Patency Rate Of Vein Grafts Research Articles

Abstract 655: Protecting The Saphenous Vein Endothelium During Bypass Surgery

Coronary artery bypass graft surgeries commonly use saphenous vein grafts to revascularize diseased coronary arteries. Despite surgical and pharmacological advancements, graft failure rates remain high. Loss of endothelial cells (EC) during saphenous vein harvest and preservation likely contributes to the high incidence of graft failure. Standard methods of saphenous vein preparation and preservation during surgery include perfusion with heparinized saline solutions, a practice known to induce EC damage. As such, improved methods of saphenous vein storage may be the key to preserving EC and reducing graft failure rates. Here, we assessed the hypothesis that maintaining saphenous veins in autologous heparinized blood would preserve EC coverage and reduce cellular damage compared to standard of care, heparinized saline. To investigate this, saphenous vein tissues from 12 patients undergoing coronary artery bypass graft surgery were split into 2 treatment groups, 1) standard maintenance in heparin-saline (n=6) and 2) maintenance in heparin-blood (n=6). At the end of the surgeries, excess saphenous vein tissues were immediately fixed in 4% PFA to analyze endothelial coverage and DNA damage. In heparin-saline veins, histological analysis by H&E and Movat pentachrome staining revealed a broken or absent luminal layer and exposed lamina matrix, suggesting a loss of endothelial cell coverage. Luminal cell coverage was notably increased in heparin-blood samples. Immunofluorescent staining of endothelial markers VE-cadherin and endothelial nitric oxide identified a significant improvement in endothelial coverage in the heparin-blood group compared to heparin-saline. To determine the health of remaining endothelial cells, DNA damage was measured using terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) staining. Our data show that most of the endothelium (VE-cadherin positive) in heparin-saline tissues was TUNEL positive compared with heparin-blood. In conclusion, our data indicate that maintaining saphenous vein tissues in solutions containing autologous heparinized blood helps preserve the endothelium and maintains vein graft health which has the potential to improve vein graft patency rates in patients.

Administration of a new nano delivery system coated with Tirofiban to prevent early thrombosis of vein graft.

To verify the administration of a new nano delivery system coated with Tirofiban on preventing early thrombosis in vein graft. Forty New Zealand white rabbits were randomly divided into five groups with eight rabbits in each group. The rabbits of all groups underwent jugular vein transplantation, except group I with only neck opening and closing operation. Vein grafts of group II were preprocessed by intravenous injection of normal saline; group III were preprocessed by tirofiban alone; group IV were preprocessed by unloaded nanoparticles of PLGA-PEG; group V were preprocessed by PLGA-PEG coated with tirofiban. Coagulation and platelet function of peripheral and vein graft blood were detected at 1, 2, 4, 12h and 1, 3, 7, 10, 14 days after operation. Patency rate of vein graft and blood flow index were measured by vascular ultrasound at third, seventh, 10th, and 14th days after operation; two rabbits in each group were randomly sacrificed at the corresponding time of detection. Pathological differences of vein grafts were observed by HE stainin. The patency rate of vein grafts in group V was significantly higher than that in group II to IV. The platelet and platelet aggregation rate in group V were inhibited in vein graft blood significantly. The post-operative PT and APTT in vein graft blood in group V were increased obviously while the FBG, D-dimer and FDP were significantly inhibited. Except group I, the lumen loss rate of vein grafts in group V was significantly lower than that in other groups, and vein graft blood in group V had a significant lower expression of platelet P-selectin and GP IIb/IIIa receptor than that in other groups. This study proves that PEG-PLGA coated with tirofiban can effectively prevent early vein graft stenosis from thrombosis by inhibition of platelet function, coagulation function.

The No-Touch Saphenous Vein Harvesting Improves Graft Patency After Off-Pump Coronary Artery Bypass Surgery: A Propensity-Matched Analysis.

