Comparison of subperiosteal or subgaleal drainage and subdural drainage in patients with chronic subdural hematoma: A systematic review and meta-analysis

Background: Chronic subdural hematoma (CSDH) is a relatively common disease, especially in the elderly, for which there is no clear standard of treatment available. The authors systematically evaluated the efficacy of various surgical procedures for the treatment of chronic subdural hematoma.Methods: Electronic databases of PubMed, EmBase, Web of Science, Medicine, and the Cochrane Library were searched systematically. Based on the PRISMA template, we finally selected and analyzed 13 eligible papers to evaluate the effect of different drainage methods on CSDH. The primary outcomes were recurrence and clinical outcomes. Secondary outcomes were mortality and postoperative complications and other parameters.Results: The meta-analysis included 3 randomized controlled trials and 10 retrospective studies (non-randomized controlled trials) involving 3619 patients. The pooled results showed no statistically significant difference between non-subdural drainage (NSD) and subdural drainage (SD) in mortality and complication rates (P > 0.05). Additionally, overall pooled results showed that the use of NSD (10.9%) has a lower recurrence rate than the use of SD (11.7%), but the results were not statistically significant (relative risk ratio [RR] = 0.98; 95% confidence interval [CI] = 0.70-1.45; I-2 = 47%; P = .92). However, the difference between NSD and SD in postoperative bleeding rate reached statistical significance (RR = 2.39; 95% CI = 1.31-4.36; I-2 = 0 %; P = .004). Subgroup analysis showed that SD was associated with similar recurrent CSDH (RR = 0.75; 95% CI = 0.52-1.09; I-2 = 0%; P = .14), good recovery (RR = 0.98; 95% CI = 0.93-1.04; I-2 = 0%; P = .50), and mortality (RR = 0.98; 95% CI = 0.37-2.57; I-2 = 0%; P = .96), compared to NSD.Conclusions: These results suggest that NSD and SD are equally effective in the treatment of patients with CSDH, with no difference in final clinical characteristics and radiologic outcomes. However, in patients with limited subdural space after evacuation of a hematoma, NSD may be the preferred strategy to avoid iatrogenic brain injury.