Here's some more information for those
interested:
Resection
of suprasellar tumors by using a modified transsphenoidal approach. Report of
four cases.
Kouri JG, Chen MY, Watson JC, Oldfield
EH.
Surgical Neurology Branch, National Institute of Neurological
Disorders and Stroke, National Institutes of Health, Bethesda, Maryland
20892-1414, USA.
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.
Acta Neurochir (Wien). 1998;140(7):715-8; discussion 719.
Transsphenoidal-transtuberculum sellae approach for
supradiaphragmatic tumours: technical note.
Kato T, Sawamura Y,
Abe H, Nagashima M.
Department of Neurosurgery, Hokkaido
University School of Medicine, Sapporo, Japan.
The Classic
transsphenoidal approach may not afford sufficient exposure for a
supradiaphragmatic tumour adjacent to the pituitary stalk. Various transcranial
approaches have been utilized to access such a lesion with adequate results.
This report describes a less invasive technique, termed
"transsphenoidal-transtuberculum sellae approach". This modified transsphenoidal
approach requires a bone ablation of the tuberculum sellae, the limbus
sphenoidalis, and a portion of the planum sphenoidale, in addition to an opening
of the anterior floor of the sella turcica. The dura mater on the tuberculum
sellae and the pituitary fossa is sectioned with a bilateral obliteration of the
anterior intercavernous sinus. The anterior pituitary gland is not necessarily
resected. The optic chiasm, optic nerves, pituitary stalk, and tuber cinereum
can be directly observed, making it possible to safely dissect a lesion from
these structures. Utilizing this approach, we have removed 14 supradiaphragmatic
tumours without complications and dealt with other lesions such as optic nerve
injuries or cerebrospinal fluid rhinorrhea, leaving pituitary function intact.
The transsphenoidal-transtuberculum sellae approach for accessing small
supradiaphragmatic tumours is a useful procedure requiring only a minor
modification of the classic transsphenoidal technique.
|
