Frontal Burr-Hole Compared with Parietal Burr-Hole in the Management of Chronic Subdural Hematoma: A Single-Center, Randomized Controlled, Noninferiority Trial

With the aging population, symptomatic chronic subdural hematoma (CSDH) is becoming increasingly prevalent in neurosurgical practice. While burr-hole drainage remains the mainstay treatment, the optimal drilling site remains controversial. This single-center, randomized controlled noninferiority trial aimed to compare frontal versus parietal burr-hole approaches in patients aged ≥18 years requiring surgical drainage for CSDH. Participants were randomized (1:1) via computer-generated allocation to frontal or parietal burr-hole groups, with blinding maintained for patients and staff except operating neurosurgeons. All patients received postoperative atorvastatin combination therapy. Primary outcomes included 6-month recurrence rates (noninferiority margin: 5.0%), with secondary outcomes assessing functional status (modified Rankin Scale [mRS] 4-6), mortality, and complications. From July 2020 to December 2022, 135 of 147 screened patients (92%) were enrolled (frontal: <i>n</i> = 67; parietal: <i>n</i> = 68), comprising 79% males (<i>n</i> = 107) and 21% females (<i>n</i> = 28). At 6-month follow-up (completed June 2023), recurrence rates were 1.5% (1/67) in the frontal group versus 4.4% (3/68) in the parietal group (difference: -2.9%; 95% confidence interval [CI]: -8.6 to 2.8; <i>p</i> = 0.31), meeting noninferiority criteria. Functional outcomes (mRS 4-6: 3.0% vs. 4.4%, <i>p</i> = 0.66) and mortality (3.0% vs. 1.5%, <i>p</i> = 0.55) showed no significant intergroup differences. Notably, postoperative pneumocephalus volume was significantly lower in the frontal group (11.6 ± 14.8 mL vs. 20.7 ± 20.4 mL; <i>p</i> = 0.038). Adverse event rates were comparable between groups, with pneumonia being most frequent (53.7% vs. 55.9%) and surgical complications similarly distributed (6.0% vs. 5.9%). These findings establish noninferiority of frontal burr-hole while demonstrating reduced postoperative pneumocephalus, supporting its clinical preference and warranting future superiority trials. (Trial registration: chictr.org.cn, ChiCTR2000033967).