Abstract Number: LBA2 Early versus Late Window in the Endovascular Management of Acute Tandem Lesions
Authors: Galecio‐Castillo Milagros , Farooqui Mudassir , Divani Afshin A , Ribo Marc , Abraham Michael , Petersen Nils , Fifi Johanna , Guerrero Waldo , Malik Amer , Siegler James E , Nguyen Thanh N , Sheth Sunil , Yoo Albert J , Linares Guillermo , Janjua Nazli , Quispe‐Orozco Darko , Tekle Wondewossen G , Oliver Marion , Zaidi Syed , Castonguay Alicia C , Kobsa Jessica , Prasad Ayush , Ikram Asad , Answer Hamza , Patterson Mary , Zevallos Cynthia B , Requena Manuel , Olive‐Gadea Marta , Qureshi Abid , Barkley Tiffany , Matsoukas Stavros , Rana Ameena , Abdalkader Mohamad , Salazar‐Marioni Sergio , Soomro Jazba , Turabova Charoskhon , Vivanco‐Suarez Juan , Rodriguez‐Calienes Aaron , Edgell Randall , Mokin Maxim , Yavagal Dileep R , Zaidat Osama , Jumaa Mouhammad A , Hassan Ameer E , Ortega‐Gutierrez Santiago 
Published: April 2023

Introduction
Despite the irrefutable benefit of mechanical thrombectomy for patients with isolated intracranial large vessel occlusions (LVO), the effect of endovascular treatment in patients with tandem lesions remains unclear. In this study from the multi‐center PICASSO registry, we compare efficacy and safety outcomes in TLs patients treated in the early versus late window.

Methods
In this study, we used the data from the multi‐center PICASSO (Proximal Internal Carotid Artery Acute Stroke Secondary to Tandem Occlusion Thrombectomy) registry. PICASSO collaboration is a retrospective observational registry from 17 stroke centers. We compared efficacy and safety outcomes in TLs patients treated in the early versus late window. Patients were divided into two groups depending on last known well (LKW) to puncture time: Early time‐window group (<6 hours), and late time‐window group (6‐24 hours).We performed multivariable logistic and multinomial regressions to evaluate the association between each group and efficacy and safety outcomes,

Results
628 patients were included in the study. There were 336 (53.5%) treated in the early time‐window and 292 (46.5%) in the late time‐window. We did not observe a statistically significant difference between groups mRS 0–2 at 90 days (46.5% vs. 49%, aOR = 1.51, 95%CI: 0.92‐2.57, p = 0.101), shift analysis of mRS (aOR = 0.93, 95%CI: 0.63‐1.38, p = 0.734), and increased time from LKW to puncture was not significantly associated with mRS 0–2 at 90 days (aOR = 1.05, 95% CI: 0.99‐1.11, p = 0.09 for each hour delay). Similarly, we did not find differences in hemorrhagic transformation of ischemic stroke types: symptomatic ICH (5.1% vs. 4.1%, aOR = 0.80, 95%CI: 0.34‐1.88, p = 0.604), parenchymal hematoma type 2 (8.1% vs. 6.9%. aOR = 0.85, 95%CI: 0.44‐1.66, p = 0.641), and in ordinal analysis of petechial hemorrhage (19.8% vs 24.7%, aOR = 1.15, 95%CI: 0.79‐1.66), p = 0.466). Additionally, there were no differences in rates of successful reperfusion (mTICI 2b‐3) (88.7% vs. 85.2%, aOR = 1.19, 95%CI: 0.67‐2.11, p = 0.546), first pass effect (61.1% vs. 56.9%, aOR = 1.01, 95%CI: 0.65‐1.56, p = 0.963), early neurological improvement (44.1% vs. 36.7%, aOR = 0.96, 95%CI: 0.64‐1.44, p = 0.833), mortality at 90‐days (15.2% vs. 19.2%, aOR = 1.62, 95%CI: 0.94‐2.8, p = 0.81) and in‐hospital mortality (9.8% vs. 10.5%, aOR = 1.28, 95% CI 0.68‐2.39, p = 0.441).

Conclusions
The therapeutic effect of endovascular therapy in patients with AIS due to tandem lesions who present in the late time‐window is similar to those presenting in the early time‐window. Furthermore, efficacy and safety outcomes rates are consistent with those found in clinical trials that included patients with isolated intracranial lesions treated in the late time‐window.