrition for T-cells from patients with PAD over a time period of six months when compared to the controls. The higher telomere loss in T-cells of patients with PAD most likely reflects a higher cell turnover of this leukocyte subset, which is involved in the process of chronic inflammatory disease underlying vascular disease. Further studies are needed to confirm these data and to assess how far this T-cell telomere attrition will correlate to the extent of the disease.

Infrapopliteal lesion morphology in patients with critical limb ischemia: implications for the development of anti-restenosis technologies.

PURPOSE: To angiographically evaluate infrapopliteal arterial lesion morphology in a consecutive series of patients presenting with critical limb ischemia (CLI) and undergoing infrapopliteal angioplasty. METHODS: A prospective analysis was undertaken of a consecutive series of CLI patients undergoing endovascular therapy in a tertiary referral center in the year 2011. Morphological assessment of baseline angiograms obtained prior to revascularization included lesion length, assessment of calcification using a semi-quantitative scoring system, and reference vessel diameter (RVD) measurement. Delta RVDs were assessed subtracting distal RVDs from proximal RVDs. A total of 197 infrapopliteal lesions in 105 CLI patients (n=106 limbs) were assessed. Of these, 136 lesions were treated by endovascular means. RESULTS: The average length of treated lesions was 87.1±43.8 mm in stenoses and 124.0±78.3 mm in chronic occlusions (p<0.001). Mean RVD proximal to the lesions was 1.88 mm whereas it was 1.66 mm distal to the lesions (p≤0.03). Mean arterial calcification was 1.15. CONCLUSION: This prospective angiographic series underlines the complex nature and extensive longitudinal involvement of infrapopliteal lesions in CLI patients. These findings should be taken into consideration for anti-restenosis concepts in this challenging subgroup of peripheral artery disease patients.

Intraarterial administration of bone marrow mononuclear cells in patients with critical limb ischemia: a randomized-start, placebo-controlled pilot trial (PROVASA).

BACKGROUND: Critical limb ischemia due to peripheral arterial occlusive disease is associated with a severely increased morbidity and mortality. There is no effective pharmacological therapy available. Injection of autologous bone marrow-derived mononuclear cells (BM-MNC) is a promising therapeutic option in patients with critical limb ischemia, but double-blind, randomized trials are lacking. METHODS AND RESULTS: Forty patients with critical limb ischemia were included in a multicenter, phase II, double-blind, randomized-start trial to receive either intraarterial administration of BM-MNC or placebo followed by active treatment with BM-MNC (open label) after 3 months. Intraarterial administration of BM-MNC did not significantly increase ankle-brachial index and, thus, the trial missed its primary end point. However, cell therapy was associated with significantly improved ulcer healing (ulcer area, 3.2±4.7 cm(2) to 1.89±3.5 cm(2) [P=0.014] versus placebo, 2.92±3.5 cm(2) to 2.89±4.1 cm(2) [P=0.5]) and reduced rest pain (5.2±1.8 to 2.2±1.3 [P=0.009] versus placebo, 4.5±2.4 to 3.9±2.6 [P=0.3]) within 3 months. Limb salvage and amputation-free survival rates did not differ between the groups. Repeated BM-MNC administration and higher BM-MNC numbers and functionality were the only independent predictors of improved ulcer healing. Ulcer healing induced by repeated BM-MNC administration significantly correlated with limb salvage (r=0.8; P<0.001). CONCLUSIONS: Intraarterial administration of BM-MNC is safe and feasible and accelerates wound healing in patients without extensive gangrene and impending amputation. These exploratory findings of this pilot trial need to be confirmed in a larger randomized trial in patients with critical limb ischemia and stable ulcers.

Endothelial progenitor cells induce a phenotype shift in differentiated endothelial cells towards PDGF/PDGFRß axis-mediated angiogenesis.

