Microsurgical treatment of arteriovenous malformations in critical areas of the brain.

Between June 1981 and November 1989, 56 patients who had arteriovenous malformations (AVMs) in critical areas of the brain, in deeply placed sites or were of large size were excised using microsurgical techniques. In 44 cases one-stage surgery was used and in 10 cases deliberate surgical staging was performed. In four cases routine postoperative angiography revealed residual AVM. Further treatment was surgical in two cases, and focused radiation in two to achieve angiographically confirmed excision or obliteration of the AVM. Referral was following haemorrhage in 41 cases, progressive neurological deficit in nine cases and epilepsy in six cases. Forty-three patients made a good recovery, seven were fair, three had a poor result and three died. Three patients developed a new or increased deficit following surgery. Seven of nine patients who presented with neurological deficit improved. Seven of nine patients who had epilepsy and who had not bled are free of epilepsy, and are not receiving anticonvulsants on long-term follow-up. No new cases of long-term epilepsy have occurred following surgery. Microsurgical excision of cerebral AVMs even in critical areas of the brain carries a better outcome than the natural history of conservatively treated lesions. Surgery should be considered not only following haemorrhage, but also in cases presenting with progressive neurological deficit or epilepsy.

Effect of calcitonin-gene-related peptide on postoperative neurological deficits after subarachnoid haemorrhage.

An infusion of calcitonin-gene-related peptide (CGRP) at progressively increased concentrations was given to 15 patients with neurological deficits after intracranial aneurysm surgery for subarachnoid haemorrhage. In 9 of the patients the deficits, quantified by a modified Glasgow coma scale, improved with no adverse effects; after a placebo infusion only 2 of the 15 patients showed improvement. If CGRP can reverse cerebral ischaemia after early intracranial aneurysm surgery, its use may improve the safety of such early surgery, remove the need for late surgery with its increased risk of death from rebleeding, and reduce overall morbidity and mortality of aneurysmal subarachnoid haemorrhage.

Epilepsy following neurosurgical intervention.

The incidence of post-surgical epilepsy has been reported to be very high, and related to the pathological condition, to the surgery itself, and, particularly in the case of aneurysms, to the site of the lesion. Prophylactic anti-convulsant medication has been widely recommended on the basis of the perceived high risk of epilepsy. A prospective analysis of one hundred consecutive survivors of aneurysm surgery treated in a consistent microsurgical manner was performed to assess the incidence and causation of post-operative seizures. Three patients had a single early post-operative seizure. All three had predisposing features; a previous epileptic history in two, and neurological deficit in the other. Only one patient developed repeated seizures (epilepsy); he had major parenchymal damage. Seizures did not occur during a two to six year follow up in survivors of aneurysm surgery who did not have a previous epileptic history or a persistent post-operative neurological deficit. The site of aneurysm did not influence the development of epilepsy, and middle cerebral aneurysms were not associated with an increased risk. The low risk of epilepsy does not justify routine anti-convulsant prophylaxis.

Spinal cord compression due to thoracic disc herniation: results of microsurgical posterolateral costotransversectomy.

Fifteen consecutive patients with thoracic disc herniation treated by posterolateral microsurgical costotransversectomy are described. With appropriate modifications to the standard technique, costotransversectomy was found to be a suitable approach even for calcified central discs, and discs which had eroded intradurally. All patients had evidence of spinal cord compression preoperatively with varying degrees of leg weakness. The results of surgery are discussed. Ten patients who were disabled but ambulant showed marked improvement in symptoms and signs. Of the remaining five, all of whom were severely disabled and nonambulant preoperatively, four demonstrated significant improvement. Most patients mobilised rapidly, 13 being able to walk unaided within 24 hours. One patient developed an intrathoracic meningocoele postoperatively, which resolved after multiple percutaneous aspirations. Otherwise there were no serious pulmonary complications. We believe that costotransversectomy is the approach of choice for central as well as centrolateral and lateral thoracic disc herniations.

Relief of lumbar canal stenosis using multilevel subarticular fenestrations as an alternative to wide laminectomy: preliminary report.

We describe an operative approach to lumbar canal stenosis which, unlike laminectomy, takes into account the segmental pathology of the disease. At each level involved, a bilateral subarticular fenestration is performed under high magnification. The medial third of each facet joint is first removed with an air-powered drill; then the remaining two-thirds of the joint is undercut with the drill to allow a generous fenestration in the thickened ligamentum flavum and adjacent laminae. All tissue responsible for neural compression is removed, but the spinous processes, interspinous ligaments, and much of the facet joints and laminae are preserved. Spinal stability is maintained and, because tissue disruption is minimized, postoperative discomfort is usually reduced, promoting early mobility and reduced hospital stay. The operation is described in detail, and the results of operation in 32 patients are assessed. The follow-up periods now range from 17 to 58 months. Of 23 patients who presented with neurogenic claudication, 14 (61%) obtained complete relief and 7 (30%) improved significantly. The mean hospital stay was 9 days (range, 4 to 17 days).

