The evolving evidence base for coronary artery bypass grafting and arterial grafting in 2021: How to improve vein graft patency.

Abstract

Central MessageSaphenous vein grafts remain the most common conduits for coronary artery bypass grafting despite limited durability. Various techniques have arisen to improve vein graft patency and outcomes.See Commentaries on pages 110 and 112. Saphenous vein grafts remain the most common conduits for coronary artery bypass grafting despite limited durability. Various techniques have arisen to improve vein graft patency and outcomes. See Commentaries on pages 110 and 112. Coronary artery bypass grafting (CABG) is foundational to managing multivessel coronary artery disease. The internal thoracic artery (ITA) remains the gold standard for left anterior descending artery (LAD) grafting. Although saphenous vein grafts (SVGs) may be considered for non-LAD targets, the right ITA (RITA) and radial artery (RA) are associated with improved outcomes1Gaudino M. Lorusso R. Rahouma M. Abouarab A. Tam D.Y. Spadaccio C. et al.Radial artery versus right internal thoracic artery versus saphenous vein as the second conduit for coronary artery bypass surgery: a network meta-analysis of clinical outcomes.J Am Heart Assoc. 2019; 8: e010839Crossref PubMed Scopus (47) Google Scholar and thus are more commonly used for CABG. A recent systematic review and a network meta-analysis of 150,000 patients2Gaudino M. Benedetto U. Fremes S. Biondi-Zoccai G. Sedrakyan A. Puskas J.D. et al.Radial-artery or saphenous-vein grafts in coronary-artery bypass surgery.N Engl J Med. 2018; 378: 2069-2077Crossref PubMed Scopus (290) Google Scholar,3Gaudino M. Benedetto U. Fremes S. Ballman K. Biondi-Zoccai G. Sedrakyan A. et al.Association of radial artery graft vs saphenous vein graft with long-term cardiovascular outcomes among patients undergoing coronary artery bypass grafting: a systematic review and meta-analysis.JAMA. 2020; 324: 179-187Crossref PubMed Scopus (50) Google Scholar highlighted that the use of RA was associated with a lower risk of major adverse cardiovascular events (MACE) at 5 and 10 years and with a higher rate of patency at 5 years. Moreover, the growing interest in and evidence supporting multiple arterial grafting has resulted in their overall favorable consideration in professional society guidelines for myocardial revascularization,4Aldea G.S. Bakaeen F.G. Pal J. Fremes S. Head S.J. Sabik J. et al.The Society of Thoracic Surgeons clinical practice guidelines on arterial conduits for coronary artery bypass grafting.Ann Thorac Surg. 2016; 101: 801-809Abstract Full Text Full Text PDF PubMed Scopus (230) Google Scholar even though most of the published evidence supporting the RITA is observational. Conversely, up to 20% of SVGs reportedly fail within 1 year post-CABG, owing primarily to technical errors, thrombosis, and intimal hyperplasia, and an additional 20% to 25% fail by 10 years post-CABG owing to arteriosclerosis.5Sabik III., J.F. Understanding saphenous vein graft patency.Circulation. 2011; 124: 273-275Crossref PubMed Scopus (75) Google Scholar The Project of Ex-Vivo Vein Graft Engineering via Transfection (PREVENT) IV, the largest angiographic trial to date (n = 3014 across 107 sites), found angiographic SVG occlusion in >26% of grafts overall and at least 1 SVG occlusion in 42% of patients at 12 to 18 months post-CABG.6Alexander J.H. Hafley G. Harrington R.A. Peterson E.D. Ferguson Jr., T.B. Lorenz T.J. et al.Efficacy and safety of edifoligide, an E2F transcription factor decoy, for prevention of vein graft failure following coronary artery bypass graft surgery: PREVENT IV: a randomized controlled trial.JAMA. 2005; 294: 2446-2454Crossref PubMed Scopus (489) Google