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Objective Markers containing dyes such as crystal violet (CAS 548-62-9) are routinely used on the adventitia of vein bypass grafts to avoid twisting during placement. Because little is known about how these dyes affect vein graft healing and function, we determined the effect of crystal violet on cell migration and proliferation, which are responses to injury after grafting. Methods Fresh human saphenous veins were obtained as residual specimens from leg bypass surgeries. Portions of the vein that had been surgically marked with crystal violet were analyzed separately from those that had no dye marking. In the laboratory, they were split into easily dissected inner and outer layers after removal of endothelium. This cleavage plane was within the circular muscle layer of the media. Cell migration from explants was measured daily as either (1) percentage of migration-positive explants, which exclusively measures migration, or (2) number of cells on the plastic surrounding each explant, which measures migration plus proliferation. Cell proliferation and apoptosis (Ki67 and TUNEL staining, respectively) were determined in dye-marked and unmarked areas of cultured vein rings. The dose-dependent effects of crystal violet were measured for cell migration from explants as well as for proliferation, migration, and death of cultured outer layer cells. Dye was extracted from explants with ethanol and quantified by spectrophotometry. Results There was significantly less cell migration from visibly blue compared with unstained outer layer explants by both methods. There was no significant difference in migration from inner layer explants adjacent to blue-stained or unstained sections of vein because dye did not penetrate to the inner layer. Ki67 staining of vein in organ culture, which is a measure of proliferation, progressively increased up to 6 days in nonblue outer layer and was abolished in the blue outer layer. Evidence of apoptosis (TUNEL staining) was present throughout the wall and not different in blue-stained and unstained vein wall segments. Blue outer layer explants had 65.9 ± 8.0 ng dye/explant compared with 2.1 ± 1.3 for nonblue outer layer explants. Dye applied in vitro to either outer or inner layer explants dose dependently inhibited migration (IC 50 ∼10 ng/explant). The IC 50 s of crystal violet for outer layer cell proliferation and migration were 0.1 and 1.2 μg/mL, whereas the EC 50 for death was between 1 and 10 μg/mL. Conclusions Crystal violet inhibits venous cell migration and proliferation, indicating that alternative methods should be considered for marking vein grafts. [ABSTRACT FROM AUTHOR]

Background: Exercise-induced external iliac artery endofibrosis (EIAE) is rare and has been described primarily in endurance male cyclists. Clinically, it presents as claudication during maximal exercise with quick resolution after exercise. Most patients have fibrotic changes within the external iliac artery (EIA). We describe our experience with EIAE and propose a hypothesis for the mechanism involved in the associated claudication. Methods: This was a retrospective review of athletes who presented with symptomatic EIAE requiring operative repair between 2001 and 2010. Data collected included demographic information, initial presentation, type of exercise, repair, and long-term outcome. Diagnostic studies consisted of duplex evaluation, modified exercise treadmill test, and angiography. Results: Eight women, presented with symptomatic EIAE. Two had bilateral EIAE. All were endurance athletes (three cyclists, one runner, and four were cyclists and runners). Median age at presentation was 42.5 years (range, 39-60 years). Median duration of symptoms was 5.5 years (range, 2-15 years). Diagnosis was confirmed with an exercise treadmill test modified to accommodate these patients' high level of conditioning and unmask the claudication. In the most recent two patients, marked EIA vasospasm was noted after exercise by duplex scanning. All patients were treated with EIA vein patch angioplasty. Follow-up ranged from 1 to 10 years. All had a normal result on the modified exercise treadmill test and resumed their athletic activities postoperatively. Conclusions: This series highlights a possible mechanism to explain the claudication associated with EIAE. Vasospasm may be more important than wall thickening for the reduction of blood flow during extreme exercise in affected athletes. Routine duplex ultrasound imaging to measure EIA diameter and flow velocities before and after maximal exercise is needed to confirm this phenomenon. [ABSTRACT FROM AUTHOR]