IntroductionThis single-center study of propensity-matched data was performed to assess the effect of the no-touch saphenous vein (NTSV) harvesting technique on early- and long-term outcomes of patients after off-pump coronary artery bypass grafting (OPCABG) in China.MethodsA retrospective analysis of 767 patients who underwent OPCABG in the Beijing Anzhen Hospital (June 2017 to October 2021) was performed, and their data entered the conventional saphenous vein (CSV) harvesting technique group or the NTSV group. In-hospital and follow-up outcomes were evaluated by adjusting baseline characteristics using propensity score matching (1:1). Clinical outcomes and postoperative angiographic results were compared.ResultsThe saphenous vein graft patency rates at postoperative three months and one year for the NTSV group vs. CSV group were 99.6% vs. 96.2% (P<0.001) and 97.3% vs. 93.1% (P<0.001), respectively. The two matched groups received a significantly different cumulative incidence function of saphenous vein graft occlusion for the longer follow-up period in Kaplan-Meier curves (χ2=4.330, log-rank P=0.037). No difference in early- and long-term mortality or major adverse cardiac and cerebrovascular events (MACCE) were observed between the groups. The rate of MACCE was not statistically significant different between the groups, but there was a tendency favoring the no-touch technique (9.8% CSV vs. 4.8% NTSV; P=0.067). More patients in the NTSV group developed postoperative leg wound exudation (5.4% vs. 1.2%; P=0.032) and skin numbness (22.2% vs. 8.9%; P=0.001) than in the CSV group.ConclusionThe NTSV is an excellent conduit to be used in OPCABG. There remains a need to reduce leg wound complications.

Evaluation of Long-Term Outcomes of Femoropopliteal Bypass Surgery in Patients With Chronic Limb-Threatening Ischemia in an Endovascular Era

To investigate the long-term outcomes of femoropopliteal bypass surgery in patients with chronic limb-threatening ischemia (CLTI) and TransAtlantic Inter-Society Consensus II (TASC II), type D (TASC D) femoropopliteal disease. A retrospective analysis was performed for all consecutive patients undergoing above-knee (AK) femoropopliteal bypass surgery at an academic vascular centre between January 2007 and March 2019. Patients with claudication (IC) and patients with CLTI were included. Patency rates and freedom from major adverse limb events (MALE) after 5 years were analysed. In total, 432 femoropopliteal grafts were performed. Indications for surgery were claudication and CLTI in 232 (53.7%) and 200 (46.3%) patients, respectively. Graft material was autologous vein in 186 patients (43.1%), polytetrafluoroethylene (PTFE) in 128 patients (29.6%), and heparin-bonded expanded polytetrafluoroethylene (HePTFE) in 118 patients (27.3%). At the 5-year follow-up, the primary patency rate was 58.1% and 58.3% in patients with CLTI and claudication, respectively. Secondary patency rates were 74.1% and 68.6%, respectively. Freedom from MALE was 64.5% and 61.9%, respectively. Analyses of graft material in the CLTI group showed that, at 5 years, autologous vein grafts had better long-term patency rates than PTFE and HePTFE grafts. At 5 years, the primary and secondary patency rate for autologous vein grafts were 63.2% (P= 0.324) and 83.2% (P = 0.020), respectively. Freedom from MALE was 72.0% with the use of autologous vein grafts, 47.9% using PTFE and, 52.9% using HePTFE, respectively (P= 0.021). Our study shows that femoropopliteal bypass surgery in patients with TASC D lesions is safe and effective in the long term. Autologous vein grafts remain the first choice for patients with CLTI, also for bypasses in AK position. However, prosthetic grafts in AK the position are an acceptable alternative for revascularisation when the saphenous vein is not available.

The expansion of no-touch harvesting sequential vein graft after off-pump coronary artery bypass grafting.

Background and Aim of the StudyMany studies support that the no‐touch (NT) procedure can improve the patency rate of vein grafts. However, it is not clear that the sequential vein graft early expansion in the NT technique during off‐pump coronary artery bypass grafting (CABG). This study will explore this issue.MethodsThis was a prospective single‐center randomized controlled clinical trial. A total of 100 patients undergoing off‐pump CABG with the sequential saphenous graft were randomly assigned to two groups: the NT and conventional (CON) groups. Perioperative and postoperative data were collected during the hospital stay. The mean diameter of sequential grafts was measured using cardiac computed tomography angiography 3 months after the operation.ResultsThere was a significant difference in the average diameter of sequential grafts between the two groups (NT: [2.98 ± 0.42], CON: [3.26 ± 0.51], p = .005). There was no difference in occlusion of sequential venous grafts between the two groups (NT: 4/48 [8.3%], CON: 5/49 [10.2%], p = 1.000). There were differences in surgery time between the two groups (NT: 220 [188,240], CON: 190 [175,230], p = .009).ConclusionsThe sequential graft early expansion in the NT technique is not as pronounced as that in the conventional technique, which may have a long‐term protective effect on the grafts.

