What happens to conservatively managed chronic subdural haematoma

Chronic subdural haematoma (CSDH) is a common neurosurgical problem, increasingly prevalent due to an ageing population. Conservative management is an option for asymptomatic or mild cases, though data on outcomes is limited.

This study aims to address critical gaps in understanding around conservatively managedCSDH and whether there are features that can predict progression and the longer-term prognosis of these patients.

A retrospective cohort study was performed at a major trauma centre in the UK. All patients with chronic subdural haematoma referred from March 2019 to March 2021 were included and grouped into surgical or conservative management. Demographic, outcome, and radiological data were collected from patient records and compared.

Of 289 patients, 90 had surgery and 199 were managed conservatively. Conservative patients were older (84 vs 77 years, p < 0.0001), had more comorbidities (4 vs 2, p < 0.0001), higher frailty (CFS > 6: 45% vs 10%, p < 0.0001), and greater anti-thrombotic use (57% vs 42%, p = 0.0175). Mortality was significantly higher in the conservative group at all time points including one month (16% vs 2%, p < 0.0001), one year (42% vs 12%, p < 0.0001) and two years (55% vs 21%, P < 0.0001). Surgical patients had significantly greater midline shift (10 mm vs 2.6 mm, p < 0.0001), and haematoma depth (24 mm vs 11 mm, p < 0.0001). Only 3% of conservative patients crossed over to surgery.

Our study highlights the high mortality rate in conservatively managed CSDH, with frailty as a key indicator for early death. The low crossover to surgery questions the necessity of radiological monitoring in conservatively managed CSDH.