overview in stereotactic radiosurgery

Efficacy and utilization of radiation as a mode of management in neurosurgical lesions has increased radically as a consequence of improvements in appreciation of the concept of stereotaxis, progress in medical imaging, computer technology, and advanced delivery devises. [19.22] Primary management alternative in patients with cerebellopontine angle lesions, skull base tumours, meningiomas, paragangliomas, AVMs etc., is increasingly being used as also in secondary management of recurrent or planned residual disease patients where a part of the lesion is deliberately left behind to avoid loss of function and prevent iatrogenic injury. [22] Contemporary understanding with adequate and proper information of this resource along with understanding the controversies regarding the use of radiation of the management of several lesions in paramount. This article is intended to provide a concise basic introduction of the technology available and the pertinent applications in the management for several lesions with a basic understanding of the advantages and disadvantages of various available devices and the outcome in using various methods based on review of available literature

Neuroendoscope in aneurysm surgeries: past, present and future / Neuroendoscopia em cirurgia de aneurismas: passado, presente e futuro

Even with the use of most sophisticated microscope sometimes the relationship between the aneurysm and the adjacent structures are not clearly defined. The straight line of view by microscope results in inadequate visualization of structures thatlie immediately behind other structures like the neck, branches or perforators of the aneurysm. Hence exposure of these structures may require risky retraction either of the parent artery or the aneurysm itself, which can be overcome by clear anatomical information obtained by the use of endoscope instead of attempting extensive manipulation under the microscope. The endoscope permits close up, wide angled views of regional anatomic features and verification of the optimal clip position. Visual conformation of regional anatomy achieved using the rigid endoscope provides valuable information for subsequent microsurgical procedures and enhances the safety and reliability. Endoscopic-assisted microsurgery is an exceptional aid and using the PIP (picture-in picture) technology, simultaneous observation of microscope and endoscopic images can be viewed through the ocular system of microscope. The advantages of neuroendoscope include the ability to look around corners and behind obstructions. With less brain retraction, smaller operative exposures and better visualization, neuroendoscopy may reduce operative morbidity. However he surgeon should be familiar with this technique and be prepared for the inconveniences and risks during the procedure.

A neuroendoscopia reflete a tendência da neurocirurgia moderna em buscar acessos mínimos., ou seja, acessar e visualizar lesões através de corredores o menor possível e com máxima efetividade ao objetivo, com mínima alteração do tecido norma;. Embora o primeiro procedimento endoscópico intracraniano tenha sido realizado no início do século 20, esta técnica tornou-se popular entre os neurocirurgiões, somente nos anos recentes, após o refinamento dos endoscópios e de seus instrumentos. Mesmo com o uso de microscópios, as vezes as relações entre os aneurismas e as estruturas vizinhas não é claramente definida. A visão reta oferecida pelo microscópio resulta em visualização inadequada de estruturas que se colocam imediatamente atrás, como o colo, ramos ou perfurantes do aneurisma. Assim, a exposição destas estruturas pode requerer retrações de risco para a artéria aferente ou o próprio aneurisma, o que pode ser superado por uma clara informação anatômica obtida com o endoscópio, ao invés de uma eventual manipulação externa com o microscópio. O endoscópio permite “close-up”, amplas e anguladas observações das características anatômicas e verificação do posicionamento ótimo do clipe. A conformação visual da anatomia regional obtida com o uso do endoscópio rígido oferece aliosa informação para subseqüentes e a confiabilidade. Microscopia assistida por endoscopia é um auxílio excepcional, e o uso de tecnologia PIP (quadro a quadro), permite a observação simultânea das imagens no microscópio e no endoscópio, através da ocular do microscópio. As vantagens da neuroendoscopia incluem a habilidade de olhar em volta de ângulos e atrás de obstáculos. Com menos retração cerebral, menores abordagens e melhor visualização, a neuroendoscopia pretende reduzir a morbidade operatória. Para tal, o neurocirurgião deve estar familiarizado com a técnica e preparado para os inconvenientes e riscos do procedimento.