OBJECTIVE
Neointimal hyperplasia secondary to vascular smooth muscle cell (VSMC) activation limits the long-term patency of saphenous vein grafts (SVGs). We compared markers of vascular injury and ...VSMC activation in SVGs harvested using the pedicled 'no-touch' (NT) vs the conventional (CON) technique.
METHODS
Patients undergoing coronary artery bypass surgery were enrolled in the PATENT SVG trial (clinicaltrials.gov NCT01488084). Patients were randomly allocated to have SVGs harvested with the NT technique from one leg and the CON method from the other. SVG segments underwent morphometry, histological and electron microscopy assessments and transcript measurements of VSMC activation and differentiation markers. Leg wound functional recovery and harvest site complications were assessed using a quality-of-life questionnaire.
RESULTS
A total of 17 patients (65.3 ± 7.3 years) were enrolled. SVGs harvested using the NT vs CON technique exhibited preserved intimal, medial and adventitial architecture. CON harvest was associated with greater medial Kruppel-like factor 4 transcript levels (0.26 ± 0.05 vs 0.11 ± 0.02, P < 0.05). CON samples had significantly lower medial serum response factor (0.53 ± 0.11 vs 1.44 ± 0.50, P < 0.05) and myocardin (0.59 ± 0.08 vs 1.33 ± 0.33, P < 0.05) transcript levels. MicroRNA-145, an inhibitor of VSMC activation and differentiation, was higher in the NT vs CON samples (1.84 ± 1.03 vs 0.50 ± 0.19, P < 0.05). Leg assessment scores were worse in the NT legs at 3 months, but similar to CON scores at 12 months.
CONCLUSIONS
SVGs harvested using the 'NT' technique exhibit an early molecular and morphological pattern consistent with decreased VSMC activation compared with CON harvesting. Functional leg recovery was similar in both groups at 12 months. Larger studies are required to corroborate these findings.
Single centre studies support No Touch (NT) saphenous vein graft (SVG) harvesting technique. The primary objective of the SUPERIOR SVG study was to determine whether NT versus conventional (CON) SVG ...harvesting was associated with improved SVG patency 1 year after coronary artery bypass grafting surgery (CABG).
Adults undergoing isolated CABG with at least 1 SVG were eligible. CT angiography was performed 1-year post CABG. Leg adverse events were assessed with a questionnaire. A systematic review was performed for published NT graft patency studies and results aggregated including the SUPERIOR study results.
Two hundred and-fifty patients were randomized across 12-centres (NT 127 versus CON 123 patients). The primary outcome (study SVG occlusion or cardiovascular (CV) death) was not significantly different in NT versus CON (NT: 7/127 (5.5%), CON 13/123 (10.6%), p = 0.15). Similarly, the proportion of study SVGs with significant stenosis or total occlusion was not significantly different between groups (NT: 8/102 (7.8%), CON: 16/107 (15.0%), p = 0.11). Vein harvest site infection was more common in the NT patients 1 month postoperatively (23.3% vs 9.5%, p < 0.01). Including this study's results, in a meta-analysis, NT was associated with a significant reduction in SVG occlusion, Odds Ratio 0.49, 95% Confidence Interval 0.29-0.82, p = 0.007 in 3 randomized and 1 observational study at 1 year postoperatively.
The NT technique was not associated with improved patency of SVGs at 1-year following CABG while early vein harvest infection was increased. The aggregated data is supportive of an important reduction of SVG occlusion at 1 year with NT harvesting.
NCT01047449 .
The purpose of this study was to present radial and saphenous vein graft (SVG) occlusion results more than 5 years following coronary artery bypass surgery.
In the RAPS (Radial Artery Patency Study) ...study, complete graft occlusion was less frequent in radial artery compared with SVG 1 year post-operatively while functional occlusion (Thrombolysis In Myocardial Infarction flow grade 0, 1, 2) was similar.
