Is Conscious Sedation Better for EVT in Acute Posterior Circulation Stroke?

Conscious sedation is not superior to general anesthesia for functional recovery among patients undergoing treatment for acute posterior circulation stroke (PCS), according to a randomized controlled trial published in JAMA Neurology.

Acute ischemic stroke (AIS) has a high rate of disability and mortality. Endovascular therapy (EVT) has been shown to be effective and safe for anterior AIS with general anesthesia leading to more favorable or similar functional outcomes to conscious sedation. However, functional outcomes of general anesthesia vs conscious sedation among patients undergoing EVT for acute PCS have been inconsistent. For this study, researchers sought to assess whether conscious sedation is superior to general anesthesia during EVT for patients with acute PCS.

Patients (N=87) with acute PCS were recruited at the Beijing Tiantan Hospital and Baiyun Hospital in China between 2018 and 2021 for the study Choice of Anesthesia for Endovascular Treatment of Acute Ischemic Stroke in Posterior Circulation (CANVAS II; ClinicalTrials.gov Identifier: NCT03317535). Researchers randomly assigned patients in a 1:1 ratio to receive general anesthesia (n=43) or conscious sedation (n=44) during EVT. The primary outcomes were mortality and functional outcomes up to 90 days, measured using the modified Rankin Scale (mRS).

Study participants in the general anesthesia and conscious sedation cohorts had the following characteristics:

• Mean age, 64 (standard deviation [SD], 11) and 60 (SD, 13) years;
• 23.3% and 13.6% were women;
• Body mass index (BMI) of 26 (SD, 3) and 26 (SD, 3) kg/m²;
• 81.4% and 79.5% had atherosclerosis stroke etiology;
• 62.8% and 54.5% had a vertebral artery V4 segment lesion; and
• Median mRS at admission was 4 (interquartile range [IQR], 4-5) and 4 (IQR, 4-4) points, respectively.

Conscious sedation was associated with shorter operating room to puncture (median, 15 vs 20 min; P =.003), operating room to reperfusion (median, 94 vs 125 min; P =.02), and door to reperfusion (median, 237 vs 284 min; P =.05) times compared with general anesthesia, respectively.

At 90 days, 61.3% of participants who received conscious sedation and 48.8% of those who received general anesthesia had a mRS score of 2 or less. Participants in the conscious sedation and general anesthesia cohorts had excellent functional outcomes (mRA ≤ 1; 45.2% vs 23.3%), poor outcomes (mRA ≥3; 38.7% vs 51.2%), and successful reperfusions (77.4% vs 95.3%), respectively.

The mortality rates were 3.2% and 11.6% at hospital discharge, 17.2% and 22.0% at 30 days, and 16.1% and 23.3% at 90 days among participants in the conscious sedation and general anesthesia cohorts, respectively.

In the per-protocol analysis, conscious sedation was associated with a decreased rate of assisted ventilation (adjusted odds ratio [aOR], 0.06; 95% CI, 0.02-0.23) and hypotension (aOR, 0.10; 95% CI, 0.03-0.40) compared with general anesthesia. No other group differences were observed.

These findings may not be generalizable for more diverse populations.

“Our study shows that patients who received CS achieved similar rates of favorable outcomes as those who received GA without an increased risk of mortality,

Pulmonary infection, deep vein thrombosis, or hemorrhagic transformation (symptomatic or intracranial hemorrhage),” the researchers stated.