Effect of target artery location and severity of stenosis on mid-term patency of aorta-anastomosed vs. internal thoracic artery-anastomosed radial artery grafts

Expert systematic review on the choice of conduits for coronary artery bypass grafting: endorsed by the European Association for Cardio-Thoracic Surgery (EACTS) and The Society of Thoracic Surgeons (STS)

PREAMBLE

The finalized document was endorsed by the EACTS Council and STS Executive Committee before being simultaneously published in the European Journal of Cardio-thoracic Surgery (EJCTS) and The Annals of Thoracic Surgery (The Annals) and the Journal of Thoracic and Cardiovascular Surgery (JTCVS).

Late Clinical Outcomes of Total Arterial Revascularization or Multiple Arterial Grafting Compared to Conventional Single Arterial with Saphenous Vein Grafting for Coronary Surgery

Coronary surgery provides better long-term outcomes than percutaneous coronary intervention. Conventional practice is to use a single arterial conduit supplemented by saphenous vein grafts. The use of multiple arterial revascularization (MAG), or exclusive arterial revascularization (TAR), however, is reported as having improved late survival. Survival is a surrogate for graft failure that may lead to premature death, and improved survival reflects fewer graft failures in the non-conventional strategy groups. The reasons for not using MAG or TAR may be due to perceived technical difficulties, a lack of definitive large-scale randomized evidence, a lack of confidence in arterial conduits, or resources or time constraints. Most people consider radial artery (RA) grafting to be new, with use representing approximately 2-5% worldwide, despite select centers reporting routine use in most patients for decades with improved results. In conclusion, the current body of evidence supports more extensive use of total and multiple arterial revascularization procedures in the absence of contraindications.

Angiographic Outcomes for Arterial and Venous Conduits Used in CABG

Coronary artery bypass grafting is the most commonly performed cardiac surgical procedure. Conduit selection is crucial to achieving early optimal outcomes, with graft patency being likely the main driver to long-term survival. We present a review of current evidence on the patency of arterial and venous bypass conduits and of differences in angiographic outcomes.

Characteristics of Radial Artery Coronary Bypass Graft Failure and Outcomes Following Subsequent Percutaneous Coronary Intervention

BACKGROUND

When patients with prior coronary artery bypass grafting (CABG) undergo percutaneous coronary intervention (PCI), targeting the native vessel is preferred. Studies informing such recommendations are based predominantly on saphenous vein graft (SVG) PCI. There are few data regarding arterial graft intervention, particularly to a radial artery (RA) graft.

OBJECTIVES

The aim of this study was to report the characteristics of arterial graft stenoses and evaluate the feasibility of RA PCI.

METHODS

This study included 2,780 consecutive patients with prior CABG undergoing PCI between 2005 and 2018 who were prospectively enrolled in the MIG (Melbourne Interventional Group) registry. Data were stratified by PCI target vessel. RA graft PCI was compared with both native vessel (native PCI) and SVG PCI. Internal mammary graft PCI data were reported. The primary outcome was 3-year mortality.

RESULTS

Overall, 1,928 patients (69.4%) underwent native PCI, 716 (25.6%) SVG PCI, 86 (3.1%) RA PCI, and 50 (1.8%) internal mammary graft PCI. Compared with SVG PCI, the RA PCI cohort presented earlier after CABG, less frequently had acute coronary syndrome, and more commonly had ostial or distal anastomosis intervention (P < 0.005 for all). Compared with patients who underwent native PCI, those who underwent RA PCI were more likely to have diabetes and peripheral vascular disease (P < 0.001 for both) and to present with non-ST-segment elevation myocardial infarction (P = 0.010). The RA PCI group had no perforations or in-hospital myocardial infarctions, though no significant difference was found in periprocedural outcomes compared with either native or SVG PCI. No differences were found between RA PCI and either native or SVG PCI in 30-day outcomes or 3-year mortality.