Long-term outcomes of reconstructive procedures on coronary arteries for diffuse coronary atherosclerosis without endarterectomy

Objective. This study evaluated the long-term clinical and angiographic outcomes of coronary artery reconstruction for a diffusely diseased coronary artery without endarterectomy.Material and Methods. We retrospectively reviewed 660 consecutive patients (mostly men (89.5%), mean age 68.3 ± 7.4 years) who underwent coronary artery bypass grafting in combination with coronary artery reconstruction between 2003 and 2016. 558 operated on patients (84.5%) were followed up for a mean of 94.3 ± 31.2 months.Results. Long-term survival was 83.2% (95% confidence interval: 74.5–89.3); freedom from cardiac death was 97.4 ± 1.2%; and freedom from major adverse cardiac and cerebrovascular events was 64.7 ± 4.1%. Independent predictors of long-term mortality were age at surgery (&lt; 70 years, p &lt; 0.001), chronic obstructive pulmonary disease (p = 0.007), peripheral arterial disease (p = 0.002), diabetes mellitus (p = 0.013) and chronic kidney disease (p = 0.034). The arterial graft patency rate was 95.2%, and the vein graft patency rate was 75.4%.Conclusion. Coronary artery bypass grafting in conjunction with coronary artery reconstruction without endarterectomy confers satisfactory long-term clinical outcomes with high probability of freedom from cardiac death and angina pectoris, good rates of angiographic patency of arterial grafts and favorable rates of vein graft patency.

Effect of ticagrelor with or without aspirin on vein graft outcome 1 year after on-pump and off-pump coronary artery bypass grafting.

BackgroundIn the present post hoc analysis of the DACAB trial, we evaluated the effects of ticagrelor with or without aspirin on 1-year vein graft outcomes after coronary artery bypass grafting (CABG) with and without cardiopulmonary bypass (CPB) (on-pump and off-pump).MethodsThe DACAB trial was a multicenter, randomized, open-label, parallel control study enrolling 500 patients with 1,460 vein grafts undergoing CABG. For current post-hoc study, all patients in the DACAB study were included in the analysis to compare the effects of different antiplatelet regimens under on/off pump. Patients were randomly assigned to 1 of 3 antiplatelet treatment regimens (ticagrelor plus aspirin, T + A; ticagrelor alone, T; or aspirin alone, A) within 24 hours after CABG, and were stratified into on-pump and off-pump subgroups. The primary outcome was 1-year vein graft patency rate.ResultsTotally 121 patients underwent on-pump CABG (39 with 121 vein grafts in T + A, 36 with 101 vein grafts in T, and 46 with 137 vein grafts in A) and 379 patients underwent off-pump CABG (129 with 336 vein grafts in T + A, 130 with 387 vein grafts in T, and 120 with 348 vein grafts in A). Compared with A, T + A showed a higher 1-year vein graft patency rate in both on-pump (adjusted OR for non-patency =0.62, 95% CI: 0.16–2.45) and off-pump (adjusted OR for non-patency =0.35, 95% CI: 0.20–0.62) subgroups, P interaction =0.647; whereas T did not in either on-pump (adjusted OR for non-patency = 0.92, 95% CI: 0.31–2.76) or off-pump (adjusted OR for non-patency =0.58, 95% CI: 0.34–1.00) subgroups, P interaction =0.430.ConclusionsIn the DACAB trial, for patients underwent either on-pump or off-pump CABG, ticagrelor plus aspirin showed consistent benefit for achieving 1-year vein graft patency, with particular benefit being seen in the off-pump.

