Ann Thorac Surg 2003;75:1428
© 2003 The Society of Thoracic Surgeons
Original article: cardiovascular
Invited commentary
David A. Fullerton, MDa
a Cardiothoracic Surgery, Northwestern University Feinberg School of Medicine, Chicago, IL 60611, USA
e-mail: dfullerton{at}nmh.org
Performing an aortic valve replacement in a patient with previous coronary artery bypass grafting may be particularly unpleasant in the setting of a patent internal thoracic artery bypass graft (LITA) to the left anterior descending coronary artery. Injury to the LITA during sternal reentry and dissection occurs in at least 5% to 10% of reoperations. It is associated with a significant mortality rate and morbidity from perioperative myocardial infarction.
Even if not injured, the LITA poses the additional challenge of controlling its blood flow during the procedure. Leaving the LITA open during aortic occlusion and administration of cardioplegia almost certainly produces inhomogenious myocardial cooling and compromises myocardial protection; it has been associated with significant rates of perioperative myocardial infarction rate and mortality. Acknowledging the potential difficulty of occluding the LITA during the period of aortic occlusion, it does offer the advantage of secure myocardial protection. Nonetheless, finding and occluding the LITA within the operative field may be hazardous.
The technique reported by Kuralay and colleagues offers a straightforward means by which to safely control the LITA. When compared with the technique of open LITA blood flow at a systemic temperature of 20°C, supraclavicular occlusion of the LITA was associated with less pump failure, less need for inotropic agents, and no cardiac deaths. While the technique did not eliminate LITA injury, it offers safe and relatively easy control of LITA blood flow. It appears to permit better myocardial protection and may prove very helpful in any reoperation in which a patent LITA is present.