Scholar A recent meta-analysis of early SVG occlusion suggests that approximately 11% of grafts occlude within 1 year post-CABG.7Antonopoulos A.S. Odutayo A. Oikonomou E.K. Trivella M. Petrou M. Collins G.S. et al.Development of a risk score for early saphenous vein graft failure: an individual patient data meta-analysis.J Thorac Cardiovasc Surg. 2020; 160: 116-127.e4Abstract Full Text Full Text PDF PubMed Scopus (16) Google Scholar Despite the evidence supporting use of the RITA and RA, the potential of SVGs cannot be dismissed, given that >80% of CABG conduits in the United States currently comprise SVGs.4Aldea G.S. Bakaeen F.G. Pal J. Fremes S. Head S.J. Sabik J. et al.The Society of Thoracic Surgeons clinical practice guidelines on arterial conduits for coronary artery bypass grafting.Ann Thorac Surg. 2016; 101: 801-809Abstract Full Text Full Text PDF PubMed Scopus (230) Google Scholar In addition, there are specific contraindications to using the RITA or RA. Accordingly, methods to improve vein graft patency are warranted. In this Invited Expert Opinion, we describe the no-touch saphenous vein graft (NT-SVG), ITA anastomosed SVG composites, externally supported SVGs (VEST), endoscopically harvested SVGs, SVG storage solutions, and pharmacotherapy as promising techniques to improve vein graft patency (Figure 1). NT-SVG is a variation of SVG whereby harvesting of the vein graft occurs with a small amount of surrounding tissue. The pedicled graft is harvested atraumatically and without manual dilatation and is checked for leaks when subjected to aortic pressure. Souza8Souza D. A new no-touch preparation technique. Technical notes.Scand J Thorac Cardiovasc Surg. 1996; 30: 41-44Crossref PubMed Scopus (98) Google Scholar was the first to report a case series on NT-SVG in 1996. Since then, an increasing number of reports have shown improved patency compared with conventional SVG (C-SVG) as well as patency approaching that achieved with the left ITA (LITA) over the long term. Recent reports even suggest that NT-SVG is associated with improved health-related quality of life after CABG.9Samano N. Bodin L. Karlsson J. Geijer H. Arbeus M. Souza D. Graft patency is associated with higher health-related quality of life after coronary artery bypass surgery.Interact Cardiovasc Thorac Surg. 2017; 24: 388-394PubMed Google Scholar However, large studies showing improved clinical outcomes are lacking, and the effects on health-related quality of life need to be confirmed in a standardized manner in future studies. The growing evidence supporting NT-SVG has led to favorable considerations in recent societal guidelines. The 2018 European Society of Cardiology/European Association for Cardio-Thoracic Surgery Guidelines on Myocardial Revascularization recommend NT-SVG as a class IIa, level of evidence (LoE) B recommendation when an open harvesting technique is used.10Neumann F.J. Sousa-Uva M. Ahlsson A. Alfonso F. Banning A.P. Benedetto U. et al.2018 ESC/EACTS guidelines on myocardial revascularization.EuroIntervention. 2019; 14: 1435-1534Crossref PubMed Scopus (198) Google Scholar These recommendations were based on the work of Samano and colleagues,11Samano N. Geijer H. Liden M. Fremes S. Bodin L. Souza D. The no-touch saphenous vein for coronary artery bypass grafting maintains a patency, after 16 years, comparable to the left internal thoracic artery: a randomized trial.J Thorac Cardiovasc Surg. 2015; 150: 880-888Abstract Full Text Full Text PDF PubMed Scopus (148) Google Scholar who showed 16-year patency with NT-SVG, and Dreifaldt and colleagues,12Dreifaldt M. Mannion J.D. Geijer H. Lidén M. Bodin L. Souza D. The no-touch saphenous vein is an excellent alternative conduit to the radial artery 8 years