A total of 510 patients <80 years of age undergoing primary isolated nonemergent coronary artery bypass grafting with 3-vessel disease were initially enrolled in 9 Canadian centers. Target vessels for the radial artery and study SVG were the right and circumflex coronary arteries, which had >70% proximal stenosis. Within-patient randomization was performed; the radial artery was randomized to either the right or circumflex territory and the study SVG was used for the other territory. The primary endpoint was functional graft occlusion by invasive angiography at least 5 years following surgery. Complete graft occlusion by invasive angiography or computed tomography angiography was a secondary endpoint.
A total of 269 patients underwent late angiography (234 invasive angiography, 35 computed tomography angiography) at a mean of 7.7 ± 1.5 years after surgery. The frequency of functional graft occlusion was lower in radial arteries compared with SVGs (28 of 234 12.0% vs. 46 of 234 19.7%; p = 0.03 by McNemar's test). The frequency of complete graft occlusion was also significantly lower in radial compared with SVGs (24 of 269 8.9% vs. 50 of 269 18.6%; p = 0.002).
Radial arteries are associated with reduced rates of functional and complete graft occlusion compared with SVGs more than 5 years following surgery. (Multicentre Radial Artery Patency Study: 5 Year Results; NCT00187356).
Background
The term Anterior Accessory of the Great Saphenous Vein suggest this is a branch tributary vein despite this vessel’s anatomic features of a truncal vein. A multisocietal group suggested ...to designate this the Anterior Saphenous Vein (ASV). This study was aimed to evaluate its ultrasound anatomy in normal and varicose limbs.
Methods
The clinical anatomy of the ASV was evaluated by narrative review of the literature. Additionally, the course of the ASV was evaluated in 62 limbs with no evidence of venous disease and 62 limbs with varicosities.
Results
The ASV length, patterns of origin and termination are reported in both normal and patients with varicose veins. Discussion of the patterns is supported by the narrative review of the literature.
Conclusions
The ASV must be considered a truncal vein and its treatment modalities should be the same that for the great and small saphenous veins rather than a tributary vein.
The long saphenous vein (LSV) is commonly used as a conduit in coronary artery bypass grafting. However, long term patency remains limited by the development of vascular inflammation, intimal ...hyperplasia and accelerated atherosclerosis. The impact of acute exposure of venous endothelial cells (ECs) to acute arterial wall shear stress (WSS) in the arterial circulation, and the subsequent activation of inflammatory pathways, remain poorly defined. Here, we tested the hypothesis that acute exposure of venous ECs to high shear stress is associated with inflammatory responses that are regulated by NF-κB both in-vitro and ex-vivo. Analysis of the LSV endothelium revealed that activation of NF-κB occurred within 30 min after exposure to arterial rates of shear stress. Activation of NF-κB was associated with increased levels of CCL2 production and enhanced binding of monocytes in LSVECs exposed to 6 h acute arterial WSS. Consistent with this, ex vivo exposure of LSVs to acute arterial WSS promoted monocyte interactions with the vessel lumen. Inhibition of the NF-κB pathway prevented acute arterial WSS-induced CCL2 production and reduced monocyte adhesion, both in vitro and in human LSV ex vivo, demonstrating that this pathway is necessary for the induction of the acute arterial WSS-induced pro-inflammatory response. We have identified NF-κB as a critical regulator of acute endothelial inflammation in saphenous vein in response to acute arterial WSS. Localised endothelial-specific inhibition of the NF-κB pathway may be beneficial to prevent vein graft inflammation and consequent failure.
Abstract Background Low and oscillatory wall shear stress promotes endothelial dysfunction and vascular disease. The aim of the study was to investigate the impact of an external stent on hemodynamic ...flow parameters in saphenous vein grafts (SVGs) and their correlation with the development of intimal hyperplasia. Methods We performed post hoc computational fluid dynamics analysis of the randomized Venous External Support Trial, in which angiography and intravascular ultrasound data were available for 29 patients, 1 year after coronary artery bypass grafting. Each patient received 1 external stent, to either the right or left coronary territories; ≥1 patients with nonstented SVGs served as control(s). Diffuse flow patterns were assessed using mean values of various hemodynamic parameters, including time-averaged wall shear stress and oscillatory shear index (OSI). Focal flow disturbances were characterized using percentile analysis of each parameter. Results Angiography and intravascular ultrasound data were available for 53 and 43 SVGs, respectively. The stented versus nonstented SVG failure rates were significantly lower in the left territory (17.6% vs 27.5%; P = .02), and significantly higher in the right territory (46.2% vs 13.4%; P = .01). In both diffuse and focal flow-pattern analyses, OSI was significantly lower in the stented versus nonstented SVG group ( P = .009 and P < .003, respectively), whereas no significant differences were observed in time-averaged wall shear stress values. High OSI values were correlated with the development of intimal hyperplasia ( P = .01). Conclusions External stenting affects SVG's hemodynamics 1 year after coronary artery bypass grafting and may mitigate the progression of intimal hyperplasia by reducing oscillatory shear stress.