Direct angiography demonstrates equal 8–12 years patency rates of radial artery and saphenous vein grafts

Objectives: The benefits of coronary artery bypass surgery depend on lasting graft patency. To aid rational graft selection, the relative long-term merits of radial artery and saphenous vein grafts need to be determined by a gold standard method and with minimal clinically driven selection bias. Methods: The patency rates of various conduits were determined by direct angiography in 76 patients from a cohort of 119 undergoing coronary artery bypass grafting 7.6–12.1 (mean 8.9) years before. Results: 14 out of 76 radial artery and 10 out of 61 saphenous vein grafts were occluded (rates 0.18 and 0.16, respectively). Conclusion: The high long-term patency rate of saphenous vein grafts does not support a preferential use of the radial artery as a coronary artery bypass conduit. Clinical registration number: ISRCTN23118170

Surgical Preparation Reduces Hydrogen Sulfide Released from Human Saphenous Veins in Coronary Artery Bypass Grafting.

The long-term patency rate of saphenous vein (SV) grafts is poor compared to arterial grafts. To investigate the effects of surgical preparation (distention) of SV on hydrogen sulfide (H2S) released from the endothelium, human SV segments were harvested from 43 patients during coronary artery bypass surgery (CABG). Acetylcholine (ACh) induced relaxation that was inhibited by NG-nitro-L-arginine + indomethacin and cysteine aminotransferase inhibitor aminooxyacetic acid in the normal SV. In contrast, ACh did not evoke relaxation in the distended SV (DSV). The concentration of H2S quantified by methylene blue assay in DSV was significantly lower than that in control. Transmission electron microscope and immunohistochemistry studies showed that the preparation destroyed the endothelium, smooth muscle, organelle, and vasa vasorum. We conclude that surgical preparation injures the endothelium and smooth muscle of the SV grafts and reduces H2S release from SV. These effects may contribute to the poor long-term patency of the SV graft.

2223Effect of ticagrelor plus aspirin, ticagrelor alone, or aspirin alone on vein-graft patency 1 year after coronary artery bypass grafting with or without diabetes: a post-hoc analysis of the DACAB tria

Abstract Introduction The association of diabetes and vein graft patency after coronary artery bypass grafting (CABG) remains controversial. In patients with diabetes, impaired endothelial function in vein grafts and high platelet turnover might result in early vein graft failure. The DACAB trial showed ticagrelor plus aspirin significantly increased 1-year vein graft patency vs. aspirin alone, while no significant difference between ticagrelor alone and aspirin alone. However, whether the results is different between the patients with or without diabetes is unknown. Purpose To assess the effects of ticagrelor with or without aspirin vs. aspirin alone on 1-year vein grafts patency after CABG in patients with or without diabetes. Methods We examined the subgroups of patients with and without diabetes from DACAB trial (NCT02201771), in which 500 patients were randomized to 1 of 3 antiplatelet regimens (ticagrelor 90mg twice daily plus aspirin 100mg once daily, T+A group; ticagrelor 90mg twice daily, T group; or aspirin 100mg once daily, A group) within 24 hours post-CABG. The primary outcome was 1-year vein graft patency (FitzGibbon grade A) assessed by multi-slice computed tomographic angiography or coronary angiography. Results According to the baseline medical history and/or glycated hemoglobin (HbA1c) ≥6.5%, 283 patients with 818 vein grafts were allocated to the non-diabetes subgroup, remaining 217 patients with 642 vein grafts to the diabetes subgroup. By per-graft analysis, no significant difference on 1-year vein graft patency rate was observed between non-diabetes and diabetes subgroup (84.6% [692/881] for non-diabetes vs. 80.2% [515/642] for diabetes, adjusted odds ratio (OR) =1.39, 95% CI: 0.92–2.09, P=0.116). In T+A group, 1-year vein graft patency rates were 91.0% (244/268) for non-diabetes vs. 85.8% (188/219) for diabetes; In T group, 85.0% (221/260) for non-diabetes vs. 80.3% (183/228) for diabetes; In A group, 78.3% (227/290) for non-diabetes vs. 73.9% (144/195) for diabetes. Ticagrelor plus aspirin showed higher vein graft patency rate than aspirin alone in both non-diabetes and diabetes subgroup (non-diabetes: adjusted OR = 0.34, 95% CI: 0.17–0.69, and diabetes: adjusted OR = 0.42, 95% CI: 0.19–0.91, P for interaction = 0.524), whereas ticagrelor alone did not show improvement on vein graft patency compared with aspirin alone in both subgroups (non-diabetes: adjusted OR=0.62, 95% CI: 0.32–1.20, and diabetes: adjusted OR = 0.65, 95% CI: 0.33–1.31, P for interaction = 0.795). Similar results were showed by per-patient analysis. A total 16 major adverse cardiovascular events occurred, 8 (2.8%) for non-diabetes and 8 (3.7%) for diabetes. Conclusion In the DACAB trial, diabetes was not found to be associated with decreased vein graft patency at 1 year after CABG. The effect of ticagrelor plus aspirin on improvement of 1-year vein graft patency, when compared with aspirin alone, is consistent in patients with or without diabetes. Acknowledgement/Funding AstraZeneca