CONCLUSIONS

Presenting and lesion characteristics differed between patients undergoing arterial compared with SVG PCI, implying a varied pathogenesis of graft stenosis. RA PCI appears feasible, safe, and where anatomically suitable, may be a viable alternative to native PCI.

Diagnostic radiology methods for assessing coronary artery bypass graft viability

The review describes available modern radiological methods which are currently applied for a detailed and comprehensive anatomical and functional assessment of the viability of various coronary artery bypass grafts. In addition, it presents some aspects of the implementation of these methods and clinical interpretation of the results.

Competitive Flow in Vein Composite Grafts Based on the Left Internal Thoracic Artery: Early and 1-Year Angiographic Analyses

We assessed the incidence of competitive flow with early postoperative angiograms in patients who received a "no-touch" saphenous vein (NT SV) composite graft and reexamined the status of competitive flow at 1-year. Early postoperative angiograms were performed in 806 patients who underwent myocardial revascularization using a NT SV Y-composite graft based on the in situ left internal thoracic artery (LITA). Competitive conduit flow was observed in 102 distal anastomoses (102 of 3039 [3.4%] anastomoses) of 94 patients (94 of 806 [11.7%]; NT SV competitive flow in 74 and LITA competitive flow in 20). Of the 94 patients, 63 patients (50 with NT SV competition and 13 with LITA competition) were re-evaluated with 1-year postoperative angiograms. Fifty-six competitive NT SV conduits in 50 patients were reevaluated at 1-year postoperatively: 44 (78.6%) early competitive anastomoses had become patent and 12 (21.4%) were occluded. NT SV with pedicle tissue showed a higher tendency of being perfectly patent at 1-year postoperatively than NT SV without pedicle tissue (17 of 40 [42.5%] vs 2 of 16 [12.5%]; P = 0.007). Thirteen competitive LITA conduit anastomoses in 13 patients were reevaluated 1-year postoperatively: 9 (69.2%) early competitive anastomoses had become patent and 4 (30.8%) were occluded. Competitive flow was shown on early postoperative angiograms in 3.4% of distal anastomoses in patients who received NT SV Y-composite grafts. Approximately 80% of the competitive NT SV conduits were patent 1-year postoperatively, and perfect patency rates were higher in patients who had received NT SV with pedicle tissue than in patients who had received NT SV without pedicle tissue.

Radial artery or saphenous vein for Coronary artery bypass grafitng

Coronary artery disease (CAD) is the most common cardiovascular disease worldwide, affecting over 18 million American adults. Coronary artery bypass grafting (CABG) is the standard of care for patients with left main or triple vessel CAD. Historically, the saphenous vein (SV) has been utilized to bypass the majority of the coronary vessels in patients undergoing CABG, but more recent data suggest that the use of the radial artery (RA), rather than the SV, is associated with improved cardiac outcomes and better survival. The aim of this review is to summarize the current literature on the use of RA and SV for CABG in patients with multivessel CAD.

The Use of Radial Artery for CABG: An Update

We used the radial artery as a second target conduit for coronary artery bypass grafting since 1971. However, randomized clinical studies have demonstrated differences in clinical outcomes between the radial artery and other grafts because these trials are underpowered. As we proceed toward 50 years of experience with radial artery grafting, we examined the literature to define the best second-best target vessel for coronary artery bypass grafting. The literature was reviewed with emphasis, and a large number of randomized controlled trials, propensity-matched observational series, and meta-analyses were identified with a large patient population who received arterial conduit and saphenous vein grafts. The radial artery has been shown to be effective and safe when used as a second target conduit for coronary artery bypass grafting. Results and patency rates were superior to those for saphenous vein grafting. It has also been shown that the radial artery is a safe and effective graft as a third conduit into the territory of the artery right coronary artery. However, there is little evidence based on a few comparable series limiting the use of the gastroepiploic artery. In its fifth decade of use, we can finally deduced that the aorto-to-coronary radial bypass graft is the conduit of choice for coronary operations after the left internal thoracic artery to the left anterior descending artery.

