Skull base techniques for aneurysm occlusion.

Aneurysms of the vertebrobasilar system carry relatively high operative mortality and morbidity due to their anatomical location. A variety of skull base techniques is described to improve access to these lesions and to reduce or abolish the need for retration on neurovascular structures. Surgical results are generally favorable and should encourage a more widespread application of these techniques in appropriate circumstances.

Meningiomas in the region of the cavernous sinus: a review of 21 patients.

This is a review of 21 patients with meningiomas involving the region of the cavernous sinus. All underwent surgery, and the fronto-zygomatic (F-Z) approach, first described by Fujitsu and Kubawara, was employed in every case. The mean age at presentation was 47 years; seven patients were male and 14 female. The mean duration of symptoms before surgery was 4 years. In 10 patients, resection was considered to be complete. Peri-operatively there were two deaths, but the majority of deficits in the survivors were temporary and quickly resolved. The mean follow-up period was 48 months. In that time, five patients experienced recurrence or progression of tumour, of whom three required repeat operation (followed by radiotherapy); and two patients were referred for radiotherapy alone. These five patients appear to be disease-free 2-5 years after their additional treatment. Of the 19 patients who left hospital, 17 were able to live independent lives. It would appear from this review that: (1) F-Z craniotomy usually gives excellent exposure to the region of the cavernous sinus; (2) selected patients should undergo angiography with balloon occlusion to evaluate the collateral vascular supply; (3) regular review should include annual MRI. Evaluation over a much longer time of both surgery and radiotherapy, individually and in combination, is needed before it will be possible to furnish a treatment protocol for individual cases at initial presentation or recurrence.

Haemangiopericytoma: a clinical and radiological comparison with atypical meningiomas.

A small number of haemangiopericytomas (HPCs) are compared with a group of cases labelled as atypical meningiomas (AMs) extracted from our records over a 10-year period. There was close convergence between the two groups in terms of clinical presentation. Radiologically, they were quite different. HPCs subjected to angiography demonstrated a major vascular supply from branches of the internal carotid or vertebral arteries, whereas this was not a feature of the meningioma group. Half the HPCs arose from the lateral petrosal attachment of the tentorium; all the meningiomas were parasagittal. The HPCs did not prove to be more formidable technical challenges than the meningiomas: the operative blood loss was much the same in both. The same number of recurrences and deaths occurred in the two groups at approximately the same interval during the follow-up period, making both conditions equally grave in terms of prognosis.

Comparison of rates of infection of two methods of emergency ventricular drainage.

The rates of infection of two methods of external ventricular drainage in use at Atkinson Morley's Hospital--namely, (a) percutaneous drainage with Rickham reservoirs and (b) tunnelled ventriculostomies--were compared in this retrospective review. Percutaneous drainage of CSF with Rickham reservoirs was associated with a 27% rate of infection as identified by positive microbiological cultures; tunnelled ventriculostomy catheters had a 10% infection rate. The difference in the infection rate between the two methods was statistically significant (P < 0.015). Other variables examined, including the age and sex of the patients and the reasons for ventricular drainage, were not associated with an increased rate of infection. Most infections from either method were caused by a coagulase negative staphylococcus. The average duration of ventricular drainage before identification of positive cultures was 5.7 days for Rickham reservoirs and 6.0 days for ventriculostomies.

Outcome after repeat lumbar microdiscectomy.

One of the standard treatments for herniation of lumbosacral disc material has become the microdiscectomy. Although multiple studies have assessed the outcome of microdiscectomy, only a few studies have evaluated the outcome of those patients who have undergone a second microdiscectomy at the same location as the original one. The purpose of this study was to review 55 patients who, over a 4-year period, underwent a second microdiscectomy at the same location as their original operation and to evaluate those factors associated with improved outcomes. The results showed the overall outcome to include 86% with complete or partial relief of all pain symptoms; 88% with complete or partial relief of sciatica; 85% with complete or partial relief of back pain; 100% returning to work in an average of 7 weeks; and 89% were glad they had the second operation. Those factors without predictive value included age, sex, weight, height, level of operation, side of operation, surgeon at the first or second operation (e.g. consultant or junior staff), length of the first operation ( < or = 60 min or > 60 min) and duration of symptoms before the first operation. The key features centred on preoperative job status, the interval between recurrence of symptoms and the second operation, and the duration of the second operation ( < or = 90 min).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult postrepair myelomeningocoele and tethered cord syndrome: good surgical outcome after abrupt neurological decline.