after coronary artery bypass grafting: a randomized trial.J Thorac Cardiovasc Surg. 2021; 161: 624-630Abstract Full Text Full Text PDF PubMed Scopus (13) Google Scholar who found a similar 8-year patency for NT-SVG compared with RA grafts. The 2011 American College of Cardiology Foundation/American Heart Association (AHA) Guideline for CABG Surgery did not specify any SVG technique in its recommendations.13Hillis L.D. Smith P.K. Anderson J.L. Bittl J.A. Bridges C.R. Byrne J.G. et al.2011 ACCF/AHA guideline for coronary artery bypass graft surgery: a report of the American College of Cardiology Foundation/American Heart Association task force on practice guidelines.Circulation. 2011; 124: e652-e735Crossref PubMed Scopus (555) Google Scholar To date, 4 randomized controlled trials (RCTs) have compared the performance of NT-SVG harvesting compared with C-SVG harvesting, 3 of which reported patency results (Table 1). At a mean follow-up of 18 months, Souza and colleagues15Souza D.S.R. Dashwood M.R. Tsui J.C.S. Filbey D. Bodin L. Johansson B. et al.Improved patency in vein grafts harvested with surrounding tissue: results of a randomized study using three harvesting techniques.Ann Thorac Surg. 2002; 73: 1189-1195Abstract Full Text Full Text PDF PubMed Scopus (130) Google Scholar reported a higher rate of leg wound complications with NT-SVG compared with C-SVG (11.1% vs 4.3%; n = 156).15Souza D.S.R. Dashwood M.R. Tsui J.C.S. Filbey D. Bodin L. Johansson B. et al.Improved patency in vein grafts harvested with surrounding tissue: results of a randomized study using three harvesting techniques.Ann Thorac Surg. 2002; 73: 1189-1195Abstract Full Text Full Text PDF PubMed Scopus (130) Google Scholar The group later reported patency rates in the 2 groups of patients of 90% versus 76% (P = .01) at a mean follow-up of 8.5 years16Souza D.S.R. Johansson B. Bojö L. Karlsson R. Geijer H. Filbey D. et al.Harvesting the saphenous vein with surrounding tissue for CABG provides long-term graft patency comparable to the left internal thoracic artery: results of a randomized longitudinal trial.J Thorac Cardiovasc Surg. 2006; 132: 373-378Abstract Full Text Full Text PDF PubMed Scopus (177) Google Scholar and 83% versus 64% (P = .03) at a mean follow-up of 16 years,11Samano N. Geijer H. Liden M. Fremes S. Bodin L. Souza D. The no-touch saphenous vein for coronary artery bypass grafting maintains a patency, after 16 years, comparable to the left internal thoracic artery: a randomized trial.J Thorac Cardiovasc Surg. 2015; 150: 880-888Abstract Full Text Full Text PDF PubMed Scopus (148) Google Scholar with NT-SVG patency rates not statistically worse than those of LITA grafts.11Samano N. Geijer H. Liden M. Fremes S. Bodin L. Souza D. The no-touch saphenous vein for coronary artery bypass grafting maintains a patency, after 16 years, comparable to the left internal thoracic artery: a randomized trial.J Thorac Cardiovasc Surg. 2015; 150: 880-888Abstract Full Text Full Text PDF PubMed Scopus (148) Google Scholar,16Souza D.S.R. Johansson B. Bojö L. Karlsson R. Geijer H. Filbey D. et al.Harvesting the saphenous vein with surrounding tissue for CABG provides long-term graft patency comparable to the left internal thoracic artery: results of a randomized longitudinal trial.J Thorac Cardiovasc Surg. 2006; 132: 373-378Abstract Full Text Full Text PDF PubMed Scopus (177) Google Scholar SUPERIOR SVG18Deb S. Singh S.K. de Souza D. Chu M.W.A. Whitlock R. Meyer S.R. et al.SUPERIOR SVG: no touch saphenous harvesting to improve patency following coronary bypass grafting (a multicentre randomized control trial, NCT01047449).J Cardiothorac Surg. 2019; 14: 85Crossref PubMed Scopus (43) Google Scholar (n = 250) was the first multicenter