Objective: About a quarter of peripheral vein grafts fail due in part to intimal hyperplasia. The proliferative capacity and response to growth inhibitors of medial smooth muscle cells and adventitial fibroblasts in vitro were studied to test the hypothesis that intrinsic differences in cells of vein grafts are associated with graft failure. Methods: Cells were grown from explants of the medial and adventitial layers of samples of vein grafts obtained at the time of implantation. Vein graft patency and function were monitored over the first 12 months using ankle pressures and Duplex ultrasound to determine vein graft status. Cells were obtained from veins from 11 patients whose grafts remained patent (non-stenotic) and from seven patients whose grafts developed stenosis. Smooth muscle cells (SMCs) derived from media and fibroblasts derived from adventitia were growth arrested in serum-free medium and then stimulated with 1 μM sphingosine-1-phosphate (S1P), 10 nM thrombin, 10 ng/ml epidermal growth factor (EGF), 10 ng/ml platelet-derived growth factor-BB (PDGF-BB), PDGF-BB plus S1P, or PDGF-BB plus thrombin for determination of incorporation of [3H]-thymidine into DNA. Cells receiving PDGF-BB or thrombin were also treated with or without 100 μg/ml heparin, which is a growth inhibitor. Cells receiving thrombin were also treated with or without 150 nM AG1478, an EGF receptor kinase inhibitor. Results: SMCs and fibroblasts from veins of patients that developed stenosis responded more to the growth factors, such as PDGF-BB alone or in combination with thrombin or S1P, than cells from veins of patients that remained patent (P = .012). In addition, while PDGF-BB-mediated proliferation of fibroblasts from grafts that remained patent was inhibited by heparin (P < .03), PDGF-BB-mediated proliferation of fibroblasts from veins that developed stenosis was not (P > .5). Conclusion: Inherent differences in the proliferative response of vein graft cells to PDGF-BB and heparin may explain, in part, the variability among patients regarding long term patency of vein grafts. [Copyright &y& Elsevier]

The American Vascular Association/Lifeline Foundation is celebrating its 20th anniversary this year. This remarkable two-decade journey represents a cumulative effort by the leaders and members of the Society for Vascular Surgery (SVS). For the historical record, we would like to chart the sequence of events leading to various programs. In 1986, the Executive Council of SVS approved the formation of an Education/Research Foundation, from which the Lifeline Foundation evolved, with the mission to support the career development of young research-oriented vascular surgeons. Since that time, Lifeline has awarded 141 Student Fellowships, 21 Wylie Traveling Fellowships, 17 Mentored Clinical Scientist Development (K08) Awards, and three Mentored Patient-Oriented Research Career Development (K23) Awards. In 2001, the American Vascular Association (AVA) was established under the aegis of American Association for Vascular Surgery (formerly International Society for Cardiovascular Surgery-North American Chapter). In 2004, with the merger of the SVS and the American Association of Vascular Surgery into a single entity (SVS), Lifeline and the AVA merged into a single foundation, the AVA. As AVA/Lifeline is poised to launch a campaign for an endowment fund, we hope this report will let the members of the SVS know what has been accomplished, what we plan to do, and, most importantly, what we need to do in the future. [Copyright &y& Elsevier]

Objective: Increased blood flow causes neointimal atrophy, whereas relief of wall tension with an external wrap causes arterial medial atrophy. To study the effects of blood flow and wall tension separately and together, we applied tight or loose wraps on high-flow or normal-flow iliac arteries in baboons. Method: Baboon external iliac arteries were wrapped with loose-fitting and tight-fitting expanded polytetrafluoroethylene (ePTFE), leaving part unwrapped. A downstream arteriovenous fistula was constructed on one side to increase blood flow approximately twofold. The arteries were perfusion-fixed with 10% formalin after 4 (n = 5) and 28 days (n = 5). Results: At 4 days, compared with the unwrapped artery, the loosely and tightly wrapped normal-flow artery showed significant medial atrophy (23% and 30%, respectively; P < .05). The tightly wrapped artery showed a loss of cells (27%; P = .02) but no change in cell density. At 28 days, the medial cross-sectional area was decreased by the tight wrap and loose wrap under normal (45% and 28%, respectively; P < .05) and high (43% and 29%, respectively; P < .05) flow. High flow did not alter the effect of wrapping nor did it affect the unwrapped medial area. At 28 days, the normal and high flow tightly wrapped media showed an insignificant loss of cells but had increased cell density (47% and 30%, respectively; P < .05), suggesting preferential loss of extracellular matrix. Decorin was expressed at the late time only in the tightly wrapped normal and high-flow media and was associated with tight packing of the collagen, as detected by picrosirius red staining. Conclusion: Loose-fitting and tight-fitting ePTFE wraps induced an inflammatory foreign body response that caused medial atrophy with loss of cells and extracellular matrix; the tight wrap was more effective. High blood flow did not prevent or augment medial atrophy. [Copyright &y& Elsevier]

