The effect of operator's experience on mechanical thrombectomy outcomes: A systematic review

Background: Mechanical thrombectomy (MT) has become the standard of care for stroke patients. The majority of the clinical trials and publications analyzing the outcomes related to the procedures report interventional performance by experienced practitioners. However, few of them individualize their preliminary metrics according to the operator's experience. Objective: To summarize the literature and report safety and efficacy outcomes following MT procedures and correlate them with the operator's experience. Primary outcomes were successful recanalization, defined as modified thrombolysis in cerebral infarction greater or equal to 2b or 3, duration of the procedure measured in minutes, and serious adverse event. Methods: This systematic review was performed according to the PRISMA guidelines. The PubMed, Embase, and Cochrane databases were utilized. Results: There were six studies comprising 9348 patients (mean age 69.8 years; 51.2% males), and 9361 MT procedures were included. Each publication used for this review used a different experience definition to report their data. Higher interventionists’ experience demonstrated a positive relationship with the possibility of successful recanalization and an inverse relationship with the duration needed for the operation in almost all of the included studies. As for the complications, none of the authors reported a statistically significant risk reduction of an adverse event, except Olthuis et al. correlating increasing training with lower odds of stroke progression. Conclusions: A higher experience level is associated with better recanalization rates and shorter procedural duration in MT operations. Further studies are warranted to define the minimum required level of experience for operational autonomy.