Adult hemorrhagic moyamoya disease: The paradoxical role of combined revascularization

Abstract

Background: Moyamoya disease (MMD) in adults often manifests with hemorrhage. Combined revascularization in hemorrhagic MMD is controversial as improvement in hemodynamics may be offset by hypervascularity-induced rebleeding. Aim: Long-term outcome assessment of adult patients from non-endemic region with hemorrhagic MMD undergoing combined revascularization. Setting: Tertiary care, academic setting. Materials and Methods: Both Suzuki′s internal carotid artery (ICA) grade (1-6) and Mugikura′s posterior cerebral artery (PCA) grade (1-4) were applied to 11 patients with hemorrhagic MMD (mean symptom duration 6.11±6.46 months) undergoing direct [superficial temporal artery-middle cerebral artery (STA-MCA) bypass] and indirect encephalomyosynangiosis (EMSA) revascularization. They were clinically graded at follow-up (F/U) as: excellent, preoperative symptoms resolved; good, preoperative symptoms resolved, neurological deficits remained; fair, symptom frequency decreased; and poor, symptoms unchanged/worsened. Digital subtraction angiogram/magnetic resonance angiography (DSA/MRA) assessed the patency of anastomosis and cerebral hemodynamics as: 0 = non-patent; 1 = patent bypass, STA perfused recipient artery, moyamoya vessels unchanged; and, 2 = patent bypass, STA widely perfused MCA territory, moyamoya vessels diminished. An acetazolamide stimulated single photon emission computed tomography (SPECT) study evaluated regional cerebral vascular reserve (RCVR). Results: Angiographic ICA grades were 5 (n=2), 4 (n=2), 3 (n=4), and 2 (n=3), and PCA grades were 1 (n=8) and 3 (n=3). At F/U (mean: 36.55±21.6 months), clinical recovery was excellent in eight and fair in one. Two patients developed delayed re-hemorrhage (in one at a site remote from previous bleed). F/U DSA/MRA (n=6) showed a good caliber, patent anastomosis with collaterals in five patients, and a narrow caliber anastomotic vessel in one patient. SPECT (n=6) revealed improved perfusion in two and normal perfusion with persisting regional decrease in RCVR in four patients. Conclusions: Combined direct and indirect revascularization improves cerebral circulation and ameliorates ischemic symptoms, but cannot irrevocably prevent rebleeding. Re-hemorrhage may occur at a site remote from previous bleeding, signifying generalized impairment in moyamoya vasculature.

Keywords

• Direct revascularization
• hemorrhage
• moyamoya disease
• stroke
• superficial temporal artery– middle cerebral artery bypass
• surgery