Identification of chronic subdural hematoma types most responsive to Goreisan, Kampo medicine: A retrospective study

Chronic subdural hematoma (CSDH) has a reported postoperative recurrence rate of 3-20% and the optimal therapeutic strategy remains controversial. Recently, in Japan, Goreisan (Kampo medicine) was used for preventing postoperative CSDH recurrence. Therefore, this study aimed to explore if Goreisan is effective against specific CSDH types by evaluating its effects on postoperative CSDH recurrence and reoperation rates based on its natural history and internal structure on CT images. This retrospective, single-center, cohort study was conducted at the Tokyo Metropolitan Hiroo Hospital. After applying the inclusion/exclusion criteria, data from 107 patients (70 men and 37 women; mean age, 77.1 ± 10.9 years), admitted for CSDH from January 2013 to December 2018, were included in the Goreisan group, whereas those of 122 patients (84 men and 38 women; mean age, 73.9 ± 13.3 years), admitted for CSDH from January 2007 to December 2012, were included in the control group. This corresponded to 114 lesions, with 14 reoperation lesions, in the Goreisan group and 108 lesions, with 16 reoperation lesions, in the control group. Lesions were categorized as homogeneous, laminar, separated, or trabecular type, and patients with homogeneous type lesions in the Goreisan group were approximately 50% less likely to undergo reoperation compared with those in the control group (7.3% versus 14%; odds ratio = 0.51; 95% confidence interval = 0.12-2.11). Thus, the homogeneous type CSDH was the most responsive to Goreisan, whereas the separated type was the least responsive. Therefore, selecting treatment strategies for preventing CSDH recurrence on CSDH type may contribute toward reducing reoperation rates.