Changes in periventricular anastomosis after indirect revascularization surgery alone for adult patients with misery perfusion due to ischemic moyamoya disease

Periventricular anastomosis in moyamoya disease (MMD) is an unusual angiographic finding that arises from perforating arteries such as the lenticulostriate artery (LSA), thalamic artery (THA), and anterior choroidal artery (AChA). This anastomosis is associated with increased hemorrhagic risk in MMD and can be corrected by direct revascularization surgery. The present supplementary analysis on a prospective cohort aimed to elucidate changes in periventricular anastomosis after indirect revascularization surgery alone for adult patients with misery perfusion due to ischemic MMD. Twenty-two patients with misery perfusion in the symptomatic cerebral hemisphere who underwent indirect revascularization surgery alone also underwent six-vessel cerebral angiography via arterial catheterization before and at 6 months after surgery. Before surgery, two patients (9%) had positive periventricular anastomosis from the LSA and another (5%) from the AChA; all three of these periventricular anastomoses regressed after surgery, but these changes were not statistically significant (p = 0.0833). The degree of formation of collateral vessels from the LSA significantly decreased after surgery (p = 0.0143), but the degree of collateral vessels from the THA or AChA did not differ between pre- and postoperative conditions. Eight patients with postoperative regression of the collateral vessels from any perforating artery exhibited postoperative rich collateral flow from indirect revascularization. Periventricular anastomosis tended to regress after indirect revascularization surgery alone for adult patients with misery perfusion due to ischemic MMD. Collateral vessels formed from the LSA likely regressed after indirect revascularization surgery alone for such patients, but those vessels from the THA or AChA seldom changed.