The radial artery in coronary surgery, 2018

It is now 25 years since the radial artery (RA) was reintroduced in coronary surgery. It has evolved into being a significant coronary artery bypass conduit and ranks third in usage after the internal thoracic artery (ITA) and saphenous vein grafts (SVG). Its advantages are that it can be readily and efficiently harvested, is of good length and appropriate size for coronary artery bypass graft (CABG) surgery, is robust and easy to handle, and remains free of atheroma, and there is minimal wound morbidity. The RA must be used judiciously with attention to spasm prophylaxis because of its muscular wall, and by avoiding competitive flow. Its patency is equivalent to the ITAs when placed to similar coronary territories and under similar conditions (stenosis, size, quality) and RA patencies are always superior to those of SVG in both observational and randomized studies-88-90% versus 50-60% at 10 years, and 80-87% versus 25-40% at 20 years. Its use and excellent patencies result in survival results equivalent to bilateral internal thoracic artery (BITA) grafting and always superior to left internal thoracic artery (LITA) +SVG. Typical radial artery multiarterial bypass grafting (RA-MABG) 10-year survivals are 80-90% versus 70-80% for LITA-SVG. In general, for every 100 patients undergoing CABG, 10 more patients will be alive at 10 years post-operatively. The RA also is important in achieving total arterial revascularization, and several reports indicate a further survival advantage for patients having three arterial grafts over two. The RAs are especially useful in diabetic, morbidly obese patients, those with conduit shortage, and leg pathology, and in coronary reoperations. Although the RA has equivalent patencies to the right internal thoracic artery (RITA), it is much more versatile. RAs that have been instrumented by angiography or percutaneous coronary intervention should be avoided. The radial artery has proved to be an excellent arterial conduit, is equivalent to but more versatile than the RITA, and is always superior to SVG. Its use should be part of every coronary surgeon's skill set.

Bilateral Versus Single Internal Thoracic Artery Grafts

Purpose of Review

Several advances have been made in recent years to improve outcome for patients with coronary artery disease. One of the most debated topics regarding surgical treatment with coronary artery bypass grafting (CABG) is graft selection. This review aims to present the current status and scientific evidence for bilateral internal thoracic artery (BITA) grafting.

Recent Findings

Observational studies and pooled analyses suggest that BITA grafting is associated with improved survival. Early results from a large randomized controlled trial report safety and efficacy of the method. The improved survival might be amplified in select groups, but with an increase in sternal wound-related complications. The benefit of BITA grafts seems to remain to an approximate age of 69 years at surgery.

Summary

CABG with BITA grafts is likely associated with improved long-term survival at a cost of an increase in sternal wound infections. Ten-year results from the Arterial Revascularization Trial are expected in 2018, providing the best evidence regarding the method yet. Early results show it is a safe method in most patient categories considerable for CABG.

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.

Is the radial artery associated with improved survival in older patients undergoing coronary artery bypass grafting? An analysis of a multicentre experience†

OBJECTIVES

Studies suggest that the radial artery (RA) may exhibit superior patency compared with the saphenous vein (SV). It is unclear whether older patients undergoing coronary artery bypass grafting (CABG) derive any survival benefit from the use of RAs. We sought to evaluate this using a multicentre database.

METHODS

From 1995 to 2010, 6059 patients with three-vessel coronary artery disease underwent primary isolated CABG at 8 centres. A study cohort of 4006 patients was formed with 3220 (80%) receiving at least 1 RA to supplement a single in situ internal thoracic artery (RA group) while 786 (20%) received only veins to supplement a single ITA (SV group). In the RA group, bilateral RAs were used in 1418 (44%) cases, while total arterial revascularization was achieved in 1859 (58%). RAs were mostly grafted to the left circumflex and right coronary territories. Survival data were obtained using the National Death Index and propensity-score matching was used for risk adjustment. Separate propensity-score analyses were conducted for the 2149 patients (1645 RA, 504 SV) who were 70 years or older.