Regardless of the type of arterial reconstruction, luminal narrowing (stenosis or restenosis) develops in approximately one third of the vessels. In the past, the focus of research has been on the mechanisms of stenosis (intimal hyperplasia, pathologic remodeling) and pharmacologic approaches to prevention. An alternative approach is to induce intimal atrophy after luminal narrowing has developed, thus limiting treatment to only those patients that develop a problem. This approach to treat established disease by reducing wall mass through induction of cell death and extracellular matrix removal would be particularly useful for treating stenosis in synthetic bypass grafts or stented vessels, in which intimal hyperplasia is the primary mechanism of stenosis. This approach may be applicable as well to other vascular proliferative disorders, such as pulmonary hypertension and chronic transplant arteriopathy. Proof of principle has been shown in experiments with antibodies to platelet-derived growth factor (PDGF) receptors that cause neointimal regression in baboon polytetrafluoroethylene (PTFE) grafts and with angiotensin-converting enzyme inhibitors that induce medial atrophy in hypertensive arteries. Possible molecular targets could include PDGF receptors, A20, and BMP4. Further studies are needed to determine the utility of such a therapeutic approach to vascular disease. [Copyright &y& Elsevier]

The Lifeline Foundation/National Heart, Lung, and Blood Institute William J. von Liebig Mentored Clinical Scientist Development (K08) Award program was established as a unique partnership to support vascular surgeon–scientists. Between 1999 and 2005, 39 applications were submitted, and the overall funding rate was 49% (14 von Liebig K08s and 5 additional NHLBI K08s). Vascular surgeon K08 recipients (median age, 38 years) had held faculty appointments for 2.5 ± 0.4 years, with 2.6 ± 0.2 years of previous research experience and 28.4 ± 6.2 publications. These individuals subsequently authored 5.1 ± 0.8 peer-reviewed publications per recipient per year, of which 35% were research and 65% were clinical. Six of seven holding the K08 over 3 years had received academic promotion, and all five completing the 5-year award had achieved independent investigator status with National Institutes of Health support. The von Liebig K08 program has therefore been an effective vehicle to stimulate research career development in the field of vascular surgery. [Copyright &y& Elsevier]

Background: Patients with critical limb ischemia (CLI) have multiple comorbidities and limited life spans. The ability of infrainguinal vein bypass to improve quality of life (QoL) in patients with CLI has therefore been questioned. Prospective preoperative and postoperative QoL data for patients undergoing lower extremity vein bypass for CLI are presented. Methods: A validated, disease-specific QoL questionnaire (VascuQoL) with activity, symptom, pain, emotional, and social domains and responses scored 1 (lowest QoL) to 7 (best QoL) was administered before surgery and at 3 and 12 months after lower extremity vein bypass for CLI. Changes in QoL at 3 and 12 months after lower extremity vein bypass and multiple predetermined variables potentially influencing QoL after lower extremity vein bypass were analyzed to determine the effect of lower extremity vein bypass on QoL in CLI patients. Results: A total of 1404 patients had lower extremity vein bypass for CLI at 83 centers in the United States and Canada as part of the PREVENT III clinical trial. Surveys were completed in 1296 patients at baseline, 862 patients at 3 months, and 732 patients at 12 months. The global QoL score (mean ± SD) was 2.8 ± 1.1 at baseline and was 4.7 ± 1.4 and 5.1 ± 1.4 at 3 and 12 months, respectively. Mean changes from baseline at 3 and 12 months were statistically significant (P < .0001). Improved QoL scores extended across all domains. Diabetes and the development of graft-related events were associated with decreased improvement in QoL scores, though the mean relative change from baseline remained positive. Conclusions: Patients with CLI have a low QoL at baseline that is improved at 3 and 12 months after lower extremity vein bypass. QoL improvements are lower in diabetic patients and those who develop graft-related events. Successful revascularization can be expected to improve QoL in patients with CLI, with benefits that are sustained to at least 1 year. [Copyright &y& Elsevier]

