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Page 6 of 8 Machiraju. Vessel Plus 2019;3:25 I http://dx.doi.org/10.20517/25741209.2019.08

much easier to use for multiple sequential grafting than mammary arteries or RA artery. LIMA graft has
varying size and blood flow depending upon the body size and patient’s age. Lt subclavian artery stenosis
used to be a problem in the pre-angioplasty era but now even a critical stenosis in the subclavian artery
is successfully dilated and stented, restoring blood flow in the mammary graft. Initially the mammary
artery was removed from underneath sternum as a pedicle graft but skeletonizing the internal mammary
became the preferred method, leaving capillary collaterals behind to feed the sternal edges. This technique
is highly recommended in diabetics, females and whenever bilateral mammary arteries are used for bypass
surgery. However skeletonizing the artery had challenges like injury to the arterial wall, development
of intramural hematoma and intimal dissection leading to failure to use the graft. Various vasodilator
pharmacological agents can be instilled over the mammary pedicle in-order to dilate the vessel and
increase the blood flow. While the LIMA graft is used preferentially as an in situ graft, RIMA is used as
an in situ or as a free graft depending upon the planned surgery. RA artery became the alternate arterial
conduit after mammary arteries but developed arterial spasm because of the thick muscular wall and also
evidence of calcification in elderly patients. Perioperative use of Calcium channel blockers has increased
the patency of the RA artery graft but the limitation is that it’s use is recommended to bypass the vessels
with 90% or more stenosis to avoid any competitive blood flow. It showed better patency on the Lt coronary
artery system than on the right side. Though RA artery showed better long-term patency as compared to
the saphenous vein graft, because of the limitations it had, it is not as frequently used as recommended in
the literature. The use of RIMA as a second arterial graft to the Lt coronary system obviated the need for
a third arterial graft. Removal of both RIMA and RA artery became a time-consuming operation with
added complications, and surgeons didn’t want to use both unless there is definite benefit to the patient.
The gastroepiploic artery also is prone for spasm and showed inconsistent blood flow. Constant research is
going to improve the patency of the vein grafts by external stenting or other methods or to find a synthetic
graft that can be used when patient doesn’t have suitable conduit.

[7]
There was a push by Taggart in UK, Puskas in USA for performing CABG with only arterial grafts.
Using both internal thoracic arteries for CABG surgery was promoted as a must to do thing. It did not
become popular among American surgeons as majority of the patients that came for surgery are not only
old but have several comorbidities that increased their over-all risk. After following for 10 years other than
a LIMA graft to the LAD using all arterial grafts when compared to a single arterial graft and remaining
venous grafts, didn’t increase the survival benefit in elderly patients but the younger patients may benefit
from multiple arterial grafts if their natural life expectancy is 10 years or beyond. The survival benefit of
any procedure depends upon the biological and anatomical age of the patient. That is also true with CR as
younger patients tend to live longer and symptom free while older patients with low ejection fraction tend
[17]
to have heart failure symptoms .

CONCLUSION
As the saying goes “There was never a successful incomplete operation”. The gold standard of CABG
still remains as the CR performed by an experienced operator so that all the blood vessels with critical
stenosis can be tackled. The goal can be achieved by off-pump or on-pump surgery or by PCI. Complete
revascularization rewards patients with symptom free or risk free postprocedural period. There were
several clinical trials that studied CAD and therapeutic interventions over the years. There may be minor
differences in the conclusions but majority of the studies do concur that CR gives better survival and
symptom free life.

SPECIAL NOTE
This article reflects the surgical practice that is popular in USA and may vary from the common practice
globally.