Management of chronic subdural hematoma: a consensus statement from the 2024 Copenhagen joint iCORIC/DACSUHS symposium

BACKGROUND: Chronic subdural hematoma (CSDH) is among the most common neurosurgical conditions, yet management strategies vary worldwide despite an expanding evidence base. To harmonize clinical practice and facilitate the establishment of transnational recommendations, the 2024 joint iCORIC/DACSUHS symposium in Copenhagen included a Delphi process on the key aspects of CSDH management. METHODS: A modified Delphi process was conducted among 32 participants from 14 countries, including neurosurgeons, neurointerventionalists, and CSDH researchers. Eighteen topics were assessed across three survey rounds, based on the revised Danish national CSDH guidelines. Consensus was defined as ≥ 75% agreement and strong consensus as ≥ 95%. RESULTS: Response rates were 84.3%, 100%, and 59.3% across the three rounds. Unanimous or strong consensus was achieved for several core practices: surgical evacuation for hematomas with significant mass effect, conservative management for mild cases, use of burr hole or twist-drill craniostomy as primary treatment, and postoperative drainage after evacuation. Consensus also supported irrigation with warm (37C°) Ringer's lactate, bilateral evacuation for large bilateral hematomas, and early postoperative mobilization. Areas lacking consensus included management of antithrombotic therapy, drain duration beyond 24 h, the role of routine postoperative Computed Tomography (CT) in asymptomatic patients, and the adoption of eMMA as standard or preventive treatment. CONCLUSIONS: The 2024 iCORIC/DACSUHS Delphi consensus process identified broad international agreement on several aspects of CSDH management while exposing persisting disagreement in others including antithrombotic reversal, imaging protocols, and embolization strategies. Knowledge of the common understanding of agreement and disagreement within CSDH treatment form a platform for future multinational collaboration and highlight priorities for further clinical research.