angiographic trial comparing NT-SVG and C-SVG. The trial's primary outcome, SVG occlusion or cardiovascular mortality at 1 year, was not statistically different between the groups (5.5% for NT-SVG vs 10.6% for C-SVG; P = .15), and neither was SVG stenosis or total occlusion (7.8% for NT-SVG vs 15.0% for C-SVG; P = .11). However, the NT-SVG group had a significantly greater incidence of early vein harvest site infection at 1 month (23.3% vs 9.5% for C-SVG; P < .01). Leg assessment scores (Total Leg Scores) were significantly worse in the NT-SVG group at 1 month (adjusted difference, 2.58; P < .001) and 3 months (adjusted difference, 2.30; P = .002) but were comparable in the 2 groups at 1 year (adjusted difference, 1.12; P = .407). Finally, Pettersen and colleagues randomized 100 patients in the IMPROVE-CABG trial to pedicled versus conventional harvesting to assess 5-year angiographic SVG function.19Pettersen Ø. Haram P.M. Winnerkvist A. Karevold A. Wahba A. Stenvik M. et al.Pedicled vein grafts in coronary surgery: perioperative data from a randomized trial.Ann Thorac Surg. 2017; 104: 1313-1317Abstract Full Text Full Text PDF PubMed Scopus (12) Google Scholar Early perioperative findings have been promising, suggesting comparable postoperative bleeding and leg wound infection rates, and long-term findings are expected in the near future.Table 1Randomized controlled trials evaluating select saphenous vein graft harvesting techniques to improve graft patencyStudyYear of primary trial completionSample sizeFollow-upIntervention(s)Primary outcomesSecondary outcomesNo-touch SVG Dreifaldt et al14Dreifaldt M. Mannion J.D. Bodin L. Olsson H. Zagozdzon L. Souza D. The no-touch saphenous vein as the preferred second conduit for coronary artery bypass grafting.Ann Thorac Surg. 2013; 96: 105-111Abstract Full Text Full Text PDF PubMed Scopus (56) Google ScholarDreifaldt et al12Dreifaldt M. Mannion J.D. Geijer H. Lidén M. Bodin L. Souza D. The no-touch saphenous vein is an excellent alternative conduit to the radial artery 8 years after coronary artery bypass grafting: a randomized trial.J Thorac Cardiovasc Surg. 2021; 161: 624-630Abstract Full Text Full Text PDF PubMed Scopus (13) Google Scholar201410836 mo (mean)97 mo (mean)No-touch SVG vs radial artery graftSVG patency by angiography at follow-upIncidence of perioperative and postoperative myocardial infarction, death, or need for revascularization Souza et al15Souza D.S.R. Dashwood M.R. Tsui J.C.S. Filbey D. Bodin L. Johansson B. et al.Improved patency in vein grafts harvested with surrounding tissue: results of a randomized study using three harvesting techniques.Ann Thorac Surg. 2002; 73: 1189-1195Abstract Full Text Full Text PDF PubMed Scopus (130) Google ScholarSouza et al16Souza D.S.R. Johansson B. Bojö L. Karlsson R. Geijer H. Filbey D. et al.Harvesting the saphenous vein with surrounding tissue for CABG provides long-term graft patency comparable to the left internal thoracic artery: results of a randomized longitudinal trial.J Thorac Cardiovasc Surg. 2006; 132: 373-378Abstract Full Text Full Text PDF PubMed Scopus (177) Google ScholarSamano et al11Samano N. Geijer H. Liden M. Fremes S. Bodin L. Souza D. The no-touch saphenous vein for coronary artery bypass grafting maintains a patency, after 16 years, comparable to the left internal thoracic artery: a randomized trial.J Thorac Cardiovasc Surg. 2015; 150: 880-888Abstract Full Text Full Text PDF PubMed Scopus (148) Google Scholar201115618 mo (mean)8.5 y (mean)16 y (mean)No-touch SVG vs standard open vs intermediate techniqueSVG patency by angiography at follow-upStenosis in grafts at follow-up PATENT-SVG17Verma S. Lovren F. Pan Y. Yanagawa B. Deb S. Karkhanis R. et al.Pedicled no-touch saphenous vein