End-to-end anastomosis of the posterior inferior cerebellar artery before excision of a meningioma involving the lower clivus and the foramen magnum. Case report.

BACKGROUND: Petroclival and foramen magnum meningiomas sometimes encase the vertebrobasilar arterial system. Magnetic resonance imaging can clearly reveal such encasement. The case presented here was of a meningioma involving the lower clivus and the foramen magnum, encasing a lateral segment of the posterior inferior cerebellar artery (PICA), despite the fact that no definitive diagnosis of the encasement of the PICA was made on preoperative radiological examination. End-to-end anastomosis of the PICA was necessary before excision of the tumor.

METHODS: A 55-year-old woman presented with complaints of headache and numbness of the right upper extremity. Gadolinium diethylene-thiamine-pentaacetic acid enhanced T1-weighted magnetic resonance (MR) images showed a homogeneously enhanced mass lesion involving the lower clivus and the foramen magnum. Direct surgery was then performed, and the lateral medullary segment of the left PICA was found to be encased by the tumor. End-to-end anastomosis was performed using No. 10-0 interrupted monofilament nylon sutures. Total removal of the tumor was performed after completion of the anastomosis. The patient was free of neurological abnormalities and no recurrence of tumor was found during a 2-year follow-up period.

CONCLUSIONS: Revascularization is sometimes thought to be required for resection of craniospinal meningiomas even when they do not appear to encase the vertebro-basilar arterial system on preoperative MR imaging and cerebral angiograms. In the present case, dissection of the PICA from the tumor was attempted, but was difficult due to tight encasement of the PICA by the tumor.