Michele Romoli, C. A. Molina, Elena Zapata-Arriaza, Vinay Jaikumar, Jessica Jesser, Mirjam R. Heldner, Giovanni Merlino, Francesco Arba, Fabrizio Giammello, Răzvan Alexandru Radu, Lucio D'Anna, Guido Bigliardi, Uta Hanning, Luca Scarcia, Volker Puetz, Abdulrahman Abu Amara, Andrea Zini, P Michel, Diana Aguiar de Sousa, Sami Al Kasab, Barbara Casolla, Jordi Kühne Escolà, Valerio Da Ros, Alessandro Pezzini, Paolo Candelaresi, A Alexandre, Danilo Toni, João Pedro Marto, Joseph Domenico Gabrieli, João André Sousa, Roland Schwab, Kemal Alpay, Maurizio Paciaroni, Costanza Maria Rapillo, Leonard Y Yeo, S Greisenegger, Christian H. Nolte, Stefano Caproni, Aikaterini Anastasiou, Rossana Tassi, Volker Maus, Simona Lattanzi, Shail Thanki, Antioco Sanna, Marcello Naccarato, Christine Hawkes, Michael Abraham, Valentina Tudisco, Manuel Requena, Piers Klein, Maria Ruggiero, Elvis Lafe, Manuel Medina-Rodríguez, Andre Monteiro, Tilman Reiff, Peter Arthur Ringleb, Markus Möhlenbruch, Adnan Mujanović, Johannes Kaesmacher, Marieta Peycheva, Mariarosaria Valente, Antonio Taglialatela, Francesco Toraldo, Simone Ferretti, Antonio Toscano, Ludovica Ferraù, Stefania Maffei, Francesca Rosafio, Karolin Schulte, Daniel Kaiser, Ludovica Migliaccio, Guillaume Thévoz, Mafalda Delgado Soares, Ahmad Abu Qdais, Anna Gardin, Martin Köhrmann, Luigi Bellini, Emanuele Spina, Vincenzo Andreone, Ettore Nicolini, Sebastiano Giacomozzi, Federica Nicoletta Sepe, Lee Rosterman, Alexandra Aust, Marios Psychogios, Maiken Nordahl Selseth, Mohamad Abdalkader, Vincent Costalat, Aristeidis H. Katsanos, Adnan H. Siddiqui, Marco Longoni, Alejandro Tomasello, Espen Saxhaug Kristoffersen, Thanh N. Nguyen, Francesco Diana, for CERES-TANDEM, Giovanna De Marco, Claudia Faini, Simon Winzer, Viola Maria Maddalena
BACKGROUND AND OBJECTIVES: The management of anterior circulation tandem lesion stroke remains controversial, given its under-representation in randomized thrombectomy trials and uncertainty regarding optimal extracranial carotid intervention. We aimed to determine whether emergent carotid stenting (eCAS) during endovascular thrombectomy (EVT) for anterior circulation tandem lesions improves 90-day functional outcomes compared with a no-stenting strategy. METHODS: We conducted an international multicenter longitudinal retrospective cohort study (CERES-TANDEM, NCT06965036) of consecutive adults treated at 49 comprehensive stroke centers in Europe, North America, and Singapore for anterior circulation acute ischemic stroke due to tandem lesions from January 1, 2018, to December 31, 2024. Exclusion criteria were primary hemorrhagic stroke, absence of intracranial occlusion, presentation >24 hours from symptom onset, and age younger than 18 years. We compared 90-day modified Rankin Scale (mRS) scores between participants receiving eCAS and those receiving no stenting during EVT. The primary estimand was mRS shift, analyzed by stabilized inverse probability of treatment weighting (IPTW)-weighted ordinal regression. Additional estimands were direct-effect estimand adjusting for successful recanalization (defined as Thrombolysis in Cerebral Infarction grade 2b or higher) and symptomatic intracranial hemorrhage (sICH) (estimand 2) and stratum estimand restricting to never-crossers (estimand 3). RESULTS: = 0.008). DISCUSSION: In this large real-world cohort, eCAS during EVT for anterior circulation tandem lesions was associated with superior 90-day functional recovery without increased hemorrhagic risk. These findings support consideration of eCAS in clinical practice and warrant confirmation in randomized trials. TRIAL REGISTRATION INFORMATION: Registered in clinicaltrials.gov, NCT06965036. CLASSIFICATION OF EVIDENCE: This study provides Class II evidence that in patients with stroke due to anterior circulation tandem lesions, eCAS during EVT improves 90-day functional outcomes compared with EVT alone.