20 medulloblastomas in children were treated at the Neurosurgical Department of Perugia over the last 6 years. The age ranged between 1.2 and 15 years, with a mean of 8 years. The ratio between males and females was 3/1. Only three tumors were localized within one cerebellar hemisphere. A shunt was performed before the removal of the tumor in 12 cases. Radical resection was completed in 15 cases, whereas a subtotal removal was performed in the cases with involvement of the brain stem. The postoperative mortality rate was 5%. The 3-year survival rate was 40% and the 5-year 25%. The postoperative radiotherapy was given at lower doses than usually reported by other authors: this seems to reduce the neuropsychological and endocrinological sequelae. CCNU or BCNU were given after radiotherapy, but this monochemotherapy seems to be less effective than polychemotherapy with CCNU, vincristine, procarbazine and dexamethasone, used in this series when relapse occurred. Radical resection improved the prognosis. The opportunity of using different protocols for ‘low risk’ and for ‘high risk’ patients is finally discussed.

Clinical and radiological data are reported concerning 44 patients suffering from cervical spondylotic myeloradiculopathy, and operated by the posterior approach; late results are evaluated. Type of onset, signs and symptoms are specified. Myeloradicular involvement was present in 52% of cases, medullary in 41%, radicular in 7%. Congenital stenosis was present in 68% of patients. Laminectomy was performed at 2-3 levels in 4 cases, at 4 levels in 10 cases, at 5 levels in 14, and extended to 6 or more levels in 16 patients. Posterior foraminotomy was performed 28 times. At follow-up evaluation (6 months to 8 years) results were "excellent good" in 46% of cases, "fair" in 34%, "unchanged" in 9%, and "worse" in 11%. First symptoms appeared more than 2 years before surgical treatment in 22 patients, between 2 years and 6 months in 15, and less than 6 months before in 7 patients. In this study a statistically significant inverse relation is demonstrated between: 1. results and duration of the disease, 2. results and gravity of motor deficits.

The importance of sealing small vessels by electrocoagulation in microsurgery is well known. In practice, the reliability of both short and long time results obtained with common and bipolar forceps with radiofrequency application is variable, particularly when encrusted coagulations adhere to the forceps tips and there is danger of damaging the vessel when the forceps are withdrawn. The coagulation process involves a sudden change in tissue characteristics, that occurs within a narrow temperature range, closely following the pattern of the applied current and is only modified by heat dissipation to the cooler parts, such as the forceps tips. Keeping these principles in mind, we developed an improved device which provides: A well-balanced current flow between the tips, which is unaffected by wiring, distributed capacitance and current leakage of the electrocoagulator ; a time-dependent heating pattern that coagulates only the core of the clamped tissue.

Neoplasms of the third ventricle are lesions arising within the ventricular cavity, often free but more often pedunculated. True third ventricle tumours are surgically removable. In a consecutive surgical series of 580 intracranial tumours the authors operated on 27 lesions of the third ventricle, 7 of which were benign gliomas. The histological diagnosis was polar spongioblastoma in 5 cases and fibrillar subependymal astrocytoma in 2 cases. The dominant clinical features were a slowly progressive or intermittently increased intracranial pressure syndrome, and mental and visual disturbances. CT and CSF contrastographic studies provided the essential diagnostic data for the therapeutic plan. CT scans at follow-up studies confirmed the successful removal of the lesions. A right trans-ventricular approach was employed in all cases. Depending on the size and position of the lesion, removal was performed through the foramen of Monro or through a sub-choroidal approach. In two patients a ventriculo-atrial shunt was necessary in spite of tumour removal. No surgical mortality occurred and patients are well at a follow-up time of from 2 to 6 years.

In surgery and particularly in neurosurgery the monopolar method of electrocoagulation is normally used.The patient is placed in direct contact with a neutral plate or ground return and the radio frequency current is applied through an electrode to the forceps.The current flows from the points of the forceps to the structure to be coagulated and tails off in a spheric shape. Any structure which is included between the forceps points is coagulated by the process of thermic induction (Fig. 1). Although this method of electrocoagulation is appropriate in most cases, it presents the following disadvantages :1. High power currents are necessary and there is severe current leakage towards the outside tissues. 3*Heruntergeladen von: University of British Columbia. Urheberrechtlich geschützt.