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REFERENCES

1. Crawford ES, Cohen ES. Aortic aneurysm: a multifocal disease. ArchSurg 1982;117:1393-400.

2. Patel VI, Ergul E, ConradMF, CambriaM, LaMuraglia GM, Kwolek CJ,et al. Continued favorable results with open surgical repair of type IVthoracoabdominal aortic aneurysms. J Vasc Surg 2011;53:1492-8.

3. Harrison GJ, Oshin OA, Vallabhaneni SR, Brennan JA, Fisher RK,McWilliams RG. Surveillance after EVAR based on duplex ultrasoundand abdominal radiography. Eur J Vasc Endovasc Surg 2011;42:187-92.

4. Schmieder GC, Stout CL, Stokes GK, Parent FN, Panneton JM.Endoleak after endovascular aneurysm repair: duplex ultrasoundimaging is better than computed tomography at determining the needfor intervention. J Vasc Surg 2009;50:1012-8.

5. Manning BJ, O’Neill SM, Haider SN, Colgan MP, Madhavan P,Moore DJ. Duplex ultrasound in aneurysm surveillance followingendovascular aneurysm repair: a comparison with computed tomog-raphy aortography. J Vasc Surg 2009;49:60-5.

6. Sternbergh WC 3rd, Greenberg RK, Chuter TA, Tonnessen BH.Redefining postoperative surveillance after endovascular aneurysmrepair: recommendations based on 5-year follow-up in the US Zenithmulticenter trial. J Vasc Surg 2008;48:278-84.

7. Chaikof EL, Brewster DC, Dalman RL, Makaroun MS, Illig KA,Sicard GA, et al. SVS practice guidelines for the care of patients with anabdominal aortic aneurysm: executive summary. J Vasc Surg 2009;50:880-96.

8. Wilmink TB, Quick CR, Day NE. The association between cigarettesmoking and abdominal aortic aneurysms. J Vasc Surg 1999;30:1099-105.

9. Vardulaki KA, Walker NM, Day NE, Duffy SW, Ashton HA, Scott RA.Quantifying the risks of hypertension, age, sex and smoking in patientswith abdominal aortic aneurysm. Br J Surg 2000;87:195-200.

10. Golledge J, van Bockxmeer F, Jamrozik K, McCann M, Norman PE.Association between serum lipoproteins and abdominal aortic aneu-rysm. Am J Cardiol 2010;105:1480-4.

11. Forsdahl SH, Singh K, Solberg S, Jacobsen BK. Risk factors forabdominal aortic aneurysms: a 7-year prospective study: the TromsøStudy, 1994-2001. Circulation 2009;119:2202-8.

12. Limet R, Sakalihassan N, Albert A. Determination of the expansion rateand incidence of rupture of abdominal aortic aneurysms. J Vasc Surg1991;14:540-8.

13. Bernstein EF, Chan EL. Abdominal aortic aneurysm in high-riskpatients. Outcome of selective management based on size and expan-sion rate. Ann Surg 1984;200:255-63.

14. Cronenwett JL, Murphy TH, Zenlock GB, Whitehouse WM Jr,Lindenauer SM, Graham LM, et al. Actuarial analysis of variablesassociated with rupture of small abdominal aortic aneurysms. Surgery1985;98:472-83.

15. Cronenwett JL, Sargent SK, Wall MH, Hawkes ML, Freeman DH,Dain BJ, et al. Variables that affect the expansion rate and outcome ofsmall abdominal aortic aneurysms. J Vasc Surg 1990;11:260-9.

16. Badran MF, Gould DA, Raza I, McWilliams RG, Brown O, Harris PL,et al. Aneurysm neck diameter after endovascular repair of abdominalaortic aneurysms. J Vasc Interv Radiol 2002;13:887-92.

17. Makaroun MS, Deaton DH, the Endovascular TechnologiesInvestigators. Is proximal aortic neck dilation after endovascularaneurysm exclusion a cause for concern? J Vasc Surg 2001;33:S39-45.

18. Cao P, Verzini F, Parlani G, De Rango P, Parente B, Giordano G,et al. Predictive factors and clinical consequences of proximal aorticneck dilation in 230 patients undergoing abdominal aorta aneu-rysm repair with self-expandable stent-grafts. J Vasc Surg 2003;37:1200-5.

19. Sternbergh WC 3rd, Money SR, Greenberg RK, Chuter TA. ZenithInvestigators. Influence of endograft oversizing on device migration,endoleak, aneurysm shrinkage, and aortic neck dilation: results fromthe Zenith Multicenter Trial. J Vasc Surg 2004;39:20-6.

Submitted Aug 16, 2012; accepted May 4, 2013.

DISCUSSION

Dr Mark Fillinger (Lebanon, NH). Nice presentation. It isinteresting that the rate of expansion for your suprarenal aorticaneurysms is lower than reported rates for infrarenal aneurysms.Is there information about how many patients were on statins oron the rate of hypertension? Were these patients more carefullymanaged medically? Or perhaps the visceral segment is just morestable?

