In vitro bench testing of the Grasper stent retriever and mechanical thrombectomy strategies

Abstract

Objective: To evaluate the efficacy and embolic profile of the Grasper stent retriever, as well as various mechanical thrombectomy strategies, in a standardized in vitro bench model; to identify independent predictors of first-pass effect (FPE) and distal embolization. Materials and methods. A pulsating flow-loop system with four anatomical configurations was employed. Three types of blood clots were simulated, involving erythrocyte-rich, mixed, and fibrin-rich. A total of 288 tests (144 scenarios) were performed. Assessment included FPE, final reperfusion, number of passes, time to reperfusion, device–clot integration, and distal embolization. Statistical analysis was performed using the chi-square test, the Kruskal–Wallis test, and multiple regression analysis. Results. The FPE rates were 60.4%, 56.2%, and 54.2%, respectively, for the three devices compared (p = 0.82). The stent retriever showed superior device–clot integration, with no cases of failure to integrate (p < 0.001). FPE correlated with integration quality (p = 0.001). At the strategy level, FPE was achieved in 64.6% of cases. The combined technique resulted in the lowest embolic burden, as opposed to the aspiration-first strategy, which increased it (p < 0.001). The presence of a fibrin-rich clot reduced the probability of FPE (OR 0.24; p < 0.001). Conclusion. In the in vitro model, the Grasper stent retriever demonstrated efficacy competitive with two reference stent retrievers.