A thoracic CT imaging parameter predicting access difficulty in acute stroke thrombectomy.

Purpose: The quick establishment of adequate vascular access is essential for the technical success of mechanical thrombectomy (MT). Focusing on shifts in aortic arch geometry and aging-related changes, we propose an imaging parameter for predicting access difficulty using chest CT.

Methods: Patients with acute anterior circulation large-vessel occlusion who underwent MT from April 2020 to September 2021 were included in this retrospective multicenter observational study. The distance from the sternum to the ascending aorta (S-AAD) was defined as the surrogate marker of access difficulty. Access was defined as difficult when the time from femoral sheath placement to guiding catheter induction (guiding time: GT) ≥ 30 minutes, and the patients were dichotomized into groups with short GT (sGT: GT < 30 min) and long GT (lGT: GT ≥ 30 min).

Results: One hundred fifteen patients were included. There were 12 patients (10.4 %) in lGT group. The median (IQR) S-AAD was 11.9 mm (6.3, 18.3 mm) in sGT group and 6.6 mm (4.0, 10.3 mm) in lGT group, and a significant difference in S-AAD was observed (P = 0.026). In multivariate analyses, dyslipidemia and S-AAD < 5 mm were significantly associated with difficult access (OR, 5.938 [95 % CI, 1.468, 24.022], P = 0.012 for dyslipidemia; OR, 5.147 [95 % CI, 1.267, 20.917], P = 0.022 for S-AAD < 5 mm).

Conclusion: S-AAD is a simple and reliable imaging parameter to predict access difficulty. This parameter may be helpful in selecting the appropriate devices and access routes in preinterventional practice.