Mid-Term Clinical Outcome of Patients Undergoing Coronary Artery Bypass Grafting with Valvulotomized Vein Grafts.

The lower patency rate of vein grafts (VG) in comparison to arterial grafts may be related to vein valves, which favor turbulences and thrombosis that lead to graft failure. The aim of this study was to determine the outcome of patients with valvulotomized VG after coronary artery bypass grafting (CABG) procedure. From 2007 to 2014, 233 patients with a mean age of 67 ± 9 years had CABG or combined CABG and valve procedures. Valvulotomized saphenous VG and arterial grafts were used. Clinical follow-up and outcome were evaluated after 6.3 ± 2 years. The graft patency was rated with multislice computed tomography in 57 patients and coronary angiography in 29 patients 3.1 ± 2 years postoperatively. Overall, 168 patients had segregated CABG surgery, and 65 patients received additional procedures, with mean 2.7 ± 1 arterial and 1.5 ± 0.7 venous anastomoses. The 30-day-mortality in isolated CABG patients was 2%. Survival at five years was 80%. Major adverse cardiac and cerebrovascular events (MACCE) free rate at five years was 80%. At the last follow up (mean 6.3 years), 94% of the patients were in Canadian Cardiovascular Society (CCS) class 0. The quote of patent valvulotomized VG was 96.1% compared to a patency rate of 96.7% for the arterial grafts in the subgroup undergoing angiography or computed tomography of the heart. Our data demonstrate good mid-term results of graft patency, and comparable clinical results in patients undergoing CABG with valvulotomized VG. A longer follow-up period and a higher number of bypass graft imaging examinations are necessary to affirm our results.

Effect of Ticagrelor Plus Aspirin, Ticagrelor Alone, or Aspirin Alone on Saphenous Vein Graft Patency 1 Year After Coronary Artery Bypass Grafting

The effect of ticagrelor with or without aspirin on saphenous vein graft patency in patients undergoing coronary artery bypass grafting (CABG) is unknown. To compare the effect of ticagrelor + aspirin or ticagrelor alone vs aspirin alone on saphenous vein graft patency 1 year after CABG. Randomized, multicenter, open-label, clinical trial among 6 tertiary hospitals in China. Eligible patients were aged 18 to 80 years with indications for elective CABG. Patients requiring urgent revascularization, concomitant cardiac surgery, dual antiplatelet or vitamin K antagonist therapy post-CABG, and who were at risk of serious bleeding were excluded. From July 2014 until November 2015, 1256 patients were identified and 500 were enrolled. Follow-up was completed in January 2017. Patients were randomized (1:1:1) to start ticagrelor (90 mg twice daily) + aspirin (100 mg once daily) (n = 168), ticagrelor (90 mg twice daily) (n = 166), or aspirin (100 mg once daily) (n = 166) within 24 hours post-CABG. Neither patients nor treating physicians were blinded to allocation. Primary outcome was saphenous vein graft patency 1 year after CABG (FitzGibbon grade A) adjudicated independently by a committee blinded to allocation. Saphenous vein graft patency was assessed by multislice computed tomographic angiography or coronary angiography. Among 500 randomized patients (mean age, 63.6 years; women, 91 [18.2%]), 461 (92.2%) completed the trial. Saphenous vein graft patency rates 1 year post-CABG were 88.7% (432 of 487 vein grafts) with ticagrelor + aspirin; 82.8% (404 of 488 vein grafts) with ticagrelor alone; and 76.5% (371 of 485 vein grafts) with aspirin alone. The difference between ticagrelor + aspirin vs aspirin alone was statistically significant (12.2% [95% CI, 5.2% to 19.2%]; P < .001), whereas the difference between ticagrelor alone vs aspirin alone was not statistically significant (6.3% [95% CI, -1.1% to 13.7%]; P = .10). Five major bleeding episodes occurred during 1 year of follow-up (3 with ticagrelor + aspirin; 2 with ticagrelor alone). Among patients undergoing elective CABG with saphenous vein grafting, ticagrelor + aspirin significantly increased graft patency after 1 year vs aspirin alone; there was no significant difference between ticagrelor alone and aspirin alone. Further research with more patients is needed to assess comparative bleeding risks. clinicaltrials.gov Identifier: NCT02201771.

