Exploring the Age of Intracranial Aneurysms Using Carbon Birth Dating

Abstract

Background and Purpose— There is a controversy about the time span over which cerebral aneurysms develop. In particular, it is unknown whether collagen in ruptured aneurysms undergoes more rapid turnover than in unruptured aneurysms. 14 C birth dating of collagen could be used to address this question. Methods— Aneurysmal domes from patients undergoing surgical treatment for ruptured or unruptured aneurysms were excised. Aneurysmal collagen was isolated and purified after pepsin digestion. Collagen from mouse tendons served as controls. F 14 C levels in collagen were analyzed by accelerator mass spectrometry and correlated with patient age and aneurysm size. Results— Analysis of 10 aneurysms from 9 patients (6 ruptured, 3 unruptured) revealed an average aneurysm collagen age of <5 years, generally irrespective of patient age and aneurysm size or rupture status. Interestingly, F 14 C levels correlated with patient age as well as aneurysm size in ruptured aneurysm collagen samples. Conclusions— Our preliminary data suggest that collagen extracted from intracranial aneurysms generally has a high turnover, associated with aneurysm size and patient age. The correlation of patient age and aneurysm F 14 C levels could explain models of aneurysm development. Although preliminary, our findings may have implications for the biological and structural stability of ruptured and unruptured intracranial aneurysms.