Objective: Resource utilization (RU) in the care of patients with critical limb ischemia (CLI) is not well quantified. We present a cohort study to quantify in-hospital RU and analyze the role of tissue loss (TL), comorbidities, and vascular graft-related events (GREs) in patients undergoing peripheral bypass for CLI. Methods: A retrospective analysis of 1404 patients enrolled in a multicenter clinical trial (PREVENT III) of vein bypass grafting for CLI was performed with analysis of RU during the 1-year follow-up period. Univariate and multivariable linear regressions were performed to determine RU predictors and outcomes. Results: Compared with patients with rest pain, patients presenting with TL as the indication for bypass surgery had a longer index length of stay (mean, 9.8 vs 6.2 days), more rehospitalizations (mean, 1.6 vs 1.2), and a longer cumulative length of stay (mean, 27.7 vs 17.3 days; P < .0001 for all comparisons). Rehospitalizations over the ensuing year were for additional procedures (37.5%), wound infection (14.6%), graft failure (10.7%), and other cardiovascular (10%) and noncardiovascular (26%) reasons. Early GRE (stenosis ≥70%, thrombosis, revision, or major amputation within 30 days) occurred in 162 (11.5%) patients, resulting in a longer index length of stay (mean, 11.8 vs 8.6 days; P = .0002) and cumulative length of stay (mean, 25.9 vs 24.6 days; P = .0043), but no difference in the number of rehospitalizations (mean, 1.6 vs 1.5 days; P = .3272). During the 1-year follow-up, 554 (39.5%) patients had GREs, and this resulted in more rehospitalizations (mean, 2.1 vs 1.1; P < .0001) and a longer cumulative length of stay (mean, 28.2 vs 21.9 days; P < .0001) compared with patients without GRE. Multivariable analysis demonstrated the highly positive association of TL (hazard ratio [HR], 1.75) and early GRE (HR, 1.77) with the index length of stay, whereas comorbidities—namely, dialysis dependency (HR, 1.31), nonsmoking status (HR, 1.29), hypertension (HR, 1.26), and increasing age (HR, 1.01)—also had strong effects. The effect of TL and GRE on later RU (number of rehospitalizations and cumulative length of stay) was present but less pronounced than patient comorbidities (namely, dialysis). Conclusions: The stage of disease at presentation (TL vs rest pain) and the patency of the bypass graft (freedom from GRE) are critical determinants of RU over the first year after limb-salvage surgery. These effects predominate early (index length of stay) and persist through 1 year. Patient-specific factors, particularly dialysis-dependent renal failure, are also critical comorbidities affecting RU in these patients. [Copyright &y& Elsevier]

