Clinical equipoise and ethical challenges in expanding endovascular stroke thrombectomy practice.

INTRODUCTION: Endovascular thrombectomy transformed acute ischemic stroke care while exposing ethical tensions in emergency research. As landmark trials rapidly shifted standards, investigators faced complex questions regarding equipoise, early stopping, and respecting autonomy when patients lack capacity and time is critical. METHODS: We conducted a focused literature analysis from 2003 to 2024 spanning practice-changing thrombectomy trials and contemporary ethics literature. We synthesized three domains: (1) equipoise dynamics during evidence accumulation; (2) balancing non-maleficence against the social value of continuing trials; and (3) consent models for incapacitated patients in time-sensitive settings. RESULTS: Initial uncertainty regarding endovascular efficacy justified early randomized controls. However, post-2015 data precipitated a rapid loss of equipoise, necessitating the early termination of trials to uphold the duty of care for control arm participants. While early stopping rules successfully minimized harm, they raised tensions regarding the precision of treatment effect estimates. Furthermore, the requirement for standard informed or surrogate consent was found to introduce selection bias against severe stroke patients lacking capacity. The literature supports shifting toward deferred or presumed consent models in these emergencies, arguing that rigid adherence to autonomy can paradoxically violate the principles of justice and beneficence by systematically excluding the most vulnerable patient populations from life-altering interventions. CONCLUSIONS: Ethical conduct of emergency stroke trials requires continuous reassessment of equipoise, pre-specified stopping rules that prioritize participant welfare, and consent pathways tailored to incapacity and time sensitivity. We explore principles integrating beneficence, non-maleficence, autonomy, and justice to maximize lives saved and prevent disability while preserving rights. These principles generalize to future trials as indications, technologies, and timelines evolve.