Journal of neurosurgery
-
Journal of neurosurgery · Oct 1997
Microsurgical anatomy of the transcondylar, supracondylar, and paracondylar extensions of the far-lateral approach.
Despite a large number of reports of the use of the far-lateral approach, some of the basic detail that is important in safely completing this exposure has not been defined or remains poorly understood. The basic far-lateral exposure provides access for the following approaches: 1) the transcondylar approach directed through the occipital condyle or the adjoining portions of the occipital and atlantal condyles; 2) the supracondylar approach directed through the area above the occipital condyle; and 3) the paracondylar exposure directed through the area lateral to the occipital condyle. The transcondylar approach provides access to the lower clivus and premedullary area. ⋯ However, these muscles provide important landmarks for the far-lateral approach and its modifications. Other important considerations include the relationship of the occipital condyle to the foramen magnum, hypoglossal canal, jugular tubercle, the jugular process of the occipital bone, the mastoid, and the facial canal. These and other relationships important to completing these exposures were examined in this study.
-
Journal of neurosurgery · Oct 1997
Comparative StudyPathophysiology of hyponatremia after transsphenoidal pituitary surgery.
Hyponatremia after pituitary surgery is presumed to be due to antidiuresis; however, detailed prospective investigations of water balance that would define its pathophysiology and true incidence have not been established. In this prospective study, the authors documented water balance in patients for 10 days after surgery, monitored any sodium dysregulation, further characterized the pathophysiology of hyponatremia, and correlated the degree of intraoperative stalk and posterior pituitary damage with water balance dysfunction. Ninety-two patients who underwent transsphenoidal pituitary surgery were studied. ⋯ It is initiated by pituitary damage that produces AVP secretion and dysfunctional osmoregulation in most surgically treated patients. Additional events that act together to promote the clinical expression of hyponatremia include nonatrial natriuretic peptide-related excess natriuresis, inappropriately normal fluid intake and thirst, as well as low dietary sodium intake. Patients should be monitored closely for plasma sodium, plentiful dietary sodium replacement, mild fluid restriction, and attention to symptoms of hyponatremia during the first 2 weeks after transsphenoidal surgery.
-
Journal of neurosurgery · Oct 1997
Comparative StudyPatients with retained transcranial knife blades: a high-risk group.
Sixty-six patients with transcranial stab wounds presenting to Groote Schuur Hospital over a 2-year period are reviewed. Two groups were identified, those with retained knife blades at presentation (Group A, 13 patients) and those without (Group B, 53 patients). ⋯ Increased mortality was a result of vascular injury, and in two patients neurological deterioration occurred only after knife blade removal. Possible reasons for these findings are that retained blades tend to be deeply penetrating with a potential for more cerebral and vascular injury, and there is a higher incidence of petrous bone penetration that results in carotid artery injury.
-
Journal of neurosurgery · Oct 1997
Selective extradural anterior clinoidectomy for supra- and parasellar processes. Technical note.
Removal of the anterior clinoid process (ACP) facilitates radical removal of tumors or radical neck clipping of aneurysms in the supra- and parasellar regions by providing a wide operative exposure of the internal carotid artery (ICA) and the optic nerve and by reducing the need for brain retraction. Over a period of 3 years, anterior clinoidectomy was performed in 40 patients, 30 of whom harbored aneurysms (18 of the ICA and 13 of the basilar artery [one patient had two aneurysms]) and 10 of whom had tumors (four large pituitary tumors, four craniopharyngiomas, and two sphenoid ridge meningiomas). The ACP was removed extradurally in 31 cases and intradurally in nine cases. ⋯ Cerebrospinal fluid rhinorrhea, which required reoperation, occurred in one patient. The authors' experience suggests that the extradural technique of ACP removal is easier and less time consuming than the intradural one and provides better operative exposure. It can be used routinely in treating lesions in the supra- and parasellar regions.