The Effect of Japanese Herbal Medicines (Kampo) Goreisan and Saireito on the Prevention of Recurrent Chronic Subdural Hematoma: A Prospective Randomized Study

BACKGROUND AND OBJECTIVES: Chronic subdural hematoma (CSDH) sometimes recurs after surgical treatment and requires reoperation. In Japan, Japanese herbal medicines (Kampo), such as Goreisan and Saireito, have been used as adjunctive therapies to prevent the recurrence of CSDH. However, no prospective randomized study has proven the efficacy of Kampo medicine in all patients. To investigate whether Goreisan and Saireito reduce the postoperative recurrence of CSDH in a prospective randomized study. METHODS: Between April 2017 and July 2019, a total of 118 patients who underwent initial burr hole surgery for CSDH were randomly assigned to the following 3 groups: (1) Goreisan for 3 months (Group G), (2) Saireito for 3 months (Group S), and (3) no medication (Group N). The primary end point was symptomatic recurrence within 3 months postoperatively, and the secondary end point was complications associated with the administration of Kampo medicine. RESULTS: Among 118 patients, 114 (Group N, n = 39; Group G, n = 37; and Group S, n = 38) were included in our analysis. In this study, byakujutsu (containing Atractylodes rhizome) Goreisan and Saireito were used, unlike other prospective randomized studies in which sojutsu (containing Atractylodes lancea rhizome) Goreisan was used. The overall recurrence rate was 11.4% (13/114: 10 for Group N, 2 for Group G, and 1 for Group S). The recurrence rate of Group G was significantly lower than that of Group N (5.4% vs 25.6%; P = .043). The recurrence rate of Group S was also significantly lower than that of Group N (2.6% vs 25.6%; P = .02). No patients developed complications associated with the administration of Kampo medicine. CONCLUSION: This is the first study to show that Kampo medicine reduced the recurrence rate of CSDH in an overall population. This study demonstrated that byakujutsu Goreisan and Saireito may have favorable effects, unlike other studies, because byakujutsu has stronger anti-inflammatory activity than sojutsu.