Artificial cerebrospinal fluid use during burr-hole surgery and reoperation rate in patients with chronic subdural hematoma: an analysis using a nationwide inpatient database.

BACKGROUND: The optimal surgical procedure to reduce the recurrence rate of chronic subdural hematoma (CSDH) after burr-hole surgery remains to be established. This study aimed to investigate the association between artificial cerebrospinal fluid (ACF) use during burr-hole surgery and reoperation rate in patients with CSDH. METHOD: In this retrospective cohort study, we used the Japanese Diagnostic Procedure Combination inpatient database. We identified patients aged 40-90 years who were hospitalized for CSDH and had undergone burr-hole surgery within 2 days of admission, between July 1, 2010 and March 31, 2019. We performed a one-to-one propensity score-matched analysis to compare the outcomes between patients with and without ACF irrigation during burr-hole surgery. The primary outcome was reoperation within 1 year of surgery. The secondary outcome was the total hospitalization costs. RESULTS: Of the 149,543 patients with CSDH from 1100 hospitals, ACF was used in 32,748 patients (21.9%). Propensity score matching created highly balanced 13,894 matched pairs. In the matched patients, the reoperation rate was significantly lower in the ACF users than that in the non-users group (6.3% vs. 7.0%, P = 0.015), with a risk difference of -0.8% (95% confidence interval, -1.5 to -0.2). There was no significant difference in the total hospitalization costs between the two groups (5079 vs. 5042 US dollars, P = 0.330). CONCLUSIONS: ACF use during burr-hole surgery may be associated with lower reoperation rate in patients with CSDH.