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Introduction
INTRODUCTION
Historical background:
One aim of coronary artery bypass grafting (CABG) surgery is to
preserve normal left ventricular (LV) function and to improve abnormal
LV function. On the other hand, LV function is an important prognostic
predictor for the outcome of patients undergoing CABG (Wheatly DJ.,
1986).
A number of surgical procedures were advocated to the control of
angina as division of cervical sympathetic nerves by Jonnesco in 1916,
total thyroidectomy with resultant complications as myxoedema and
frequent tetany, to be discarded in the early 1940s (Kshettry VR, et al.,
2000).
Other techniques were employed as ligation of both internal
mammary arteries to increase blood flow to the heart via the
pericardiophrenic branches proximal to the ligatures in 1939 (Ascione R,
et al., 1999).
Creation of epicardial and pericardial abrasion to provoke adhesion
with a variety of chemical and physical irritants was also used to
improve blood supply to myocardium. Many attempts were made to
provide additional perfusion to the myocardium by wrapping omentum,
skeletal muscle flaps or lung around the heart (Ochsner JL and Mills
NL., 1978).
Performed surgical stenosis of the coronary sinus (Beck I
procedure) and implantation of a vein graft to the coronary sinus (Beck II
procedure-two stage operation) to produce venous stasis was done to
improve blood supply via thebesian veins. In 1946 Vineberg introduced
the procedure of implanting the freely bleeding divided end of the
internal mammary artery into the myocardium, with 90%of patients
having complete or near complete relief of angina (Kshettry VR, et al.,
2000).
The first coronary artery bypass operation was performed by
Sabiston in 1962, and patient died of cerebrovascular accident
afterwards the first successful coronary bypass surgery was in 1964 by
Garrett. Aiicen and associates reported clinical use of internal
mammary artery to coronary artery anastomosis in 1968 (Stephenson
LW., 2003).
Cardiopulmonary bypass (CPB) and cardioplegic cardiac arrest
have become the mainstays of coronary artery bypass grafting (CABG),
providing still, bloodless, and accessible coronary artery sites for
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Introduction
anastomosis. The high incidence of coronary artery disease along with
the ease and safety of performing (CABG) have made this procedure
common (Wheatly DJ., 1986).
Conventional coronary artery bypass grafting (CABG) is both safe
and effective. Nevertheless, the use of cardiopulmonary bypass (CPB)
and cardioplegic arrest are associated with several adverse effects. The
morbidity and mortality of (CABG) is to a significant extent secondary
to the use of (CPB), cardiac arrest, and hypothermia, with a generalized
inflammatory response, including complement activation, cytokine
release (Stephenson LW., 2003).
Myocardial revascularization "off pump" was first performed by
Kolessov in 1967 to the anterior arteries of the heart, preferably to the
anterior descending artery, the right coronary artery (RCA), or a diagonal
artery, and Favaloro in 1968 mainly to (RCA). The goal of off-pump
(CABG) was to decrease trauma while maintaining surgical efficacy.
Over the last 2 years there has been a revival of interest in performing
(CABG) on the beating heart. Off-pump coronary artery bypass
(OPCAB) is an emerging procedure. It is assumed that elimination of
cardiopulmonary bypass for coronary artery bypass grafting has the
potential for reducing postoperative morbidity (Weinschelbaum EE, et
al., 2000).
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