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Dewantoro et al. Vessel Plus 2018;2:20 I http://dx.doi.org/10.20517/2574-1209.2018.50 Page 3 of 9
[7,8]
eration while being chosen as a conduit . As discussed above, there is a requirement for the adequacy of
ulnar flow in order to act as a collateral blood supply. This can be assessed by modified Allen’s test and com-
plemented by pulse oximetry and echo-Doppler. Also, calcified radial arteries or those with diameter of less
than 2 mm are generally excluded from harvesting. There might be sensory abnormalities and motor weak-
ness in the forearm after removal of radial arteries, and there is a requirement for the use of vasodilators as
radial arteries are infamous for their striking spastic reactions to vasoconstrictors and hypothermia. While
skeletonization is described to provide a longer graft with larger diameters, less spasms, and better patency
[8]
frequencies, it increases the harvesting time and the risk of severe graft injury .

However, a recent metanalysis evaluated 534 patients with radial-artery grafts and 502 patients with saphe-
nous-vein grafts, concluding that as compared with the use of saphenous-vein grafts, the use of radial-artery
grafts for CABG resulted in a lower rate of adverse cardiac events and a higher rate of patency at 5 years of
follow-up. At follow-up angiography, the use of radial-artery grafts was also associated with a significantly
lower risk of occlusion (hazard ratio: 0.44); lower incidence of myocardial infarction (hazard ratio: 0.72) and
[9]
a half incidence of repeat revascularization .

POST-OPERATIVE OUTCOMES
The post-operative outcome of a procedure is crucial in deciding on whether such procedure is worth doing,
especially in term of benefits and harm for the patients. Several studies have compared the outcome of coro-
nary artery revascularization that will be compared in this article (considering only CABG) and comparing
the data based on whether CABG done in the study is TACABG or VCABG.

Patency
In general, when comparing ITA and SV when they were acting as conduits, several studies such as a follow-
[10]
up Cooperative Studies Trial done by Goldman et al. , showed that ITA had better patency as shown by the
10-year angiogram of the study mentioned. The 10-year patency was 61% for SVG and 85% for ITA. Howev-
er, the number of patients has been declining during the 10 years’ period, so that at 1 week the study cohort
consisted of 1025 patients but at 10 years follow up the study cohort declined to just 85 patients. However,
from the study’s graft, it is shown that the percentage of patent grafts has always been higher in ITA as com-
[10]
pared to SVG . Another study done in order to determine the post-CABG prognostic factors for athero-
sclerosis progression that further supports the superiority of arterial grafts as the saphenous vein conduit’s
patency, due to it being prone to develop atherosclerosis, may act as a limiting factor for better prognosis of
[11]
revascularization .
This is confirmed by a prospective study aiming to find out the patency of right ITA (RITA) as compared to
other conduit vessels. The study showed that, at 10 years, the patency of RITA is at least 90%; RA is 70%; and
[12]
SVG is 50% . Thus, confirming that arterial conduits are more patent than saphenous venous conduits.

Long-term clinical outcomes
Mortality and serious adverse events are the key points when comparing TACABG with VCABG. However,
no direct comparison could be made using current clinical data due to the lack of tailored studies, but TA-
CABG and VCABG could be indirectly evaluated with the results of some trials.

According to a non-blinded prospective, randomized, open-label, non-inferiority trial published in 2016, out
of 592 patients with left main disease, with mean age of 66.2 years, the 5-year Kaplan-Meier outcome esti-
mated for all-cause mortality is 32 patients (9%); major adverse Cardiac and Cerebrovascular Events (MACCE)
[13]
occurred in 80 patients (18%); total revascularization rate is 10%, and stroke incidence was 2% . During this
study, there seem to be no propensity score analysis done but the 5-year Kaplan-Meier estimates were strati-
fied into groups based on SYNTAX score in order to reduce propensity bias.