Abstract Number: Esoc2026a736 Tortuosity Index Predicts Complete Recanalization in Distal M2 Thrombectomy: Results of the D-Motive Study

Abstract Background and aims Mechanical thrombectomy (MT) for distal medium-vessel occlusions (DMVO) remains controversial. Anatomical predictors of MT success are underexplored. This study evaluated whether simple computed tomography angiography (CTA)-derived metrics are associated to recanalization and clinical outcomes in distal M2 occlusions. Methods D-MOTIVE included consecutive patients treated with MT at our center with distal M2 occlusion between January 2023 and December 2024, defined according to DISCOUNT trial criteria. Anatomical measurements—including tortuosity index (TI) in three planes, acute angles, and vascular loops—were obtained from baseline CTA. ROC-derived thresholds dichotomized sagittal TI for analyses. Primary efficacy outcome was complete recanalization (mTICI 3). Primary safety outcome was symptomatic intracranial hemorrhage (sICH). Results Among 262 patients with M2 occlusion, 51 met eligibility DISCOUNT trial criteria (median age 72, 53% male). High sagittal TI (TI≥ 1.19) was associated with lower complete recanalization (39% vs 70%; area under the curve AUC 0.71), reduced first-pass effect (11.1% vs 38.9%), and fewer patients achieving mRS 0–2 at 90 days (16.7% vs 72.7%; AUC 0.82). After adjustment, high tortuosity independently predicted lower odds of mTICI 3 (OR 0.18, p=0.018), more device passes (median +1.0; p=0.042) and worse functional independence at 90 days (OR 9.49, p0.01). Hemorrhagic and procedural complications were uncommon and similar between groups. Conclusions Higher sagittal M2 TI was associated with lower likelihood of complete recanalization and worse 90-day outcomes in distal M2 MT. These exploratory findings suggest that simple CTA-based anatomical markers may help to predict MT success in DMVO, warranting prospective multicenter validation. Conflict of interest The authors declare no competing interests.