E-126 Comparison of stent retriever thrombectomy using 3D patient specific models of intracranial circulation with actual middle cerebral artery occlusion thrombectomy cases

Background Stent retriever (SR) thrombectomy is commonly used for the treatment of emergent large vessel occlusion (ELVO) in acute ischemic stroke (AIS). Clot imaging parameters such as clot length, diameter, distance to the internal carotid artery (ICA) terminus and vessel angle where the SR is deployed may predict the likelihood of achieving first-pass effect (FPE). Most of the proposed factors that seem to affect recanalization success have been studied individually, and conflicting data derived from clinical versus in vitro studies using 3D printed models of intracranial circulation currently exist. Methods Using patient-specific 3D phantoms of the cervical and intracranial circulation, we simulated MCA M1 and M2 occlusions treated with SR thrombectomy using Solitaire (Medtronic) or Trevo (Styker). Our primary outcome was first-pass effect, defined as Thrombolysis in Cerebral Infarction score of 2c-3 achieved after a single thrombectomy attempt. We also performed retrospective analysis of same clot imaging characteristics of consecutive cases of MCA occlusion and its association with FPE matching the 3D in vitro experiments. Analysis was conducted using IBM SPSS Statistics Version 25 (IBM Corp., Armonk, NY). Chi-square tests, and bivariate logistic regressions were the main statistical tests used in analysis. A p-value of less than 0.05 was considered to indicate statistical significance. 95% confidence intervals (95CI) were generated. Results We compared 42 thrombectomy experiments performed using patient-specific 3D in vitro models with a retrospective cohort of 42 patients treated with SR thrombectomy. We found that in the in vitro cohort, higher MCA angulation was associated with a lower likelihood of FPE (Odds ratio (OR) = 0.967 95CI = 0.944-0.991, p = 0.008). Meanwhile in the in vivo cohort, higher MCA angulation was associated with a higher likelihood of FPE (OR = 1.039 95CI = 1.003-1.077, p = 0.033). Neither clot length nor location of clot (M1 vs M2) was associated with a difference in FPE rates in either cohort. Discussion Comparison of SR thrombectomy performed during actual MCA occlusion cases versus patient specific 3D replicas revealed MCA angulation as an independent predictor of procedure success or failure. However, the opposite direction of effect was observed between the two studied environments, indicating potential limitations of studying SR thrombectomy using 3D models of LVO. Disclosures M. Mokin: 1; C; NIH R21NS109575. E. Pressman: None. K. Sommer: None. C. Ionita: None.