Is a drainage time of less than 24 h sufficient after chronic subdural hematoma evacuation?

BACKGROUND: It is well established that the use of a postoperative drain after chronic subdural hematoma surgery reduces recurrence rates, and it is common to use a postoperative drain for longer than 24 h. It is unclear whether this is superior to a shorter drainage time of less than 24 h. Our aim was to compare a postoperative drainage longer or shorter than 24 h after chronic subdural hematoma evacuation. MATERIALS AND METHODS: In this retrospective single centre study, 207 adult patients undergoing chronic subdural hematoma evacuation with a postoperative drainage longer (LDT-group) or shorter (SDT-group) than 24 h were compared regarding recurrence, mortality within 6 months and complications requiring hospital admission within 30 days. Length of hospital stay was also recorded. An active subgaleal drain was used. In addition to the retrospective cohort, we also studied the total volume drained per hour after cSDH surgery in a prospective cohort of 10 patients. RESULTS: Recurrence occurred in 12/96 (12.5%) in the LDT-group and in 13/111 (11.7%) patients in the SDT-group (p = 0.15). There was no significant difference between groups regarding recurrence, complications or mortality. The prospective cohort showed that most of the drainage occurred within the first hours after surgery. CONCLUSION: Our data show that a postoperative drainage duration of less than 24 h does not lead to an increase in recurrence, complications or mortality compared to a drainage time of more than 24 h. A shorter drainage duration (< 24 h) after cSDH surgery facilitated earlier mobilisation and shorter hospital stay. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s00701-023-05511-y.