The development and mechanical characterisation of a novel reinforced venous conduit that mimics the mechanical properties of an arterial wall

Venous grafts have been used to bypass stenotic arteries for many decades. However, this “gold standard” treatment is far from optimal, with long-term vein graft patency rates reported to be as low as 50% at >15 years. These results could be a result of the structural and functional differences of veins compared to arteries. In this study we developed a new protocol for manufacturing reinforced fresh veins with a decellularized porcine arterial scaffold. This novel method was designed to be replicated easily in a surgical setting, and manufactured reinforced constructs were robust and easier to handle than the veins alone. Furthermore, we demonstrate that these Reinforced Venous-Arterial Conduits have comparable mechanical properties to native arteries, in terms of ultimate tensile strength (UTS) (2.36 vs. 2.24MPa) and collagen dominant phase (11.04 vs. 12.26MPa). Therefore, the Reinforced Venous-Arterial Conduit combines the benefits of using the current gold standard homogenous venous grafts composed of a confluent endothelial surface, with an “off-the-shelf” decellularized artery to improve the mechanical properties to closely mimic those of native arteries, while maintaining the self-repairing characteristics of native tissue. In conclusion in this study we have produced a construct and a new technique that combines the mechanical properties of both a natural vein and a decellularized artery to produce a reinforced venous graft that closely mimics the mechanical response of an arterial segment.

Single-Centre Experience of Off-Pump Multi-Vessel Coronary Artery Bypass Grafting Using Proximal Suture Device

To investigate the results of off-pump coronary artery grafting (OPCAB) with the proximal suture device (PSD) regarding postoperative stroke and graft patency. The PSD was used in 376 patients (32.0%), aorta-no-touch OPCAB was performed in 523 patients (45.2%), on-pump beating coronary artery bypass surgery (CABG) (on-beat group) in 125 patients (10.6%) including 51 conversions (conversion rate: 5.4%), and CABG with aortic clamp use (clamp group) in 152 patients. In the PSD group, Enclose II was used in 267 patients (71.0%). The hospital mortality rate was 1.95%. There was no early stroke in the OPCAB group, whereas the early-stroke rate was 0.8% in the on-beat group and 2.6% in the clamp group. The incidences of stroke at one month were: PSD group, 1.6%; no-touch group, 1.1%; on-beat group, 1.6%; and clamp group, 4.6% (p=0.014). The rates of complete revascularisation were higher in the PSD and clamp groups (94.7 and 94.0%, respectively) compared with the no-touch and on-beat groups (81.5 and 84.9%, respectively; p<0.001). The vein graft patency rates were comparable between the PSD and clamp groups. In multiple logistic regression analysis, OPCAB using the PSD did not increase the risk of stroke compared with the no-touch group (adjusted odds ratio [AOR]: 1.40; p=0.594) or on-beat group (AOR: 0.99; p=0.206), but reduced the risk of stroke compared with the clamp group (AOR: 0.19; p=0.005). Off-pump coronary artery grafting using the PSD was a safe and effective procedure. It led to lower incidences of postoperative stroke and excellent rates of graft patency and complete revascularisation compared with conventional CABG.