graft harvest limits vascular smooth muscle cell activation: the PATENT saphenous vein graft study.Eur J Cardiothorac Surg. 2014; 45: 717-725Crossref PubMed Scopus (64) Google Scholar20121712 moNo-touch SVG vs standard open harvestingSVG morphometry and early markers of vascular smooth muscle cell activationLeg wound healing and functional recovery at 3 and 12 mo SUPERIOR-SVG18Deb S. Singh S.K. de Souza D. Chu M.W.A. Whitlock R. Meyer S.R. et al.SUPERIOR SVG: no touch saphenous harvesting to improve patency following coronary bypass grafting (a multicentre randomized control trial, NCT01047449).J Cardiothorac Surg. 2019; 14: 85Crossref PubMed Scopus (43) Google Scholar201525012 moNo-touch SVG vs standard open harvestingIncidence of complete SVG occlusion at 1 y or death due to cardiovascular or unknown causes•Significant stenosis and MACCE at 1 y•Leg adverse events and leg quality of life at 1 y IMPROVE-CABG19Pettersen Ø. Haram P.M. Winnerkvist A. Karevold A. Wahba A. Stenvik M. et al.Pedicled vein grafts in coronary surgery: perioperative data from a randomized trial.Ann Thorac Surg. 2017; 104: 1313-1317Abstract Full Text Full Text PDF PubMed Scopus (12) Google Scholar20161005 yPedical vs conventional SVG harvestingSVG function by angiography at 6 mo and 5 y•Morphological appearance of SVG at 6 mo and 5 y•Leg wound complications at 6 wk•Postoperative complications at discharge, 6 wk, 6 mo, and 5 y SWEDEGRAFT20Ragnarsson S. Janiec M. Modrau I.S. Dreifaldt M. Ericsson A. Holmgren A. et al.No-touch saphenous vein grafts in coronary artery surgery (SWEDEGRAFT): rationale and design of a multicenter, prospective, registry-based randomized clinical trial.Am Heart J. 2020; 224: 17-24Crossref PubMed Scopus (4) Google ScholarOngoing9022 yNo-touch SVG vs standard open harvesting•SVG occlusion or stenosis on CCTA at 2 y or earlier•Death within 2 y•Wound healing in SVG sites at 2 y•Incidence of MACE at 2 y Wang et al21Wang X. Tian M. Zheng Z. Gao H. Wang Y. Wang L. et al.Rationale and design of a multicenter randomized trial to compare the graft patency between no-touch vein harvesting technique and conventional approach in coronary artery bypass graft surgery.Am Heart J. 2019; 210: 75-80Crossref PubMed Scopus (3) Google ScholarOngoing265512 moNo-touch SVG vs standard open harvestingSVG occlusion on CCTA at 3 mo•MACCE at 3 and 12 mo•SVG occlusion at 1 yITA anastomosed SVG composite SAVE-RITA22Kim K.B. Hwang H.Y. Hahn S. Kim J.S. Oh S.J. A randomized comparison of the Saphenous Vein Versus Right Internal Thoracic Artery as a Y-Composite Graft (SAVE RITA) trial: one-year angiographic results and mid-term clinical outcomes.J Thorac Cardiovasc Surg. 2014; 148 (discussion 907-8): 901-907Abstract Full Text Full Text PDF PubMed Scopus (48) Google Scholar20122245 ySVG vs RITA as Y-composite graftSVG or RITA patency by angiography at 1 y•Overall survival at 1 and 4 y•Incidence of MACCE at 1 and 4 yExternally supported SVGs (VEST) VEST I23Taggart D.P. Ben Gal Y. Lees B. Patel N. Webb C. Rehman S.M. et al.A randomized trial of external stenting for saphenous vein grafts in coronary artery bypass grafting.Ann Thorac Surg. 2015; 99: 2039-2045Abstract Full Text Full Text PDF PubMed Scopus (63) Google Scholar20133012 moVEST-supported vein graft•SVG intimal hyperplasia area by intravascular ultrasound at 1 y•Incidence of MACCE at 6 wkSVG failure, ectasia, and Fitzgibbon classification at 1 y VEST III24Taggart D.P. Gavrilov Y. Krasopoulos G. Rajakaruna C. Zacharias J. De Silva R. et al.External stenting and disease progression in saphenous vein grafts two years after coronary artery bypass grafting: a multicenter randomized trial.J Thorac Cardiovasc Surg. April 21, 2021; ([Epub ahead of print])Abstract Full Text Full