Brainstem cavernomas: a surgical challenge.

OBJECTIVE: The authors show their experience with brainstem cavernomas, comparing their data with the ones of a literature review. METHODS: From 1998 to 2009, 13 patients harboring brainstem cavernomas underwent surgical resection. All plain films, medical records and images were reviewed in order to sample the most important data regarding epidemiology, clinical picture, radiological findings and surgical outcomes, as well as main complications. RESULTS: The mean age was 42.4 years (ranging from 19 to 70). No predominant gender: male-to-female ratio, 6:7. Pontine cases were more frequent. Magnetic resonance imaging was used as the imaging method to diagnose cavernomas in all cases. The mean follow-up was 71.3 months (range of 1 to 138 months). Clinical presentation was a single cranial nerve deficit, VIII paresis, tinnitus and hearing loss (69.2%). All 13 patients underwent resection of the symptomatic brainstem cavernoma. Complete removal was accomplished in 11 patients. Morbidity and mortality were 15.3 and 7.6%, respectively. CONCLUSIONS: Cavernomas can be resected safely with optimal surgical approach (feasible entry zone) and microsurgical techniques, and the goal is to remove all lesions with no cranial nerves impairment.

Brainstem cavernomas: a surgical challenge / Cavernomas de tronco: desafio cirúrgico

Objective: The authors show their experience with brainstem cavernomas, comparing their data with the ones of a literature review. Methods: From 1998 to 2009, 13 patients harboring brainstem cavernomas underwent surgical resection. All plain films, medical records and images were reviewed in order to sample the most important data regarding epidemiology, clinical picture, radiological findings and surgical outcomes, as well as main complications. Results: The mean age was 42.4 years (ranging from 19 to 70). No predominant gender: male-to-female ratio, 6:7. Pontine cases were more frequent. Magnetic resonance imaging was used as the imaging method to diagnose cavernomas in all cases. The mean follow-up was 71.3 months (range of 1 to 138 months). Clinical presentation was a single cranial nerve deficit, VIII paresis, tinnitus and hearing loss (69.2%). All 13 patients underwent resection of the symptomatic brainstem cavernoma. Complete removal was accomplished in 11 patients. Morbidity and mortality were 15.3 and 7.6%, respectively. Conclusions: Cavernomas can be resected safely with optimal surgical approach (feasible entry zone) and microsurgical techniques, and the goal is to remove all lesions with no cranial nerves impairment.

Objetivo: Os autores mostram sua experiência com cavernomas de tronco cerebral, comparando seus dados com os de uma revisão da literatura. Métodos: De 1998 a 2009, 13 pacientes com cavernoma de tronco cerebral foram submetidos a ressecção cirúrgica. Todos os filmes, prontuários e imagens foram revisados para exposição dos dados mais importantes, como epidemiologia, detalhes clínicos, achados radiológicos e resultados cirúrgicos, bem como as principais complicações. Resultados: A média de idade foi de 42,4 anos (variação de 19 a 70). Não houve predominância de gênero na taxa masculino versus feminino, 6:7. Os casos pontinos foram os mais frequentes. Ressonância nuclear magnética foi o método de imagem para o diagnóstico de cavernomas em todos os casos. A média do acompanhamento foi de 71,3 meses (variação de 1 a 138 meses). A apresentação clínica mais frequente foi a paresia do VIII nervo craniano, tinitus e perda auditiva (69,2%). Todos os 13 pacientes com cavernomas de tronco sintomáticos foram submetidos à ressecção cirúrgica. A remoção total foi realizada em 11 pacientes. A morbidade e a mortalidade foram de 15,3 e 7,6%, respectivamente. Conclusão: Os cavernomas podem ser seguramente ressecados por meio de acessos cirúrgicos ideais (zonas de entrada seguras) e técnicas de microcirurgia, sendo que o objetivo é remover toda a lesão sem o comprometimento dos nervos cranianos.

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.