Abstract 15140: VEGFR2 Blockade in Murine Vein Grafts Reduces Intraplaque Hemorrhage due to Enhanced Plaque Neovessel Maturation

Introduction: Vein graft patency rates are poor due to the development of extensive neointimal thickening, atherosclerosis and lesion instability. We have previously shown that murine vein graft lesions exhibit leaky neovessels and that intraplaque hemorrhage induces lesion growth. Immature plaque neovessels contribute to atherosclerotic plaque instability by leakage of erythrocytes and leukocytes (intraplaque haemorrhage) in the plaque. Vascular Endothelial Growth Factor Receptor 2 (VEGFR2), together with the angiopoietin (Ang)-Tie2 system, regulates the maturation of neovessels. Hypothesis: VEGFR2 blockade induces plaque neovessel maturation resulting in reduced intraplaque hemorrhage and plaque instability. Methods: Donor caval veins were engrafted in carotid arteries of recipient hypercholesterolemic ApoE3*Leiden mice (n=14/group). Mice were treated at day 14, 17, 21 and 25 with VEGFR2 blocking antibodies (DC101) or control IgG antibodies. At day 28 vein grafts were harvested for histological and RNA analysis. Results: Morphometric analysis revealed a striking 50% decrease in vein graft segments that expressed intraplaque hemorrhage in the DC101 treated group. This was accompanied by a significant 25-fold decrease in extravasated erythrocytes. DC101 treatment resulted in a decrease in VEGF expression whereas VEGFR1 and VEGFR2 expression was comparable between the two groups. Connexin 37 and 43 expression was also comparable between the groups, indicating that gap junctions were not affected upon DC101 treatment. However, lesions that exhibit intraplaque hemorrhage showed a strong increase in destabilizing Ang-2. The vein graft lesion area was significantly reduced in the DC101 group, which was accompanied by an increased plaque stability phenotype as a result of a significant reduction in macrophage content and increases in smooth muscle cells and collagen content. Conclusions: Blockade of VEGFR2 leads to reduced intraplaque hemorrhage, decreased vein graft lesion area and increased plaque stability as a result of increased neovessel maturation. This identifies plaque neovascularization as an attractive target for the treatment of unstable atherosclerotic diseases.

The no-touch vein graft harvesting technique for coronary artery bypass grafting surgery reduces mortality: a long-term follow-up study

Background The saphenous vein is still the most widely used conduit in CABG surgery despite its poor long term patency. In the 1990’s a new No-touch technique for saphenous vein graft harvesting for CABG was introduced where the vein graft is harvested with a pedicle of surrounding tissue. With the No-touch technique the vein graft does not go into spasm and the vessel wall does not have to be exposed to distension-induced trauma. A previous randomized trial has shown a significantly higher patency rate for vein grafts harvested with the No-touch technique compared to vein grafts harvested with conventional technique and the patency for No-touch vein grafts was comparable to the patency of the left internal thoracic artery, 8.5 years after surgery. The aim of this study was to evaluate whether the increased patency rate for No-touch vein grafts is reflected in clinical outcome.

A Systematic Review of the Outcomes of Distal Upper Extremity Bypass Surgery With Arterial and Venous Conduits

To conduct a systematic review of literature evaluating efficacy of venous and arterial grafts for distal upper extremity bypass surgery. A PubMed search using MeSH terms "veins/surgery" OR "arteries/surgery" AND "radial artery/surgery" OR "ulnar artery/surgery" yielded 794 studies. Manual review produced 42 studies based on inclusion criteria of reported distal upper extremity bypass surgery, complete information on graft type used, examined patency of reconstruction, and described method for determining patency. Studies meeting inclusion criteria underwent data extraction focusing on demographics, revascularization site, conduit type, microsurgical technique, subjective/objective outcomes, and postoperative anticoagulation regimens. Sixteen studies met the inclusion criteria. In 145 patients, 152 grafts were performed for upper extremity revascularization, including 120 grafts for revascularization of distal ulnar artery circulation, 31 for distal radial artery circulation, and 1 for both distal ulnar and radial artery occlusions. Overall patency rate was 87% at an average follow-up of 34 months. Of 152 bypass grafts, 19 were arterial conduits. Donor sites included the deep inferior epigastric artery, subscapular artery, thoracodorsal artery, and descending branch of the lateral femoral circumflex artery. At a mean follow-up of 18 months, arterial conduit patency was 100%. The remaining 133 bypass procedures used vein grafts from various donor sites, including the saphenous, cephalic, and basilic veins. At an average follow-up of 37 months, overall vein graft patency rate was 85%. There was a statistically significant difference between patency rates of arterial conduits compared with venous conduits. All studies reported improved ischemic symptoms including reduction of cold sensitivity, pain, and digital ulceration. This review showed a high patency rate and clinical efficacy of distal upper extremity bypass surgery with a mean follow-up of almost 3 years. There may be a benefit of using arterial versus venous conduits, although further examination is needed given the small number of arterial reconstructions reported.

