Growth rate of abdominal aortic aneurysms as measured by computed tomography.

The risk of rupture of an abdominal aortic aneurysm increases with size. It has thus been recommended that small aneurysms be continuously followed with some type of imaging technique to detect when aneurysm size constitutes an indication for surgery. The present study focuses on the growth rate of abdominal aortic aneurysms in 35 patients who were subjected to repeated computerized tomographic examinations of their abdominal aortic aneurysms. Several aneurysms were measured more than twice resulting in 57 different examinations. The mean growth rate of the transverse diameter was 0.52 cm/year. The individual growth rates were, however, variable. Aneurysms with an initial transverse diameter exceeding 6 cm showed a slightly but not significantly faster increase in size compared with smaller aneurysms. No correlation between initial size and growth rate could be established. Six patients died during the study period, two from myocardial infarction, three after elective aneurysm operations and one, refused for elective operation, died after rupture. It is concluded that the growth rate measured with computed tomography agrees well with previously reported estimates obtained with ultrasonography. It is recommended that small aneurysms particularly in patients with relative contraindications to surgery be followed with repeated examinations of size.