Spinal cord injury increases the risk of abdominal aortic aneurysm

We have observed apparently disproportionate numbers of abdominal aortic aneurysms (AAAs) in chronic spinal cord injury (SCI) patients. To test whether aortic enlargement is more frequent in SCI, we measured maximum infrarenal aortic diameters (AoDmax) by B mode ultrasound in 89 SCI subjects and 223 age and sex matched controls. The average AoDmax in SCI subjects (mean age 60.3 years) was 2.27 ± 0.80 cm compared to 2.07 ± 0.69 cm in the controls. This difference was significant (P = 0.023), as were the proportions of subjects with AoDmax ≥ 3 cm. A total of 20.2 per cent of the SCI group had AoDmax ≥ 3 cm compared to 8.9 per cent for the controls (P < 0.0001, chi-square). Race, height, and weight distributions were similar. SCI patients had lower levels of hypertension and cigarette smoking than controls. Within the SCI and control groups, subjects with AoDmax ≥ 3 cm had increased cigarette consumption compared to ≤ 3 cm subjects (P = 0.048 and 0.0049, respectively). Average level of spinal injury was more caudad in the SCI ≥ 3 cm group than in the ≤ 3 cm group, T6 versus T8, but not significantly (P = 0.23). Based on these results, SCI patients have over a two-fold risk of aortic enlargement as a consequence of spinal cord injury.