Right internal thoracic or radial artery as the second arterial conduit for coronary artery bypass surgery

PURPOSE OF REVIEW

To summarize the available evidence on the use of the right internal thoracic artery (RITA) and the radial artery as the second arterial graft in coronary artery bypass surgery.

RECENT FINDINGS

The current data support the equipoise of the two conduits in terms of clinical and angiographic outcomes. Both RITA and radial artery have better patency than saphenous vein grafts. The use of the RITA carries an increased risk of deep sternal wound infection (DSWI) if the artery is harvested as pedicle. Bilateral internal thoracic artery grafting is more technically demanding than radial artery use and there is a volume-outcome relationship in terms of mortality and incidence of DSWI. The radial artery is preferable over RITA in right-sided or distal circumflex artery targets with high-degree stenosis and in patients at higher risk for DSWI, whereas it is not recommended to graft vessels with moderate stenosis and in cases of insufficient collateralization from the ulnar artery or previous transradial procedures.

SUMMARY

The patency rate and clinical outcomes of radial artery and RITA are similar. The use of one or the other should be based on a careful evaluation of the patient's coronary anatomy and comorbidities, the conduit availability and the surgeon's and center's experience.

State-of-the-Art Coronary Artery Bypass Grafting: Patient Selection, Graft Selection, and Optimizing Outcomes

Despite the progressive expansion of clinical indications for percutaneous coronary intervention and the increasingly high risk profile of referred patients, coronary artery bypass grafting (CABG) remains the mainstay in multivessel disease, providing good long-term outcomes with low complication rates. Multiple arterial grafting, especially if associated with anaortic techniques, might provide the best longer-term outcomes. A surgical approach individualized to the patients' clinical and anatomic characteristics, and surgeon and team experience, are key to excellent outcomes. Current evidence regarding patient selection, indications, graft selection, and potential strategies to optimize outcomes in patients treated with CABG is summarized.

The Risk Factor Analysis for the Late Graft Failure of Radial Artery Graft in Coronary Artery Bypass Grafting

Objective: The aim of this retrospective study was to investigate the early operative results and detect the factors influencing the fate of radial artery grafts (RAGs) by evaluating the mid-term patency.

Methods: We retrospectively reviewed 410 patients who underwent isolated coronary artery bypass grafting using RAG. RAGs were anastomosed to 526 coronary arteries. Mid-term angiography was performed in 214 patients at an average 4.9 years after the operation.

Results: The early patency of RAGs was 97.6%. Cumulative 5-year patency was 86.5% for RAG, 94.1% for LITA graft, and 81.0% for saphenous vein graft (SVG). RAG was significantly superior to SVG in mid-term patency. Individual grafting (not sequential grafting) (hazard ratio [HR]: 2.535; 95% confidence interval [CI]: 1.293–5.281; p = 0.006) and grafting to the target coronary artery with ≤75% proximal stenosis (HR: 1.947; 95% CI: 1.090–3.484; p = 0.025) were found to be independent risk factors influencing late RAG patency.

Conclusions: The patency of RAGs was superior to that of SVGs in the studied population. When using RAGs, grafting to the target vessel with severe proximal stenosis is favorable. The RAG is suitable for sequential grafting.

On-Pump Coronary Artery Bypass Graft: The State of the Art

BACKGROUND

Coronary artery bypass grafting (CABG) remains the standard of care for patients with coronary artery disease (CAD). Debate exists concerning several factors, which include percutaneous coronary intervention (PCI) vs. CABG, single vs. bilateral mammary artery grafts, radial artery vs. saphenous vein grafts, right internal mammary artery vs. radial artery grafts, endoscopic vs. open vein-graft harvesting, and on-pump vs. off- pump surgery. Moreover, challenging is the management of diabetic patients with CAD undergoing CABG. This review reports current indications, practice patterns, and outcomes of CABG.

