Endoscopic Hematoma Evacuation and Controlled Inner Membranectomy Using a Modified Single Burr-Hole Technique Under Local Anesthesia for Septated Chronic Subdural Hematomas in Elderly Patients: A Multicenter Retrospective Study

ABSTRACT Objective Septated chronic subdural hematoma (sCSDH) in elderly patients may contain organized components that limit conventional burr-hole drainage. This study evaluates the technical feasibility, perioperative course, and early clinical and radiological outcomes of controlled partial inner membranecotomy using modified single-port endoscopic drainage under local anesthesia in selected elderly patients with sCSDH. Methods We retrospectively analyzed patients aged 65 and older who underwent endoscopic drainage of MRI-confirmed sCSDH under local anesthesia at two neurosurgical centers between March 2022 and July 2025. Demographic characteristics, anesthesia records, complications, radiological findings, and early clinical outcomes were evaluated. Results Eleven of 29 patients (38%) received antiplatelet or anticoagulant therapy. Mean hematoma thickness was 21 ± 6 mm, preoperative midline shift was 10 ± 4 mm, and operative time was 47 ± 10 minutes. At postoperative one month, 26 patients (90%) had an mRS score of 0–1, compared with 9 (31%) preoperatively. Recurrence occurred in 3 patients (10%); 1 (3%) required reoperation, while 2 (7%) were treated conservatively. Postoperative seizures occurred in 2 patients (7%). No patient required conversion to general anesthesia, and no perioperative deaths, surgical site infections, or permanent neurological deficits were observed. Conclusion Endoscopic hematoma evacuation and controlled partial membranecotomy via a single burr hole under local anesthesia and sedation were technically feasible in selected patients and associated with acceptable short-term outcomes. Without a control group, superiority over other surgical approaches or an independent benefit of inner membranotomy cannot be demonstrated.