Study From ETIS Registry Evaluates Impact of Operator Volume in Mechanical Thrombectomy

February 21, 2019—Findings on the impact of operator volume of mechanical thrombectomy (MT) procedures for acute ischemic stroke (AIS) in the ETIS registry were published by Rody El Nawar, MD, et al in Journal of the American College of Cardiology (JACC): Cardiovascular Interventions (2019;12:385–391).

The investigators concluded that the data suggest that operator volume of MT has a positive impact on successful reperfusion in AIS but not on clinical outcomes or complication rates. Further studies are warranted to investigate threshold procedure numbers associated with better outcomes, advised the investigators in JACC: Cardiovascular Interventions.

As summarized in JACC: Cardiovascular Interventions, the aim of this study was to determine whether individual operator characteristics have an impact on reperfusion and procedural complication rates in the prospective, multicenter, observational, real-world ETIS registry of MT.

The study assessed the effect of individual operator characteristics on successful reperfusion, defined as modified thrombolysis in cerebral infarction 2b/3 at the end of MT, and procedural complications using multivariable hierarchical logistic regression models. The study included all patients with AIS who were consecutively treated with MT by 19 operators at three high-volume comprehensive stroke centers between January 2012 and March 2017. Investigators enrolled 1,541 patients (mean age, 67 years; median National Institutes of Health Stroke Scale score, 16) with anterior and posterior AIS.

The investigators found that there was a significant operator effect on successful reperfusion (intraclass correlation coefficient = 0.036 [P = .046]) but not on complications (intraclass correlation coefficient = 0). There was a dose-response relationship between annual operator volume and successful reperfusion rate (P = .003) with an adjusted odds ratio for successful reperfusion of 2.52 (95% confidence interval, 1.37–4.64) for patients treated by an operator with an annual volume of ≥ 40 MTs per year compared with those treated by an operator with < 14 MTs per year (first tertile). Nevertheless, this result did not translate to better clinical outcomes, reported the investigators in JACC: Cardiovascular Interventions.