BACKGROUND: Endothelial Progenitor Cells (EPC) support neovascularization and regeneration of injured endothelium both by providing a proliferative cell pool capable of differentiation into mature vascular endothelial cells and by secretion of angiogenic growth factors. OBJECTIVE: The aim of this study was to investigate the role of PDGF-BB and PDGFRß in EPC-mediated angiogenesis of differentiated endothelial cells. METHODS AND RESULTS: Conditioned medium from human EPC (EPC-CM) cultured in hypoxic conditions contained substantially higher levels of PDGF-BB as compared to normoxic conditions (P<0.01). EPC-CM increased proliferation (1.39-fold; P<0.001) and migration (2.13-fold; P<0.001) of isolated human umbilical vein endothelial cells (HUVEC), as well as sprouting of vascular structures from ex vivo cultured aortic rings (2.78-fold increase; P = 0.01). The capacity of EPC-CM to modulate the PDGFRß expression in HUVEC was assessed by western blot and RT-PCR. All the pro-angiogenic effects of EPC-CM on HUVEC could be partially inhibited by inactivation of PDGFRß (P<0.01). EPC-CM triggered a distinct up-regulation of PDGFRß (2.5±0.5; P<0.05) and its phosphorylation (3.6±0.6; P<0.05) in HUVEC. This was not observed after exposure of HUVEC to recombinant human PDGF-BB alone. CONCLUSION: These data indicate that EPC-CM sensitize endothelial cells and induce a pro-angiogenic phenotype including the up-regulation of PDGFRß, thereby turning the PDGF/PDGFRß signaling-axis into a critical element of EPC-induced endothelial angiogenesis. This finding may be utilized to enhance EPC-based therapy of ischemic tissue in future.

Current developments in the use of stem cell for therapeutic neovascularisation: is the future therapy "cell-free"?

The plasticity and self-regenerative properties of stem cells have opened new avenues in regenerative medicine. Greater understanding of the biology of stem cells is followed by growing expectations of a rapid translation into alternative therapeutic options. Recent preclinical studies and clinical trials employing stem and progenitor cells from different sources have shown encouraging results. However, their underlying mechanisms are still poorly understood, the potential adverse effects and the discrepancy in efficacy remain to be further investigated. Their essential role in vessel regeneration has made endothelial progenitor cells (EPC) a suitable candidate for therapeutic applications aiming at tissue revascularisation. Recent evidence suggests that EPC contribute to neovascularisation not only by direct participation in tissue homeostasis but mainly via paracrine mechanisms. In future, novel therapeutic strategies could be based on EPC paracrine factors or synthetic factors, and replace cell transplantation.

Paracrine factors secreted by endothelial progenitor cells prevent oxidative stress-induced apoptosis of mature endothelial cells.

Endothelial progenitor cells (EPC) play a fundamental role in tissue regeneration and vascular repair. Current research suggests that EPC are more resistant to oxidative stress as compared to differentiated endothelial cells. Here we hypothesized that EPC not only possess the ability to protect themselves against oxidative stress but also confer this protection upon differentiated endothelial cells by release of paracrine factors. To test this hypothesis, HUVEC incubated with conditioned medium obtained from early EPC cultures (EPC-CM) were exposed to H2O2 to assess the accumulation of intracellular ROS, extent of apoptosis and endothelial cell functionality. Under oxidative stress conditions HUVEC treated with EPC-CM exhibited substantially lower levels of intracellular oxidative stress (0.2+/-0.02 vs. 0.4+/-0.03 relative fluorescence units, p<0.05) compared to control medium. Moreover, the incubation with EPC-CM elevated the expression level of antioxidant enzymes in HUVEC (catalase: 2.6+/-0.4; copper/zinc superoxide dismutase (Cu/ZnSOD): 1.6+/-0.1; manganese superoxide dismutase (MnSOD): 1.4+/-0.1-fold increase compared to control, all p<0.05). Furthermore, EPC-CM had the distinct potential to reverse the functional impairment of HUVEC as measured by their capability to form tubular structures in vitro. Finally, incubation of HUVEC with EPC-CM resulted in a significant reduction of apoptosis (0.34+/-0.01 vs. 1.52+/-0.12 relative fluorescence units, p<0.01) accompanied by an increased expression ratio of the anti/pro-apoptotic factors Bcl-2/Bax to 2.9+/-0.7-fold (compared to control, p<0.05). Most importantly, neutralization of selected cytokines such as VEGF, HGF, IL-8 and MMP-9 did not significantly reverse the cyto-protective effect of EPC-CM (p>0.05), suggesting that soluble factors secreted by EPC, possibly via broad synergistic actions, exert strong cyto-protective properties on differentiated endothelium through modulation of intracellular antioxidant defensive mechanisms and pro-survival signals.