Histopathology of the Longest-Lived Saphenous Vein Graft in a Patient With Kawasaki Disease

The patency rate of saphenous vein grafts (SVGs) for children with Kawasaki disease (KD) tends to decline during the early years after coronary artery bypass grafting (CABG). Although degenerative changes have been considered the main cause of SVG occlusion, there have been no reports on the histopathologic features of the SVG in patients with KD. We herein describe a redo off-pump total arterial revascularization in a 43-year-old man with KD, 34 years after the first CABG using SVG. The histopathologic examination of the longest-lived SVG demonstrated that graft occlusion was mainly caused by the diffuse intimal hyperplasia.

Comments regarding ‘Infrainguinal Bypass for Peripheral Arterial Occlusive Disease: When Arms Save Legs’

Despite advances in endovascular management of critical limb ischaemia (CLI) there remains a cohort of patients which will ultimately require a bypass for limb salvage. Great long saphenous (GSV) remains the conduit of choice for infrainguinal revascularisation.1e3 However it may not always be available owing to previous surgery or may not be suitable owing to a small calibre, phlebitis or the presence of varicosities. Concerns have previously been raised about the long term patency of prosthetic grafts to infrapopliteal vessels4 and the associated risk of graft infection. A number of studies have reported arm vein graft patency rates and leg salvage rates at 3 years ranging between 40%e73% and 62%e92% respectively. The 3 year primary patency rate in this study of 47% compares favourably with other reported series in the literature.5,6 The primary assisted patency rates of 96%, 96% and 82% at 1, 2 and 3 years respectively and the secondary patency rates of 92%, 88% and 88% at 1, 2 and 3 years are superior to previous reports. The authors report a limb salvage rate of 88% at 3 years. In all patients the authors chose arm veins as the most suitable conduit even if the GSVwas available. In this analysis vein diameter was shown to be an important factor in assisted primary patency rates but did not exert a statistically significant effect on secondary patency rates. The authors had an aggressive approach to graft surveillance and subsequent intervention commencing in the operating room at the time of the primary procedure. Sixteen (28.5%) patients required an intervention for >70% graft stenosis. Again this compares favourably with Arvela et al. who report a 27% graft intervention rate while a higher rate of 48% has been reported by Armstrong et al.5,6 The preferred choice of intervention varies between open patch angioplasty and balloon angioplasty taking

Paradigm Shift to Functional Angioplasty

Inducible myocardial ischemia during functional testing has crucial prognostic significance in determining whether or not to treat coronary artery stenosis.1–3 In real-world practice, however, fewer than half of all patients are evaluated noninvasively for myocardial ischemia before revascularization therapy.4 Thus, coronary angiograms are still frequently used as a cornerstone of decision making, despite the substantial discrepancy between the angiographic and functional severity of stenosis. Therefore, adjuvant technologies such as fractional flow reserve (FFR) and intravascular ultrasound (IVUS) are considered in daily practice to overcome the limitations of coronary angiography for diagnostic and interventional procedures. The present review evaluates the roles of FFR and IVUS in coronary stenosis and their incorporation into practice in contemporary catheterization laboratories. In contrast to the benefits of percutaneous coronary intervention (PCI) in patients with unstable angina and myocardial infarction, the benefits of PCI in patients with stable angina are less clear.5,6 Nevertheless, recent advances in drug-eluting stents (DES) and adjuvant pharmacological agents may reduce the thresholds for revascularization therapy in the absence of firm evidence of objective ischemia. Thus, consideration is sometimes given to treating stenoses of intermediate degree without consideration of their functional significance.7 In addition, although most surgical recommendations for patients with multivessel coronary artery disease are to bypass all lesions with diameter stenosis of >50% for complete revascularization, the patency rate of vein grafts on vessels with functionally insignificant proximal stenosis has been in question.8 Because revascularization treatment based on ischemia may improve patient outcomes, guidelines have recommended noninvasive functional evaluation before revascularization treatment.3,9 Despite these recommendations, however, noninvasive functional evaluations before revascularization are underutilized in real-world practice. Twenty years ago, Topol et al10 reported that of a total of 2101 patients who underwent coronary angioplasty, only 29% had …