Minimally Invasive Interhemispheric Approach for Giant Olfactory Groove Meningioma: Technical Note.

BACKGROUND: Skull base tumors, such as large olfactory groove meningiomas (OGMs), are a challenge for neurosurgeons. However, the tendency to reduce invasive surgeries is gaining more adepts. We describe a minimally invasive interhemispheric approach with a falx window for microsurgical resection of the giant OGM as a technical note. METHODS: A minimal medial frontal craniotomy measuring 3-5 cm in size is performed, and an interhemispheric approach is combined with an opening in the falx to improve microsurgical resection of the giant OGM. The technique and more details are described. RESULTS: A minimally invasive interhemispheric approach with a falx window was performed in this case. Gross total resection of the OGM was possible with minimal brain retraction. Simpson grade I was achieved, and there was a good outcome on the postoperative recovery period of the patient, with vision improvement, preservation of olfaction, and no other complications. CONCLUSIONS: The minimally invasive interhemispheric approach with a falx window is effective and safe for giant OGM with a good outcome for the patient. The opening in the falx improves the interhemispheric pathway and allows gross total resection with minimal brain retraction and low morbidity.

"Next Door" intraoperative magnetic resonance imaging for awake craniotomy: Preliminary experience and technical note.

BACKGROUND: During glioma surgery "maximal safe resection" must be the main goal. Intraoperative magnetic resonance imaging (iMRI) associated with awake craniotomy (AC) is a valuable tool to achieve this objective. In this article, AC with a "next-door" iMRI concept is described in a stepwise protocol. METHODS: This is a retrospective analysis of 18 patients submitted to AC using iMRI; a stepwise protocol is also discussed. RESULTS: The mean age was 41.7 years. Hemiparesis, aphasia, and seizures were the main initial symptoms of the patients. Sixty-six percent of the tumors were located in the left hemisphere. All tumors were near or within eloquent areas. Fifty-three percent of the cases were glioblastomas multiforme and 47% of the patients had low grade gliomas. The mean surgical time and iMRI time were 4 h 4 min and 30 min, respectively. New resection was performed in 33% after iMRI. Extent of resection (EOR) higher than 95% was possible in 66.7% of the patients. The main reason of EOR lower than 95% was positive mapping of eloquent areas (6 patients). Eighty percent of the patients experienced improvement of their deficits immediately after the surgery or had a stable clinical status whereas 20% had neurological deterioration, however, all of them improved after 30 days. CONCLUSION: AC associated with "next-door" iMRI is a complex procedure, but if performed using a meticulous technique, it may improve the overall tumor resection and safety of the patients.

Intraventricular meningiomas in adults: clinical series and review of the literature

Background: Intraventricular meningiomas are rare tumors and pose clinical, radiological, and surgical challenges. Individualized approach helps to establish successful results. Methods: Thirteen patients underwent craniotomy for intraventricular meningioma resection from 1999 to 2007. The mean age was 45 years (23-64), time of presentation between 25 days to three years. There were ten females and three males. Headaches and seizures were the most frequent initial presentations. Tumors were located in the ventricular trigone in 11 patients and in the temporal horn in two. Results: There were seven posterior temporal and seven parieto-occipital transcortical craniotomies, one patient was operated two times. Resection grade was Simpson I in nine patients, Simpson II in four, and Simpson III in one case. Surgical mortality was zero. There were six complications. Two patients had ventriculitis, one patient had hematoma of the surgical bed, one patient had severe post-operative cognitive impairment and one presented with progression of motor deficits. In two patients, there was transient memory disturbance after the parieto-occipital approach. Conclusion: Correct understanding of microsurgical anatomy cooperates for further success in operation of intraventricular meningiomas. Pre-operative embolization is helpful to reduce bleeding when a suitable tumor feeder can be accessed with no reflux. Dynamic changes in the shape of the ventricular cavity have to be considered when planning the most suitable route. Rigorous hemostasis and ventricular drainage are important points to avoid main complication.

Petroclival meningiomas: surgical management and common complications.

Petroclival meningiomas are technically challenging lesions. They have a tendency to grow slowly, involve cranial nerves and compress the brainstem and basilar artery, pushing them to the opposite side. Their natural history is marked by clinical deterioration and fatal outcome. They were once considered inoperable lesions; decades ago, mortality rates were higher than 50%. The authors describe 15 petroclival meningiomas treated surgically between 1995 and 2007. The main approaches used were combined anterior petrosectomy and retrosigmoid (3 cases), retrosigmoid (8 cases), and pre-sigmoid and subtemporal (4 cases). The mortality rate was 13.5% due to surgical bed hematoma and brain ischemia. The post-operative complications were hydrocephalus in 2 cases, cerebrospinal fluid leak in 2 cases and infection of surgical flap in one case. Limiting factors for surgical removal are tumor consistency, encasement of brainstem perforators and pre-operative clinical status.

Middle cerebral artery aneurysms: challenges for microsurgical approach

The authors present their series about middle cerebral artery (MCA) aneurysms. They discuss anatomical aspects as well as the results and complications of surgical treatment. Besides, they defend the idea that for having good results, it is necessary an extent Sylvian´s cistern dissection, permitting an adequate exposure of the aneurysms and their relationships not only with the MCA but with its branches, emphasizing too the not usefulness of temporary clipping in the approach of this pathology.