Summary Background Comparative assessment of clinical outcomes after use of drug-eluting stents versus bare-metal stents for treatment of aortocoronary saphenous vein graft lesions has not been ...undertaken in large randomised trials. We aimed to undertake a comparison in a randomised trial powered for clinical endpoints. Methods In this randomised superiority trial, patients with de-novo saphenous vein graft lesions were assigned by computer-generated sequence (1:1:1:3) to receive either drug-eluting stents (one of three types: permanent-polymer paclitaxel-eluting stents, permanent-polymer sirolimus-eluting stents, or biodegradable-polymer sirolimus-eluting stents) or bare-metal stents. Randomisation took place immediately after crossing of the lesion with a guidewire, and was stratified for each participating centre. Investigators assessing data were masked to treatment allocation; patients were not masked to allocation. The primary endpoint was the combined incidence of death, myocardial infarction, and target lesion revascularisation at 1 year. Analysis was by intention to treat. This trial is registered at ClinicalTrials.gov , number NCT00611910. Findings 610 patients were allocated to treatment groups (303 drug-eluting stent, 307 bare-metal stent). Drug-eluting stents reduced the incidence of the primary endpoint compared with bare-metal stents (44 15% vs 66 22% patients; hazard ratio HR 0·64, 95% CI 0·44–0·94; p=0·02). Target lesion revascularisation rate was reduced by drug-eluting stents (19 7% vs 37 13% patients; HR 0·49, 95% CI 0·28–0·86; p=0·01). No significant differences were seen between drug-eluting stents and bare-metal stents regarding all-cause mortality (15 5% vs 14 5% patients; HR 1·08, 95% CI 0·52–2·24; p=0·83), myocardial infarction (12 4% vs 18 6%; HR 0·66, 95% CI 0·32–1·37; p=0·27), or definite or probable stent thrombosis (2 1% in both groups; HR 1·00, 95% CI 0·14–7·10; p=0·99). Interpretation In patients undergoing percutaneous coronary intervention for de-novo saphenous vein graft lesions, drug-eluting stents are the preferred treatment option because they reduce the risk of adverse events compared with bare-metal stents. Funding Deutsches Herzzentrum.
Introduction The efficacy of coronary artery bypass graft (CABG) surgery for patients with ischemic heart disease is dependent on the patency of the selected conduit. The left internal thoracic ...artery is considered to be the best conduit for CABG. However, the preferred conduit between the radial artery (RA) and saphenous vein (SV) remains controversial. The present meta-analysis aims to establish the current level IA evidence on patency outcomes comparing the RA and SV. Methods Electronic searches were performed using 6 databases from their inception to March 2012. Two reviewers independently identified all relevant randomized controlled trials (RCTs) comparing patency outcomes of RA and SV grafts after CABG. Data were extracted and meta-analyzed according to angiographic end points at specified follow-up intervals. Results Five relevant RCTs were identified for inclusion in the present meta-analysis. Angiographic results indicated that the RA was significantly more likely to be completely patent and less likely to be associated with graft failure or complete occlusion at 4 years' follow-up and beyond. However, the RA was significantly more likely to be associated with string sign at 1 year of follow-up. Conclusions While acknowledging the limitations of heterogeneous surgical techniques, results from the present meta-analysis suggest potential superiority of the RA compared with the SV at midterm angiographic follow-up. However, the increased incidence of string sign associated with the RA is of potential clinical concern. Further research should be directed at correlating angiographic findings of string sign and graft failure to clinical symptoms and major adverse cardiac and cerebrovascular events at long-term follow-up.
