High-flow bypass for giant dolichoectatic vertebrobasilar aneurysms: illustrative cases.

BACKGROUND: Giant fusiform dolichoectatic vertebrobasilar artery aneurysms are challenging lesions with a poor natural history. When there is progressive brainstem compression from these lesions, endovascular treatment can be insufficient, and bypass surgery remains a possible salvage option. High-flow bypass surgery with proximal occlusion can potentially arrest aneurysm growth, promote aneurysm thrombosis, and reduce rupture risk. The authors describe their experience in two patients with giant fusiform dolichoectatic vertebrobasilar artery aneurysms treated with high-flow bypass. OBSERVATIONS: Both patients presented with enlarging giant dolichoectatic vertebrobasilar aneurysms causing symptomatic brainstem compression. The authors performed staged treatment involving high-flow bypass from the external carotid artery to the posterior cerebral artery using a saphenous vein graft, Hunterian proximal vertebrobasilar occlusion, and finally posterior fossa decompression with or without direct aneurysm thrombectomy and debulking. Postoperative angiography revealed successful flow reversal, aneurysm exclusion, and no brainstem stroke. Clinically, one patient had improvement in their modified Rankin Scale (mRS) score from 3 preoperatively to 1 at 12-month follow-up. The second patient had a deterioration in their mRS score from 4 to 5 at 12-month follow-up. LESSONS: High-flow bypass strategies remain high risk but can be a viable last resort in patients with neurological deficits and enlarging giant fusiform dolichoectatic vertebrobasilar artery aneurysms.

Idiopathic intradural dorsal thoracic arachnoid cysts: A case series and review of the literature.

BACKGROUND: Spinal intradural arachnoid cysts (SIAC) are cerebrospinal fluid (CSF) filled sacs formed by arachnoid membranes and may be either idiopathic or acquired. Idiopathic cysts represent a separate entity and their aetiology remains uncertain. By far the most difficult differential diagnosis is distinguishing between idiopathic anterior spinal cord herniation (IASCH) and dorsal thoracic intradural arachnoid cysts (TIAC), due to their similarity in radiological appearance. Cine-mode (SSFP) is emerging as a novel technique in the diagnosis and operative planning of SIAC. METHOD: Retrospective analysis of patients with idiopathic TIACs that were surgically managed at Royal North Shore Hospital and North Shore Private Hospital between November 2000 and November 2015. RESULTS: Ten patients were included in this study. Age ranged from 20 to 77years with a mean age of 60years and a female preponderance. The most common clinical features were progressive gait ataxia and lower limb myelopathy. Radicular pain tends to improve following surgery, however gait ataxia may not. DISCUSSION: While there are circumstances in which the distinction between dorsal thoracic intradural arachnoid cysts and idiopathic anterior spinal cord herniation are radiologically obvious, in cases where the appearances are less clear, cine-mode SSFP MRI imaging can provide an invaluable tool to differentiate these pathologies and lead the clinician towards the correct diagnosis and management. The mainstay of surgical management for dorsal TIACs is laminectomy and cyst excision or fenestration. Surgery for gait ataxia should be aimed towards preventing deterioration, while maintaining the potential for symptomatic improvement, whereas surgery for radicular pain should be curative.

External ventricular drain as a nontraumatic suction device in carotid endarterectomy.

Carotid endarterectomy is a commonly performed operation to remove plaque at the region of the carotid bifurcation. We present our technique to keep the field clear and to minimize potential trauma to the carotid using a neurosurgical external ventricular drain passed behind the common carotid and placed in the dependent position under the arteriotomy.

Growth hormone secreting pituitary adenoma with admixed gangliocytoma and ganglioglioma.

Pituitary adenomas are the most common tumours found in the sellar region and, when both functioning and non-functioning adenomas are combined, account for 7-15% of primary brain tumours in adults. Rarely, admixed or discrete groups of cells comprising two or more tumour subtypes are seen; the so-called 'collision tumour'. We present a case of a 54-year-old-woman with a growth hormone-secreting pituitary adenoma admixed with both ganglioglioma and gangliocytoma. The possible mechanisms by which this may occur include a pre-existing gangliocytoma promoting the development of pituitary adenoma by hypersecretion of releasing hormones or aberrant migration of hypothalamic neurons in early embryogenesis.

