Abstract 200: ICA Lesion Etiology does not affect the Outcomes after Endovascular Treatment of Acute Tandem LVO
Authors: Castillo Milagros R. Galecio , Farooqui Mudassir , Hassan Ameer , Jumaa Mouhammad , Divani Afshin , Ribo Marc , Abraham Michael , Petersen Nils , Fifi Johanna , Guerrero Waldo , Malik Amer , Siegler James , Nguyen Thanh , Sheth Sunil , Yoo Albert , Linares Guillermo , Janjua Nazli , Quispe‐Orozco Darko , Tekle Wondewossen , Ali Syed Zahid , Ikram Asad , Zevallos Cynthia , Olivé‐Gadea Marta , Qureshi Abid , Devarajan Alex , Vigilante Nicholas , Abdalkader Mohamad , Salazar‐Marioni Sergio , Soomro Jazba , Gordon Weston , Turabova Charoskhon , Vivanco‐Suarez Juan , Rodriguez‐Calienes Aaron , Mokin Maxim , Yavagal Dileep , Ortega‐Gutierrez Santiago 
Published: March 2024

Introduction
Tandem lesions (TLs) are present in up to 15% of patients with stroke due to acute large vessel occlusions.(1) Nevertheless, published research on endovascular treatment outcomes in this population is scarce. Although TLs are most commonly of atherosclerotic etiology, some patients present with dissection of the ICA.(2, 3) In this study, we compared the clinical outcomes of TL patients with the two etiologies.

Methods
A retrospective analysis was performed on a multicenter cohort of patients with TLs who underwent endovascular treatment. The patients were categorized into two groups according to the etiology of the ICA lesion: atherosclerosis and dissection. Patients were matched by baseline characteristics. Clinical outcomes, including recanalization success, functional independence and hemorrhagic events were assessed with multivariable analyses.

Results
Of 691 patients from the database, 526 met the inclusion criteria of this study. 467 (88.8%) patients presented with atherosclerosis of the ICA, and 59 (11.2%) patients presented dissection. Univariable differences were found in median age (69 y. [IQR 61 ‐ 76] vs. 52 y. [IQR 44 ‐ 63], p<.001), rates of hypertension (74.5% vs. 52.5%, p<0.001), hyperlipidemia (49.2% vs. 27.1%, p=.001), diabetes (29.8% vs. 15.3%, p=.019), and prior antiplatelets use (36.8% vs. 22.8%, p=.037).
After matching and adjusting for confounders, we did not find differences between both groups for the main outcomes: Successful reperfusion (89.1% vs. 79.7%, aOR 0.46, 95% CI 0.20 – 1.08, p=.074), mRS 0‐2 at 90 days (47.5% vs. 47.4%, aOR 0.80, 95% CI 0.44 – 1.48, p=.381), and sICH (4.3% vs. 6.8%, aOR 0.96, 95% CI 0.17 – 5.58, p=0.965). Similarly, no differences were found for the secondary outcomes: Excellent recanalization (51.1% vs. 40.7%, aOR 0.86, 95% CI 0.46 – 1.60, p=.632), early neurological improvement (41% vs. 36.2%, aOR 0.76, 95% CI 0.40 – 1.43, p=.392), parenchymal hematoma type 2 (7.8% vs. 8.5%, aOR 0.59, 95% CI 0.17 – 2.03, p=.400), mortality at 90 days (17.4% vs. 14%, aOR 1.17, 95% CI 0.49 – 2.81, p=.726), and intrahospital mortality (9.6% vs. 8.6%, aOR 0.91, 95% CI 0.31 – 2.62, p=.859).

Conclusion
In our cohort, patients with lesions of atherosclerotic etiology achieved higher rates of successful and excellent recanalization, but the effect disappeared when matching the groups and adjusting for confounders. The results of this study show that the etiology of the ICA lesion does not affect the clinical outcomes of endovascular treatment in tandem lesions.