Objective: The PREVENT III study was a prospective, randomized, double-blinded, multicenter phase III trial of a novel molecular therapy (edifoligide; E2F decoy) for the prevention of vein graft failure in patients undergoing infrainguinal revascularization for critical limb ischemia (CLI). Methods: From November 2001 through October 2003, 1404 patients with CLI were randomized to a single intraoperative ex vivo vein graft treatment with edifoligide or placebo. After surgery, patients underwent graft surveillance by duplex ultrasonography and were followed up for index graft and limb end points to 1 year. A blinded Clinical Events Classification committee reviewed all index graft end points. The primary study end point was the time to nontechnical index graft reintervention or major amputation due to index graft failure. Secondary end points included all-cause graft failure, clinically significant graft stenosis (>70% by angiography or severe stenosis by ultrasonography), amputation/reintervention-free survival, and nontechnical primary graft patency. Event rates were based on Kaplan-Meier estimates. Time-to-event end points were compared by using the log-rank test. Results: Demographics, comorbidities, and procedural details reflected a population with CLI and diffuse atherosclerosis. Tissue loss was the presenting symptom in 75% of patients. High-risk conduits were used in 24% of cases, including an alternative vein in 20% (15% spliced vein and 5% non–great saphenous vein) and 6% less than 3 mm in diameter; 14% of the cases were reoperative bypass grafts. Most (65%) grafts were placed to infrapopliteal targets. Perioperative (30-day) mortality occurred in 2.7% of patients. Major morbidity included myocardial infarction in 4.7% and early graft occlusion in 5.2% of patients. Ex vivo treatment with edifoligide was well tolerated. There was no significant difference between the treatment groups in the primary or secondary trial end points, primary graft patency, or limb salvage. A statistically significant improvement was observed in secondary graft patency (estimated Kaplan-Meier rates were 83% edifoligide and 78% placebo; P = .016) within 1 year. The reduction in secondary patency events was manifest within 30 days of surgery (the relative risk for a 30-day event for edifoligide was 0.45; 95% confidence interval, 0.27-0.76; P = .005). For the overall cohort at 1 year, the estimated Kaplan-Meier rate for survival was 84%, that for primary patency was 61%, that for primary assisted patency was 77%, that for secondary patency was 80%, and that for limb salvage was 88%. Conclusions: In this prospective, randomized, placebo-controlled clinical trial, ex vivo treatment of lower extremity vein grafts with edifoligide did not confer protection from reintervention for graft failure. [Copyright &y& Elsevier]

Objective: Placement in baboons of a distal femoral arteriovenous fistula increases shear stress through aortoiliac polytetrafluoroethylene (PTFE) grafts and induces regression of a preformed neointima. Atrophy of the neointima might be controlled by shear stress-induced genes, including the bone morphogenetic proteins (BMPs). We have investigated the expression and function of BMPs 2, 4, and 5 in the graft neointima and in cultured baboon smooth muscle cells (SMCs). Methods: Baboons received bilateral aortoiliac PTFE grafts and 8 weeks later, a unilateral femoral arteriovenous fistula. Results: Quantitative polymerase chain reaction showed that high shear stress increased BMP2, 4, and 5 messenger RNA (mRNA) in graft intima between 1 and 7 days, while noggin (a BMP inhibitor) mRNA was decreased. BMP4 most potently (60% inhibition) inhibited platelet-derived growth factor-stimulated SMC proliferation compared with BMP2 and BMP5 (31% and 26%, respectively). BMP4 also increased SMC death by 190% ± 10%. Noggin reversed the antiproliferative and proapoptotic effects of BMP4. Finally, Western blotting confirmed BMP4 protein upregulation by high shear stress at 4 days. BMP4 expression demonstrated by in situ hybridization was confined to endothelial cells. Conclusions: Increased BMPs (particularly BMP4) coupled with decreased noggin may promote high shear stress-mediated graft neointimal atrophy by inhibiting SMC proliferation and increasing SMC death. [Copyright &y& Elsevier]

