الفهرس 
grafting (CABG)Only 14 pages are availabe for public view
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Abstract
Coronary artery bypass grafting (CABG) became a common procedure in the 1970s largely as a result
of the excellent result afforded by a safe CPB and a still protected heart. However, high risk
group (e.g. old ages, patients with comorbidities) not able to tolerate this invasiveness.
Therefore, the surgical community has developed new techniques m order to make surgical coronary
revascularization more attractive to patients by trying to reduce the morbidity and cost associated
with the standard cardiac surgery.
Different surgical techniques were developed recently to perform CABG on the beating heart without
CPB to reduce the surgical trauma as well as reduce the need for transfusion and decrease the cost.
Sternotomy reql!ires a large incision, and the recovery to the point of normal use of upper limbs
takes 6-8 weeks. Therefore, avoidance of full sternotomy is another goal of the techniques.Alternative surgical approaches to the coronary vessels have been suggested and include a left
anterior thoracotomy, aright thoracotomy, and a variety of parasternal or partial sternotomy
incisions. The left thoracotomy approach has been termed the ”minimal invasive direct coronary
artery bypass” or (MIDCAB) and has been the most popular. The anastomosis is performed under direct
vision on the beating heart without CPB.
The motion of the heart in the area of anastomosis can be reduced by 90-95% with the placement of
the retractor’s stabilizing foot, a still bloodless field is then obtained with a tourniquet or
snare around the proximal vessel or intraluminal occluding device, these allowing for a safe and
technically accurate anastomosis to be done.
MIDCAB was standardized since the first specially designed devices became available for graft
harvesting and for local immobilization of the coronary anastomosis. An excellent approach can be
achieved by using the CTS cardiothoracic systems.
The main reason to reduce invasiveness of CABG is to perform the procedure without CPB. It is
important to have optimal immobilization of the myocardial surface at the site of
the target coronary artery. Different devices were compared, and the best immobilization could be
achieved with the CTS, and Medtronic Octopus device.
One of the main issues during MIDCAB is how to deal with systemic circulation without stressing the
heart during grafting. Systemic circulation must remain above certain level in order to prevent
organ failure beside the heart. Cardiac function is different due to possible ischemia during the
anastomotic phase and due to the dislocation of the heart in order to reach the different target
areas.
An important phase is also the period of applying the stabilizer. This may lead to substantial
cardiac compression, abrupt reduction in stroke volume and severely impaired systemic circulation.
Of course, this can be accepted for a short time, but how to normalize the heart and the systemic
circulation is a crucial issue for the anesthesiologist. Timing and anticipating on these events
are essential.
With the rapid introduction of ”minimal invasive” procedure, the anesthesiologist assumes
interactive role during surgery. The two major goals driving the development of minimally invasive cardiac surgery are the desire to avoid
CPB and the desire to use smaller incision.
The range of minimal-access approaches has many anesthetic implication (pre-intra-postoperative).
Much of the monitoring used during conventional CABG involves direct observation of the heart. This
is obviously not possible with smaller incisions, requiring the use of such new technologies as TEE
to supplement hemodynamic monitors. Many of the anesthetic concern will depend on the type of
surgical exposure and whether CPB is used. New techniques of intraoperative management developed to
meet the specific needs of minimally invasive cardiac procedure.
Again, it is concluded that the morbidity of CPB is a much greater medical consideration than the
morbidity of sternotomy. However, in the mind of the patient the cosmetic and pain aspect of
sternotomy predominate. MIDCAB on the beating heart can avoid many problems of CPB. Therefore, it
is important to encourage (CPB avoidance) and (sternotomy avoidance). The goal is to provide better
overall revascularization to a greater number of patients, with Jess physiologic trespass and
reduced morbidity, cost, and mortality.