A modified far-lateral approach for large or giant meningiomas of the posterior fossa.
OBJECTIVE
Resecting large meningiomas along the posterior fossa convexity or cerebellopontine angle (CPA) through a suboccipital approach can be challenging. Limitations include a restricted angle of view, high venous pressures, and suboptimal brain relaxation. While a far-lateral craniotomy is a viable alternative, the risks associated with condylar resection are undesirable.


METHODS
The authors retrospectively evaluated a modified far-lateral approach in a consecutive series of 12 patients with large or giant posterior fossa convexity and CPA meningiomas. This approach incorporates transverse-sigmoid sinus exposure and C-1 laminectomy, but there is no condylar resection.


RESULTS
Between January 2006 and February 2008, 12 patients (mean age 52 years) presented with large or giant meningiomas of the posterior fossa convexity or CPA. The mean tumor volume was 72.6 cm3 (range 8-131 cm3). Signs and symptoms at presentation included headache (in 8 patients), cranial neuropathy (in 4), and progressive hemiparesis (in 4). There were no operative complications, and the majority of patients (9) had Simpson Grade I or II resections. There were no new permanent neurological deficits following resection, although 2 patients (17%) had transient deficits. The mean modified Rankin score decreased from 2.2 preoperatively to 0.6 postoperatively.


CONCLUSIONS
A modified far-lateral approach to the posterior fossa and CPA allows for safe, and often total, resection of large meningiomas with minimal morbidity. While avoiding the risks of condylar resection, this microsurgical strategy allows for greater field of view, minimal venous bleeding, and immediate access to the spinal subarachnoid space.
Sanai
Nader
N
Brain Tumor Research Center, Department of Neurological Surgery, University of California at San Francisco, California 94143, USA.
McDermott
Michael W
MW
D000328:Adult; D000368:Aged; D002530:Cerebellopontine Angle / Q000473:pathology / Q000601:surgery; D002550:Cerebral Veins / Q000601:surgery; D003388:Cranial Fossa, Posterior / Q000473:pathology* / Q000601:surgery*; D003399:Craniotomy / Q000379:methods; D019299:Decompression, Surgical; D005260:Female; D006801:Humans; D007431:Intraoperative Complications / Q000517:prevention & control; D008297:Male; D008335:Mandibular Condyle / Q000098:blood supply; D008579:Meningioma / Q000473:pathology* / Q000601:surgery*; D008875:Middle Aged; D009361:Neoplasm Invasiveness; D019635:Neurosurgical Procedures / Q000379:methods*; D056888:Patient Positioning; D010579:Petrous Bone / Q000473:pathology / Q000601:surgery; D011300:Preoperative Care; D012189:Retrospective Studies