Abstract
This study evaluated CT scans of small abdominal aortic aneurysms (AAAs) (< 5 cm) to assess anatomic features associated with rapid expansion. Serial CT scans obtained at least 10 months apart (mean 15 months) from patients with small AAAs were reviewed. Each cross-sectional image of the AAAs was analyzed using a computer-assisted design program. The circumference of the AAA in each CT image was divided into eight equal arcs, from which the apparent radius of curvature (Rc) for each segment was calculated. Flattening of the wall curvature results in an increased segmental Rc. The CT scans of nine patients with expanding AAAs (expansion ≥0.5 cm/yr) were compared to those of 10 patients with stable AAAs (expansion <0.2 cm/yr). To adjust for differences in AAA size, the Rc for each segment was normalized by dividing each individual Rc by the average of the eight Res (RcAvg) calculated for that cross-sectional CT image. Analysis of variance showed that the left posterolateral segments in expanding AAAs had larger Rc/RcAvg ratios than those segments in stable AAAs (1.14 ± 0.19 vs. 0.80 ± 0.09, p < 0.02). Laplace's law indicates that the left posterolateral segment in AAAs that grow more rapidly is subjected to greater wall tension. Flattening in the curvature of the left posterolateral wall segment was significantly associated with an increased rate of expansion in small AAAs. This finding, readily derived from standard CT scan images, may predict which small AAAs are more prone to rapid expansion.
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References
Estes E. Abdominal aortic aneurysm: A study of one hundred and two cases. Circulation 1950;11:258–264.
Bernstein EF, Dilley RB, Goldberger LE. Growth rates of small abdominal aortic aneurysms. Surgery 1976;80:765–773.
Cronenwett JL, Sargent SK, Wall MH. Variables that affect the expansion rate and outcome of small abdominal aortic aneurysms. J Vasc Surg 1990;11:260–269.
Ohlsen H, Delin A, Swedenborg J. Aneurysms as measured by computed tomography. Br J Surg 1985;72:530–532.
Dubost C, Oeconomos N, Allary M. Resection of an aneurysm of the abdominal aorta. Arch Surg 1952;64:405.
Szilagyi DE, Smith RF, DeRusso FJ, et al. Contribution of abdominal aortic aneurysmectomy to prolongation of life. Ann Surg 1966;164:678–699.
Hollier LH, Taylor LM, Ochsner J. Recommended indications for operative treatment of abdominal aortic aneurysms. J Vasc Surg 1992;15:1046–1056.
Treiman RL, Hartunian SL, Cossman DV, et al. Late results of small untreated abdominal aortic aneurysms. Ann Vasc Surg 1991;5:359–362.
Ernst CB. Abdominal aortic aneurysm. N Engl J Med 1993;328:1167–1172.
Guirguis EM, Barber GG. The natural history of abdominal aortic aneurysms. Am J Surg 1991;162:481–483.
Littooy AN, Steffan G, Greisler HP. Use of sequential B-mode ultrasonography to manage abdominal aortic aneurysms. Arch Surg 1989;124:419–421.
Nevitt MP, Ballard DJ, Hallett JW. Prognosis of abdominal aortic aneurysms. A population-based study. N Engl J Med 1989;321:1009–1014.
Perko MJ, Schroeder TV, Olsen PS, et al. Natural history of abdominal aortic aneurysm: A survey of 63 patients treated nonoperatively. Ann Vasc Surg 1993;7:113–116.
Crawford ES, Hess KR. Abdominal aortic aneurysm. N Engl J Med 1989;321:1040–1042.
Brown PM, Pattenden R, Gutelius JR. The selective management of small abdominal aortic aneurysms: The Kingston Study. J Vasc Surg 1992;15:21–27.
Sterpetti AV, Schultz RD, Feldhaus RJ. Factors influencing enlargement rate of small abdominal aortic aneurysms. J Surg Res 1987;43:211–219.
Ouriel K, Green RM, Donayre C, et al. An evaluation of new methods of expressing aortic aneurysm size: Relationship to rupture. J Vasc Surg 1992;15:12–20.
Pillari G, Chang JB, Zito J. Computed tomography of abdominal aortic aneurysm. Arch Surg 1988;123:727–732.
Krupski WC, Bass A, Thurston DW, et al. Utility of computed tomography for surveillance of small abdominal aortic aneurysms. Arch Surg 1990;125:1345–1350.
Dobrin PB. Mechanics of normal and diseased blood vessels. Ann Vasc Surg 1988;2:282–293.
Darling RC. Ruptured arteriosclerotic abdominal aortic aneurysms. Am J Surg 1970;119:397–406.
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Veldenz, H.C., Schwarcz, T.H., Endean, E.D. et al. Morphology predicts rapid growth of small abdominal aortic aneurysms. Annals of Vascular Surgery 8, 10–13 (1994). https://doi.org/10.1007/BF02133400
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DOI: https://doi.org/10.1007/BF02133400