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Page 2 of 15 Ashenhurst et al. Vessel Plus 2024;8:3 https://dx.doi.org/10.20517/2574-1209.2023.90

[1]
globally in 2019 . Coronary artery disease (CAD) is the most common cardiovascular disease and is
associated with a significant economic and social burden. The direct and indirect cost of healthcare
[1]
expenditures and loss of productivity, for example, are estimated to be a multi-billion-dollar loss .

[2]
Evidently, the treatment of CAD has had a robust history. First conceptualized in 1910 by Carrel as an
experimental procedure, coronary artery bypass grafting gained popularity as a surgical treatment for CAD
[3]
in the 1960s after its initial iteration by Kolesov and Potashov . Venous or arterial conduits are used to
bypass atheromatous blockages in coronary arteries, restoring blood supply to the ischemic myocardium.
The median sternotomy incision typically employed in the surgery provides a clear view of the operating
field and easy manipulation of the heart . Although still considered the “gold standard” incision , the
[4]
[5]
invasiveness of sternotomy is nearly unchanged from its inaugural procedure. Each year, nearly 300,000 and
15,000 individuals undergo CABG in the United States and Canada, respectively, making it one of the most
common surgeries performed . Still, traditional CABG is associated with significant invasiveness,
[5-7]
including that related to the use of cardiopulmonary bypass (CPB) and a sternotomy incision [8-10] .
Procedures that reduce the morbidity of CABG through less invasive techniques have been developed and
adopted . This article summarizes the evolution of minimally invasive coronary artery bypass grafting, the
[11]
early, long-term, and functional outcomes, and outlines strategies to implement MICS CABG in cardiac
surgery programs.

INDICATIONS
The 2021 ACC/AHA/SCAI Guidelines outline the indications for patients to undergo coronary
revascularization . The patients’ preferences, goals, cultural beliefs, health literacy, and social determinants
[4]
of health are to be considered and adequate information concerning benefits, risks, and potential
consequences is to be disclosed before proceeding to ensure their best interest is at the center of the
treatment decision.

For patients presenting with stable ischemic heart disease (SIHD) and significant left main stenosis, CABG
is indicated. Historically, CABG was also indicated in patients with SIHD, triple vessel disease, and normal
left ventricular ejection fraction (LVEF) . However, the 2021 guidelines lowered the indication of CABG
[12]
for these patients from a Class 1 to a Class 2b recommendation . There has been controversy surrounding
[4]
the downgrade of these indications, and this change has not been endorsed by several cardiologic and
surgical societies [13,14] . Instead, the societies suggest that randomized control trials and meta-analyses have
established strong evidence that surgical intervention does improve patient survival over medical
[15]
intervention .

Healthcare professionals must assess the perioperative risks and comorbidities and consider if they
outweigh the surgery’s benefit before proceeding. Patient refusal and anatomical incompatibility with
grafting constitute the general contraindications for CABG. Unsuitable conduits and targets, non-viable
myocardium after infarct, and the presence of anatomical barriers such as porcelain aorta or mediastinal
radiation make surgical revascularization complex and more risky [4,5,16] .

The indications for MICS CABG are similar to that of conventional sternotomy CABG. Additionally, MICS
CABG is employed in cases of left main coronary artery disease with normal right coronary artery disease,
previous unsuccessful PCIs, triple vessel disease with medium to large PDA or left ventricular branch of the
RCA, and complex proximal left-sided lesions in the presence or absence of main branch involvement .
[17]
Patients with less diffuse coronary artery may elect to undergo MICS CABG due to its reduced invasiveness
[18]
and improved functional outcomes . Furthermore, for patients who are at high risk of complications