Chronic subdural hematoma represents one of the most frequent neurosurgical emergencies encountered in clinical practice today. As life expectancy rises worldwide, clinicians observe a steep increase in patients presenting with intracranial fluid collections. However, surgical practices and perioperative routines have varied substantially across international centers. Consequently, therapeutic inconsistency has complicated standardized care delivery. To harmonize clinical workflows, experts recently gathered at the 2024 joint iCORIC/DACSUHS symposium in Copenhagen. The panel performed a modified Delphi study involving thirty-two neurosurgeons, neurointerventionalists, and neurosurgical researchers from fourteen nations. Therefore, this international consensus statement clarifies best practices while outlining ongoing research priorities.

Standardizing Chronic Subdural Hematoma Evacuation Techniques

The symposium reached decisive consensus regarding the primary surgical management of symptomatic collections. Specifically, the panel unanimously recommended surgical decompression for any hematoma producing significant mass effect or progressive neurological deficits. Conversely, clinicians should manage asymptomatic or mild cases conservatively with rigorous clinical observation. When surgical intervention becomes mandatory, surgeons strongly advocate burr hole craniostomy or twist-drill craniostomy as first-line approaches. In contrast, surgeons reserve formal craniotomy primarily for refractory, highly organized, or solid recurrent membranes. Furthermore, the expert panel evaluated the challenge of bilateral collections. The participants achieved strong consensus advising bilateral evacuation during a single surgical session when both collections cause significant mass effect. This standardized approach prevents secondary midline shifts and reduces readmission rates. Additionally, selecting minimally invasive craniostomy decreases operative time, reduces general anesthesia burdens, and accelerates postoperative recovery in fragile geriatric patients. Therefore, uniform adherence to these primary evacuation pathways establishes a reliable foundation for institutional neurosurgical care.

Intraoperative Irrigation Protocols and Closed Drainage Systems

Surgical technique extends far beyond simply creating burr holes. Indeed, the consensus highlights technical specifics during intraoperative clearance. The panel achieved strong consensus supporting generous subdural irrigation with body-temperature fluid. Specifically, surgeons should irrigate the hematoma cavity using warm Ringer's lactate solution at thirty-seven degrees Celsius. Several clinical trials show that cold fluids can induce cortical irritation, cerebral vasospasm, and postoperative seizures. Moreover, warm irrigation significantly lowers recurrence rates compared to room-temperature saline. Following thorough clearance of the subdural space, surgeons must consistently place a closed subdural drainage system. The panel unanimously confirmed that closed-system postoperative drainage drastically decreases hematoma recurrence without elevating infection risks. However, significant controversy remains regarding the ideal duration of postoperative drainage. While most neurosurgeons maintain catheters for up to twenty-four hours, the panel lacked consensus on prolonging drainage beyond that window. Thus, centers must weigh the marginal benefits of prolonged drainage against the possible risks of catheter-related infections.

Postoperative Mobilization and Patient Recovery Pathways

Postoperative nursing protocols represent another area where traditional clinical dogma has rapidly evolved. Historically, many neurosurgical units enforced prolonged flat bed rest for several days following hematoma evacuation. Clinicians previously assumed that horizontal positioning promoted brain re-expansion and prevented acute recurrence. However, the Copenhagen Delphi panel firmly challenged this outdated doctrine. Instead, the participants achieved robust consensus advocating early postoperative patient mobilization. In fact, early mobilization minimizes life-threatening hospital complications, including deep vein thrombosis, pulmonary embolism, hypostatic pneumonia, and rapid functional decline. Fragile older adults suffer devastating physical deconditioning after only forty-eight hours of strict immobilization. Therefore, allowing patients to sit upright and mobilize within twenty-four hours after surgery substantially improves functional discharge scores. Furthermore, recent prospective studies demonstrate that early mobilization does not increase recurrence rates or compromise brain parenchymal expansion. Consequently, multimodal rehabilitation should commence promptly once the patient demonstrates clinical stability and anesthesia emergence.

Clinical Debates Surrounding Antithrombotic Management and Reversal

Despite broad consensus on operative strategies, antithrombotic management remains a highly contentious clinical dilemma. A vast majority of individuals who develop chronic subdural collections take antiplatelet agents or direct oral anticoagulants for cardiovascular indications. Nonetheless, the panel revealed a marked lack of international agreement regarding pre-operative reversal protocols and optimal resumption timelines. Clinicians currently balance two severe competing risks. On one hand, rapid complete reversal reduces intraoperative bleeding and immediate hematoma re-accumulation. On the other hand, aggressive prothrombotic reversal triggers catastrophic ischemic strokes, myocardial infarctions, or systemic thromboembolism. Similarly, neurosurgeons disagree on when to safely restart prophylactic or therapeutic anticoagulation postoperatively. Some centers restart anticoagulation within three to five days, while others delay initiation for up to four weeks. Because high-quality randomized evidence remains scarce, local neurosurgical departments continue to rely on subjective risk stratification. Therefore, multinational clinical registries and randomized clinical trials are urgently needed to establish clear antithrombotic algorithms.