Epilepsy after operation for aneurysms.

The authors reviewed 100 consecutive survivors of aneurysm operations and identified 3 patients who developed postoperative epilepsy. The use of prophylactic phenytoin in the first 67 cases did not seem to influence the patient's risk of developing epilepsy. It is concluded that with present microneurosurgical techniques the risk of postoperative epilepsy is small and unselective use of phenytoin prophylaxis should be reconsidered.

Surgical treatment of cryptic AVM's and associated hematoma in the brain stem and spinal cord.

Most surgically treated cases of brain-stem hematomas have been attributed to rupture of cryptic arteriovenous malformations (AVM's); however, very few cases have been histologically proven. Similarly, there are very few reports of surgically treated spontaneous hematomyelia, in which the hemorrhage has been histologically confirmed as being due to a purely intramedullary AVM. The authors report three cases with surgically treated, histologically confirmed AVM's, of which two were in the brain stem and the third was in the spinal cord. In all these cases, abnormal vascular tissue in the wall of the hematoma cavity was recognized at operation and excised.

Traumatic carotid-cavernous fistula due to transection of the intracavernous carotid artery. Case report.

The authors report a case of a high-flow posttraumatic carotid-cavernous fistula, with complete steal of the blood flow from the ipsilateral internal carotid artery (ICA). Direct attack on the intracavernous carotid artery was performed using the approach of Parkinson with temporary isolation of the ICA. Complete transection of the artery within the cavernous sinus was encountered. The fistula was occluded by clipping the two ends of the ICA within the sinus. The implications of this previously unreported finding are discussed.

Spinal cord compression due to prolapse of cervical intervertebral disc (herniation of nucleus pulposus). Treatment in 26 cases by discectomy without interbody bone graft.

Twenty-six patients who presented with spinal cord compression due to cervical disc prolapse (herniation of the nucleus pulposus) were treated by anterior discectomy. There was a high incidence of disc prolapse at the C3-4 level. The most severe degrees of preoperative disability were associated with prolapse at that level. Impairment of posterior column function, particularly in the upper limbs, played a major part in producing disability. High cervical disc prolapse can produce a clinical picture that is predominantly like that of a posterior cord syndrome. Preexisting fusion of vertebral bodies in the cervical spine and a history of cervical spinal trauma appear to be predisposing factors. Discectomy is an effective treatment of this condition. Spinal cord compression due to cervical disc prolapse should be distinguished from spondylotic myelopathy.

A report of six surgically treated cases.

Six cases of brain-stem hematoma are described. The clinical presentation in these cases was extremely variable. Operative evacuation of the hematoma resulted in immediate improvement in all cases, and a full or nearly full recovery in five. Untreated brain-stem hematoma is probably always fatal, whereas surgical evacuation is effective and safe. The diagnosis of brain-stem hematoma should be considered in any case of brain-stem lesion.

Transoral approach to the cervical spine: report of four cases.

The transoral approach to the upper cervical spine is an established but little used route, offering excellent access with good wound healing, to lesions of the bodies of the atlas, axis and upper part of the third cervical vertebra. The authors report four cases which demonstrate the value of the procedure.

An investigation with serial angiography into the evolution of cerebral arterial spasm following aneurysm surgery.

Serial postoperative angiograms were performed in 28 patients with intracranial aneurysms, 26 of whom had presented with a subarachnoid hemorrhage. The clinical state and intracranial pressure (ICP) were also measured. Angiograms were performed in the ward using a cannula, which was passed into the proximal external carotid artery via the superficial temporal artery. Measurements of the vessel diameters were made, with the preoperative angiogram as a baseline. Patients could be placed into one of five groups depending on the presence or absence of significant arterial spasm, the clinical state of the patient, and the normality or otherwise of the ICP. No patient's condition deteriorated without an elevated ICP and/or significant arterial spasm. The study shows that this spasm is usually associated with a poor clinical state if it reaches a maximum 8 to 12 hours after the operation, although the clinical deterioration is not apparent for a further 6 to 12 hours. Knowledge of the natural history of postoperative arterial spasm may allow earlier treatment of the spasm, which may be more successful than delaying treatment until clinical deterioration has occurred. The worth of the varied drugs proposed for the treatment of spasm may be assessed using this type of protocol.

Intracranial aneurysms: analysis of results of microneurosurgery.

Subarachnoid haemorrhage from intracranial aneurysms has a poor prognosis. Operative management of intracranial aneurysms was once considered ineffective. The first 100 cases treated by micorsurgery were analysed to see whether mortality and morbidity were reduced. Modern surgical techniques halved the total mortality but the morbidity was unaltered. Results can be improved by delaying surgery seven days and by treating any hypertension before surgery.