Local anesthesia versus general anesthesia for surgical drainage of chronic subdural hematoma: a systematic review and meta-analysis

Purpose The optimal anesthetic technique for surgical drainage of chronic subdural hematoma (CSDH) is still uncertain. We performed this systematic review and meta-analysis to determine if local anesthesia with or without sedation (LA) or general anesthesia (GA) results in better outcomes for surgical drainage of CSDH. Methods We searched PubMed, EMBASE, Scopus, Cochrane Central Register of Controlled Trials and ClinicalTrials.gov for randomized controlled trials (RCTs) and prospective or retrospective studies that compared GA vs LA for adult patients undergoing surgical drainage of CSDH and reported at least one outcome of interest. Primary outcomes of interest included total duration of surgery, recurrence rate, and length of hospital stay (LOS). Secondary outcomes included intraoperative adverse events, postoperative complications, and postoperative mortality. Results Eight studies (1,542 patients; 926 LA; 616 GA) were included-two were RCTs and six were observational studies. Pooling the estimates of all available studies, we found that LA was associated with a decreased mean LOS by about two days (95% confidence interval [CI], -3.47 to -0.77; P = 0.01; low certainty of evidence) as well as a lower risk of postoperative complications (odds ratio, 0.31; 95% CI, 0.17 to 0.58; P = 0.004; very low certainty of evidence). There was no significant difference in terms of duration of surgery, recurrence rate, intraoperative adverse events, or mortality. The quality of the observational studies was poor to fair, largely because of heterogeneity among the studies. Among the RCTs, one had a low risk of bias and one was deemed to be at high risk of bias. Conclusions Local anesthesia with/without sedation for surgical drainage of CSDH may be associated with a shorter LOS, and lower postoperative complications. As most of our included studies were observational in nature, our results should be interpreted as summaries of unadjusted group comparisons. In view of the low certainty of evidence, higher quality evidence is required to corroborate these findings.