Angled rigid neuroendoscope for continuous intraoperative visual monitoring: technical note

We developed and tested a new, angled rigid endoscope as a tool for performing continuous visual monitoring during microsurgery. The shaft of the scope is angled 110 degrees at its midportion using a prism. We used the scope continuously in 30 cases including 15 pituitary tumours, 7 brain tumours, 7 cerebral aneurysms, and one hemifacial spasm. For pituitary tumours the tip of the scope was positioned in the sphenoid sinus or in the cavity formed by tumour removal; for cerebral aneurysms it was placed behind the parent artery or the aneurysmal neck. Image quality was acceptable for intraoperative monitoring. In no case did the neuroendoscope have a deleterious impact on th e proper function of the microscope or surgical instruments. This angled rigid scope was more effective for intraoperative monitoring than conventional straight scopes.