Hemodynamic analysis of the recipient parasylvian cortical arteries for predicting postoperative hyperperfusion during STA-MCA bypass in adult patients with moyamoya disease

OBJECTIVE Superficial temporal artery–middle cerebral artery (STA-MCA) bypass is a common approach for treating moyamoya disease (MMD); however, the selection of recipient vessels is still controversial, and its relationship with postoperative cerebral hyperperfusion (CHP) has not been revealed. The aim of the study was to investigate the relationship between the hemodynamic sources of the recipient parasylvian cortical arteries (PSCAs) and the occurrence of postoperative CHP. METHODS The authors retrospectively analyzed the clinical data from 68 adult patients (75 hemispheres) with MMD who underwent STA-MCA bypass. Based on their hemodynamic sources from the MCA and non-MCAs, the PSCAs were classified as M-PSCAs and non–M-PSCAs, and their distributional characteristics were studied. Moreover, the patients’ demographics, incidence of postoperative CHP, and post- and preoperative relative cerebral blood flow values were examined. RESULTS The digital subtraction angiography analysis demonstrated that 40% (30/75) of the recipient PSCAs had no hemodynamic relationship with the MCA. The post- and preoperative relative cerebral blood flow values of the M-PSCA group were significantly higher than those of the non–M-PSCA group (p < 0.001). Multivariate analysis revealed that the hemodynamic source of PSCAs from the MCA was significantly associated with the development of focal (p = 0.003) and symptomatic (p = 0.021) CHP. Twelve (85.7%) of the 14 patients with symptomatic CHP and all 4 (100%) patients with postoperative hemorrhage were from the M-PSCA group. CONCLUSIONS This study revealed that direct anastomoses of PSCAs with anterograde hemodynamic sources from the MCA had a high risk of postoperative CHP during STA-MCA bypass in adult patients with MMD.