Whole-Field Indocyanine Green Intensity Analysis to Intraoperatively Predict Cerebral Hyperperfusion Syndrome Following Superficial Temporal Artery-Middle Cerebral Artery Bypass: A Retrospective Case-Control Study in 7-Year Experience With 112 Cases

BACKGROUND: Intraoperative prediction of postoperative cerebral hyperperfusion syndrome (CHS) after cerebrovascular bypass surgery is challenging. OBJECTIVE: To conduct a retrospective case-control study with indocyanine green (ICG) intensity analysis of the superficial temporal artery-middle cerebral artery (STA-MCA) bypass and investigate whether its washout pattern might be a marker for intraoperative prediction of CHS. METHODS: Between 2012 and 2018, 6 of 112 patients (5.4%) that underwent STA-MCA bypass exhibited CHS. We selected 5 patients with CHS (3 with atherosclerotic cerebrovascular disease [ASCVD] and 2 with moyamoya) and 15 patients without CHS (60% ASCVD and 40% moyamoya) as a matched control group. During prebypass and postbypass, washout times (WTs) for the first 10%, 25%, 50%, and 75% of maximum ICG intensity measured in the whole-camera field were compared between groups. The changes in WT (Delta WT) from prebypass to postbypass for each ICG intensity level were compared between groups. The cutoff Delta WTs, sensitivities, and specificities were also calculated. RESULTS: Postbypass WTs were significantly longer in the CHS group than the control group at all ICG intensities (P < .05). Delta WT was significantly greater in the CHS group than the control group for the first 10%, 25%, and 50% ICG intensities (P < .001). A cutoff Delta WT of >= 2.66 s for the first 50% ICG intensity showed a sensitivity of 100% and specificity of 100%. CONCLUSION: We found that a Delta WT >= 2.66 s for the first 50% ICG intensity could be an intraoperative predictive factor for CHS.