clopidogrel inhibits intimal hyperplasia in animal studies and therefore may reduce saphenous vein graft (SVG) intimal hyperplasia after coronary artery bypass grafting. The Clopidogrel After Surgery ...for Coronary Artery DiseasE (CASCADE) study was undertaken to evaluate whether the addition of clopidogrel to aspirin inhibits SVG disease after coronary artery bypass grafting, as assessed at 1 year by intravascular ultrasound.
in this double-blind phase II trial, 113 patients undergoing coronary artery bypass grafting with SVGs were randomized to receive aspirin 162 mg plus clopidogrel 75 mg daily or aspirin 162 mg plus placebo daily for 1 year. The primary outcome was SVG intimal hyperplasia (mean intimal area) as determined by intravascular ultrasound at 1 year. Secondary outcomes were graft patency, major adverse cardiovascular events, and major bleeding. One-year intravascular ultrasound and coronary angiography were performed in 92 patients (81.4%). At 1 year, SVG intimal area did not differ significantly between the 2 groups (4.1 ± 2.0 versus 4.5 ± 2.1 mm(2), aspirin-clopidogrel versus aspirin-placebo, P=0.44). Overall 1-year graft patency was 95.2% in the aspirin-clopidogrel group compared with 95.5% in the aspirin-placebo group (P=0.90), and SVG patency was 94.3% in the aspirin-clopidogrel group versus 93.2% in the aspirin-placebo group (P=0.69). Freedom from major adverse cardiovascular events at 1 year was 92.9 ± 3.4% in the aspirin-clopidogrel group and 91.1 ± 3.8% in the aspirin-placebo group (P=0.76). The incidence of major bleeding at 1 year was similar for the 2 groups (1.8% versus 0%, aspirin-clopidogrel versus aspirin-placebo, P=0.50).
compared with aspirin monotherapy, the combination of aspirin plus clopidogrel did not significantly reduce the process of SVG intimal hyperplasia 1 year after coronary artery bypass grafting.
Great saphenous vein (GSV) incompetence, causing varicose veins and venous insufficiency, makes up the majority of lower-limb superficial venous diseases. Treatment options for GSV incompetence ...include surgery (also known as high ligation and stripping), laser and radiofrequency ablation, and ultrasound-guided foam sclerotherapy. Newer treatments include cyanoacrylate glue, mechanochemical ablation, and endovenous steam ablation. These techniques avoid the need for a general anaesthetic, and may result in fewer complications and improved quality of life (QoL). These treatments should be compared to inform decisions on treatment for varicosities in the GSV. This is an update of a Cochrane Review first published in 2011.
To assess the effects of endovenous laser ablation (EVLA), radiofrequency ablation (RFA), endovenous steam ablation (EVSA), ultrasound-guided foam sclerotherapy (UGFS), cyanoacrylate glue, mechanochemical ablation (MOCA) and high ligation and stripping (HL/S) for the treatment of varicosities of the great saphenous vein (GSV).
The Cochrane Vascular Information Specialist searched the Cochrane Vascular Specialised Register, CENTRAL, MEDLINE, Embase, CINAHL, and AMED databases, and World Health Organization International Clinical Trials Registry Platform and ClinicalTrials.gov trials registers to 2 November 2020. We undertook reference checking to identify additional studies.
We included randomised controlled trials (RCTs) treating participants for varicosities of the GSV using EVLA, RFA, EVSA, UGFS, cyanoacrylate glue, MOCA or HL/S. Key outcomes of interest are technical success, recurrence, complications and QoL.
Two review authors independently selected trials, applied Cochrane's risk of bias tool, and extracted data. We calculated odds ratios (ORs) with 95% confidence intervals (CIs) and assessed the certainty of evidence using GRADE.
