Prognostic value of intracranial vascular tortuosity in thrombectomy for distal vessel occlusion

Abstract Introduction Neutral results from trials assessing mechanical thrombectomy (MT) for medium/distal vessel occlusions (MDVO) suggest the need for better selection criteria in these patients. Tortuous vascular anatomies may negatively influence MT efficacy and safety. Patients and methods Consecutive patients with middle cerebral artery (MCA)-MDVO (M2/M3) who underwent MT at our center between January 2017 and September 2024 were included. Baseline CTAs were semi-automatically analyzed using an in-house vascular analysis framework. The internal carotid artery (ICA) tortuosity index (TI) and anatomical features of the MCA were extracted. Logistic regression adjusted for intravenous thrombolysis administration and onset-to-puncture time evaluated associations of anatomical features with treatment efficacy and safety endpoints. Primary endpoints were complete recanalization (final eTICI 2c/3) and symptomatic intracranial hemorrhage (sICH). Results 213 patients (81 years IQR 72–87, 51.2% female) were included. MCA bending length (aOR 0.48 95%CI 0.27–0.86, p = 0.013), MCA-TI (aOR 0.77 0.60–0.98, p = 0.032) and ICA-TI (aOR 0.59 0.36–0.96, p = 0.034) were associated with lower probability of complete recanalization. ICA-TI (aOR 0.51 0.31–0.84, p = 0.008) and mean MCA diameter (aOR 0.34 0.13–0.90, p = 0.030) correlated with decreased odds of first-pass recanalization. Large mean MCA diameter was associated with lower likelihood of excellent functional outcome (aOR 0.30 0.09–0.96, p = 0.042). Regarding safety endpoints, larger diameter at occlusion was associated with sICH (aOR 4.04 1.03–15.87, p = 0.046), while MCA bending length (aOR 2.47 1.24–4.92, p = 0.010) was linked to subarachnoid hemorrhage. Discussion Automatic evaluation of anatomical vascular features may predict safety and efficacy of MT in stroke patients with MCA-MDVO. The value of these features as inclusion criteria for future MCA-MDVO clinical trials should be explored. Conclusion Intracranial vascular tortuosity is associated to poor thrombectomy outcomes in patients with MDVO.