METHODS

Randomized controlled trials comparing CABG to other therapeutical strategies for CAD were searched through MEDLINE, EMBASE, Cochrane databases, and proceedings of international meetings.

RESULTS

Large multicenter randomized and observational studies (SYNTAX, BEST, PRECOMBAT, ASCERT) have reported excellent outcomes in CABG patients, with always fewer rates of operative mortality and major morbidity, than PCI. The 10-year follow-up of ARTS II trial showed no difference between single and bilateral mammary artery. BARI 2D, MASS II, CARDia, FREEDOM trials showed that CABG is the best choice for diabetic patients.

CONCLUSION

CABG still represents one of the most widespread major surgeries, with well-known benefits on symptoms and prognosis in patients with CAD. However, further studies and follow-up data are needed to validate these evidences.

Technical Aspects of the Use of the Radial Artery in Coronary Artery Bypass Surgery

BACKGROUND

The radial artery has been used for coronary artery bypass surgery for more than 25 years. The recent confirmation of the clinical benefits associated with the use of the artery is likely to drive a new interest toward this conduit in the next few years.

METHODS

A group of surgeons with extensive experience in the systematic use of the radial artery summarize here the key technical aspects of the use of the conduit for coronary bypass operations.

RESULTS

Preoperative evaluation of the ulnar collateral circulation and attention to the characteristics of the target vessel are keys for the successful use of the radial artery. Open or endoscopic harvesting can be used, preferentially with the aid of the harmonic scalpel. The use of vasodilatory and antispastic protocols is probably important but poorly supported by the current evidence. The radial artery can be used for multiple grafting strategies with a variable degree of technical complexity.

CONCLUSIONS

With attention to few technical key points, the radial artery is a versatile conduit that can be easily introduced in the everyday practice of coronary artery bypass surgery.

Optimal management of radial artery grafts in CABG: Patient and target vessel selection and anti-spasm therapy

The current literature on radial artery grafting is reviewed focusing on the optimal deployment of radial artery grafts in coronary artery bypass surgery with specific attention to the selection of patients and target vessels for radial artery grafting.

The Surgical Treatment of Coronary Artery Occlusive Disease: Modern Treatment Strategies for an Age Old Problem

Coronary artery disease remains a formidable challenge to clinicians. Percutaneous interventions and surgical techniques for myocardial revascularization continue to improve. Concurrently, in light of emerging data, multiple practice guidelines have been published guiding clinicians in their therapeutic decisions. The multidisciplinary Heart Team concept needs to be embraced by all cardiovascular providers to optimize patient outcomes.

Does Previous Transradial Catheterization Preclude Use of the Radial Artery as a Conduit in Coronary Artery Bypass Surgery?

The radial artery (RA) is a commonly used conduit for coronary artery bypass grafting, and recent studies have demonstrated that it provides superior long-term patency rates to the saphenous vein in most situations. In addition, the RA is also being used with increasing frequency as the access point for coronary angiography and percutaneous coronary interventions. However, there has been concern for many years that these transradial procedures may have a detrimental impact on the function of RA grafts used in coronary artery bypass grafting, and there is now comprehensive evidence that such interventions cause morphologic and functional damage to the artery in situ. Despite this, there remain remarkably few studies investigating the use of previously cannulated RAs as grafts in coronary artery bypass surgery, and there are no clear guidelines on the use of the RA in coronary artery bypass grafting after its catheterization. This article will review concisely the evidence that transradial procedures cause damage to the RA, and discuss the impact this could have on previously cannulated RAs used as coronary artery bypass grafting conduits. On the basis of the evidence assessed, we make a number of recommendations to both surgeons and cardiologists regarding use of the RA in cardiovascular procedures.

Short- and long-term results of radial artery and saphenous vein grafts in the right coronary system: a propensity-matched study

PURPOSE

The selection of optimal grafts for the right coronary artery remains controversial. This study aims to evaluate the short- and long-term results of radial artery (RA) grafts and saphenous vein grafts (SVGs) to the right coronary artery.

