Morphology and diameter of infrarenal aortic aneurysms: a prospective autopsy study

Abstract

Purpose: To determine the diameter and morphology of infrarenal aortic aneurysms in 78 fresh autopsy specimens. Methods: To avoid underestimation of the arterial diameter postmortem and to re-establish aneurysm morphology, a device was designed and introduced into the vessel, inflated to 80 mm Hg, and the largest external diameter was measured. Results: The ages of the individuals ranged from 40 to 97 yr (mean 70). Thirty-eight aneurysms were ruptured with diameters ranging from 5.3 to 17.0 cm (mean 7.97), and 40 aneurysms were nonruptured with variations in diameters from 2.8 to 6.1 cm, mean 4.02 cm ( P<0.01). Fusiform aneurysms were more frequent, and when they ruptured their diameters were smaller than the diameters of the spherical aneurysms ( P<0.05). Aneurysms ruptured more frequently in the posterior wall (67%) and in the inferior portion (61%). A mural thrombus was found at the site of rupture in 80% of the specimens. Conclusion: In our samples, rupture was found solely in those aneurysms with a diameter over 5.0 cm, ruptures occurred earlier in fusiform aneurysms, mural thrombus was not a protective factor, and finally, aneurysms ruptured mainly in the posterior and inferior portions.