Strict anesthesia protocol may improve intraoperative variability in encephaloduroarteriosynangiosis revascularization

1. In a prospective cohort study of 24 adults with intracranial arterial stenosis (ICAS) treated with encephaloduroarteriosynangiosis (EDAS) revascularization, a strict perioperative anesthesia protocol demonstrated significant reductions in intraoperative physiologic variations compared to routine anesthesia care.

Evidence Rating Level: 2 (Good)

Study Rundown: EDAS is surgical procedure involving the approximation of the superficial temporal and middle meningeal arteries to the intracranial vessels, allowing indirect revascularization in patients with ICAS. Patients with ICAS undergoing EDAS are particularly susceptible to variations in cerebral perfusion and have a heightened risk of perioperative strokes. The purpose of this prospective trial was to determine whether a strict anesthesia protocol is effective in reducing intraoperative physiologic variability.

The study prospectively followed 24 patients with ICAS undergoing EDAS. The strict perioperative anesthesia protocol included normocapnia and intentional hypertension. At the conclusion of the trial, patients with strict anesthesia protocol demonstrated significant reductions in intraoperative variability of mean arterial blood pressure (MAP) and end-tidal CO₂ (ETCO₂) compared to patients receiving routine anesthesia care. The results of this study support the hypothesis that strict anesthesia protocol may be effective in reducing physiologic variability in patients undergoing EDAS. However, the study is limited by the small sample size which resulted in significant intra-group heterogeneity. Additional trials are warranted to determine whether strict maintenance of hemodynamic variables result in improved surgical outcomes.

Click to read the study in BMJ Open

Relevant Reading: Encephaloduroarteriosynangiosis for adult intracranial arterial steno-occlusive disease: long-term single-center experience with 107 operations

In-Depth [prospective cohort]: Twenty-four patients were included as part of the EDAS Revascularization for Symptomatic Intracranial Arterial Stenosis (ERSIAS) trial. Overall, 12 patients underwent a strict anesthesia protocol and 12 patients received standard anesthesia care. The strict anesthesia protocol include intentional hypertension set at 20% over the patient’s baseline, ETCO₂ between 35 to 45 mm Hg, and administration of antiplatelet medication 3 days prior to the procedure. Minute-by-minute physiological parameters were collected throughout the surgical procedure. The outcome of interest were the intraoperative variability of heart rate (HR), MAP, systolic blood pressure, and ETCO₂. At the conclusion of the trial, patients that underwent strict anesthesia protocol demonstrated significantly higher mean MAP (98 vs. 75 mmHg; p < 0.001) and ETCO₂ (38 vs. 32 mmHg; p < 0.001) compared to the control group. Additionally, there was a significant reduction in the standard deviation (SD) in the MAP (4.26 vs. 10.23 mm Hg; p = 0.007) and ETCO₂ (0.94 vs. 1.26 mm Hg; p = 0.05). There were no significant differences in the SD of HR and SBP between the 2 groups.

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