Combined burr hole approach for epidermoid cysts with infra- and supratentorial extension

Background. Surgical treatment of large epidermoid cysts located of the cerebellopontine angle (CPA) with supra- and infratentorial extension poses significant challenges due to complex anatomy and potential neurovascular involvement. Standard approaches may require extensive bone resection with considerable risks. Objective. To evaluate the efficacy and safety of a combined retrosigmoid and subtemporal burr-hole microsurgical approach for epidermoid cysts with infra- and supratentorial extension. Material and methods. Four patients with large epidermoid cysts involving multiple anatomical compartments (CPA, prepontine, interpeduncular, and supratentorial regions) underwent surgery between 2017 and 2024. A combined retrosigmoid and subtemporal burr-hole microsurgical approach was performed without extensive bone resection, tentorial incision or petrous bone involvement. Results. Subtotal (>95%) resection was achieved in three patients. There was dense adhesion of cyst capsule to critical neurovascular structures. Total resection was feasible in one patient. Transient postoperative deficit involved cranial nerves III, VI, VII, IX and X. Permanent sensorineural hearing loss occurred in two patients. No cerebrospinal fluid leakage or infectious complications were observed. Patients experienced rapid postoperative recovery. Conclusion. A combined retrosigmoid and subtemporal burr-hole approach offers an effective and safe alternative to traditional skull base approaches for extensive epidermoid cysts minimizing surgical trauma and reducing postoperative morbidity.