Ischemic complications occurring in the contralateral hemisphere after surgical treatment of adults with moyamoya disease

Abstract

Objective: Direct revascularization surgery is regarded as the most effective method of treatment of adults with moyamoya disease. These patients, however, have a higher risk of perioperative ischemic complications than do patients with atherosclerotic stroke, and are at risk for ischemic complications in the hemisphere contralateral to the one operated on. We investigated the incidence and risk factors for ischemic stroke in the contralateral hemisphere after surgical treatment of adults with moyamoya disease.

Methods: We retrospectively reviewed the medical records and results of neuroimaging studies on 79 hemispheres of 73 consecutive patients with adult moyamoya disease (mean±SD age, 37.96±11.27 years; range, 18-62 years) who underwent direct bypass surgery over 6 years.

Results: Ischemic complications occurred in 4 of 79 (5.1%) contralateral hemispheres, one with Suzuki stage 3 and three with Suzuki stage 4. Three patients showed posterior cerebral artery (PCA) involvement by moyamoya vessels. Advanced stage of moyamoya disease (Suzuki stages 4/5/6; p=0.001), PCA involvement (p=0.001) and postoperative hypotension (mean arterial blood pressure <80% of preoperative mean arterial blood pressure) on the first (p<0.0001) and second (p=0.003) days after surgery were significantly correlated with postoperative contralateral ischemic complications.

Conclusion: In patients with advanced moyamoya disease and involvement of the PCA, intentional hypotension can result in ischemic stroke in the hemisphere contralateral to the one operated on. Careful control of perioperative blood pressure is crucial for good surgical results.

Keywords: Cerebral revascularization; Complications; Moyamoya diseases; Perioperative period.

Fig. 1

A : T2 weighted MRI showing an old infarction in the left temporo-occipital cortex. B, C and D : Preoperative angiography showing findings typical of moyamoya disease with involvement of bilateral PCA. E : Immediate postoperative CT scan showing neither focal hematoma nor acute infarction on the operated hemisphere. An extraventricular drainage catheter was placed on the frontal horn of the lateral ventricle. F : TTP image of the perfusion CT showing improvements in delayed time on the left compared with the right hemisphere after STA-MCA bypass with encephalomyoarteriosynangiosis. G : Follow-up SPECT 9 days after surgery showing perfusion defects in the right frontal cortex and right ACA-MCA watershed zone due to a newly developed infarction. H : Non-enhanced CT scan showing focal low density on the left frontal area, the same area of the left frontal cortex. MRI : magnetic resonance image, PCA : posterior cerebral artery, CT : computed tomography, STA : superficial temporal artery, SPECT : single photon emission computed tomography, ACA : anterior cerebral artery, MCA : middle cerebral artery.