Larger Posterior Revascularization Associated with Reduction of Choroidal Anastomosis in Moyamoya Disease: A Quantitative Angiographic Analysis

Abstract

BACKGROUND AND PURPOSE: Choroidal anastomosis, a hemorrhage-prone periventricular collateral manifestation in Moyamoya disease, outflows to the cortex posterior to the central sulcus. The objective of the present study was to test whether the angiographic extent of revascularization posterior to the central sulcus contributes to the postoperative reduction of choroidal anastomosis. MATERIALS AND METHODS:This retrospective cohort study included choroidal anastomosis-positive hemispheres before direct bypass surgery. The postoperative reduction of choroidal anastomosis was determined by a consensus of 2 raters according to the previous research. An imaging software automatically traced the angiographic revascularization area, which was subsequently divided into anterior and posterior parts by an anatomic line corresponding to the central sulcus. Each area was quantitatively measured as a percentage relative to the whole supratentorial area. RESULTS:Postoperative reduction of choroidal anastomosis was achieved in 68 (85.0%) of the 80 included hemispheres. The revascularization area posterior to the central sulcus was significantly larger in the hemispheres with reduction than in those with no reduction (mean, 15.2% [SD, 7.1%] versus 4.2% [SD, 3.4%], P , .001), whereas no significant difference was observed in the revascularization area anterior to the central sulcus. Multivariate analysis revealed that the revascularization area posterior to the central sulcus was the only significant factor associated with reduction (OR, 1.57; 95% CI, 1.21-2.03, for every 1% increase). CONCLUSIONS:The results suggest that a larger revascularization posterior to the central sulcus is associated with postoperative reduction of choroidal anastomosis regardless of the extent of anterior revascularization. It might facilitate optimal selection of the revascularization site for preventing hemorrhage.ABBREVIATIONS: CS ¼ central sulcus; PCA ¼ posterior cerebral artery; STA ¼ superficial temporal artery C horoidal anastomosis is one of the abnormal periventricular collaterals in Moyamoya disease. [1][2][3][4][5] The collateral is characterized by a connection between the choroidal and medullary arteries, which outflows to the cortex via retrograde flow in the medullary artery (Fig 1). 2,3,6 Choroidal anastomosis is commonly observed in hemorrhagic Moyamoya disease [7][8][9] and is associated with an extremely high risk of bleeding. 4,5,10 After bypass surgery, the normalized direction of flow in the medullary artery can induce angiographic reduction of choroidal anastomosis. 6,11 This change might explain the effectiveness of direct bypass in preventing bleeding. 12-14 However, only a few studies have focused on the factors contributing to this change. 15 A recent study revealed that choroidal anastomosis outflows to the cortex posterior to the central sulcus (CS). 16 We hypothesized that a larger angiographic extent of revascularization posterior to the CS is associated with the reduction of choroidal anastomosis. Testing this hypothesis m...

Microanatomical study of the posterior medial choroidal artery

“…existence of ventricular microaneurysms in the choroidal arteries [23]. Reduction of choroidal anastomoses, after the superficial temporal-middle cerebral artery bypass surgery, was confirmed in 85% of hemispheres [21].…”

“…The existence of abnormal periventricular collaterals from the choroidal vessels is typically connected to Moyamoya disease. The existence of enlarged pathological interconnections between the deep parts of the medullary and choroidal arteries results in reversed blood flow to the cortical area[21]. The occurrence of periventricular subependymal hemorrhage is a common manifestation of Moyamoya disease in adults.…”