Intra-Arterial Therapy for Acute Ischemic Stroke Under General Anesthesia versus Monitored Anesthesia Care

BACKGROUND: Recent studies have shown that intra-arterial recanalization therapy (IAT) for acute ischemic stroke (AIS) is associated with worse clinical outcomes when performed under general anesthesia (GA) compared to local anesthesia, with or without conscious sedation. The reasons for this association have not been systematically studied. METHODS: We retrospectively reviewed 190 patients who underwent IAT for anterior circulation AIS from January 2008 to December 2012 at our institution. Baseline demographics, vessels involved, acute stroke treatment including intravenous tissue type plasminogen activator (tPA) use, use of GA vs. monitored anesthesia care (MAC), location of thrombus, recanalization grade, radiologic post-procedural intracerebral hemorrhage, and 30-day outcomes were collected. Relevant clinical time points were recorded. Detailed intra-procedural hemodynamics including maximum/minimum heart rate, systolic blood pressure (BP), diastolic BP, mean BP, use of pressors and episodes of hypotension were collected. Our study's outcomes were as follows: in-hospital mortality, 30-day good outcome (mRS ≤2), successful recanalization and radiologic post-procedural intracerebral hemorrhage. RESULTS: Ninety-one patients received GA and 99 patients received MAC. There was no significant difference in the NIHSS score between the two groups but the GA group had a higher number of ICA occlusions (31.9 vs. 18.2%, p = 0.043). The time from the start of anesthesia to incision (23.0 ± 12.5 min vs. 18.7 ± 11.3 min, p = 0.020) and the time from the start of anesthesia to recanalization (110 ± 57.2 vs. 92.3 ± 43.0, p = 0.045) was longer in the GA group. The time from incision to recanalization was not significantly different between the two groups. mRS 0-2 was achieved in 22.8% of patients in the MAC group compared to 14.9% in GA (p = 0.293). Higher mortality was seen in the GA group (25.8 vs. 13.3%, p = 0.040). Successful recanalization (TICI 2b-3) was similar between the GA and MAC (57.8 vs. 48.5%, p = 0.182) groups, but GA had a higher number of parenchymal hematomas (26.3 vs. 10.1%, p = 0.003). There was no difference in the intra-procedural hemodynamic variables between the GA and MAC groups. Anesthesia type was an independent predictor for mortality (along with age and initial NIHSS), and the only independent predictor for parenchymal hematomas, with MAC being protective for both. CONCLUSION: Our study has confirmed previous findings of GA being associated with poorer outcomes and higher mortality in patients undergoing IAT for AIS. Detailed analysis of intra-procedural hemodynamics did not reveal any significant difference between the two groups. Parenchymal hematoma was the major driver of the difference in outcomes.