Retrosigmoid Transmeatal Endoscope-Assisted Approach in Semi-Sitting Position for Resection of Vestibular Schwannoma: 2-D operative Video.

We present a case of a mid-sized vestibular schwannoma (T3b according to the Hannover classification) that was resected through a retrosigmoid transmeatal approach in semi-sitting position under endoscopic assistance. The patient is a 52-year-old male with acute loss of functional hearing on the right side. Audiometry confirmed a loss of up to 60 dB and lost speech discrimination, there were no associated symptoms such as tinnitus or vertigo. This 2D video demonstrates positioning, OR set-up, anatomical and surgical nuances of the skull base approach and the operative technique for microdissection of the tumor from the critical neurovascular structures, especially the facial and cochlear nerves. A gross total resection was achieved and the patient discharged home after four days with unaltered function of the facial nerve (HB I). At one year follow up there was no indication of residual or recurrence. In summary, the retrosigmoid transmeatal approach is an important and powerful tool in the armamentarium for the microsurgical management of all kinds of vestibular schwannomas. Provided the necessary anesthesiological precautions and intraoperative procedures the semi-sitting position is safe and effective. If needed, the approach can be complemented by the use of an endoscope for visualization of the distal internal auditory canal. The link to the video can be found at: https://youtu.be/pPKT4_5nIn0 .