METHODS

We reviewed, retrospectively, isolated coronary artery bypass grafts, placed between 1997 and 2007, and compared the long-term results of patients who received RA (n = 110) grafts with those of patients who received SVGs (n = 264) using propensity-score matching for risk. The preoperative predictors of graft occlusion were investigated on a per case basis.

RESULTS

Superior survival was noted in the unmatched RA group, but late outcomes after propensity-score matching yielded 91 patient pairs that were similar in the two groups. Graft failure was not correlated with mortality, but showed strong correlation with cardiac events in all patients. The predictors of graft occlusion in the RA group were mild proximal stenosis and low indexing glomerular filtration rates for body surface area, whereas those in the SVG were female gender and off-pump coronary artery bypass grafting.

CONCLUSIONS

There were no significant differences in long-term outcomes between the RA and SVG groups. Predictors of graft occlusion differed between the groups. Notably, renal dysfunction impaired radial patency, emphasizing the importance of careful graft selection.

Multiple arterial grafting for coronary revascularization: "A guide for the perplexed"

The surgical literature abounds with articles extolling the benefits of arterial grafting for patients with advanced coronary artery disease in need of surgical revascularization. However, examination of clinical performance demonstrates that extensive use of arterial grafting is highly selective and generally uncommon. Rather than to merely repeat multiple excellent recent literature reviews, the goal herein is to provide the reader with a guide to the evaluation of the current literature as well as to suggest fruitful areas for further research. More circumspect understanding of the strengths and weaknesses of our current knowledge base will not only help to explain the current apparent disparity between theory and practice but will hopefully inform future decision-making and patient care.

The Choice of Conduits in Coronary Artery Bypass Surgery

Coronary artery bypass grafting is the most common cardiac surgery operation performed worldwide. It is the most effective revascularization method for several categories of patients affected by coronary artery disease. Although coronary artery bypass grafting has been performed for more than 40 years, no detailed guidelines on the choice of coronary artery bypass grafting conduits have been published and the choice of the revascularization strategy remains more a matter of art than of science. Moreover, there is a clear contradiction between the proven benefits of arterial grafting and its very limited use in everyday clinical practice. In the hope of encouraging wider diffusion of arterial revascularization and to provide a guide for clinicians, we discuss current evidence for the use of different conduits in coronary artery bypass surgery and propose an evidence-based algorithm for the choice of the second conduit during coronary artery bypass operations.

The present day potential role of fractional flow reserve-guided coronary artery bypass graft surgery

The favorable impact of fractional flow reserve measurements on the decision-making and overall outcomes of percutaneous coronary artery intervention is well established. However, the clinical application of fractional flow reserve in surgical revascularizations is still debated. The purpose of this article is to provide a comprehensive review on the current potential role of fractional flow reserve guidance in coronary artery bypass grafting.

The radial artery: a forgotten conduit

We reviewed the published literature on the clinical and angiographic outcome of radial artery (RA) grafts and on the comparison between the RA and the other conduits used in coronary operations. The RA is a better graft than the saphenous vein and comparable to the right internal thoracic artery (RITA); moreover, the RA seems a better choice than the RITA in patients at risk of sternal or pulmonary complications. We conclude that the RA should be preferred to the saphenous vein and considered at least equivalent to the RITA as the second conduit during every elective coronary artery bypass procedure.

Right-sided reverse T composite arterial grafting to complete revascularization of the right coronary artery

Complete arterial revascularization for the right coronary artery is underused mainly due to technical issues. Herein we report on a new approach for complete arterial revascularization of arterial revascularization for the right coronary artery branches. Complete arterial revascularization for the right coronary artery revascularization was performed in 8 patients using a reverse T composite arterial graft. None of the patients suffered perioperative myocardial infarction. All patients underwent noninvasive coronary imaging, displaying an early patency rate of 100%. Complete arterial arterial revascularization for the right coronary artery revascularization using a reverse T graft offers a new paradigm with enhanced technical flexibility in performing all arterial myocardial complete revascularizations in selected patients.

