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Surgical strategies for supra- and infratentorially grown occipital meningeomas.

BACKGROUND
Extensive tentorial meningeomas which are growing supra- and infratentorially are a surgical challenge, and a distinct surgical strategy is required for good results.


PATIENTS
3 patients, 2 with asymptomatic tumor and 1 with signs of increased intracranial pressure and visual disorder underwent microsurgery.


RESULTS
In 2 patients, the semi-sitting position was taken. A lateralized occipital/suboccipital craniotomy with exposure of the confluens sinuum, transverse and superior sagittal sinus was performed. First, the dura was opened infratentorially allowing good cerebrospinal fluid (CSF) release. In a second step the dura was opened supratentorially sparing the sinus. The tumor was then removed completely without brain swelling or significant venous bleeding. One patient underwent surgery in prone position. A unilateral occipital/suboccipital craniotomy with exposure of the confluens sinuum and the ipsilateral transverse sinus was made. The dura was opened supratentorially. A resulting occipital lobe swelling made enlargement of the craniotomy and additional infratentorial dura opening necessary. All patients recovered well without postoperative morbidity. Complete tumor resection was confirmed by early postoperative MRI.


CONCLUSION
The authors recommend a semi-sitting position (less venous bleeding, less brain swelling) and a lateralized occipital and suboccipital craniotomy for optimal control of the venous sinuses. Opening of the dura should start infratentorially to allow for CSF drainage and brain relaxation but should be combined with a sinus sparing supratentorial dura opening for adequate visualization and total meningioma removal.