Future Directions
Computer-assisted surgery has made it possible to perform total
endoscopic coronary artery bypass grafting on the arrested heart.[39]
[40]
[41]
The interests
in avoiding the morbidity of cardiopulmonary bypass and performing coronary artery
bypass grafting on the beating heart have shown it to be applicable.[52]
[53]
[54]
[55]
[56]
[57]
Various
stabilization
Figure 66-10
Ultrasound image of the Remote Access Perfusion (Estech
Systems, Inc., Plano, TX) catheter balloon in situ. Transesophageal echocardiography
allows the anesthesiologist to keep track of migration of the catheter balloon.
The balloon should be positioned in the ascending aorta 2 to 4 cm distal to the aortic
valve. Right radial pressure catheter dampening can detect balloon malposition when
occlusion of the innominate artery occurs.
devices have made beating-heart surgery commonplace with conventional sternotomy,
and miniaturization of the stabilization devices have allowed their use in closed-chest,
robot-assisted surgery.[58]
Problems do exist and
need to be overcome. Because tactile sensation or palpation is not possible in closed-chest
surgery, intramyocardial arteries or vessels that are hidden under epicardial fat
are elusive. Internal thoracic arteries can also be less than superficial, adding
to the problem. The proposed target site may contain plaque or heavy calcification
that may make the anastomosis difficult and inferior. Epicardial ultrasound imaging
could possibly circumvent poor target sites and has been shown with the help of Doppler
to locate the course of intramyocardial coronaries and arteries hidden by epicardial
fat.[59]
Visualization systems are being developed that will improve surgery
on the beating heart. Advances in motion gating technology will allow the heart
to appear as if it is standing still. A properly timed strobe light that is synchronized
with the heart rate will achieve the proper virtual image of a heart standing still
or of virtual stillness.[2]