Adults who have had repair of an open myelomeningocoele at birth are susceptible to a variant of adult onset tethered cord syndrome (ATCS). Precipitous and profound loss of lower extremity motor function occurred in two postrepair adult patients, but was not seen in any of our 12 cases of adult tethered cord with any other aetiologies. Both postrepair ATCS patients made a good recovery after surgical release of the tether. For the patients with other aetiologies, surgery yielded improvement or recovery of urinary continence in 57%, relief from pain in 78% and improved strength in 80%. Evidence of retethering was observed in 25% of the operated patients at intervals ranging from 1 to 9 years postoperatively. We conclude that surgical release of tether can reverse incontinence in ATCS of any aetiology and that in the post-myelomeningocoele repair patient, both dexamethasone and surgical intervention are helpful in reversing acute neurological deterioration.

Multiple dural metastases from a pituitary adenoma. Case report.

Only 12 cases of pituitary tumors that metastasized within the central nervous system have been reported. A further case is presented in which the histology of the multiple dural metastases remained identical to that of the original tumor, a pituitary adenoma. The authors discuss management of these rare lesions that appear histologically benign.

Aspergillosis infection in neurosurgical practice.

Fungal infections including those due to aspergillus are rare in neurosurgical practice despite their possible inclusion in many differential diagnoses. Recently, these diseases have been diagnosed with increasing frequency, principally as opportunistic infections in patients undergoing treatment for diseases resulting in immune compromise. The epidemiology is poorly understood as mycoses are not notifiable diseases. We have recently been involved in the care of seven patients with aspergillosis between 1988 and 1991. Its presentation, with abscess formation, granulomas, the rhinocerebral form, meningitis, hydrocephalus and vascular involvement, is varied. The majority of cases were seen in immunocompromised patients following haematogenous dissemination from a pulmonary or gastro-intestinal focus. Direct spread from sinus infection has also been seen. The prognosis is poor despite modern antifungal treatment, which in part reflects the primary underlying condition.

Prolactinomas in men masquerading as invasive skull base tumours.

Four giant prolactin-secreting tumours invading the skull base are described. All of them occurred in men. The presenting features were sufficiently diverse to be clinically misleading. We advocate the estimation of prolactin levels before embarking on complicated skull base surgery in men where doubt remains regarding the diagnosis after clinical and radiological study.

Long-term results of microlumbar discectomy.

A long-term prospective study was carried out of 100 consecutive patients undergoing microlumbar discectomy (MLD) and fulfilling stringent selection criteria. A 95% long-term follow-up result was obtained at a mean duration of 8.6 years. At the 7-11-year assessment, 88% of patients had an excellent result, 5% a good result and 7% had either a poor result or new symptoms. Ten patients (10.5%) underwent repeat MLD during the course of the study; nine of the ten reoperations were performed at the same level as the original surgery. The percentage with an excellent result remained relatively constant (88-89%) throughout the study. No reliable predictors of long-term outcome were identified. The results suggest that microlumbar discectomy compares favourably with other surgical techniques with regard to long-term outcome.

Primary spinal malignant schwannoma.

Malignant schwannomas are uncommon primary tumours of nerve sheath origin. They are rarely found within the spine and spinal canal, and little is known about their management in this unusual location. We describe the presentation of three patients with primary spinal malignant schwannomas and discuss the surgical management.

Imaging after titanium cranioplasty.

Titanium cranioplasty has been used in our unit for reconstruction of cranial defects following trauma, tumour resection and bone loss due to postcraniotomy infection. It has previously been assumed that imaging to assess recurrence of disease progression after cranioplasty would be severely compromised in the presence of metallic material. Titanium is a non-ferrous metal of low atomic number, which is relatively radiolucent and allows exceptionally clear images to be obtained without significant degradation of image quality, on CT and magnetic resonance (MR) imaging. Cases are presented that demonstrate the use of CT contrast cisternography and MR imaging after titanium cranioplasty. On the basis of its strength, biocompatibility and excellent handling characteristics, allied to its suitability for all post-operative imaging techniques, we conclude that titanium plate is the material of choice for cranioplasty.

The long-term efficacy of conservative surgery and radiotherapy in the control of pituitary adenomas.

