Differences in Pressure Within the Sac of Human Ruptured and Nonruptured Cerebral Aneurysms

BACKGROUND Hemodynamics plays a critical role in the development, growth, and rupture of intracranial aneurysms. This data could be vital in determining individual aneurysm rupture risk and could facilitate our understanding of aneurysms. OBJECTIVE To present the largest prospective cross-sectional cohort study of intrasaccular pressure recordings of ruptured and nonruptured intracranial aneurysms and describe the hemodynamic differences that exist between ruptured and nonruptured aneurysms. METHODS During endovascular treatment, a standard 1.8-Fr 200 m length microcatheter was navigated into the dome of the aneurysm prior to coil embolization. With the microcatheter centralized within the dome of the aneurysm, an arterial pressure transducer was attached to the proximal end of the microcatheter to measure the stump pressure inside the aneurysm dome. RESULTS In 68 aneurysms (28 ruptured, 40 nonruptured), we observed that ruptured cerebral aneurysms had a lower systolic and mean arterial pressure compared to nonruptured cohort (P=.0008). Additionally, the pulse pressures within the dome of ruptured aneurysms were significantly more narrow than that of unruptured aneurysms (P=.0001). These findings suggest that there may be an inherent difference between ruptured and nonruptured aneurysms and such recordings obtained during routine digital subtraction angiography could potentially become a widely applied technique to augment risk stratification of aneurysms. CONCLUSION Our preliminary data present new evidence distinguishing ruptured from unruptured aneurysms that may have a critical role as a predictive parameter to stratify the natural history of nonruptured intracranial aneurysms and as a new avenue for future investigation.