Middle Meningeal Artery Embolization and Routine Follow-Up Imaging

The panel also debated emerging minimally invasive technologies and neuroimaging protocols. In recent years, endovascular middle meningeal artery embolization has garnered substantial enthusiasm across neurointerventional communities. Proponents argue that devascularizing the fragile neo-membranes arrests inflammatory exudation and reduces recurrences. However, the Delphi panel found no consensus for adopting middle meningeal artery embolization as a routine primary or preventive therapy. Instead, participants recommended reserving endovascular embolization for clinical trials or highly recurrent collections until definitive Phase III trial data mature. Furthermore, the panel debated the necessity of routine postoperative computed tomography in asymptomatic patients. Many neurosurgical units routinely scan patients before hospital discharge. Nevertheless, the consensus process revealed persisting disagreement regarding this practice. Routine scans frequently display residual subdural fluid that does not correlate with clinical outcomes, often prompting unnecessary intervention. Consequently, many experts recommend reserving follow-up computed tomography strictly for patients demonstrating new neurological signs or failing clinical progress.

Implications for Global Neurosurgical Practice and Clinical Guidelines

The findings from the Copenhagen symposium deliver vital guidance for neurosurgical departments, intensive care units, and emergency teams globally. By clearly separating established evidence from persistent uncertainties, the panel provides a practical framework for hospital protocols. For instance, teams can readily standardize burr hole evacuation, warm Ringer's lactate irrigation, closed drainage placement, and early mobilization. Meanwhile, identifying areas of discordance directs institutional priorities toward high-yield clinical research. Surgical teams must refrain from premature widespread adoption of costly therapies without robust clinical trial justification. Similarly, managing anticoagulation reversal requires nuanced, multidisciplinary decision-making between neurosurgeons, cardiologists, and hematologists. As healthcare systems care for an expanding geriatric demographic, harmonizing international practices becomes indispensable. Ultimately, this landmark consensus statement lays the groundwork for transnational prospective collaborations, standardized clinical audits, and improved functional independence for vulnerable patients worldwide.

Frequently Asked Questions

What is the preferred surgical technique for chronic subdural hematoma?

Surgeons consider burr hole craniostomy or twist-drill craniostomy the primary surgical treatments for symptomatic chronic subdural hematoma. These minimally invasive procedures effectively evacuate the liquefactive collection with low operative morbidity. Surgeons reserve formal craniotomy specifically for solid, highly organized, calcified, or multi-recurrent hematoma membranes that cannot drain through burr holes.

Why is warm Ringer's lactate recommended for subdural irrigation?

The consensus strongly recommends irrigating the subdural space with Ringer's lactate solution warmed to thirty-seven degrees Celsius. Clinical trials confirm that warm irrigation significantly reduces hematoma recurrence rates. Furthermore, cold solutions can irritate the underlying cerebral cortex, triggering intraoperative or postoperative seizures, cortical vasospasm, and unnecessary neurological complications.

When should clinicians resume antithrombotic therapy following hematoma evacuation?

The international symposium revealed persisting disagreement regarding the precise timing for restarting antithrombotic therapy. Clinicians must carefully balance individual thromboembolic risk against recurrent intracranial hemorrhage risk. While many centers resume antiplatelet or anticoagulant agents within one to four weeks, individualized multidisciplinary risk assessment remains essential until definitive clinical trials conclude.

Disclaimer: This content is for informational and educational purposes only and should not be taken as professional medical advice. Always consult a qualified healthcare provider for personal health concerns and clinical decision-making. The views and opinions expressed in this article are those of the authors and do not necessarily reflect the official policy or position of any other agency, organization, employer or company. Refer to the latest local and national guidelines for clinical practice.

References

1. Hansen JT et al. Management of chronic subdural hematoma: a consensus statement from the 2024 Copenhagen joint iCORIC/DACSUHS symposium. Acta Neurochir (Wien). 2026 Apr 14. doi: 10.1007/s00701-026-06854-y. PMID: 41981236.
2. Hjortdal Grønhøj M, Jensen TSR, Miscov R, Sindby AK, Debrabant B, Hundsholt T, et al. Optimal drainage time after evacuation of chronic subdural haematoma (DRAIN TIME 2): a multicentre, randomised, multiarm and multistage non-inferiority trial in Denmark. Lancet Neurol. 2024;23(8):787-796.
3. Schack A, Jensen TSR, Jensen MH, Miscov R, Sindby AK, Fugleholm K, et al. Intraoperative Irrigation and Risk of Chronic Subdural Hematoma Recurrence. Oper Neurosurg (Hagerstown). 2024;26(2):203-212.