V-composite grafting using the right internal thoracic artery grafts anastomosed to aorto-coronary bypass grafts

OBJECTIVES

Composite grafting using the right internal thoracic artery (RITA) is occasionally performed when the in situ RITA does not have sufficient length to reach the target vessel. In this study, we assessed the clinical and angiographic outcomes of coronary artery bypass grafting (CABG) with V-composite grafting (defined as a distance between the proximal anastomosis of the RITA and the ascending aorta of ≤1 cm) using the RITA anastomosed to aortocoronary (A-C) bypass grafts.

METHODS

Between September 2004 and December 2012, 177 patients underwent CABG with V-composite grafting using the RITA and the A-C bypass graft [radial artery (RA) or saphenous vein graft (SVG)] at our institution. The mean age was 69.2 ± 8.5 years and 149 (84.2%) were men. The clinical outcomes and patency rates of distal anastomoses of the composite RITA were retrospectively evaluated.

RESULTS

Mean distal anastomoses per patient were 4.6 ± 1.0, and mean distal anastomoses of the RITA per patient were 1.3 ± 0.5. Inflow conduit of the RITA was the RA in 16 (9.0%) patients and an SVG in 161 (91.0%) patients. The 30-day mortality rate was 1.1% (2/177). The overall patency rate of distal anastomoses of the composite RITA on early (before discharge) and follow-up (at 1 year) angiography was 97.6 and 93.6%, respectively. The inflow conduit (RA or SVG), stenosis grade of target vessel and sequential grafting did not affect the patency rate of the composite RITA.

CONCLUSIONS

V-composite grafting using the RITA and the A-C bypass graft provides excellent clinical outcomes with satisfactory early and 1-year patency rates.

Radial artery as graft for coronary artery bypass surgery: Advantages and disadvantages for its usage focused on structural and biological characteristics

Radial artery (RA) is the most popular arterial graft after the left internal thoracic artery in both low- and high-risk patients undergoing coronary artery bypass grafting. Various arterial grafts such as the right internal thoracic artery, the right gastroepiploic artery, and the inferior epigastric artery have also gained ground over the past 30 years because of the intimal hyperplasia and atherosclerosis of the saphenous vein leading to late graft occlusion. In this review article we would like to present the utility of the RA as a graft, focused mainly on its structural and biological characteristics.

Competitive flow in coronary bypass surgery: is it a problem?

PURPOSE OF REVIEW

Competition flow is a common finding in arterial grafting. This phenomenon can lead to graft occlusion.

RECENT FINDINGS

Internal thoracic arteries are the best equipped arterial conduit to withstand the competition flow thanks to their endothelial function. Radial as well as right gastroepiploic arteries support much less flow competition because of their different anatomy, histology and endothelial function than that of internal thoracic artery, leading to spasm and occlusion. Therefore, these two arterial conduits should be used only in case of critical lesion to avoid graft occlusion. Saphenous vein graft is the only conduit that is not significantly affected by flow competition, mainly because of its nonresistivity and common reimplantation in the aorta. Graft configuration is the second important factor influencing the equation between graft flow and native coronary flow. Therefore, composite grafting should be reserved for the case of severely stenotic coronary target, especially if multiple arterial sequential anastomoses have to be performed on the lateral-inferior wall of the heart. Finally, an accurate tool such as the fractional flow reserve to evaluate the stenosis severity should be the milestone of coronary surgery in order to decrease the rate of flow competition and improve arterial grafting functionality.

CONCLUSION

Competition flow plays a crucial role in arterial grafting functionality. Grafting strategy should address this by appropriate graft choice and configuration in order to avoid graft attrition.

WITHDRAWN: Endoscopic Radial Artery Harvesting: Long-Term Results and Graft Patency Rate

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