Faculty Bibliography

An anatomic classification of lesions affecting the skull base is proposed according to which this region can be divided into a midline compartment and two lateral compartments: a petrotemporal and an infratemporal. The majority of lesions studied radiographically in 56 patients were confined to one of these anatomic subdivisions. The advantages of such a classification are discussed. The surgical approaches to these compartments and to the anterior middle and posterior cranial fossae are described relative to the lesions we have encountered

Three patients with giant aneurysms (2 internal carotid and 1 anterior communicating) were treated by internal carotid occlusion with a detachable balloon. 133Xe regional cerebral blood flow (rCBF) was performed on each patient on admission. Due to low CBF, one patient received a superficial temporal artery--middle cerebral artery (STA-MCA) bypass. The rCBF was repeated when the balloon was inflated in the internal carotid prior to detachment of the balloon. All three patients were discharged within one week with no neurologic deficit. The rCBF assessment appears useful to decide which patient will tolerate acute balloon occlusion of the internal carotid and to help select patients who will need an extra-cranial-intracranial (EC-IC) bypass to avoid ischemic complication

B-mode real-time ultrasound using 5 or 7.5 MHz transducer has been employed during 21 operations for brain pathology and spinal cord lesions. Ultrasonic scanning was performed at the following operations: 10 brain tumors (4 glioblastomas multiforme, 2 astrocytomas, 1 medulloblastoma, 2 metastatic tumors), 2 brain cysts (arachnoid, epidermoid), 1 tuberculous abscess, 3 cerebral hematomas: 2 spinal cord tumors (malignant melanoma, glioma), 2 syringomyelias, 1 posterior longitudinal ligament thickening. Operative ultrasound was useful prior to dural incisions and particularly for subcortical lesions. In addition, ultrasound provided assistance at spinal cord surgery. Our experience has been reviewed and summarized in this report in terms of specific usefulness of assistance of this method which has proven helpful to the neurosurgeons. The types of assistance provided by operative ultrasonography include: Location of dural incision. Localization of brain and spinal cord lesions prior to biopsy. Diagnosis which has not been made preoperatively (e.g. necrosis or cystic area in tumor). Consistency of each lesion (e.g. solid or cystic, necrosis, loculation). Size, extent and depth of brain tumor, cyst, abscess and hematoma. Presence and extent of spinal cord syrinx. Relation of tumor to spinal cord and dura. Access route for biopsy and drainage (avoiding critical areas such as motor strip). Exclusion of bleeding or hematoma following biopsy. Confirmation of the effectiveness of drainage or resection of lesions. Relationship between pathology and surrounding anatomic structures. A number of important assistance by the utilization of ultrasound during neurological surgery have been identified.(ABSTRACT TRUNCATED AT 250 WORDS)

Imaging ultrasonography was performed during 23 brain and five spinal cord operations with real-time B-mode instruments. Criteria for the utilization of ultrasound at neurosurgical procedures were identified in terms of assistance in the diagnosis or better definition of lesions. The diagnosis criteria were detection and exclusion. Because of the accuracy of preoperative imaging, usually little further help was provided by operative ultrasonography in detecting previously totally unknown abnormalities or excluding lesions found on positive studies. The definition criteria were localization, distinction of tissue features, and assessment of spatial relations. Operative ultrasonography was most useful when applied on the basis of these definition criteria. Operative ultrasonography was considered to be useful in 22 of 28 operations (79 per cent) in which it assisted in exposing, accessing, and extirpating disease