We identified 11 new RCTs for this update. Therefore, we included 24 RCTs with 5135 participants. Duration of follow-up ranged from five weeks to eight years. Five comparisons included single trials. For comparisons with more than one trial, we could only pool data for 'technical success' and 'recurrence' due to heterogeneity in outcome definitions and time points reported. All trials had some risk of bias concerns. Here we report the clinically most relevant comparisons. EVLA versus RFA Technical success was comparable up to five years (OR 0.98, 95% CI 0.41 to 2.38; 5 studies, 780 participants; moderate-certainty evidence); over five years, there was no evidence of a difference (OR 0.85, 95% CI 0.30 to 2.41; 1 study, 291 participants; low-certainty evidence). One study reported recurrence, showing no clear difference at three years (OR 1.53, 95% CI 0.78 to 2.99; 291 participants; low-certainty evidence), but a benefit for RFA may be seen at five years (OR 2.77, 95% CI 1.52 to 5.06; 291 participants; low-certainty evidence). EVLA versus UGFS Technical success may be better in EVLA participants up to five years (OR 6.13, 95% CI 0.98 to 38.27; 3 studies, 588 participants; low-certainty evidence), and over five years (OR 6.47, 95% CI 2.60 to 16.10; 3 studies, 534 participants; low-certainty evidence). There was no clear difference in recurrence up to three years and at five years (OR 0.68, 95% CI 0.20 to 2.36; 2 studies, 443 participants; and OR 1.08, 95% CI 0.40 to 2.87; 2 studies, 418 participants; very low-certainty evidence, respectively). EVLA versus HL/S Technical success may be better in EVLA participants up to five years (OR 2.31, 95% CI 1.27 to 4.23; 6 studies, 1051 participants; low-certainty evidence). No clear difference in technical success was seen at five years and beyond (OR 0.93, 95% CI 0.57 to 1.50; 5 studies, 874 participants; low-certainty evidence). Recurrence was comparable within three years and at 5 years (OR 0.78, 95% CI 0.47 to 1.29; 7 studies, 1459 participants; and OR 1.09, 95% CI 0.68 to 1.76; 7 studies, 1267 participants; moderate-certainty evidence, respectively). RFA versus MOCA There was no clear difference in technical success (OR 1.76, 95% CI 0.06 to 54.15; 3 studies, 435 participants; low-certainty evidence), or recurrence (OR 1.00, 95% CI 0.21 to 4.81; 3 studies, 389 participants; low-certainty evidence). Long-term data are not available. RFA versus HL/S No clear difference in technical success was detected up to five years (OR 5.71, 95% CI 0.64 to 50.81; 2 studies, 318 participants; low-certainty evidence); over five years, there was no evidence of a difference (OR 0.88, 95% CI 0.29 to 2.69; 1 study, 289 participants; low-certainty evidence). No clear difference in recurrence was detected up to three years (OR 0.93, 95% CI 0.58 to 1.51; 4 studies, 546 participants; moderate-certainty evidence); but a possible long-term benefit for RFA was seen (OR 0.41, 95% CI 0.22 to 0.75; 1 study, 289 participants; low-certainty evidence). UGFS versus HL/S Meta-analysis showed a possible benefit for HL/S compared with UGFS in technical success up to five years (OR 0.32, 95% CI 0.11 to 0.94; 4 studies, 954 participants; low-certainty evidence), and over five years (OR 0.09, 95% CI 0.03 to 0.30; 3 studies, 525 participants; moderate-certainty evidence). No clear difference was detected in recurrence up to three years (OR 1.81, 95% CI 0.87 to 3.77; 3 studies, 822 participants; low-certainty evidence), and after five years (OR 1.24, 95% CI 0.57 to 2.71; 3 studies, 639 participants; low-certainty evidence). Complications were generally low for all interventions, but due to different definitions and time points, we were unable to draw conclusions (very-low certainty evidence). Similarly, most studies evaluated QoL but used different questionnaires at variable time points. Rates of QoL improvement were comparable between interventions at follow-up (moderate-certainty evidence).
Our conclusions are limited due to the relatively small number of studies for each comparison and differences in outcome definitions and time points reported. Technical success was comparable between most modalities. EVLA may offer improved technical success compared to UGFS or HL/S. HL/S may have improved technical success compared to UGFS. No evidence of a difference was detected in recurrence, except for a possible long-term benefit for RFA compared to EVLA or HL/S. Studies which provide more evidence on the breadth of treatments are needed. Future trials should seek to standardise clinical terminology of outcome measures and the time points at which they are measured.
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