Forearm Blood Flow Preserved Long After Radial Artery Harvest

Patrice Wendling

October 17, 2018

The longest postoperative follow-up thus far of radial artery grafts in patients undergoing coronary artery bypass grafting (CABG) surgery speaks to the long-term safety of this oft-overlooked conduit.

"Harvesting of the radial artery is safe for the forearm in terms of both blood flow and its propensity to form atherosclerosis in the long-term," study author Alistair G. Royse, MBBS, MD, Royal Melbourne Hospital, Australia, told | Medscape Cardiology.

Among 86 patients who underwent CABG 12 to 22 years ago, high-frequency ultrasound showed total forearm flow was not different between the harvested and nonharvested side at rest (238 vs 249 mL/min; P = .123) or after maximum ischemic exercise (918 vs 963 mL/min; P = .114).

"This provides assurance that the harvested forearm and hand may be used in vigorous daily activities without restriction," Royse and his colleagues write in a letter published online October 8 in the Journal of the American College of Cardiology.

Flow in the remaining ulnar artery was stronger on the harvested side than on the nonharvested side (84 vs 43 mL/min; < .001). At rest, there was a small reduction in flow at the wrist in the ulnar artery compared with the combined ulnar artery and radial artery flow on the nonharvested side (84 vs 92 mL/min; P = .04), "but this secondary outcome was not considered clinically significant," they note.

Further, there was no evidence of accelerated atheroma formation in the ulnar artery as a result of chronically increased blood flow.

Although there is a fair amount of data supporting radial or mammary arteries over saphenous vein grafts (SVG), up to 95% of contemporary CABG is performed without use of the radial artery. Royse said he hasn't used a vein graft in more than 10 years and that the total arterial revascularization rate at the Royal Melbourne approximates 85% since 1996.

"So our practice is vastly different to what is the case in almost every center across the United States, and the primary reason to be able to achieve that total arterial revascularization rate is reliance on the radial artery," he said.

"I'd say 90% of patients having multivessel coronary bypass would have one or more radials used," Royse continued. "That flies in the face of pretty much every other general consideration elsewhere, where they think it's a terribly sensitive conduit that has to be used sparingly and in special circumstances and so on and so forth. We say that is not the case and we have over 20 years of use to prove it."

When a saphenous vein graft is used, however, survival suffers, according to a recent study by the investigators using data from more than 50,000 CABG patients in the Australian and New Zealand Society of Cardiothoracic Surgeons database.

It showed that survival out to 12.5 years was 19% lower if even one SVG was used and 24% lower if one or more SVGs were used. Rates were similar, at 22%, for both comparisons in propensity score-matched analyses.

Limitations of this study include a lack of long-term functional assessment of the arm, although this was done in early follow-up and no significant impact of the harvest on sensation or strength was shown, Royce said.

"From the patients that we followed-up in this study and anecdotally from pretty much every other patient we've done coronary bypass on, there's essentially no functional or significant sensation loss," he said.

Early in their experience, two patients had small-vessel digit ischemia related to the radial artery harvest but both had a collagen-vascular disorder. As to the use of radial artery conduit in such patients, Royce said, "we would be cautious but not prohibit it."

Of the study's 86 patients (mean age, 74.2 years; 94% male), nearly half (47%) had diabetes, 92% had hypertension, and 34% had body mass index of 30 kg/m2. or higher.

The authors report no relevant financial relationships.

J Am Coll Cardiol. 2018;72:1981-1982. Abstract

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