Surgery of Large and Giant Petroclival Region Tumors with Middle Fossa Extension
Background: The most challenging point in petroclival dumb bell tumor removal is negotiation of the tumor isthmus. We review our clinical experience of retrosigmoid craniotomy with tentoriotomy and suprameatal petrosectomy for this type of tumor removal.
Methods: Seventeen consecutive patients are included in this prospective study: 12 patients with petroclival meningiomas and 5 with trigeminal schwannomas. In 12 cases the tumor size was more than 40 mm and in 5 cases more than 25 mm. Access to the supratentorial part of the tumors was enhanced by a tentorial incision in 17 cases, suprameatal petrosectomy was performed in 5 patients. Mean follow-up was 23 months.
Results: Mean age was 48.5 years. Clinical findings included: headaches (15 patients), visual problems (6 cases), pyramidal signs (9), cerebellar signs (11), hydrocephalus (9). Preoperative cranial nerves dysfunction: facial pain more than 7 points in VAS was observed in 5 patients, facial numbness in 3, hearing disturbances in 3, diplopia in 4, low cranial nerves dysfunction in 4 cases. Simpson I-II tumor removal was achieved in 8 patients (47%), Simpson III in 7 (53%). In 6 patients with preoperative visual defects, 4 patients had improved vision. Hydrocephalus was resolved in all cases. Postoperatively facial numbness was observed in 5 cases, facial pain was improved in all 5 patients. Dysfunction of IV nerve was in 4 patients. Function of low cranial nerves improved in 2 cases. There was no CSF leakage and infection complication in our series. Recurrent tumors were identified in 2 patients with meningiomas in 2 and 3 years. Tree patients with Simpson III resection received Gamma knife surgery.
Conclusions: Retrosigmoid craniotomy with tentoriotomy and suprameatal petrosectomy may be effective alternative to the combined approaches for large petroclival tumors with middle fossa extension. Fourth nerve is the most vulnerable one during this approach.