Abstract TP83: Impaired Cerebrovascular Reactivity to Acetazolamide in Parent Arterial Territory of Major Artery Aneurysms in Adult Patients with Moyamoya Disease
Background— Recent studies have suggested that haemodynamic stress probably induces the formation of major artery aneurysms around the circle of Willis in adult patients with moyamoya disease (MMD). Theoretically, cerebrovascular reactivity (CVR) to acetazolamide (ACZ) is gradually reduced in the conditions that cerebral perfusion pressure is decreased. If arterial narrowing progress, CVR to ACZ would be reduced (Kuroda’s Type 2 or 3 ischemia) in the parent arterial territory of these aneurysms owing to elevated cerebrovascular resistance. This study was aimed to test the hypothesis whether the CVR to ACZ is reduced in the parent arterial territory of the major artery aneurysms.
Methods— This retrospective study included 172 adult patients with MMD diagnosed at our institutes between 1980 and 2011. Eight major artery aneurysms was found in 7 (4.1%) of these patients, including 5 women and 3 men at the mean age of 47.4 years. Aneurysm location and perfusion territory of the parent artery were determined on digital subtraction angiography. Regional cerebral blood flow (CBF) was quantitatively measured, using 123I-IMP SPECT. Subsequently, ACZ was intravenously injected to determine the reactivity of CBF. CVR to ACZ in the parent arterial territory was calculated (n=8). CVR in the contralateral arterial territory of the parent artery was utilized as a control (n=6).
Results— Four (50%) of 8 major artery aneurysms were located in the vertebrobasilar system. All aneurysms were saccular and small, ranging from 2.0 and 5.0 mm. CVR to ACZ were reduced in 5 (62.5%) of 8 parent arterial territory (Type 2 or 3). All the contralateral arterial territory of the parent artery had normal CBF and CVR to ACZ (Type 1). Compared with contralateral side (32.0 ± 10.7%), CVR to ACZ was not significantly reduced in the parent artery side (16.5 ± 19.0%, P=0.11; paired-t). Fisher’s exact test, however, demonstrated a significant association between the existence of major artery aneurysms and reduced CVR to ACZ in the parent arterial territory (P=0.03).
Conclusions— These findings suggest that reduced CVR in the parent arterial territory of the major artery aneurysms indicates underlying hemodynamic vascular stress inducing aneurysm formation in adult patients with MMD.
- © 2012 by American Heart Association, Inc.