Fully endoscopic retrosigmoid approach for posterior petrous meningioma and trigeminal microvascular decompression

Abstract

Background: Cerebellopontine angle tumor resection and cranial nerve microvascular decompression are usually performed with the aid of the surgical microscope. The endoscope is commonly used as an adjuvant.

Method: A retrosigmoid craniectomy is done. Upon dural opening, the endoscope is inserted into the operative field along the petrotentorial junction. Cerebrospinal fluid drainage provides a wider space for introduction of the endoscope and surgical instruments. Traditional microsurgical techniques are used during the entire procedure.

Conclusion: A fully endoscopic retrosigmoid approach is a safe and effective procedure for cerebellopontine angle tumor resection and cranial nerve microvascular decompression.

Key points: • Careful examination of preoperative studies is needed to identify anatomical peculiarities. • Patient positioning: the head must be gently flexed and its vertex gently tilted toward the floor. • Neurophysiologic monitoring and intraoperative navigation. • Craniectomy: partial exposure of the transverse and sigmoid sinuses. • Curvilinear dural incision reflected laterally to minimize the risk of sinus injury. • Opening the cerebellomedullary cistern for CSF drainage and cerebellar relaxation. • Dynamic endoscopy enhances depth perception and must be performed by a team with experience in endoscopic intracranial surgery. • Traditional microsurgical techniques have to be applied during the entire operation. • Multilayer reconstruction, including watertight dural closure. • Meningiomas causing brainstem shift are not suitable for endoscopic resection.