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Show EDITORIAL Management of Suprasellar Meningiomas William F. Chandler, MD In this issue of the Journal ofNeuro- Ophthalmology, Chicani and Miller ( 1) have provided a valuable contribution to the understanding of the overall management of meningiomas arising in the suprasellar region. Most of these benign tumors arise from the tuberculum sellae or the diaphragma sellae and they almost always cause some loss of vision. Authors since the time of Cushing and Eisenhardt ( 2) have reported the general and ophthalmologic results of surgical resection of these tumors, but the extraordinary aspect of this report is the average follow- up of nearly 17 years. The authors point out that progressive loss of vision over the long- term is usually related to tumor recurrence, and that those recurrences may occur more than 10 years after an initial surgery. These data provide ample evidence to emphasize to our patients the importance of life long vigilance with modern magnetic resonance imaging. This article does not delineate the specifics of the neurosurgical resection of these anatomically complex tumors. The most common surgical approach, and the one that I favor, is a right frontotemporal pterional craniotomy carried exactly to the midline and extending lateral to the Sylvian fissure. With bone removal extending to the skull base anteriorly, the intradural approach is subfrontal over the roof of the orbit. Using the operating microscope, the surgeon opens the Sylvian fissure widely and notes the anterior cerebral artery crossing over the right optic nerve. Being careful to preserve the arachnoid planes that protect the optic nerve and chiasm, the surgeon gradually debulks the tumor and folds it in on itself. The blood supply is interrupted as the base of the tumor is separated from its origin along the tuberculum sellae and diaphragma sellae. In larger tumors it may be difficult to safely separate the vessels in the anterior communicating artery region from the tumor capsule. Larger tumors may completely encompass the optic nerves, making it difficult to preserve the blood supply to the nerves. These tumors usually separate easily from the pituitary stalk and the basilar artery, but these are potentially dangerous areas. In my experience, the most likely area to leave residual tumor behind is beneath the optic nerves as they enter the optic foramina. If the meningioma invades the dura in this region it becomes very difficult to completely resect the tumor. The other major surgical approach is a bifrontal craniotomy with a midline interhemi-spheric dissection. Rarely these tumors have been removed via a transnasal endoscopic skull base approach ( 3). Although complete resection can be accomplished in over 90% of these cases, I agree with the authors that postoperative radiation therapy should be given if a well- defined massive tumor is left behind. I have seen regrowth of tumor from a small residual mass beneath the optic nerve cause significant loss of vision. Situations in which surgery might not be considered would include elderly or medically compromised patients, or certain recurrent and highly invasive tumors. Obviously if the patient is very elderly or is an extremely high risk medically, then the balance between the risk and benefit of surgical resection may be tipped toward conservative measures. In Professor of Neurosurgery, Department of Neurosurgery, University of Michigan, Ann Arbor, Michigan. Address correspondence to William F. Chandler, MD, Department of Neurosurgery, 2124D Taubman Center, 1500 East Medical Center Drive, Ann Arbor, MI 48109, USA; E- mail: wchndlr@ umich. edu Copyright © Lippincott Williams & Wilkins. Unauthorized reproduction of this article is prohibited. J Neuro- Ophthalmol, Vol. 23, No. 1, 2003 1 JNeuro- Ophthalmol, Vol. 23, No. 1, 2003 EDITORIAL these cases, conventional radiation would likely prevent further growth of the tumor, but would not be expected to improve lost vision. Recurrent tumors that are highly invasive generally do as well with radiation alone as with additional surgery. The authors have pointed out that repeat surgery rarely helps lost vision. In a newly diagnosed patient, if the majority of the tumor is invasive into the cavernous sinus with very little suprasellar component, radiation without biopsy is a viable option. If vision is compromised, however, surgical decompression is generally advised. This article does not address the important fact that these meningiomas often cause significant compression of the pituitary gland and stalk. This was recently studied in detail in 47 patients by Fahlbush and Schott ( 4) and, surprisingly, pituitary function is rarely seriously affected. Nevertheless, patients should have careful preoperative endocrine evaluation and receive corticosteroid supplementation at the time of surgery. I also agree with the authors that minimizing the time from initial onset of symptoms to diagnosis and treatment is important in achieving the optimal preservation of vision. The report by Fahlbush and Schott ( 4) supports this finding and also emphasizes that advanced age is a negative factor. These facts combine to support the earliest possible diagnosis and rapid referral to an experienced neurosurgeon. REFERENCES 1. Chicani CF, Miller NR. Visual outcome in surgically- treated suprasellar meningiomas. J Neuro- Ophthalmol 2003; 23( 1): 3- 10. 2. Cushing H, Eisenhardt L. Meningiomas arising from the tubercu-lum sellae, with syndrome of primary optic atrophy and bitemporal field defects combined with normal sella turcica in middle- aged person. Arch Ophthalmol 1929; 1: 1^ U, 168- 206. 3. Jho HD. Endoscopic transsphenoidal surgery. J Neuro- Oncology 2001; 54: 187- 95. 4. Fahlbush R, Schott W. Pterional surgery of meningiomas of the tu-berculum sellae and planum sphenoidale: surgical results with special consideration of ophfhalmological and endocrinological outcomes. J Neurosurg 2002; 96: 235- 43. Copyright © Lippincott Williams & Wilkins. Unauthorized reproduction of this article is prohibited. 2 © 2003 Lippincott Williams & Wilkins |