Intraoperative ultrasonography after dural closure for early detection of bleeding in cranial surgery

Background: Postoperative hematoma is a serious complication of cranial surgery and may require reoperation. This study evaluated intraoperative ultrasonography (US) performed immediately after dural closure and before bone replacement for detecting bleeding within the surgical cavity and confirming hemostasis. Methods: This retrospective single-center observational study included 192 patients who underwent cranial surgery between January 2024 and October 2025. B-mode US was performed after dural closure in all cases. Postoperative brain computed tomography (CT) was obtained within 6 h. Intraoperative findings, postoperative imaging, and reoperation requirements were analyzed. Hematomas causing mass effect or neurological deterioration and requiring evacuation were considered clinically significant. Results: Intraoperative US detected bleeding in 5 patients (2.6%). All underwent immediate re-exploration and additional hemostasis during the same surgical session, and none had hematoma on postoperative CT. Postoperative imaging demonstrated hematoma in 24 patients (12.5%) with negative intraoperative findings; 22 were managed conservatively and 2 (1.0%) required reoperation. These postoperative hematomas may have developed after dural closure during the interval before imaging. The overall reoperation rate was 1.0%. Conclusion: US after dural closure is a safe and practical method for confirming hemostasis and detecting bleeding before completion of cranial surgery. Although it cannot predict small delayed hematomas, it may support immediate intraoperative intervention before wound closure.