Need for a definitive trial of local versus general anaesthesia in chronic subdural haematoma; survey and literature review of ongoing trials

Abstract Background Chronic subdural haematoma (cSDH) is a common neurosurgical condition, many patients have significant comorbidity or are living with frailty. Surgery is effective and can be performed under local anaesthesia (with or without sedation) (LAS) or general anaesthesia (GA). Optimal technique for both GA and LAS is poorly defined but similar questions have been explored in other surgical settings. We sought to clarify the breadth of evidence for anaesthetic technique in cSDH surgery, while drawing on relevant literature from other disciplines to understand how a definitive trial of this question could be performed. Materials and methods We used a combination of review of trial registries, the Cochrane database, and a survey of anaesthetic and neurosurgical practitioners. Results We identified a paucity of high-quality studies, especially randomised trials, exploring this question. The literature, and survey of anaesthetists and surgeons suggest that LAS may achieve equivalent outcomes, but significant confounding exists in current studies. Registered trials are single centre, and Cochrane reviews in other fields present issues of equipoise, study design, and outcome choice as key challenges in designing a definitive trial. Conclusions There is significant interest in this topic as evidenced by published and emerging literature and views of anaesthetists and surgeons. No registered trial is multi-centre or draws on challenges identified in similar trials from other disciplines.