Purpose:
This prospective study was aimed to evaluate the effects of surgical revascularization on cerebral oxygen metabolism in moyamoya disease.
Methods:
This study included totally 41 patients who underwent STA-MCA anastomosis and indirect bypass for moyamoya disease between 2000 and 2011. There were 12 children and 29 adults. Totally 67 hemispheres underwent surgery. MR imaging and 15O-gas positron emission tomography (PET) were performed before and 3 to 4 months after surgery. Hemodynamic and metabolic parameters were precisely quantified.
Results:
Preoperative PET scans revealed that cerebral metabolic rate for oxygen (CMRO2) was kept normal in 15 hemispheres (22%), but decreased in other 52 (78%). The incidence did not differ between pediatric and adult patients. Pronounced cerebral ischemia was observed in all hemispheres with decreased CMRO2. After surgery, CMRO2 value significantly improved to the normal level in 20 (38%) of 52 hemispheres, but did not change in other 32 (62%). Multivariate analysis showed that the predictors for postoperative CMRO2 normalization were patient’s age (younger than 40 years) and no parenchymal damage on MRI.
Conclusion:
These findings strongly suggest that cerebral oxygen metabolism is often depressed in response to dense and chronic cerebral ischemia in moyamoya disease. The phenomenon may be advantageous to protect the involved hemispheres against ischemia. Surgical revascularization may readily normalize oxygen metabolism in young patients without any parenchymal damage.
Depressed Cerebral Oxygen Metabolism in Patients with Chronic Renal Failure: A Positron Emission Tomography Study.