Introduction In patients undergoing endovascular thrombectomy (EVT) for acute ischemic stroke, higher recanalization scores using the Thrombolysis In Cerebral Ischemia (TICI) score were demonstrated to predict EVT outcomes. Successful recanalization is commonly used to report TICI 2B score or higher corresponding to recanalization of at least 50% of the target territory. In this work, we study the risk-benefits associated with continued attempt to achieve higher TICI score beyond TICI 2B as function of procedure time.

Methods This is a retrospective registry-based study of patients undergoing EVT for AIS at 30 centers internationally. Patients were reviewed for their demographics, admission deficits, and technical outcomes. The cohort was split into 4 groups: (1) patients with TICI 2B recanalization without attempts to enhance score, (2) patients with TICI 2B recanalization for whom additional attempts were made for higher score, and (3) patients with TICI 0–2A. Primary outcome is modified Rankin Score (mRS) at 90 days, secondary outcomes included improvement in post-procedural National Institute of Health Stroke Scale (NIHSS), final TICI score, and symptomatic intracranial hemorrhage (sICH). Successful recanalization was defined as TICI-2B or more, and complete recanalization was defined as TICI-3. Logistic regression models were used to study outcome predictors while controlling for admission and technical covariates using step-wise backpropagation to avoid bias in variable selection. Adjusted odds ratios (aOR) were reported.

Results A total of 3071 patients were included in this study with mean age of 68, 48% females, and 89% rate of successful recanalization. We first compared groups (1) and (2) using logistic regression models, patients with additional attempts to improve TICI 2B score (Group 2) were associated with higher odds of achieving TICI 3 (aOR=6.8,p<0.001), but had significantly lower odds of good outcome (mRS 0–2) (aOR=0.73,p<0.001) without impact on rates of sICH. When comparing patients in group (2) to patients without successful recanalization (group 3), continued EVT past TICI-2B did not result in higher odds of good outcome compared to those with TICI1–2A (aOR=1.17,p=0.41). Using sensitivity analysis, we demonstrate that in patients who achieve TICI-2B within 15 min of puncture, additional attempts at improving the score was associated with higher odds of TICI-3 (aOR=35,p<0.01) without negative influence on functional outcome.(aOR=0.96,p=0.89). However, in patients where initial TICI-2B score was attained after 15 min of puncture, further attempts are associated with higher odds of TICI-3 (aOR=6.8,p<0.01) but with significantly lower odds of good outcome (aOR=67,p=0.015). Finally, longer time to conclude EVT procedure after TICI-2B was independently associated with lower odds of good outcome (aOR=0.88,p=0.021).

Conclusions In patients with successful recanalization who achieved below perfect reperfusion scores, additional recanalization trials carry the cost of worsening outcomes specifically in patients whose initial recanalization required more than 15 min. Future prospective studies are needed to study whether achieving the point of trade-off between achieving perfect recanalization scores and patient outcomes.

Disclosures B. El Baba: None. Y. Zohdy: None. R. Chalhoub: None. B. Howard: None. C. Cawley: None. F. Akbik: None. D. Barrow: None. A. Pabaney: None. F. Tong: None. S. Alkasab: 1; C; Stryker. P. Jabbour: 2; C; Balt, Cerus endovascular, MicroVention, Medtronic. N. Goyal: None. A. Arthur: 1; C; Balt, Medtronic, Microvention, Penumbra, Siemens. 2; C; Arsenal, Balt, Johnson and Johnson, Medtronic, Microvention, Penumbra, Scientia, Siemens, Stryker. 4; C; Azimuth, Bendit, Cerebrotech, Endostream, Magneto, Mentice, Neurogami, Neuros, Scientia, Serenity, Synchron, Tulavi, Vastrax, VizAI. F. Siddiqui: None. S. Yoshimura: None. M. Park: 5; C; Medtronic. W. Brinjikji: None. C. Maatouk: 2; C; Silk Road, Penumbra, Microvention, Stryker. 3; C; Silk Road, Penumbra. D. Romano: None. D. Altschul: None. R. Williamson: None. M. Moss: None. R. De Leacy: 1; C; Hyprevention, Kaneka Medical, Siemens Healthineers, SNIS foundation. 2; C; Stryker Neurovascular, Imperative Care, Cerenovus, Asahi Intec. 4; C; Synchron, Endostream, Q’Apel, Spartan Micro. 6; C; Editorial Board JNIS. M. Ezzeldin: None. P. Kan: 1; C; U18EB029353–01. 2; C; Stryker Neurovascular, Imperative Care, Microvention. 6; C; Editorial Board JNIS. M. Levitt: 1; C; Stryker, Medtronic. 2; C; Medtronic, Aeaean Advisers. 4; C; Hyperion Surgical, Proprio, Synchron, Cerebrotech, Fluid Biomed, Stereotaxis. 6; C; Travel support: Penumbra, Editorial board, Journal of NeuroInterventional Surgery, Metis Innovative: Adviser. R. Grandhi: None. A. Spiotta: 2; C; Stryker, Terumo, Penumbra, RapidAI. J. Mascitelli: 2; C; Stryker. J. Grossberg: 1; C; Georgia Research Alliance, Emory Medical Care Foundation, Department of Defense, Neurosurgery Catalyst. 4; C; NTI, Cognition. A. Alawieh: 6; C; Penumbra.