Seizures after aneurysmal subarachnoid hemorrhage: a systematic review of outcomes.

OBJECTIVE: The risk for early and late seizures after aneurysmal subarachnoid hemorrhage (aSAH), as well as the effect of antiepileptic drug (AED) prophylaxis and the influence of treatment modality, remain unclear. We conducted a systematic review of case series and randomized trials in the hope of furthering our understanding of the risk of seizures after aSAH and the effect of AED prophylaxis and surgical clipping or endovascular coiling on this important adverse outcome. METHODS: We performed a MEDLINE (1985-2011) search to identify randomized controlled trials and retrospective series of aSAH. Statistical analyses of categorical variables such as presentation and early and late seizures were carried out using χ(2) and Fisher exact tests. RESULTS: We included 25 studies involving 7002 patients. The rate of early postoperative seizure was 2.3%. The rate of late postoperative seizure was 5.5%. The average time to late seizure was 7.45 months. Patients who experienced a late seizure were more likely to have MCA aneurysms, be Hunt/Hess grade III, and be repaired with microsurgical clipping than endovascular coiling. CONCLUSIONS: Despite improved microsurgical techniques and antiepileptic drug prophylaxis, a significant proportion of patients undergoing aneurysm clipping still experience seizures. Seizures may occur years after aneurysm repair, and careful monitoring for late complications remains important. Furthermore, routine perioperative AED use does not seem to prevent seizures after SAH.

International subarachnoid trial in the long run: critical evaluation of the long-term follow-up data from the ISAT trial of clipping vs coiling for ruptured intracranial aneurysms.

The International Subarachnoid Trial (ISAT), the largest prospective randomized study into endovascular and neurosurgical treatment of ruptured intracranial aneurysms, recently reported long-term follow-up in >The Lancet Neurology. In this cohort, the risk of death at 5 years was significantly lower in the coiled group, but the proportion of survivors who were independent was not statistically different between the groups, and rebleeding was higher in the coiled group. This article critically evaluates the long-term ISAT data from an evidence-based perspective and places it in the context of the overall approach to treatment of ruptured intracranial aneurysms. ISAT has been a strong driver of change in the management of ruptured aneurysms. Nevertheless, the evidence for the superiority in coiling in the long term should not be assumed from ISAT data alone. Potential biases of patient characteristics and national referral patterns, as well as the methodological problems already described from the original trial, contribute to the difficulty in interpreting differences in long-term outcomes. These new data should be regarded as Level 2b evidence, suitable for treatment recommendations but not guidelines.

Aqueduct stenosis-?Benign.

'Benign' aqueduct stenosis is a common cause of hydrocephalus in the paediatric population and is frequently treated by endoscopic third ventriculostomy. Occasionally, aqueduct stenosis can be a prelude to the development of other pathology, as is seen in these two cases of pineal tumours developing in patients whose hydrocephalus was successfully treated with endoscopic third ventriculostomy. The case histories are presented, along with the recommendation for increased radiological screening of patients with this usually 'benign' presentation.

Recurrent medulloblastoma--violation of Collin's law by 14 years.

We present a case of recurrent medulloblastoma, which violates Collin's law by 14 years. This is one of the longest exceptions to this rule published to date and serves as a reminder of the need for continued vigilance for many years after the original diagnosis.

Subtemporal decompression for slit-ventricle syndrome: successful outcome after dramatic change in intracranial pressure wave morphology. Report of two cases.

Subtemporal decompression is recognized as an effective treatment for slit-ventricle syndrome; however, the effects of this procedure have not been demonstrated using both pre- and postsurgical intracranial pressure (ICP) monitoring. The authors report two cases in which slit-ventricle syndrome and elevated ICP had been diagnosed. Each patient underwent ICP monitoring before and after subtemporal decompression; the dramatic changes in the ICP measurements are presented along with findings from 1-year follow-up examinations.