Anesthesia Technique and Outcomes in Mechanical Thrombectomy for Acute Ischemic Stroke

This retrospective observational cohort study was conducted at the University of Health Sciences Bakirkoy Dr. Sadi Konuk Training and Research Hospital. Medical records of patients who underwent mechanical thrombectomy for acute ischemic stroke between 2014 and 2018 were reviewed. Patients who received mechanical thrombectomy within 6 hours of symptom onset and achieved a Thrombolysis in Cerebral Infarction (TICI) reperfusion grade of 2a, 2b, or 3 were included. Patients with TICI grades of 0 or 1, those younger than 18 years, patients with an APACHE II score ≥25, a Glasgow Coma Scale score <10, those requiring endotracheal intubation before the procedure, or patients discharged from the procedure intubated to the intensive care unit were excluded.

Based on anesthesia records, patients were classified into two cohorts: those who underwent the procedure under general anesthesia and those managed with sedoanalgesia. No assignment to anesthesia technique was performed as part of the study, and anesthesia management was determined according to routine clinical practice. Demographic characteristics, medical history, radiological findings, procedural details, and perioperative variables were extracted from hospital records. Neurological status was assessed using the National Institutes of Health Stroke Scale (NIHSS) at 4 and 24 hours after the procedure, and functional outcome was evaluated using the modified Rankin Scale during hospitalization and at 3 months after thrombectomy. Intraoperative bispectral index (BIS) values and cerebral oxygenation measured by near-infrared spectroscopy (NIRS) were recorded when available. Safety outcomes including peri-procedural hemodynamic instability, vasopressor or antihypertensive use, need for pacing, and intensive care unit (ICU) length of stay will be evaluated.

Neurological outcomes will be assessed longitudinally using NIHSS at baseline, 4 hours, 24 hours, and modified Rankin Scale (mRS/TICI) immediately after the procedure and at 3 months.

The primary outcome of the study was all-cause mortality. Secondary outcomes included neurological and functional outcomes, perioperative variables, intensive care unit length of stay, and procedure-related complications. Comparisons between anesthesia cohorts were performed using routinely collected clinical data. Postoperative delirium occurring during the first 7 days after the procedure was evaluated as a secondary safety outcome when documented in the medical records

Inclusion criteria

• Age ≥18 years
• Acute ischemic stroke due to large vessel occlusion (MCA M1)
• Mechanical thrombectomy performed within 6 hours of symptom onset
• Pre-procedural TICI score 0-1

Exclusion criteria

• Age ≥100 years
• APACHE II score of 25 or higher
• Glasgow Coma Scale score below 10
• Requirement for endotracheal intubation before the procedure
• Patients discharged from the procedure to the intensive care unit while intubated
• Time from symptom onset to procedure exceeding 6 hours