Transcranial Ultrasound Monitoring of Chronic Subdural Hematoma

Chronic subdural hematoma (cSDH) is predicted to become the most common neurosurgical pathology by 2030. Surgical evacuation is a critical component of cSDH management, and postoperative monitoring is important given high recurrence rates and concerns related to restarting anticoagulation. Given issues related to cost, radiation exposure, and time for computerized tomography (CT) and magnetic resonance imaging examinations, we developed a novel technique to detect, assess, and quantify residual and/or recurrent subdural hematoma with point-of-care, hand-held ultrasound and sonolucent burr-hole covers placed during the initial surgery. We prospectively collected and retrospectively analyzed clinical and radiographical data for cSDH patients treated with burr-hole evacuation and implanted sonolucent burr-hole covers. Postoperative outpatient follow-up included direct comparison of point-of-care ultrasound (US) and head CT as the gold standard. Implant-to-cortical distance and absolute hematoma thickness were measured using ImageJ and Unity PACS on follow-up scans. Nine patients underwent burr-hole evacuation of cSDH with placement of a sonolucent cover. Hematoma thickness and cover-to-septum pellucidum distance did not differ between the two techniques. Both US and CT detected recurrent subdural hematoma in one of the nine patients. US and CT showed resolution of cSDH for the remaining seven subjects at follow-up, demonstrating 100% concordance between the US and CT methods. No immediate or short-term complications and infections related to the use of the sonolucent cover were noted in this cohort. Ultrasound-based assessment using a sonolucent burr-hole cover showed good concordance with CT for detecting and ruling out recurrent cSDH in a small cohort of patients. Point-of-care US could become a supplemental imaging modality for postoperative evaluation of cSDH.