Prediction of cerebral hyperperfusion syndrome in adults with moyamoya disease after combined bypass surgery using perioperative hemodynamic and blood pressure changes

OBJECTIVE: Cerebral hyperperfusion syndrome (CHS) represents a significant complication following superficial temporal artery (STA)-middle cerebral artery (MCA) bypass surgery for moyamoya disease (MMD), characterized by the onset of various neurological symptoms. The aim of this study was to explore the predictive role of perioperative hemodynamic parameters and blood pressure (BP) in postoperative CHS among adult patients with MMD who undergo STA-MCA bypass surgery. METHODS: This study included 284 hemispheres from 218 patients with MMD who underwent STA-MCA bypass surgery. Perioperative hemodynamics were monitored using carotid Doppler ultrasound (CDU) and microprobe-vascular Doppler (MVD), assessing the recipient proximal M4 segment of the middle cerebral artery (pM4) and donor STA parietal branch parameters, with simultaneous perioperative BP monitoring. Patients are divided into the CHS group and non-CHS groups according to whether CHS occurred. Univariate and multivariate logistic regression identified CHS predictors, supplemented by correlation analysis of post/preanastomosis (post/preanast) fold increase in pM4 mean flow velocity (MFV) versus the postoperative/preoperative (post/preop) regional cerebral blood flow (rCBF) ratio and longitudinal hemodynamic comparisons of STA. RESULTS: CHS occurred in 72 hemispheres (25.4%), with 212 classified as non-CHS. Multivariate analysis identified 3 independent CHS predictors: pM4 MFV post/preanast fold increase > 8.8 (OR 1.37, 95% CI 1.18-1.59), systolic blood pressure (SBP) on postoperative day (POD) 1 > 127 mm Hg (OR 1.13, 95% CI 1.07-1.19), and time-averaged peak velocity (TAPV) of STA on POD 3 > 66 cm/sec (OR 1.02, 95% CI 1.00-1.05). The combined model demonstrated superior accuracy (area under the curve 0.88, 95% CI 0.85-0.94, p < 0.001) with 80.6% sensitivity/84.9% specificity. pM4 MFV post/preanast fold increase strongly correlated with rCBF post/preop ratio in the CHS group (r = 0.8782, p < 0.001). Both groups showed increased STA diameter, TAPV, and time-averaged mean velocity (TAMV) after surgery, with CHS patients having greater TAPV and TAMV at POD 3 (p < 0.001). CONCLUSIONS: Intraoperative pM4 MFV post/preanast fold increase > 8.8, POD 1 SBP > 127 mm Hg, and POD 3 STA TAPV > 66 cm/sec were potential risk factors for postoperative CHS in adults with MMD. Therefore, postoperative management in these cases must be approached with heightened vigilance.