Abstract 2413: Postoperative Cerebral Hyperperfusion after Superficial Temporal Artery-Middle Cerebral Artery Anastomosis and Indirect Synangiosis in Moyamoya Disease: PET and SPECT Study

Abstract

Background Postoperative cerebral hyperperfusion is known to occur after superficial temporal artery to middle cerebral artery (STA-MCA) anastomosis and indirect synangiosis in moyamoya disease. However, the clinical features and pathophysiology still remain to be elucidated. Objective To clarify the incidence and pathogenesis of postoperative hyperperfusion after surgical revascularization for moyamoya disease. Methods This study included 41 consecutive patients (58 surgeries) who underwent STA-MCA anastomosis and indirect synangiosis for moyamoya disease. Their medical records were evaluated to identify clinical features of postoperative hyperperfusion. Using 15O-gas positron emission tomography (PET), cerebral hemodynamics and metabolism were determined before surgery in all patients. Using 123I-IMP single photon emission computed tomography (SPECT), cerebral blood flow was qualitatively measured on Day 0, 2, and 7 after surgery in all patients. A multivariate logistic regression analysis was conducted to identify the predictors for postoperative hyperperfusion. Results Postoperative hyperperfusion was observed in 29 (50.0%) of 58 operated sides. In pediatric patients, it was quite rare. Thus, symptomatic and asymptomatic hyperperfusion occurred in 1 (5%) and 3 (15%) of 20 sides, respectively. In adult cases, however, symptomatic and asymptomatic hyperperfusion were significantly more often (P=0.0037 and P=0.026, respectively) and were noted in 12 (31.5%) and 13 (34.2%) of 38 sides, respectively. A logistic regression analysis revealed that cerebral blood volume (CBV) increase before surgery was a significant predictors for symptomatic hyperperfusion in adults (P=0.036). Furthermore, hyperperfusion immediately after surgery was at significantly higher risk to be symptomatic (7/9=77.7%, P=0.033). Conclusions Postoperative hyperperfusion after STA-MCA anastomosis in adult moyamoya disease is not rare. Preoperative CBV increase was closely related to the occurrence of symptomatic hyperperfusion in adult cases. Hyperperfusion immediately after surgery may easily cause neurological deficits or other symptoms. Precise evaluation of cerebral hemodynamics and metabolism before and after surgery would be valuable to predict postoperative hyperperfusion and prevent perioperative complications.