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Page 4 of 8 Machiraju. Vessel Plus 2019;3:25 I http://dx.doi.org/10.20517/25741209.2019.08
[10]
where a durable LITA graft to LAD is created through a Lt anterior small thoracotomy and remaining
stenotic vessels were dilated and stented by the cardiologists. In addition, the mean age of patients having
surgery became much higher and several comorbidities that increased overall surgical risk. Pre-existing
cerebrovascular disease, chronic hemodialysis, advanced malignancy and severe chronic obstructive
lung disease are few conditions to name that influenced plan of surgical treatment. More females are
having surgery who are in general are higher surgical risk compared to men with similar risk factors. The
difficulties encountered in constructing a satisfactory bypass graft through a small thoracotomy incision
resulted in off-pump bypass surgery through median sternotomy. This approach also broadened the access
to bypass other vessels like Rt. and Cx. coronary artery branches.

With rapid expansion of cardiac surgery into the community hospital setting, the total number of
CABG surgeries performed by an individual surgeon has significantly decreased and simultaneously the
experience to tackle difficult coronary surgical cases. They have adopted the general notion that bypassing
one vessel in each territory of myocardium is enough to relieve the patient of his anginal symptoms and
multiple bypass grafts will only prolong the operation and subsequently increase the immediate post op
complications like perioperative bleeding, low cardiac output syndrome and need for prolonged ventilatory
support. At one time majority of the surgeons had the comfort zone and experience to expose deep
intramuscular LAD embedded in the interventricular septum, perform extensive endarterectomies in the
vessels with diffuse atherosclerosis and bypass even the main CX coronary artery in the atrioventricular
(AV) groove when the marginal branches were too many and too small for bypass. Generally main CX
in the AV groove is free of atherosclerosis and is of larger caliber. Though coronary vessels are epicardial,
some-times the proximal LAD and ramus or the first marginal branches are deeply embedded in the
cardiac muscle that needed patience to identify and dissect out these vessels for bypass. These intra-
muscular vessels are again free of atherosclerosis that they are best suitable for bypass. These anatomical
variations are the cause of IR in the hands of less experienced Surgeons. The difficulty is compounded in
obese patients where the heart is covered with lot of fatty tissue and during redo coronary artery bypass
graft surgery. PCI also became an established modality to treat CAD and experienced interventional
cardiologist had shown excellent results in stenting multiple stenotic coronary arteries. Vein graft
atherosclerosis resulted in stenotic bypass grafts which required redo-CABG. In late 90s, 15%-20% of the
coronary artery surgical volume in all major surgical centers happened to be redo bypass surgery. With
the advances in medical therapy and PCI, redo bypass surgery has significantly decreased. Perioperative
use of statins helped to stabilize vein graft atherosclerosis so that cardiologists are able to address vein
graft stenosis. As the surgical volume decreased, the peripheral cardiac surgical centers which at one
time had two cardiac surgeons, are able to hold on to only one cardiac surgeon who doesn’t want to take
excessive responsibility of tackling difficulty cases. Public awareness of individual surgeon’s data including
surgical volume, mortality, morbidity and hospital readmissions following CABG surgery by the local
state governments did not help the matters either. The number of grafts they are performing had come
down as evidenced by the society of thoracic surgeons (STS) data base published in 2018. As per the STS
the published data in 2016 showed that in spite of increase in CABG procedures per the year by 6.1% to a
[11]
total of 156,931, the number of 4 and 5 distal anastomosis are much fewer than the previous years . As
the isolated CABG procedures have gone down there has been a significant increase of valve with CABG
procedures like aortic valve replacement or mitral valve/replacement. This has changed the complexity
of the surgery as such surgeons focused on the main coronary artery branches for revascularization and
proceeded with valve surgery. This is evidenced by the higher pre-operative risk assessment both by
euroscore and STS risk calculator.

Off-pump coronary artery bypass surgery
While majority of cardiac surgeons are able to perform a satisfactory bypass to the blood vessels that
are in the front of the heart while the heart is beating, only a few surgeons could master the technique