Text PDF Scopus (5) Google Scholar20191842 yVEST-supported vein graft•Proportion of SVGs with perfect patency at 2 y•Intimal hyperplasia area at 2 y•MACCE at 2 y•SVG failure at 2 y•Early SVG failure at 6 mo VEST IV25Taggart D.P. Webb C.M. Desouza A. Yadav R. Channon K.M. De Robertis F. et al.Long-term performance of an external stent for saphenous vein grafts: the VEST IV trial.J Cardiothorac Surg. 2018; 13: 117Crossref PubMed Scopus (27) Google Scholar2013304.5 y (mean)VEST-supported vein graft•MACCE at follow-up•Intimal hyperplasia and thickness at follow-up•Graft occlusion and Fitzgibbon perfect patency rates at follow-upNot specified VEST PivotalOngoing2245 yVEST-supported vein graftIntimal hyperplasia area and graft occlusion at 1 y•Lumen diameter uniformity at 1 y•Vein graft failure (≥50% stenosis) by cardiac angiography at 1 y•Incidence of MACCE annually over 5 ySVG storage solutions Perrault et al26Perrault L.P. Carrier M. Voisine P. Olsen P.S. Noiseux N. Jeanmart H. et al.Sequential multidetector computed tomography assessments after venous graft treatment solution in coronary artery bypass grafting.J Thorac Cardiovasc Surg. 2021; 161: 96-106.e2Abstract Full Text Full Text PDF Scopus (7) Google Scholar201612512 moDuraGraft graft storage solution•Change in wall thickness between 1 and 3 mo•Change in maximum narrowing between 1 and 12 mo•MDCT angiography measurements for wall thickness, lumen diameter, maximum narrowing, and vessel diameter at 3 and 12 mo•Changes in MDCT angiography measurements between 1 and 3 mo and between 1 and 12 mo•Incidence of SVG thrombosis and occlusion, MACE, angina, arrhythmias, shortness of breath, significant stenosisSVG, Saphenous vein graft; MACCE, major adverse cardiovascular and cerebrovascular events; CABG, coronary artery bypass grafting; CCTA, coronary computed tomography angiography; MACE, major adverse cardiovascular events; ITA, internal thoracic artery; RITA, right internal thoracic artery; VEST, externally supported saphenous vein graft; MDCT, multidetector computed tomography. Open table in a new tab SVG, Saphenous vein graft; MACCE, major adverse cardiovascular and cerebrovascular events; CABG, coronary artery bypass grafting; CCTA, coronary computed tomography angiography; MACE, major adverse cardiovascular events; ITA, internal thoracic artery; RITA, right internal thoracic artery; VEST, externally supported saphenous vein graft; MDCT, multidetector computed tomography. Meta-analytic findings,18Deb S. Singh S.K. de Souza D. Chu M.W.A. Whitlock R. Meyer S.R. et al.SUPERIOR SVG: no touch saphenous harvesting to improve patency following coronary bypass grafting (a multicentre randomized control trial, NCT01047449).J Cardiothorac Surg. 2019; 14: 85Crossref PubMed Scopus (43) Google Scholar including SUPERIOR SVG, concluded that graft occlusion was significantly reduced with NT-SVG versus C-SVG as treated (odds ratio [OR], 0.49; 95% confidence interval [CI], 0.29-0.82; P = .007) at 1 year across 3 trials and 1 observational study. A recent network meta-analysis of patency confirmed significantly reduced graft occlusion in NT-SVG compared with C-SVG.27Gaudino M. Hameed I. Robinson N.B. Ruan Y. Rahouma M. Naik A. et al.Angiographic patency of coronary artery bypass conduits: a network meta-analysis of randomized trials.J Am Heart Assoc. 