Anatomia Microcirúrgica do Segmento Clinóide da Artéria Carótida Interna e do Cavo Carotídeo / Microsurgical Anatomy of the Clinóide Segment of the Internal Carotid Artery and Carotid Cave

Embora a região clinóide seja comumente abordada pelos neurocirurgiões em várias afecções, sua anatomia e extremamente complexa e variável. O segmento clinóide da artéria carótida interna (ACI) se encontra na transição entre o seio cavernoso e o espaço subaracnóide, limitado pelos dois anéis durais. O segmento posteromedial do anel dural distal não tem contato com nenhuma estrutura óssea, esta peculiaridade anatômica facilita a formação do cavo carotídeo. Os anéis proximal e distal tornam-se relevantes por serem os limites anatômicos. O entendimento do segmento clinóide é importante para o correto diagnóstico e abordagem dos aneurismas desta região. Controle proximal, clinoidectomia anterior, opções de clips fenestrados e auxílio do endoscópio são detalhes técnicos de grande utilidade no manejo dos aneurismas do cavo carotídeo.

Is sagittal sinus resection in falcine meningiomas a factor of bad surgical outcome?

OBJECTIVE: Meningiomas arising purely from the falx below the longitudinal sinus represents a surgical challenge for the neurosurgeon. The authors discuss the new aspects of surgical details that may avoid complications and determine the prognosis. MATERIALS AND METHODS: We retrospectively evaluated our surgical experience from June 2004 to January 2010. Seventy patients harboring falcine meningiomas were included and submitted for surgical resection. All historical records, office charts and images were reviewed in order to sample the most important data regarding epidemiology, clinical pictures, radiological findings and surgical results, as well as the main complications. The patients were divided into three main groups: anterior third 32 patients (Group A), middle third 15 patients (Group B), 23 patients in the posterior third of falx (Group C). RESULTS: In Group A, total macroscopic resection was achieved in 31 out of 32 cases (96.87%). Twenty five patients had Rankin 0, five patients had Rankin 1-2, two patients had Rankin 6. In Group B (15 patients), 10 patients had gross resection and Rankin 0, four patients had Rankin 1-2 and one patient had Rankin 6. In Group C (23 patients), 20 patients were absolutely able, Rankin score 0, after six months postoperative period (83.3% had excellent results) and no mortality. Four cases had Rankin score 1 - 2 (16.6%). Ten cases (43.47%) had Simpson I resection and ten cases (43.47%) had Simpson II. CONCLUSION: Despite larger lesion volumes, Group A meningiomas had a better outcome due to the position they were in, the tumor and surrounding structures. The preoperative preparation and surgical planning can preserve sagittal sinus; but in some cases, this is not possible. Sagittal sinus resection, as proven by this paper, is still a factor of bad surgical outcome. In the middle and posterior third, resection of sagittal sinus is a factor of a bad outcome, due to cerebral infartion.

Microsurgical treatment of tentorial meningiomas: Report of 30 patients.

BACKGROUND: Tentorial meningiomas represent about 5% of intracranial meningiomas. This article reviews our recent institutional series of patients with tentorial meningiomas, proposes a simplified classification and analyzes postoperative evolution, discussing the salient features in the management of these patients. METHODS: From 1998 to 2005, 30 patients (22 female and 8 male) with tentorial meningiomas were operated at our institution. Thirteen patients had tumor restricted to the infratentorial space; 12, to the supratentorial space; and in 5 cases, the tumor involved both compartments. Follow-up ranged from 1 to 8 years. A total of 35 surgical procedures were performed in 30 patients, where 26 procedures were performed through a single approach (2, ITSC; 10, RS; 5, SOIH; 5, ST; and 4, TT); and 9, through combined approaches (7, ITSC/ SOIH; and 2, RS/ST). RESULTS: Simpson I resection was achieved in 17 patients. Tumors involving both compartments, involving the petrous sinus, and attached to the torcula limited complete resection. Twenty-two out of 30 patients were able to return to their regular life with no or minimal neurological sequelae. Most frequent complications in our series were shunt dependence, CSF fistulae, diffuse brain injury and visual field defects. Overall, our series revealed 3% mortality and 23% morbidity. CONCLUSION: Tentorial meningiomas are associated with significant morbidity related to the nervous and vascular structures surrounding the tumor. Partial tumor removal may be necessary in some cases.

