Combined Transpetrosal Approach With Preservation of Superior Petrosal Vein Drainage for a Cerebellopontine Angle Epidermoid Cyst Extending Into Meckel's Cave: 3-Dimensional Operative Video.

ABSTRACT

The combined transpetrosal approach enables wide exposure around the petroclival region by cutting the tentorium and superior petrosal sinus. We often choose this approach for removal of tumors ventral to the facial and vestibulocochlear nerves, such as petroclival meningioma and epidermoid cyst, because complete removal of the tumor under direct visualization is required to prevent its later recurrence, especially in young patients. Recent reports revealed anatomical variations of the drainage of the superior petrosal sinus, and dural incision considering preservation of the superior petrosal vein was proposed.1-3 This 3-dimensional video shows a patient with an epidermoid cyst, which was surgically treated using the combined transpetrosal approach, with consideration of the variation of the superior petrosal sinus and preservation of the drainage route of the superior petrosal vein. The video was reproduced after informed consent of the patient. The patient is a 31-yr-old woman who presented with a left cerebellopontine angle epidermoid cyst extending into Meckel's cave. The superior petrosal sinus was of the lateral type, draining only laterally into the transverse-sigmoid junction without medial connection with the cavernous sinus.1 The combined transpetrosal approach was performed with cutting of the superior petrosal sinus medial to the entry point of the superior petrosal vein, in order to preserve its drainage into the transverse-sigmoid junction. Meckel' cave was opened along its lateral margin, and tumor removal was accomplished, leaving only a minute part of the capsule strongly adhering to the neurovascular structures. The patient had no new permanent neurological deficits during follow-up. The figures in the video were modified from Matsushima et al1 by permission of the Congress of Neurological Surgeons.