Treatment of chronic subdural hematoma by closed-system drainage without irrigation

BACKGROUND: Recurrence of chronic subdural hematoma after surgery has not been eliminated. We sought to determine whether irrigation influences recurrence rate. METHODS: Patients who had undergone surgery for chronic subdural hematoma were reviewed retrospectively. RESULTS: Between 1986 and 1993, 186 cases of chronic subdural hematoma were treated surgically at Mito National Hospital. Recurrence was limited to six cases (3.2%). A closed drainage system without irrigation has been used since 1988 in 119 patients. Before 1988, 67 cases were treated with single burr hole irrigation and drainage. The rate of recurrence with the closed drainage system was 3.4% (four cases), compared with 3.0% (two cases) for irrigation and drainage. CONCLUSION: Compared with irrigation and drainage, the closed drainage system without irrigation was safe and effective, and recurrence of chronic subdural hematoma is not influenced by irrigation.