Measuring anesthesia process reliability during endovascular thrombectomy for acute ischemic stroke: insights from...

Endovascular thrombectomy (EVT) is an established therapy for acute ischemic stroke (AIS) caused by large-vessel occlusion (LVO); however, its effectiveness relies on rapid workflow and coordinated multidisciplinary care. Temporal variation in care delivery during nights and weekends, known as the "off-hours effect," has been linked to treatment delays in large stroke registries, although high-volume centers often preserve clinical outcomes. This observation indicates that mature stroke systems may sustain outcome resilience despite workflow variability. Therefore, evaluating process reliability may offer additional insights beyond traditional outcome measures. This study examined whether the timing of groin puncture (in-hours versus out-of-hours) was associated with anesthesia process reliability in an EVT program with continuous 24/7 in-house anesthesia coverage.

We conducted a single-center retrospective quality-improvement study of adults undergoing EVT for anterior-circulation LVO between January 2020 and August 2024 in a system with continuous 24/7 in-house anesthesia coverage. Using a Donabedian structure-process-outcome framework, anesthesia process reliability was defined a priori as a stringent composite requiring: (1) operating room arrival-to-groin puncture ≤12 min, (2) no unplanned conversion from conscious sedation to general anesthesia, and (3) cumulative intra-procedural mean arterial pressure reduction ≥20% from baseline ≤10 min. The primary exposure was Groin puncture (GP) time (in-hours vs out-of-hours). Pareto analysis characterized contributors to composite failure. Multivariable regression assessed associations with process reliability. Ninety-day functional outcome and in-hospital mortality were treated as balancing measures.

Among 361 patients, anesthesia process reliability was achieved in approximately 30% of cases. Composite failure rates were similar across time-of-presentation strata. Pareto analysis demonstrated that hemodynamic control and workflow timeliness accounted for over 90% of composite failures, whereas unplanned anesthetic conversion contributed minimally. Out-of-hours GP was not associated with anesthesia process reliability or 90-day functional outcomes after adjustment. Longer procedure duration, older age, and higher baseline MAP were independently associated with reliability failure.

In a mature EVT system supported by continuous in-house anesthesia coverage, OOH care was not associated with reduced anesthesia process reliability or worse clinical outcomes. Despite preserved functional outcomes, stringent composite metrics revealed frequent deviations concentrated in hemodynamic control and workflow timeliness. These findings highlight the value of process-level assessment as a diagnostic quality tool and identify priority targets for focused quality-improvement efforts in EVT anesthesia care.