OBJECTIVES: We assessed the long-term efficacy and toxicity of conservative surgery and radiotherapy in the control of pituitary adenomas. DESIGN: Retrospective study of patients treated at the Royal Marsden Hospital. PATIENTS: Four hundred and eleven patients with pituitary adenomas treated with conventional external beam radiotherapy at the Royal Marsden Hospital between 1962 and 1986. Two hundred and fifty-two patients had clinically non-functioning pituitary adenomas, 131 had hormone secreting tumours and in 28 patients the secretory status was not known. Three hundred and thirty-eight patients had surgical intervention of whom only 11 had complete tumour excision. All patients received conventional fractionated external beam radiotherapy to a dose of 45-50Gy in 25-30 fractions. MEASUREMENTS: Actuarial progression free survival and overall survival and assessment of toxicity, particularly in terms of vision, requirement for hormone replacement therapy and incidence of second tumours. RESULTS: The actuarial progression free survival was 94% at 10 years and 88% at 20 years for all patients and 97% at 10 years and 92% at 20 years for patients with clinically non-functioning adenomas. Only secretory status was an independent prognostic factor for disease control. The 10 and 20-year survivals for all patients were 77 and 58% respectively. When compared with the normal population the relative risk of death was 1.76 (P < 0.001) and no prognostic factors for survival were identified. The morbidity of radiotherapy was low. Visual deterioration, assumed to be radiation induced, occurred in 1.5% of patients and the risk of second brain tumour was 1.9% at 20 years. Fifty per cent of patients received hormone replacement therapy by 19 years. CONCLUSION: Conventional external beam radiotherapy as described here combined with conservative surgery is safe and effective in the control of pituitary adenomas. These results should form a baseline for comparison with new treatment strategies.

Chondrosarcoma of the skull base: a series of eight cases.

Chondrosarcomas of the skull base are indolent, locally invasive tumors with a marked tendency to recur. Surgery is the mainstay of treatment because these tumors are generally resistant to other forms of treatment. A surgical approach with wide access to the skull base and one that is easily repeatable is required, because recurrence is common. We have used the LeFort I maxillotomy or mobilization of the zygoma at the time of craniotomy to obtain wide access to the skull base in eight cases of chondrosarcoma. Three patients have undergone subsequent procedures by us for recurrent disease. One patient died 30 days after the operation, and one has required an open repair of a cerebrospinal fluid leak. Good palliation of symptoms has been achieved in all survivors. These approaches fulfill the criteria for the surgical management of these difficult tumors by allowing excellent exposure, safe repetition if required, satisfactory palliation, and acceptable morbidity.

The pathophysiology of infant subdural haematomas.

The widely accepted theories concerning the pathophysiology of infant subdural haematoma (SDH) were formulated in the pre-computed tomographic (CT) scan era. Violent shaking is considered to be a crucial cause of SDH in non-accidentally injured infants. This theory has been re-examined in a clinical and CT scan review, and our findings have been correlated with results of recent head injury research. A retrospective review was conducted of all head injured infants (up to 18 months old) treated at Atkinson Morley's Hospital over a recent 20-year period (n = 100). Twenty-eight infants with a SDH were identified. CT scans were reviewed and each SDH greater than 0.5 cm thick was morphometrically analysed. Seventeen infants were Caucasian, 10 were non-Caucasian and one was of mixed race. A race-dependent pattern of SDH pathophysiology was noted, with non-Caucasian infants with a head injury more likely to have a SDH than Caucasian infants (67 v 21%, p < 0.01). All had a history of, or radiographic and clinical findings most consistent with, an impact injury, and non-Caucasian infants were significantly more likely to have a normal scalp examination despite the impact injury (p < 0.05) and to have developed the SDH after a relatively trivial fall (p < 0.01). They were also more likely to have a large (> 0.5 cm thick) SDH (p < 0.05), and to suffer post-traumatic seizures (p < 0.05). Our findings do not support shaking as the only cause of infant SDH formation and also suggest that non-accidental injury is a less common cause of SDH than it is believed to be.

Midline aneurysms of the vertebrobasilar junction: an effective anterior approach.

There are acknowledged difficulties associated with operations on midline aneurysms at the vertebrobasilar junction. This report describes a series of such aneurysms treated by an anterior approach using a Le Fort maxillotomy to gain access via the clivus to the aneurysm. In each case the aneurysm was dealt with satisfactorily with no long-term morbidity or mortality. Attention is directed to the necessity for a water-tight dural seal postoperatively. We advocate wider use of this technique in appropriate circumstances.

Intracranial aneurysm formation following radiotherapy.

Two patients sustained a subarachnoid haemorrhage secondary to radiation-induced vasculopathy and associated aneurysm. A 65-year-old woman was treated by radiotherapy for a stereotactically biopsied left parieto-temporal astrocytoma. Three-and-a-half years later, she suffered a subarachnoid haemorrhage secondary to a giant aneurysm arising from the middle cerebral artery bifurcation. A 44-year-old man sustained a subarachnoid haemorrhage 21 years after receiving whole brain irradiation for a large left parietal angioma. Angiography following his subarachnoid haemorrhage revealed a distal right middle cerebral artery aneurysm that was not visible on earlier angiograms. Both patients underwent craniotomy for their aneurysms with good postoperative recoveries.