Adjuvant oral tranexamic acid and reoperation after burr hole surgery in patients with chronic subdural hematoma: propensity score-matched analysis using a nationwide inpatient database.

Adjuvant medical treatment to reduce the recurrence rate after burr hole surgery for chronic subdural hematoma (CSDH) has not yet been established. This study aimed to investigate the association between tranexamic acid (TXA) use after burr hole surgery and the reoperation rate in patients with CSDH. This observational study used the Japanese Diagnostic Procedure Combination inpatient database, a nationwide inpatient database in Japan, from July 1, 2010, to March 31, 2019. The authors identified patients who were hospitalized for CSDH and underwent burr hole surgery within 2 days of admission. The primary outcome measure was reoperation within 1 year after surgery. One-to-one propensity score-matched analysis was performed to compare the outcomes between patients who started oral TXA within 2 days after surgery (TXA users) and those who did not (TXA nonusers). Robustness of the analyses was assessed using the instrumental variable analysis. Of the 149,543 patients with CSDH treated at 1100 hospitals, 7366 (4.9%) were TXA users. Propensity score matching created 6564 matched pairs with highly balanced baseline characteristics. The reoperation rate was significantly lower in TXA users than in nonusers (1.9% vs 6.1%, p < 0.001) with a risk difference of -4.1% (95% CI -4.8% to -3.4%). There was no significant difference in composite adverse events (0.6% vs 0.5%, p = 0.817). Total hospitalization costs were also significantly lower in TXA users than in nonusers ($5229 vs $5344 [USD], p < 0.001). The results of the instrumental variable analysis were consistent with those of the propensity score-matched analysis. Findings of this study, using a nationwide inpatient database, suggest that adjuvant TXA use after burr hole surgery was associated with a reduced reoperation rate in patients with CSDH.