ABDOMINAL AORTIC-ANEURYSM - A GENERAL DEFECT IN THE VASCULATURE WITH FOCAL MANIFESTATIONS IN THE ABDOMINAL-AORTA

Purpose: It has been suggested that abdominal aortic aneurysms (AAA) d evelop as a result of an alteration in the systemic connective tissue metabolism. This might change wall mechanics and diameter, not only in the AAA but also in the rest of the vascular system. This hypothesis was tested by studying the mechanical properties of AAAs as well as th e common carotid artery (CCA) in the same patient population. Methods: AAA and carotid artery stiffness (beta) was studied in 121 individual s (101 men, 20 women) who were admitted for elective repair of AAA. St iffness (beta) was calculated from diameter and pulsatile diameter cha nge determined noninvasively from an ultrasonic echo-tracking system a nd blood pressure obtained by the auscultatory method. The results wer e compared with those of healthy individuals of corresponding age and gender published elsewhere. Results: The stiffness of the AAA was incr eased in both men and women (p = 0.0001). The increase was more pronou nced in women compared with men (p = 0.0003) to a mean of 435% and 189 % of the normal predicted values, respectively. In the CCA, the stiffn ess was increased in men (p = 0.027) and in women (p = 0.0001) to a me an of 131% and 149% of the normal predicted values, respectively. A si gnificant correlation between stiffness in the aneurysm and in the car otid artery was seen (p = 0.0031). The carotid diameter was unchanged in men (p = 0.924) and in women (p = 0.070) if adjusted for the differ ence in blood pressure between the individuals with AAAs and control s ubjects. There was no correlation between stiffness and diameter of th e aneurysm in men (r = 0.16, p = 0.119) nor in women (r = 0.12, p = 0. 598). Conclusions: This investigation demonstrated altered mechanical properties of the aneurysmal wall as well as in the CCA in individuals with AAAs. The normal age-and gender-related differences seen in the healthy aorta and CCA vanished. The results suggest that AAA is a gene ralized process of the vasculature with focal manifestation in the abd ominal aorta.