HE transsphenoidal route has been the favored ap- proach for resection of most intrasellar tumors for longer than three decades. 46,48 For many nonadeno- matous suprasellar tumors, however, the transcranial route, taken either by performing a pterional or subfrontal ap- proach, has continued to be used by a majority of neurosur- geons. More recently, a modification of the transsphenoidal approach that allows additional exposure of the suprasellar space has been followed for various pathological conditions such as tuberculum sellae meningiomas, craniopharyngio- mas, and supraglandular Rathke cleft cysts. 15,20,29,34–36,38,39,43, 51,61 Termed the extended transsphenoidal approach and originally described by Weiss 61 in 1987, this approach re- quires removal of additional bone along the tuberculum sel- lae and the posterior planum sphenoidale with subsequent opening of the dura mater above the diaphragma sellae. This route allows excellent midline access and visibility to the suprasellar space while obviating brain retraction. The technique does require a large opening in the dura mater over the tuberculum sellae and the posterior planum sphe- noidale and typically results in large intraoperative CSF leaks, which necessitate precise and effective dural closure to prevent a postoperative CSF fistula and meningitis. In all early reports of this technique, with the exception of those by de Divitiis, et al., 15 and Jho and Ha, 34 who used an endonasal endoscopic approach, the technique is de- scribed in conjunction with a sublabial or transcolumellar (transseptal) endonasal route. We recently reported our ex- perience with the extended transsphenoidal approach in which we used a direct endonasal route for three patients with tuberculum sellae meningiomas. 12 This more minimal- ly invasive transsphenoidal approach was originally de- scribed by Griffith and Veerapen 23 in 1987 and is being in- creasingly used for sellar lesions. Our report and those by others 20,35 on the extended approach have been technical notes or small case series in which the largest included 14 patients. Here we present our initial experience with the extended direct endonasal transsphenoidal route in 24 pa- tients with suprasellar nonadenomatous lesions. Attention is focused on tumor removal rates, visual recovery, technical complications, and postoperative neuroendocrine function. J Neurosurg 102:832–841, 2005 832 The extended direct endonasal transsphenoidal approach for nonadenomatous suprasellar tumors JOSHUA R. DUSICK, M.D., FELICE ESPOSITO, M.D., DANIEL F. KELLY , M.D., PEJMAN COHAN, M.D., ANTONIO DESALLES, M.D., DONALD P. BECKER, M.D., AND NEIL A. MARTIN, M.D. Divisions of Neurosurgery and Endocrinology, University of California at Los Angeles School of Medicine; and UCLA Pituitary Tumor and Neuroendocrine Programs, and UCLA Gonda Diabetes Center, Los Angeles, California Object. The extended transsphenoidal approach, which requires a bone and dural opening through the tuberculum sell- ae and posterior planum sphenoidale, is increasingly used for the treatment of nonadenomatous suprasellar tumors. The authors present their experiences in using the direct endonasal approach in patients with nonadenomatous suprasellar tumors. Methods. Surgery was performed with the aid of an operating microscope and angled endoscopes were used to assess the completeness of resection. Bone and dural defects were repaired using abdominal fat, collagen sponge, titanium mesh, and, in most cases, lumbar drainage of cerebrospinal fluid (CSF). Twenty-six procedures for tumor removal were performed in 24 patients (ages 9–79 years), including two repeated op- erations for residual tumor. Gross-total removal could be accomplished in only 46% of patients, with near-gross-total re- moval or better in 74% of 23 patients (five of eight with craniopharyngiomas, six of seven with meningiomas, five of six with Rathke cleft cysts, and one of two with a dermoid or epidermoid cyst); a patient with a lymphoma only underwent biopsy. Of 13 patients with tumor-related visual loss, 85% improved postoperatively. The complications that occurred in- cluded five patients (21%) with postoperative CSF leaks, one patient (4%) with bacterial meningitis; five patients (21%) with new endocrinopathy; and two patients (8%) who needed to undergo repeated operations to downsize suprasellar fat grafts. The only permanent neurological deficit was anosmia in one patient; there were no intracranial vascular injuries. Conclusions. The direct endonasal skull-base approach provides an effective minimally invasive means for resecting or debulking nonadenomatous suprasellar tumors that have traditionally been approached through a sublabial or transcranial route. Procedures in the supraglandular space can be performed effectively with excellent visualization of the optic appa- ratus while preserving pituitary function in most cases. The major challenge remains developing consistently effective techniques to prevent postoperative CSF leaks. KEY WORDS • extended transsphenoidal surgery • endonasal approach • suprasellar tumor • meningioma • craniopharyngioma • Rathke cleft cyst T J. Neurosurg. / Volume 102 / May, 2005 See the Editorial and the Response in this issue, pp 825–828. Abbreviations used in this paper: CA = carotid artery; CSF = cerebrospinal fluid; DI = diabetes insipidus; MR = magnetic reso- nance.