Ann Thorac Surg 2000;70:8-9
© 2000 The Society of Thoracic Surgeons
Discussion
Discussion
DR M. ARISAN ERGIN (New York, NY): Doctor Kazui, I always admire your results. I think this is one of the largest series of selective cerebral perfusion in the literature—220 patients with impressive mortality and stroke rates. I have one question for you. We heard yesterday that even in routine coronary artery bypass grafting, regardless of whether the pump was used or not, stroke rate is still in the neighborhood of 2%. So your extensive surgery with a stroke rate of 3% is quite remarkable. I wonder if you have any tricks that you haven’t shared with us that would account for this excellent result?
DR KAZUI: Thank you for your comment and question. Data from The Society of Thoracic Surgeons indicate that stroke rate during coronary artery bypass grafting is about 5% or so. The main source of this stroke is probably the atherosclerotic plaque in the ascending aorta and the aortic arch, which dislodges and produces embolic stroke. So our philosophy is that in order to eliminate the main cause of this embolic stroke during surgery of the aortic arch aneurysms, the ascending aorta and the total arch should be resected at the same time to reduce the incidence of stroke. That is why I think the stroke rate in our hands is relatively lower than it is using other techniques. And I also think that antegrade cerebral perfusion and total arch replacement using an aortic arch branched graft play important roles in reducing stroke rate.
DR JOHN W. FEHRENBACHER (Indianapolis, IN): I have three questions for you, and two of them are technical. First, what was the temperature of the blood perfusate in your antegrade cerebral perfusion? Second, are there any tricks that you use when you put the catheters in the open arch vessels to get rid of air? And third, in your 3% of patients who had strokes, did computed tomography or magnetic resonance imaging indicate that the causes were mainly embolic or give any clues why those people had strokes?
DR KAZUI: As to the first question, the temperature of the perfusate is around 22°C. It sometimes falls further to 20°C. During the process of warming by extracorporeal circulation, the temperature of the perfusate might be higher than 22°C. But usually it does not take too long to perform the innominate and left common carotid artery reconstruction after the initiation of rewarming. In reply to the second question, the technique used in arch vessel cannulation is very important to prevent complications, and we usually completely transect arch vessels at undiseased sites, where atherosclerotic plaque or dissection is not present. Then we cannulate directly through the arteriectomy site. In the case of acute dissection, it is not difficult to distinguish between the false and true lumen from the lumen of the aortic arch. Therefore, it is not difficult to cannulate the true lumen through the arteriectomy site. When cannulating the arch vessels, blood perfusion is continued to get rid of air from the cannula while the arch vessels are cross-clamped. As for the third question, in 2 out of the 7 patients who had ischemic strokes after the operation, the strokes were probably due to profound shock before the operation. Of the other patients, 3 had strokes because of embolisms documented on computed tomography and 1 had a left vertebral artery ischemic stroke.
DR JOSEPH E. BAVARIA (Philadelphia, PA): I would like to congratulate you on a phenomenal series. These are incredibly extensive operations, and to have a 9.3% overall neurological dysfunction rate for such procedures is truly impressive. I noticed that your total circulatory arrest time for these big operations was on average well over 60 minutes and approaching 90 minutes. I might add that in our experience we would also go to an antegrade cerebral perfusion system for operations that take that long, which generally would include total aortic arch with brachiocephalic repair. Some extensive pulmonary thromboendarterectomies also may require antegrade cerebral perfusion. But my question for you is, What was the difference in total neurological dysfunction rate between the emergent group and the elective group?
DR KAZUI: Well, unless the patients were in profound shock before the operation, I think there was no significant difference between the stroke rates of the emergency and the nonemergency groups.
Related Article
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Total arch replacement using aortic arch branched grafts with the aid of antegrade selective cerebral perfusion
- Teruhisa Kazui, Naoki Washiyama, Bashar A.H. Muhammad, Hitoshi Terada, Katsushi Yamashita, Makoto Takinami, and Yukihiko Tamiya
Ann. Thorac. Surg. 2000 70: 3-8.
[Abstract]
[Full Text]
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