2021; 10: e019206Crossref PubMed Scopus (9) Google Scholar Although a majority of the early NT-SVG experience and reports stem from the same center, 2 major ongoing RCTs will add further to our knowledge of NT-SVG. In Sweden and Denmark, SWEDEGRAFT20Ragnarsson S. Janiec M. Modrau I.S. Dreifaldt M. Ericsson A. Holmgren A. et al.No-touch saphenous vein grafts in coronary artery surgery (SWEDEGRAFT): rationale and design of a multicenter, prospective, registry-based randomized clinical trial.Am Heart J. 2020; 224: 17-24Crossref PubMed Scopus (4) Google Scholar has recruited 902 patients to assess graft failure by computed tomography angiography, repeat target vessel revascularization, or death at 2 years as the primary composite endpoints and leg wound assessment scores as secondary endpoints (ClinicalTrials.gov identifier NCT03501303). In China, Wang and colleagues21Wang X. Tian M. Zheng Z. Gao H. Wang Y. Wang L. et al.Rationale and design of a multicenter randomized trial to compare the graft patency between no-touch vein harvesting technique and conventional approach in coronary artery bypass graft surgery.Am Heart J. 2019; 210: 75-80Crossref PubMed Scopus (3) Google Scholar have recruited 2655 patients in a multicenter RCT with graft occlusion at 3 months as the primary endpoint and a major adverse cardiovascular and cerebrovascular event (MACCE) at 3 and 12 months postoperatively and graft occlusion at 12 months postoperatively as secondary endpoints (ClinicalTrials.gov identifier NCT03126409). An arterial–arterial composite graft is a strategy to achieve more complete arterial revascularization with fewer conduits while also reducing aortic manipulation and decreasing neurologic events. An arterial–venous composite graft is usually considered a bail-out strategy for patients with limited conduit options and/or a hostile aorta. Theoretical advantages of arterial–venous composite are that the SVG is subjected to dampened pressure waves from the ITA compared with the aorta, whereas the SVG may be bathed with vasodilatory, antithrombotic, and antiatherosclerotic mediators from the ITA due to a proximal anastomosis to the LITA. However, a graft size mismatch and the greater sensitivity of arterial grafts to competitive flow compared with SVGs may lead to the steal sign or string sign (ie, diffuse narrowing of part of or the entire graft). This has been observed in up to 7% of RA grafts.4Aldea G.S. Bakaeen F.G. Pal J. Fremes S. Head S.J. Sabik J. et al.The Society of Thoracic Surgeons clinical practice guidelines on arterial conduits for coronary artery bypass grafting.Ann Thorac Surg. 2016; 101: 801-809Abstract Full Text Full Text PDF PubMed Scopus (230) Google Scholar In addition, the usual concerns about T-graft (ie, side-to-end) anastomoses remain, including obstruction due to kinking of the graft or misplacement of the pedicle, competition of flow with bypassed vessels, and the need for technical experience. Current trial evidence evaluating ITA-anastomosed SVG composites remains scarce (Table 1). The SAVE RITA trial (n = 224) found that SVG composites were noninferior to the RITA as Y-composites proximally anastomosed to LITAs graft at 1 year (97.1% for SVG composites vs 97.1% for RITA composite grafts; P < .001), albeit with a large (8%) noninferiority margin.22Kim K.B. Hwang H.Y. Hahn S. Kim J.S. Oh S.J. A randomized comparison of the Saphenous Vein Versus Right Internal Thoracic Artery as a Y-Composite Graft (SAVE RITA) trial: one-year angiographic results and mid-term clinical outcomes.J Thorac Cardiovasc Surg. 2014; 148 (discussion 907-8): 901-907Abstract Full Text Full Text PDF PubMed Scopus (48) Google Scholar In addition, a recent propensity-matched analysis of 196 patients suggested further improvement of 1-year arterial–venous composite patency when using the NT-SVG for the venous limb (97.3% for NT-SVG vs 92.6% for minimal manipulation; P = .051).28Kim Y.H. Oh H.C. Choi J.W. Hwang H.Y. Kim K.B. No-touch saphenous vein harvesting may improve further the patency of saphenous vein composite grafts: early outcomes and 1-year angiographic results.Ann Thorac Surg. 2017; 103: 1489-1497Abstract