Streptococcus pneumoniae serotype 1 capsular polysaccharide induces CD8CD28 regulatory T lymphocytes by TCR crosslinking.

Zwitterionic capsular polysaccharides (ZPS) of commensal bacteria are characterized by having both positive and negative charged substituents on each repeating unit of a highly repetitive structure that has an alpha-helix configuration. In this paper we look at the immune response of CD8(+) T cells to ZPSs. Intraperitoneal application of the ZPS Sp1 from Streptococcus pneumoniae serotype 1 induces CD8(+)CD28(-) T cells in the spleen and peritoneal cavity of WT mice. However, chemically modified Sp1 (mSp1) without the positive charge and resembling common negatively charged polysaccharides fails to induce CD8(+)CD28(-) T lymphocytes. The Sp1-induced CD8(+)CD28(-) T lymphocytes are CD122(low)CTLA-4(+)CD39(+). They synthesize IL-10 and TGF-beta. The Sp1-induced CD8(+)CD28(-) T cells exhibit immunosuppressive properties on CD4(+) T cells in vivo and in vitro. Experimental approaches to elucidate the mechanism of CD8(+) T cell activation by Sp1 demonstrate in a dimeric MHC class I-Ig model that Sp1 induces CD8(+) T cell activation by enhancing crosslinking of TCR. The expansion of CD8(+)CD28(-) T cells is independent, of direct antigen-presenting cell/T cell contact and, to the specificity of the T cell receptor (TCR). In CD8(+)CD28(-) T cells, Sp1 enhances Zap-70 phosphorylation and increasingly involves NF-kappaB which ultimately results in protection versus apoptosis and cell death and promotes survival and accumulation of the CD8(+)CD28(-) population. This is the first description of a naturally occurring bacterial antigen that is able to induce suppressive CD8(+)CD28(-) T lymphocytes in vivo and in vitro. The underlying mechanism of CD8(+) T cell activation appears to rely on enhanced TCR crosslinking. The data provides evidence that ZPS of commensal bacteria play an important role in peripheral tolerance mechanisms and the maintenance of the homeostasis of the immune system.

Lack of extended venous thromboembolism prophylaxis in high-risk patients undergoing major orthopaedic or major cancer surgery. Electronic Assessment of VTE Prophylaxis in High-Risk Surgical Patients at Discharge from Swiss Hospitals (ESSENTIAL).

Extended pharmacological venous thromboembolism (VTE) prophylaxis beyond discharge is recommended for patients undergoing high-risk surgery. We prospectively investigated prophylaxis in 1,046 consecutive patients undergoing major orthopaedic (70%) or major cancer surgery (30%) in 14 Swiss hospitals. Appropriate in-hospital prophylaxis was used in 1,003 (96%) patients. At discharge, 638 (61%) patients received prescription for extended pharmacological prophylaxis: 564 (77%) after orthopaedic surgery, and 74 (23%) after cancer surgery (p < 0.001). Patients with knee replacement (94%), hip replacement (81%), major trauma (80%), and curative arthroscopy (73%) had the highest prescription rates for extended VTE prophylaxis; the lowest rates were found in patients undergoing major surgery for thoracic (7%), gastrointestinal (19%), and hepatobiliary (33%) cancer. The median duration of prescribed extended prophylaxis was longer in patients with orthopaedic surgery (32 days, interquartile range 14-40 days) than in patients with cancer surgery (23 days, interquartile range 11-30 days; p<0.001). Among the 278 patients with an extended prophylaxis order after hip replacement, knee replacement, or hip fracture surgery, 120 (43%) received a prescription for at least 35 days, and among the 74 patients with an extended prophylaxis order after major cancer surgery, 20 (27%) received a prescription for at least 28 days. In conclusion, approximately one quarter of the patients with major orthopaedic surgery and more than three quarters of the patients with major cancer surgery did not receive prescription for extended VTE prophylaxis. Future effort should focus on the improvement of extended VTE prophylaxis, particularly in patients undergoing major cancer surgery.