Ann Thorac Surg 1995;59:834
© 1995 The Society of Thoracic Surgeons
Discussion
DISCUSSION
See also page 829.
DR HENRICK B. BARNER (St. Louis, MO): The authors have had a lot of experience with this particular model, and as was indicated, the ITA in the dog is rather large and has great capacity to supply flow versus the human ITA. It is a little difficult in studies like this to know whether the effects of a vasoactive drug, whether a dilator or a constrictor, are on the conduit itself or on the perfusion bed. It is not clear in my mind that it's readily possible to separate these effects in this model, although you have certainly made an effort to do so.
DR OTAKI: Thank you very much for your comments. This approach was chosen because the ITA is relatively large with respect to the coronary in dogs, as compared to humans, and so we elected to increase the fixed demands on the graft in this canine model by forcing it to perfuse two coronary systems. It is also important to note ITA graft dependent myocardial perfusion decreased with phenylephrine, although native coronary flow was increased under the same conditions, suggesting the potential for relative myocardial ischemia with systemic phenylephrine, secondary to ITA graft vasoconstriction.
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Distal Flow Determinants in Canine Myocardium Perfused Through Internal Thoracic Artery Bypass Grafts
- Masaki Otaki, Robert M. Lust, You Su Sun, Terry O. Norton, and W. Randolph Chitwood, Jr
Ann. Thorac. Surg. 1995 59: 829-834.
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