Panel Discussion: Session III—Natural History and Dissection Moderator: Joseph S. Coselli, MD Panelists: Joseph E. Bavaria, MD, John A. Elefteriades, MD, Anthony L. Estrera, MD, Steven L. Lansman, MD, PhD, Christoph Nienaber, MD, PhD, Thoralf M. Sundt, III, MD, and Stephen Westaby, PhD, MS DR JOSEPH S. COSELLI (Houston, TX): I believe we have some time for a panel discussion. First question. DR FREDERICK A. MEADORS (Little Rock, AR): My question has to do with the 5-cm ascending aorta. I think all of us are called to the catheterization laboratory or by the radiologist to evaluate patients with the incidentally discovered 5-cm ascending aorta. In the course of discus- sions yesterday, it came out that the Marfan patient with a positive family history of catastrophic proximal dissec- tion would be one patient group that we would recom- mend surgical treatment at less than 5-cm maximal diameter, and I think the bicuspid aortic valve patients perhaps would fall into this category also. My question is are there any other groups that we should include in this category of patients that might warrant surgery for 5 cm or less? And also I was a little taken aback and interested that 40% of our acute dissections in the IRAD database are smaller than 5 cm, and that leads me to my next question. Is there anything that we as community surgeons should be doing in the next couple of years— before the next convening of this meeting when perhaps we will have more information about biological markers—to help us pinpoint which patients other than the two groups I mentioned might be at risk for acute aortic dissection, which is obviously a very real entity and a risk to the general population? DR COSELLI: For the first part, from my own work, I am fairly aggressive about aortas even in the 4-, 4.5-cm range, when I have to be there for another reason, valve, coronary, et cetera. When I am looking at aortic size of the ascending aorta as a stand-alone issue, I follow the 5.5-cm criterion, by and large, and then I lower that for patients with Marfan syndrome and for patients with familial aortic dissection. Does anyone else on the panel care to address this? DR JOSEPH E. BAVARIA (Philadelphia, PA): Just like you, I use 4.5 cm if there is a positive family history of Marfan’s or dissection. The Marfan’s is a little bit more complicated, because I am with Reed Pyeritz—you saw the data from Duke Cameron yesterday—and he is pretty aggressive about trying to get some of these 4.6-, 4.7-cm aortas in Marfan’s done. We use 5.0 cm if you have moderate or worse aortic valve disease, because that is kind of a two-for-one operation, and we use 5.5 cm for everybody else. But John is here, and I would like to ask him a question. Your talk today was interesting concerning measurement of aortic wall thickness. We are getting our engineers at Penn involved in this, too. That would be one area where you would operate earlier: if you knew the wall thickness to be very thin, especially in some of these little ladies. What is your opinion? DR JOHN A. ELEFTERIADES (New Haven CT): We measure the wall thickness by epiaortic echo. I didn’t think we would be able to do this, but George Kulius was determined, and if you magnify your image, you can actually get a very reproducible measurement. We mea- sure it three times in a row and then we average those measurements. We are in the process now of trying to use TEE to do that. I was speaking with one of the members in the audience about that, and I think pretty soon we will be able to get the same measurements by TEE before going to the OR, so that it can be incorporated into the preoperative measurements. In terms of the size for intervention, I think we have to be careful, as coronaries become less frequent, not to get overenthusiastic in our intervention criteria for ascend- ing aneurysms. When you look at it from the point of view of patients who have dissected and come to you, there are a couple of important factors to keep in mind. One is that the aorta grows acutely at the time of dissection, somewhere between a half a centimeter and a centimeter. So that aorta was smaller before the acute event occurred. The other thing is that you don’t know how large your denominator is, of patients floating around in the world with aortas in the range of 4, 4.5, 4.8 cm. I think that denominator is very large. So just a word of caution not to become overaggressive in intervening in these patients before the risk level becomes very high. DR COSELLI: If you are measuring an epiaortic scan, you have already decided to be there. Have you used aortic wall thickness as a marker for preoperative deci- sion-making yet, or is that still in evolution? DR ELEFTERIADES: It is still in evolution; we have used it to calculate the wall stress. The thicker the wall, the less the stress: that is part of Laplace’s law. We hope to be able to convert our measurement to a preoperative criterion for intervention. Presented at Aortic Surgery Symposium X, New York, NY, April 27–28, 2006. © 2007 by The Society of Thoracic Surgeons Ann Thorac Surg 2007;83:S846–50 • 0003-4975/07/$32.00 Published by Elsevier Inc doi:10.1016/j.athoracsur.2006.11.091 SUPPLEMENT