Generally accepted contraindications to using a transsphenoidal approach for resection of tumors that arise in or extend into the suprasellar region include a normal-sized sella turcica, normal pituitary function, and adherence of tumor to vital intracranial structures. Thus, the transsphenoidal approach has traditionally been restricted to the removal of tumors involving the pituitary fossa and, occasionally, to suprasellar extensions of such tumors if the sella is enlarged. However, conventional transcranial approaches to the suprasellar region require significant brain retraction and offer limited visualization of contralateral tumor extension and the interface between the tumor and adjacent structures, such as the hypothalamus, third ventricle, optic apparatus, and major arteries. In this paper the authors describe successful removal of suprasellar tumors by using a modified transsphenoidal approach that circumvents some of the traditional contraindications to transsphenoidal surgery, while avoiding some of the disadvantages of transcranial surgery. Four patients harbored tumors (two craniopharyngiomas and two hemangioblastomas) that arose in the suprasellar region and were located either entirely (three patients) or primarily (one patient) within the suprasellar space. All patients had a normal-sized sella turcica. Preoperatively, three of the four patients had significant endocrinological deficits signifying involvement of the hypothalamus, pituitary stalk, or pituitary gland. Two patients exhibited preoperative visual field defects. For tumor excision, a recently described modification of the traditional transsphenoidal approach was used. Using this modification, one removes the posterior portion of the planum sphenoidale, allowing access to the suprasellar region. Total resection of tumor was achieved (including absence of residual tumor on follow-up imaging) in three of the four patients. In the remaining patient, total removal was not possible because of adherence of tumor to the hypothalamus and midbrain. One postoperative cerebrospinal fluid leak occurred. Postoperative endocrinological function was worse than preoperative function in one patient. No other new postoperative endocrinological or neurological deficits were encountered. This study demonstrates the feasibility of using a modified transsphenoidal approach for resection of certain suprasellar, nonpituitary tumors.

The CED method can be used to deliver AAV capsids and similar sized particles to the CNS safely and effectively over clinically relevant volumes. Moreover, real-time MR imaging of ferumoxtran-10 during infusion reveals that AAV capsids and similar sized particles have different convective delivery properties than smaller proteins and other compounds.

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