Objectives: Patients who require infrainguinal revascularization for critical limb ischemia (CLI) are at elevated risk for cardiovascular events. The PREVENT III study was a prospective, randomized, multicenter, phase 3 trial of edifoligide for the prevention of vein graft failure in patients with CLI. We examined the baseline characteristics, perioperative medical therapies, and 30-day incidence of major cardiovascular events in the PREVENT III cohort. Methods: Demographics, medical and surgical history, mode of presentation for the index limb, procedural details, and concomitant medications were reviewed for all patients enrolled in PREVENT III (N = 1,404). Major adverse cardiovascular events, including death, myocardial infarction, or cerebrovascular event (stroke or transient ischemic attack) were tabulated. Univariate and multivariate analyses were performed to discern factors that were associated with the utilization of medical therapies and with perioperative events. Results: Demographics and comorbidities reflected a population with diffuse, advanced atherosclerosis. Perioperative mortality was 2.7%, and major morbidity included myocardial infarction in 4.7% and stroke/transient ischemic attack in 1.4%. Among this population of CLI patients, 33% were not on antiplatelet therapy at study entry, and 24% were not receiving antithrombotics of any type. In addition, 54% of patients were not receiving lipid-lowering therapy, and 52% were not prescribed β-blocker medications at study entry. On multivariate analysis, race was a significant determinant of antithrombotic utilization, with African-American patients less frequently treated both at baseline and discharge (adjusted odd ratios, 0.5 and 0.6, P < .0001). Antithrombotic and β-blocker drug usage increased in the overall cohort from baseline (76% and 48%) to discharge (88% and 60%; P < .0001). Patients treated in a university hospital setting were more likely to be prescribed antiplatelet, lipid-lowering, and β-blocker medications. Advanced age (>75 years), coronary artery disease (prior myocardial infarction or revascularization), and dialysis-dependent renal failure were associated with an increased 30-day risk of death, myocardial infarction, or stroke. Protective effects of β-blocker and lipid-lowering medications were noted in these defined subgroups. Conclusions: A significant percentage of the population that undergoes surgical revascularization for CLI is not prescribed therapies of proven benefit in reducing cardiovascular events. Utilization of antithrombotics and β-blockers increases during hospitalization for limb salvage surgery but that of lipid-lowering therapy does not. African-American patients appear to be at greater risk for undertreatment with antithrombotics, and the data suggest that patients undergoing leg bypass surgery in a university hospital setting receive more comprehensive medical treatment of atherosclerosis. Treatment guidelines for medical therapy are needed to standardize care and improve outcomes for patients with CLI. [Copyright &y& Elsevier]

Objective Approximately 30% of autogenous vein grafts develop luminal narrowing and fail because of intimal hyperplasia or negative remodeling. We previously found that vein graft cells from patients who later develop stenosis proliferate more in vitro in response to growth factors than cells from patients who maintain patent grafts. To discover novel determinants of vein graft outcome, we have analyzed gene expression profiles of these cells using a systems biology approach to cluster the genes into modules by their coexpression patterns and to correlate the results with growth data from our prior study and with new studies of migration and matrix remodeling. Methods RNA from 4-hour serum- or platelet-derived growth factor (PDGF)-BB-stimulated human saphenous vein cells obtained from the outer vein wall (20 cell lines) was used for microarray analysis of gene expression, followed by weighted gene coexpression network analysis. Cell migration in microchemotaxis chambers in response to PDGF-BB and cell-mediated collagen gel contraction in response to serum were also determined. Gene function was determined using short-interfering RNA to inhibit gene expression before subjecting cells to growth or collagen gel contraction assays. These cells were derived from samples of the vein grafts obtained at surgery, and the long-term fate of these bypass grafts was known. Results Neither migration nor cell-mediated collagen gel contraction showed a correlation with graft outcome. Although 1188 and 1340 genes were differentially expressed in response to treatment with serum and PDGF, respectively, no single gene was differentially expressed in cells isolated from patients whose grafts stenosed compared with those that remained patent. Network analysis revealed four unique groups of genes, which we term modules, associated with PDGF responses, and 20 unique modules associated with serum responses. The “yellow” and “skyblue” modules, from PDGF and serum analyses, respectively, correlated with later graft stenosis ( P = .005 and P = .02, respectively). In response to PDGF, yellow was also associated with increased cell growth. For serum, skyblue was also associated with inhibition of collagen gel contraction. The hub genes for yellow and skyblue (ie, the gene most connected to other genes in the module), scavenger receptor class A member 5 ( SCARA5 ) and suprabasin ( SBSN ), respectively, were tested for effects on proliferation and collagen contraction. Knockdown of SCARA5 increased proliferation by 29.9% ± 7.8% ( P < .01), whereas knockdown of SBSN had no effect. Knockdown of SBSN increased collagen gel contraction by 24.2% ± 8.6% ( P < .05), whereas knockdown of SCARA5 had no effect. Conclusions Using weighted gene coexpression network analysis of cultured vein graft cell gene expression, we have discovered two small gene modules, which comprise 42 genes, that are associated with vein graft failure. Further experiments are needed to delineate the venous cells that express these genes in vivo and the roles these genes play in vein graft healing, starting with the module hub genes SCARA5 and SBSN , which have been shown to have modest effects on cell proliferation or collagen gel contraction. [ABSTRACT FROM AUTHOR]