Full Text Full Text PDF PubMed Scopus (42) Google Scholar To date, these superb results have been reported only from a single center, however; larger multi-institutional studies are needed to confirm these findings before the widespread adoption of this technique. A more recently introduced technique is the use of a cobalt–chromium mesh stent to externally support the SVG and improve graft hemodynamic properties. The VEST device (Vascular Graft Solutions, Tel Aviv, Israel) has been approved for clinical use in Europe following a series of VEST trials (Table 1). VEST I (n = 30) was a first-in-human trial highlighting a reduced mean intimal hyperplasia area (4.37 ± 1.40 mm2 vs 5.12 ± 1.35 mm2; P = .04) at 1 year for stented SVGs versus nonstented SVGs.23Taggart D.P. Ben Gal Y. Lees B. Patel N. Webb C. Rehman S.M. et al.A randomized trial of external stenting for saphenous vein grafts in coronary artery bypass grafting.Ann Thorac Surg. 2015; 99: 2039-2045Abstract Full Text Full Text PDF PubMed Scopus (63) Google Scholar VEST III (n = 184) later confirmed these findings at 2 years with a substantially larger sample.24Taggart D.P. Gavrilov Y. Krasopoulos G. Rajakaruna C. Zacharias J. De Silva R. et al.External stenting and disease progression in saphenous vein grafts two years after coronary artery bypass grafting: a multicenter randomized trial.J Thorac Cardiovasc Surg. April 21, 2021; ([Epub ahead of print])Abstract Full Text Full Text PDF Scopus (5) Google Scholar Although patency rates were comparable for stented and nonstented SVGs (78.3% vs 82.2%; P = .43), the Fitzgibbon patency scale was improved significantly (OR, 2.02; P = .03), and mean intimal hyperplasia area (3.07 ± 0.37 mm2 vs 3.96 ± 0.38 mm2; P < .001) and thickness (0.26 ± 0.03 mm vs 0.34 ± 0.31 mm; P < .001) were reduced. The longer but smaller VEST IV (n = 21) found higher Fitzgibbon perfect patency with VEST at 1 year (81% vs 48%; P = .002) and 5 years (79% vs 50%; P = .002) compared with C-SVG.25Taggart D.P. Webb C.M. Desouza A. Yadav R. Channon K.M. De Robertis F. et al.Long-term performance of an external stent for saphenous vein grafts: the VEST IV trial.J Cardiothorac Surg. 2018; 13: 117Crossref PubMed Scopus (27) Google Scholar Vest II (n = 30) provided a postmarket clinical assessment of the VEST device to the right coronary artery to identify graft failure by CT angiography at 3 to 6 months.29Taggart D.P. Amin S. Djordjevic J. Oikonomou E.K. Thomas S. Kampoli A.M. et al.A prospective study of external stenting of saphenous vein grafts to the right coronary artery: the VEST II study.Eur J Cardiothorac Surg. 2017; 51: 952-958Crossref PubMed Scopus (21) Google Scholar Avoidance of external stent fixation to anastomoses and the use of metallic clips to ligate SVG branches was found to improve the patency of stented SVGs to the right coronary territory (86.2%), in agreement with VEST I findings (88.8%).23Taggart D.P. Ben Gal Y. Lees B. Patel N. Webb C. Rehman S.M. et al.A randomized trial of external stenting for saphenous vein grafts in coronary artery bypass grafting.Ann Thorac Surg. 2015; 99: 2039-2045Abstract Full Text Full Text PDF PubMed Scopus (63) Google Scholar These findings are encouraging and are being longitudinally assessed in the VEST EU Registry (n > 1000), an ongoing prospective cohort (2017-2025). Although VEST is yet to be approved in North America, the Food and Drug Administration is running the VEST Pivotal RCT (n = 224) (ClinicalTrials.gov identifier NCT03209609) to confirm earlier trial results. The primary study outcome is intimal hyperplasia as assessed by intravascular ultrasound at 12 months. To address the leg wound infections, healing issues, and associated postoperative pain observed with NT-SVG