The influence of hemodynamic stress factors on intracranial aneurysm formation

Object. Applanation tonometry is a noninvasive method of assessing both per ipheral and central arterial blood pressure (BP) profiles. In this study th e authors examine whether there are differences in these profiles in patien ts with intracranial aneurysms when compared with age-matched controls. Methods. Carotid artery (CA) and derived aortic BP waveforms were obtained using a pulse wave analysis system. The ratio of the pressure wave amplitud e above the systolic shoulder to the total systolic BP (augmentation index [AI]) was recorded. One hundred seventy-three patients with intracranial aneurysms (23 unruptur ed lesions) and 173 healthy control volunteers were examined. For the patie nts with aneurysms the right and left CA Als (mean +/- standard deviation) were 125.6 +/- 23.1% and 128.3 +/- 22.1%, respectively. Corresponding value s for the control group were 118.4 +/- 22.6% and 119.4 +/- 21.8%. The calcu lated Al for the ascending aorta was 29.8 +/- 10.5% and 25.6 +/- 12.2% for patients with aneurysms and control volunteers, respectively. Significant a symmetry in CA Al was seen in patients with aneurysms, the left being great er (p = 0.002). No significant differences were seen in mean BP (108 +/- 14 mm Hg in patients with aneurysms compared with 106 +/- 16 mm Hg in control s; p = 0.2). Multivariate analysis excluded the influence of BP and other p otential confounding vascular risk factors for increased AL Conclusions. Significant differences in AT, both in magnitude and symmetry, were identified in patients with intracranial aneurysms when compared with matched controls.