Background: All humans have natural, protective antibodies directed against phosphorylcholine (PC) epitopes, a common inflammatory danger signal appearing at sites of cell injury, oxidative stress, and on bacterial capsules. In large human cohorts, low levels of anti-PC IgM were associated with a significantly increased risk of stroke or myocardial infarction. However, it is not known if these antibodies protect against the premature closure of arterial reconstructions. Methods: A prospective, observational study of patients undergoing elective, infrainguinal, autogenous vein bypasses for atherosclerotic occlusive disease of the legs was conducted. Clinical data were recorded prospectively, and preoperative levels of anti-PC IgM measured with the CVDefine kit from Athera Biotechnologies (Solna, Sweden). The principal clinical end point was the loss of primary patency (loss of graft flow, or any intervention for stenosis). Patients were followed regularly by duplex ultrasound at 1, 3, 6, 12, 18 months, and yearly thereafter. Results: Fifty-six patients were studied, for an average of 1.3 years. Indications for surgery were claudication (33.9%), ischemic rest pain (17.9%), and ischemia with ulceration or gangrene (48.2%). Seventeen (30.4%) patients experienced loss of primary patency (10 graft occlusions, seven surgical or endovascular revisions of graft stenoses). Kaplan-Meier survival analysis showed that the quartile of patients with the lowest anti-PC IgM levels had significantly worse primary graft patency (log-rank test, P = .0085). Uni- and multivariate Cox proportional hazards analysis revealed that the preoperative anti-PC IgM level was an important predictor of graft failure. Patients with IgM values in the lowest quartile had a 3.6-fold increased risk of graft failure (95% confidence interval: 1.1-12.1), even after accounting for other significant clinical or technical factors such as indication for surgery, site of distal anastomosis, or vein graft diameter. Conclusions: A naturally occurring IgM antibody directed against the proinflammatory epitope PC may be protective against vein graft stenosis and failure, through anti-inflammatory mechanisms. Measurement of this antibody may be a useful prognostic indicator, although larger studies of more diverse populations will be needed to confirm these results. The biological actions of anti-PC IgM suggest it may be useful in developing immunotherapies to improve bypass longevity. [Copyright &y& Elsevier]

