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Harik et al. Vessel Plus 2023;7:30 https://dx.doi.org/10.20517/2574-1209.2023.124 Page 9 of 16

associated with significantly lower early postoperative arm pain (mean visual analog scale [VAS] score 0.35
[61]
vs. 2.64; P < 0.001) and an overall increase in patient satisfaction (mean VAS score 9.83 vs. 5.2, P < 0.001) .
However, ERAH may be associated with poorer graft patency and cardiac outcomes compared to ORAH, a
safety concern based on studies that report lower patency rates of the endoscopically harvested SVG [31,32] .
Older in vitro studies found no difference in endothelial function between ORAH and ERAH [62,63] , but a
more recent organ bath study found ORAH to be associated with better preservation of endothelial function
than ERAH . The data on cardiac outcomes after ERAH are limited. A meta-analysis of four small RCTs
[64]
and two propensity-matched observational studies and 743 patients (324 ERAH) comparing ERAH and
ORAH found no difference in 30-day mortality (OR 0.78, 95%CI: 0.10-6.11; P = 0.81), five-year mortality
[65]
(OR 0.67, 95%CI: 0.11-4.17; P = 0.66), or graft patency (OR 1.32, 95%CI 0.76-2.27; P = 0.32) ; another
meta-analysis of 24 studies, including 15 observational studies (12 unadjusted studies) found a similar
association between ERAH andORAH and 30-day mortality, survival, and graft patency . To date, there
[66]
has been no adequately powered RCT comparing cardiac outcomes of ERAH and ORAH, and the topic
requires further study.

Graft configuration
The RA may be anastomosed directly to the aorta, or as a composite with other grafts , typically the ITA as
[10]
a Y-graft . While the majority of available evidence about the RA is derived from RA-aortic
[67]
anastomoses , little evidence to date suggesting that RA graft configuration influences patency. In a
[67]
retrospective study of 228 CABG patients receiving the RA (131 grafted directly to the aorta), there was no
difference between the patency of the RA grafted directly to the proximal aorta (92.0%) and the RA grafted
to the ITA (86.3%; P = 0.81) at mean 6.5-year follow-up .
[68]

Target vessels
The RA is at higher risk of vasospasm and competitive flow than other conduits if grafted to coronary target
vessels with only mild or moderate degrees of stenosis [69-71] . A retrospective study of 123 CABG patients (382
distal anastomoses) found an overall RA patency of 92% at a mean angiographic follow-up of 2.7 years;
however, RA patency was lower when grafted to the right coronary circulation than to the left(79.4% vs.
94.4%; P < 0.05) and was also lower when grafted to targets with 50%-90% stenosis than with > 90% stenosis
[70]
(83.3% vs. 98.0%; P < 0.05) .
Sequential grafting
Evidence on the effect of individual vs. sequential grafting on RA patency is limited. A recent study of 208
CABG patients (125 with individual grafting) and 293 anastomoses reported no difference in individually
grafted or sequentially grafted RA patency at 10-year follow-up (88.7% vs. 87.4%; P = 0.88) . However,
[72]
another retrospective observational study of 410 CABG patients receiving the RA with five-year mean
angiographic follow-up found that sequential RA grafting was associated with better patency compared with
individual grafting (HR 2.53, 95%CI: 1.29-5.28; P = 0.006) . The degree of target vessel stenosis may
[73]
mediate the patency of the sequentially grafted RA. A recent study of 432 patients (1,221 distal RA
sequential anastomoses) found that patency was higher for the sequentially grafted RA when grafted to
coronary arteries with > 76% stenosis than coronary arteries with 51%-75% stenosis (88.6% vs. 59.1%; P <
0.001) .
[74]
Pharmacotherapy
The RA is a highly muscular conduit with a potential risk of vasospasm, demonstrated in both
pharmacologic studies and reporting from RA access during coronary angiography and stenting [66,75] , and its
prevention is the target of antispasm medical treatment with calcium channel blockers (CCBs). However,
the available data on the effect of CCB on the RA are mixed. Two small RCTs, one examining the effect of