Aneurismas da artéria cerebelar posterior inferior: revisão crítica da técnica cirúrgica / Critical review of surgical techniques for posterior inferior cerebellar aneurysms

Objetivo: Revisão crítica dos aspectos anatômicos da abordagem dos aneurismas da artéria cerebelar inferior posterior (ACIP); a abordagem extremo-lateral e os detalhes de suas variantes foram analisados. Métodos: Revisão da literatura e análise da experiência dos autores. Resultado: A abordagem extremo-lateral é a melhor abordagem cirúrgica para os aneurismas da ACIP. As indicações de by-pass e tratamento endovascular também devem ser consideradas. A principal complicação é a fístula de liquor, mas isquemia do tronco, hematoma de leito cirúrgico, contusão cerebelar, lesão dos nervos bulbares e instabilidade condilar também devem ser citadas. Conclusão: O conhecimento da anatomia microcirúrgica é fundamental na abordagem dos aneurismas da ACIP.

Objective: To review several aspects of posterior inferior cerebellar artery aneurysms regarding anatomy and approaches. Methods: A critical review of literature is performed with emphasis on the complications and surgical technical details. Results: the main approach advocated by the authors isthe far-lateral approach and its variants. The indications of by-pass with saphenous or radial artery graftand endovascular treatment are also considered. The main complication is cerebrospinal fluid leakage, but brain stem ischemia, surgical bed hematoma, venous infarction, cerebellar contusion, bulbar nerve damage, condylar instability must also be mentioned. Conclusion: Knowledge of microsurgical anatomy is fundamental for any kind of procedure regarding clipping of posterior inferior cerebellar artery aneurysms. Endovascular treatment is a safe option in the majority of the cases.

Abordagem atual aos aneurismas do topo da artéria basilar / Approaches to the basilar artery aneurysm

Objetivo: Revisão crítica das abordagens atuais para aneurismas do topo da artéria basilar. Análise dos aspectos anatômicos e angiográficos relevantes para cirurgia. Métodos: Revisão crítica da literatura e relato da experiência dos autores. Resultados: Os principais acessos para aneurismas de topo de basilar de acordo com sua posição em relação ao dorso da sela são: Kawase transpetroso para os aneurismas baixos, transcavernoso para os médios e temporopolar para os altos. A monitoração eletrofisiológica e com doppler pode minimizar complicações isquêmicas por clipagem prolongada, estenose ou fechamento inadvertido de perfurantes. Neuroproteção e hipotermia devem ser consideradas em lesões gigantes e complexas. Lesões complexas geralmente excedem ao tratamento endovascular. Conclusão: Existe uma tendência na literatura a considerar o tratamento cirúrgico dos aneurismas como método ultrapassado; entretanto a tecnologia de novas formas de proteção cerebral, técnicas microcirúrgicas e evolução dos clipes são indispensáveis para lidar com o cérebro em condições ruins na fase aguda. Os procedimentos endovasculares não drenam hematomas, não tratam hidrocefalia nem retiram coágulos das cisternas para prevenir o vasoespasmo. Entretanto é necessário um seguimento a longo prazo para uma avaliação mais precisa. O neurocirurgião deve dominar as duas opções de tratamento e ser hábil para indicar o tratamento mais apropriado.

