Rate of change in abdominal aortic aneurysm diameter after endovascular repair.

Published

Journal Article

OBJECTIVE: Untreated abdominal aortic aneurysms (AAAs) enlarge at a mean rate of 3.9 mm/y with great individual variability. We sought to determine the effect of endovascular repair on the rate of change in aneurysm size. METHODS: There were 110 patients who underwent endovascular AAA repair at Stanford University Medical Center and who were followed up for 1 to 30 months (mean, 10 months) with serial contrast-infused helical computed tomography (CT). Maximal aneurysm diameter was determined using two independent methods: (1) measured manually, from cross-sectional computed tomography (XSCT) angiograms and (2) calculated from quantitative three-dimensional computed tomography (3DCT) data as orthonormal diameter. RESULTS: Maximal cross-sectional aneurysm diameter measured by hand (XSCT) and calculated as orthonormal values (3DCT) correlated closely (r = 0.915; P <.001). The XSCT-measured diameter was larger by 2.3 +/- 3. 75 mm (P <.001), and the 95% CI for SE of the bias was 1.85 to 2.75 mm. Preoperative aneurysm diameter (XSCT 59.1 +/- 8.4 mm; 3DCT 58.1 +/- 9.3 mm) did not differ significantly from the initial postoperative diameter. Considering all patients, XSCT diameter decreased at a rate of 0.34 +/- 0.69 mm/mo, and 3DCT diameter decreased at a rate of 0.28 +/- 0.79 mm/mo. Aneurysms in patients without endoleaks had a higher rate of decrease, an XSCT diameter by 0.50 +/- 0.74 mm/mo, and 3DCT diameter by 0.46 +/- 0.84 mm/mo. In these patients, mean absolute decrease in diameter at 6 months was 3. 4 +/- 4.5 mm (XSCT) and 3.3 +/- 5.9 mm (3DCT) and at 12 months, 5.9 +/- 5.7 mm (XSCT) and 5.4 +/- 5.7 mm (3DCT). Aneurysms in patients with persistent endoleaks did not change in mean XSCT diameter, and 3DCT diameter increased by 0.12 +/- 0.52 mm/mo (not significant). Aneurysm diameter remained within 4 mm of original size in 68% (3DCT) to 71% (XSCT) of patients. In one patient, aneurysm diameter increased (XSCT and 3DCT) more than 5 mm. Four patients who had a new onset endoleak had a much higher expansion rate than those with a chronic endoleak (P <.05). CONCLUSIONS: The rate of decrease in aneurysm size (annualized 3.4-4.1 mm/y) after endovascular repair of AAA approximates the reported expansion rate in untreated aneurysms. However, individual aneurysm behavior is unpredictable, and the presence of an endoleak is unreliable in predicting changes in diameter. New onset endoleaks are associated with an enlargement rate greater than that of untreated aneurysms.

Full Text

Duke Authors

Cited Authors

  • Wolf, YG; Hill, BB; Rubin, GD; Fogarty, TJ; Zarins, CK

Published Date

  • July 2000

Published In

Volume / Issue

  • 32 / 1

Start / End Page

  • 108 - 115

PubMed ID

  • 10876211

Pubmed Central ID

  • 10876211

International Standard Serial Number (ISSN)

  • 0741-5214

Digital Object Identifier (DOI)

  • 10.1067/mva.2000.107754

Language

  • eng

Conference Location

  • United States