Irrigation versus no irrigation in the treatment of chronic subdural hematoma: An updated systematic review and meta-analysis of 1581 patients

Burr hole craniotomy is a common technique employed in the treatment of chronic subdural hematoma. However, its effectiveness and the occurrence of additional complications with various irrigation techniques utilized during the surgery remain unclear. The paper aims to compare the effectiveness and safety of burr hole craniotomy with and without irrigation in the treatment of chronic subdural hematoma. We conducted a systematic review by searching PubMed, Cochrane Library, Scopus, Ovid, and Web of Science for comparative studies that fit the eligibility criteria. All studies up to January 2023 were included, and the two groups were compared based on five primary outcomes using Review Manager Software. Data reported as odds ratio (OR) or risk ratio (RR) and 95% confidence interval (CI). A p-value of less than 0.05 was considered statistically significant. Our analysis included 12 studies with a total of 1581 patients. There was no significant difference between the two techniques in terms of recurrence rate (OR = 0.94; 95% CI [0.55, 1.06], p-value = 0.81) and mortality rate (RR = 1.05, 95% CI [0.46, 2.40], p-value = 0.91). Similarly, there was no significant difference in postoperative infection (RR = 1.15, 95% CI [0.16, 8.05], p-value = 0.89) or postoperative pneumocephalus (RR = 2.56, 95% CI [0.95, 6.89], p-value = 0.06). The burr hole drainage with irrigation technique was insignificantly associated with a higher risk of postoperative hemorrhagic complication (RR = 2.23, 95% CI [0.94, 5.29], p-value = 0.07); however, sensitivity analysis showed significant association based on the results of two studies (RR = 4.6, 95% CI [1.23, 17.25], p-value = 0.024). The two techniques showed comparable recurrence, mortality rate, postoperative infection, and postoperative pneumocephalus results. However, irrigation in burr hole craniotomy could possibly have a higher risk of postoperative hemorrhage compared with no irrigation, as observed during sensitivity analysis, which requires to be confirmed by other studies. Further research and randomized controlled trials are required to understand these observations better and their applicability in clinical practice.