Objective: High blood flow induces neointimal atrophy in polytetrafluoroethylene (PTFE) aortoiliac grafts and a tight external PTFE wrap of the iliac artery induces medial atrophy. In both nonhuman primate models, atrophy with loss of smooth muscle cells and extracellular matrix (ECM) begins at ≤4 days. We hypothesized that matrix loss would be linked to cell death, but the factors and mechanisms involved are not known. The purpose of this study was to determine commonly regulated genes in these two models, which we hypothesized would be a small set of genes that might be key regulators of vascular atrophy. Methods: DNA microarray analysis (Sentrix Human Ref 8; Illumina, San Diego, Calif; ∼23,000 genes) was performed on arterial tissue from the wrap model (n = 9) and graft neointima from the graft model (n = 5) 1 day after wrapping or the switch to high flow, respectively. Quantitative reverse-transcription polymerase chain reaction (qRT-PCR) was also performed. Expression of this vascular atrophy gene set was also studied after Fas ligand-induced cell death in cultured smooth muscle cells and organ cultured arteries. Results: Microarray analysis showed 15 genes were regulated in the same direction in both atrophy models: 9 upregulated and 6 downregulated. Seven of nine upregulated genes were confirmed by qRT-PCR in both models. Upregulated genes included the ECM-degrading enzymes ADAMTS4, tissue plasminogen activator (PLAT), and hyaluronidase 2; possible growth regulatory factors, including chromosome 8 open reading frame 4 and leucine-rich repeat family containing 8; a differentiation regulatory factor (musculoskeletal embryonic nuclear protein 1); a dead cell removal factor (ficolin 3); and a prostaglandin transporter (solute carrier organic anion transporter family member 2A1). Five downregulated genes were confirmed but only in one or the other model. Of the seven upregulated genes, ADAMTS4, PLAT, hyaluronidase 2, solute carrier organic anion transporter family member 2A1, leucine-rich repeat family containing 8, and chromosome 8 open reading frame 4 were also upregulated in vitro in cultured smooth muscle cells or cultured iliac artery by treatment with FasL, which causes cell death. However, blockade of caspase activity with Z-VAD inhibited FasL-mediated cell death, but not gene induction. Conclusion: Seven gene products were upregulated in two distinctly different in vivo nonhuman primate vascular atrophy models. Induction of cell death by FasL in vitro induced six of these genes, including the ECM-degrading factors ADAMTS4, hyaluronidase 2, and PLAT, suggesting a mechanism by which the program of tissue atrophy coordinately removes extracellular matrix as cells die. These genes may be key regulators of vascular atrophy. [Copyright &y& Elsevier]

Platelet-derived growth factor (PDGF) is a major stimulant for smooth muscle cell migration and proliferation, and blockade of PDGF receptors in vivo reduces intimal growth after arterial injury. Signalling by PDGF receptors has been extensively studied and involves multiple signal transduction pathways. These include ras/Extracellular Signal Regulated Kinase (ERK), a pathway critical for controlling cell cycle progression. We have recently discovered that release of fibroblast growth factor 2 and the subsequent activation of fibroblast growth factor receptor 1 are required for maximal induction by PDGF of ERK and of human smooth muscle cell proliferation. This review summarizes our latest findings and discusses the potential implications of this novel signaling mechanism for restenosis. [ABSTRACT FROM AUTHOR]

Thrombin is a mitogen and chemoattractant for vascular smooth muscle cells (SMCs) and may contribute to vascular lesion formation. We have previously shown that human SMCs, when stimulated with thrombin, release basic fibroblast growth factor (bFGF), causing phosphorylation of FGF receptor-1 (FGFR-1). Treatment with bFGF-neutralizing antibodies (anti-bFGF) or heparin inhibits thrombin-induced DNA synthesis. We concluded that thrombin may stimulate entry into the cell cycle via bFGF release and FGFR-1 activation. In the present study, we demonstrate a requirement for not only FGFR-1 but also syndecan-4, a transmembrane heparan-sulfate preteoglycan. Inhibition of syndecan4 expression using small interfering RNA (siRNA) resulted in reduced DNA synthesis by human SMCs after stimulation with thrombin (10 nmol/liter). Anti-bFGF antibody, which inhibits DNA synthesis in control cells, had no inhibitory effect when syndecan-4 expression was reduced by siRNA. Thrombinor bFGF-induced SMC migration, determined in Boyden chamber assays, was reduced in cells treated with syndecan-4 or FGFR-1 siRNA or by anti-bFGF. Thrombin induced phosphorylation of extracellular signal-regulated kinase (ERK) 1/2 in a biphasic pattern. Although thrombin-mediated ERK phosphorylation at 5 rain was not affected by syndecan-4 or FGFR-1 siRNA, ERK phosphorylation at later time points was reduced. We conclude that thrombin-released bFGF binds to syndecan-4 and FGFR-1, which is required for thrombin-induced mitogenesis and migration. [ABSTRACT FROM AUTHOR]