Objective: To review the main approaches to basilar aneurysms and discuss relevant anatomy and angiographic features to choose the appropriate approach in each case. Methods: Literature review and author´s experiences are presented. Results: Current main approaches to basilar aneurysms regarding the level of the lesion from sellae dorsum are: Kawase transpetrosous for lower, transcavernous for middle and temporopolar for higher positioned aneurysms. Doppler, electroencephalography, somatosensory and motor evoked potential might minimize incidence of ischemic complications attributable to prolonged temporary occlusion or inadvertent perforator occlusion. Circulatory arrest and hypotermia may be considered for giant and complex aneurysms. The main principle applied is maximization of bone resection, which facilitates the use of surgical instruments and minimizes brain retraction. Complex basilar aneurysms frequently outdo endovascular treatment. Conclusion: There is a tendency in literature to consider the aneurysm surgery as an outdated method; however, technology of intensive care and anesthesia for brain protection, surgical techniques and clips evolution are indispensable for manipulate angry brain in aneurysms surgery after subarachnoid hemorrhage. Endovascular procedures do not remove clots from cisterns to avoid vasospasm, treat hydrocephalus or fenestrate the lamina terminalis to the same purpose; besides, longer follow up is necessary according to the final result. The neurosurgeon must dominate both treatment options and be able to differentiate exact indications.

Olfactory groove meningiomas: approaches and complications.

Olfactory groove meningiomas (OGM) account for 4.5% of all intracranial meningiomas. We report 21 patients with OGMs. Tumors were operated on using three surgical approaches: bifrontal (7 patients), fronto-pterional (11 patients) and fronto-orbital (3 patients). Total tumor removal (Simpson Grade 1) was achieved in 13 patients and Simpson II in 8 patients. Perioperative mortality was 4.76%. The average size of the OGM was 4.3+/-1.1cm. The overall recurrence rate was 19%. We preferred to use the pterional approach, which provides quick access to the tumor with less brain exposure. It also allows complete drainage of cisternal cerebrospinal fluid, providing a good level of brain relaxation during surgery. However, for long, thin tumors, hemostasis can be difficult using this approach.

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.

Tratamento cirúrgico dos aneurismas do complexo da artéria comunicante anterior: detalhes técnicos / Surgical treatment of anterior communicating artery aneurysms: technical details

Objetivo: Discutir as nuances técnicas das abordagens cirúrgicas dos aneurismas do complexo da artéria comunicante anterior conforme as características anatômicas e angiográficas das lesões.Métodos:com base na experiência obtida com craniotomia pterional realizada em 30 casos de aneurismas do complexo da artéria comunicante anterior, complementada com retirada do processo clinoide anterior e teto orbitário.Resultados:A direção do segmento A1 se correlaciona com a do aneurisma.A patência dos segmentos A1 e A2 contralaterais deve ser observada.A aderência do aneurisma ao nervo óptico restringe a retração do lobo frontal.A aspiração do giro reto é útil quando o aneurisma tem localização alta.Conclusões:Os aneurismas da comunicante anterior estão entre os aneurismas intracranianos mais complexos.Os detalhes técnicos acima apontados são essenciais para o sucesso terapêutico.

Multiple separated and multi-lobular aneurysms of the anterior communicating artery complex

The anterior communicating artery complex [ACoA] is the most common site of occurrence of intracranial aneurysms, harboring about 30 percent of these lesions. Multiple aneurysms account for 20 percent of all cerebral aneurysms. Multiple aneurysms on the same artery correspond to 2.8 percent of aneurysms, usually found in the internal carotid artery or middle cerebral artery. Multiple aneurysms of the ACoA are very rare and there are only a few cases reported in the literature. In cases of multiple aneurysms of the anterior communicating artery complex, not all lesions may be detected on preoperative radiological studies, due to the complex angio-archiecture around the ACoA. Careful dissection is mandatory to ensure the completeness of aneurysm surgery. Multiple separated and multi-lobular aneurysms of the anterior communicating artery are unusual lesions and should be studied as a special topic. The authors present four cases of these rare aneurysms, namely three multiple separated aneurysms and one multi-lobular aneurysm of the ACoC. Three of these patients presented with subarachnoid hemorrhage [SAH]. There were no familial or arteriovenous malformation.related aneurysms reported in our series. We propose a new classification for this type of aneurysm on the ACoA. The literature is reviewed. The results, physiopathology and management are dis cussed.