[Characteristics of visual impairment complicated with planum sphenoidale and tuberculum sellae meningiomas and their surgical results].

It is well known that it is difficult to remove the planum sphenoidale and tuberculum sellae meningioma without damaging the optic nerves. The visual outcome after this operation has been unacceptable in such tumors, especially in large ones. This review propounds a strategy to secure visual acuity through operation. A total of eight cases are summarized. In five midline symmetrical meningiomas, the tumors compressed the nerves at the portion of the optic chiasma, causing a typical bitemporal hemianopsia. Four large tumors were resected by the frontobasal interhemispheric approach to minimize the intraoperative damage to the optic chiasma, and a small one was removed by the pterional approach. Visual deficits were recovered immediately after the operation in all cases without any surgical complications. Three meningiomas were attached to the lateral part of the planum sphenoidale or tuberculum sella. Although the sizes were relatively small in all cases, they caused ipsilateral severe visual loss by direct compression to optic nerves. MRI and three-dimensional CT angiography showed the tumor extension into the optic canal. The ipsilateral pterional approach was selected in these cases. To avoid additional nerve damage, we tried to reduce the tension of nerves which were compressed by the tumors. We removed the anterior clinoid process and opened the optic canal before surgical manipulation of the tumor. In two cases, tumors severely compressed the optic nerves from the medial side, and nerves were stretched laterally. Great care was required to separate the optic nerves from tumors in those two cases. In contrast, the resection seemed to be very easy in one of the cases where the optic nerve was displaced infero-medially. Visual symptoms were improved in all cases, although one case became worse temporarily. Although planum sphenoidale and tuberculum sellae meningiomas are still troublesome, appropriate preoperative management would allow us to expect an excellent visual outcome. Especially, selection of the surgical approach should be based on the anatomical analysis of the nerve displacement.