Dr Benjamin J. Herdrich. I think based on this study it isreally unclear. We did not have demographic data on thesepatients, so we don’t know what percentage were on statins orwhat their blood pressure control was. We just had radiographicdata, such as the measurements of their aortas over time andwhether or not they had stent grafts and suprarenal fixation. Soit is really hard to draw conclusions from these data to answeryour question.

As to why the suprarenal aorta growth rates were less thanreported growth rates in the infrarenal aorta, I would just bespeculating. I will say it is interesting that the growth rates inour endovascular aortic repair (EVAR) patients were significantlyless than the growth rates in our control patients. And while Iwouldn’t go out on a limb and say that this proves that EVARcan promote remodeling of the suprarenal aorta, it is kind of aninteresting finding.

Dr Tara Mastracci (Cleveland, Ohio). I am interested toknow if you have any data on the rate of reintervention for theinfrarenal devices that were in these patients where you implantedthem with a concomitant aneurysm above. Specifically, did younotice there was a rate of failure for the devices when youimplanted with an aneurysm so close?

Dr Herdrich. This was primarily an anatomic study and notdesigned to look at additional outcome measures. I did presentdata showing that overall, for patients in both of our EVARgroups, the mean infrarenal aortic aneurysm size and volumedecreased in both of those groups. Now, that wasn’t true for everypatient. Some of those patients did go on to have increasing aorticsize, and we really don’t have data on the outcomes of that. Butoverall, I think that the procedures seemed to have been successfulgiven the fact that the infrarenal aneurysms shrunk.

Dr Mark Farber (Chapel Hill, NC). It appears these aren’tnecessarily your patients, these are M2S data sets that you are look-ing atddo you have any data on what the size of the suprarenaland superior mesenteric artery diameter is vs the infrarenal diam-eter? In our experience, rarely do we find patients with normalsuprarenal aortas and infrarenal aortic aneurysms that arecompletely isolated, as they generally have a dilated segment.

Because we are getting ready to embark on fenestrated graftsin the United States and we know from the Cleveland Clinic’sexperience that if you place grafts in already dilated or preaneurys-mal segments they tend to fail at a much higher rate, I am surprisedthat you haven’t looked at failure rates of the infrarenal devicesbecause I think it would be an interesting finding if you couldlook into that and let us know what those diameters are if youhave that data.

Dr Herdrich. We just don’t have the data on the failure ratesbecause this was an anatomic study. As for the diameters, ouraverage diameters of our infrarenal aortic aneurysms for our control,suprarenal, and infrarenal groups were 3.5 cm, 6 cm, and, I believe,5.4 cm. Now, the diameter at the renals, or actually 1 mm below the

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renals, for those groups was 27 mm, 27 mm, and 26 mm. And thenour suprarenal aortic sizes were 34 to 36 mm. So there is someinfrarenal aortic neck in all of these patients. The average infrarenalneck length was 18 to 22 mm, depending on the group. Now, insome of the patients, the neck was only a couple millimeters;however, in many patients, it was a sizable neck.

Dr Frederick Beavers (Washington, D.C.). I’d like to convertthis over to a little bit of just everyday practical medicine on twopoints. Number one, the majority of us probably don’t use M2Sas an imaging modality. It costs money, and insurance doesn’tcover it in a lot of locations. So we rely on our community radiol-ogists to read the computed tomography (CT) scans for us, unlesswe read them ourselves. Some reported literature says there isinterobserver error. And usually, if we rely on our community radi-ologists, we won’t get the same radiologist reading this CT scan.So how does that play into the data that you presented?

The second question is: There is a recent report out that in CTscans in adolescents, there is an increased incidence of brain cancerand leukemia. Once the lay public gets a hold of these data, I amconcerned that they may not want to follow these protocols thatwe are putting forth. Do you have any data that magnetic reso-nance (MR) technology is as sensitive as the CT scan results thatyou’ve reported?

Dr Herdrich. With regard to places that may not have accessto M2S, I think generally the measurements that we have pre-sented here are fairly basic measurements that can be made ona routine axial CT angiography. So I don’t know that you needM2S to make these measurements, but the M2S database wasa good source to get a large number of patients that had theseconcomitant aneurysms. I think out in the community, peoplewill still be able to use these data and make these measurements.

Dr Beavers. How about correlating the ability of MR tech-nology to be equivalent to CT?

Dr Herdrich. Well, I think that whatever test you use tomeasure the aortic size that as long as you get an accurate aorticsize that that is sufficient. Now, with MR technology the questionis, do you get an accurate aortic size? And I think that there aremany factors that go into itdwhat type of stent graft is beingused, what is the material of the stent graft, what is the experiencewith MR at your institutiondso you have to take all those thingsinto consideration.

We use ultrasound in some of these patients to monitor them,and that is another alternative. In patients who are thin and youcan get good views of the aorta, they don’t necessarily needa CT scan every 6 months or every year. You could consider usingultrasound in those patients.