RESULTS

Patients receiving RAs were younger (mean age in years RA: 68 ± 9.7 vs SV: 71 ± 7.9, P < 0.001) and less likely to have cerebrovascular disease, obstructive airways disease, myocardial infarction within 7 days and left-main coronary disease. At 30 days, RA patients experienced reduced unadjusted mortality (49 of 3220, 1.5% vs 25 of 786, 3.2%, P = 0.004). At 15 years, the RA group showed superior unadjusted survival (51 ± 1.1 vs 35 ± 1.9%, P < 0.001). After propensity-score matching of 507 patient pairs, there was comparable 30-day mortality between groups (RA: 9, 1.8 vs SV: 14, 2.8%, P = 0.41). However, at 15 years, the RA group still showed superior survival (42 ± 2.6 vs 35 ± 2.5%, P = 0.008). Among those 70 years and older (327 matched pairs), despite similar 30-day mortality (RA: 6, 1.8% vs SV: 10, 3.1%, P = 0.42), RA patients again exhibited improved survival (35 ± 3.3 vs 22 ± 2.8%, P = 0.004) at 15 years.

CONCLUSIONS

This multicentre analysis suggests that the use of an RA is associated with a survival benefit in older patients undergoing CABG.

Coronary artery bypass grafting: Part 2--optimizing outcomes and future prospects

Since first introduced in the mid-1960s, coronary artery bypass grafting (CABG) has become the standard of care for patients with coronary artery disease. Surprisingly, the fundamental surgical technique itself did not change much over time. Nevertheless, outcomes after CABG have dramatically improved over the first 50 years. Randomized trials comparing percutaneous coronary intervention (PCI) to CABG have shown converging outcomes for select patient populations, providing more evidence for wider use of PCI. It is increasingly important to focus on the optimization of the short- and long-term outcomes of CABG and to reduce the level of invasiveness of this procedure. This review provides an overview on how new techniques and widespread consideration of evolving strategies have the potential to optimize outcomes after CABG. Such developments include off-pump CABG, clampless/anaortic CABG, minimally invasive CABG with or without extending to hybrid procedures, arterial revascularization, endoscopic vein harvesting, intraprocedural epiaortic scanning, graft flow assessment, and improved secondary prevention measures. In addition, this review represents a framework for future studies by summarizing the areas that need more rigorous clinical (randomized) evaluation.

Late effects of radial artery vs saphenous vein grafting for multivessel coronary bypass surgery in diabetics: a propensity-matched analysis

OBJECTIVES

To determine whether the use of the radial artery (RA) vs the saphenous vein (SV) as the second grafting conduit with the internal thoracic artery (ITA) confers a late-survival advantage in diabetes mellitus (DM).

METHODS

We reviewed our 1996-2007 DM coronary artery bypass grafting (CABG) experience. Study patients (N = 2281) included all primary, non-salvage multigraft CABG discharged alive and receiving ≥1 ITA graft. Bilateral ITA, ITA-only grafts or concomitant valve/aortic surgery patients were excluded. A non-parsimonious, RA use propensity model (42 variables) was derived excluding five factors [gender, vessel disease, insulin, renal failure and left ventricular (LV) dysfunction] that were always strictly matched for all pairs. Greedy matching resulted in well-matched ITA/RA and ITA/SV cohorts (N = 578 each). The late follow-up was truncated at 16 years, and survival comparisons were done by Kaplan-Meier analysis.

RESULTS

RA grafting was used in 933 (41%) DM patients and was more frequent for non-insulin (513/1348; 49.1%) compared with insulin (271/784; 34.6%) dependent patients. Relatively fewer insulin ITA/RA (169; 62%) could be matched vs non-insulin (469; 71%). Late survival was significantly better for ITA/RA overall [hazard ratio, HR (95% confidence interval) = 0.78 (0.65-0.95); P = 0.012], but this was primarily due to the non-insulin sub-cohort [HR = 0.72 (0.56-0.91); P = 0.007] as opposed to no effect for insulin [HR = 0.92 (0.68-1.26); P = 0.61]. Sub-cohort analysis revealed a significant ITA/RA survival advantage in males, preserved LV function and three-vessel disease. No sub-cohorts were associated with superior ITA/SV survival.

CONCLUSION

Our analysis indicated that RA grafting confers a significant late-survival advantage and, thus, supports its liberal use in DM patients undergoing multivessel CABG.