Initial clinical experience with a high-definition exoscope system for microneurosurgery

Advances in rigid-lens telescope systems provide an alternative method for magnification and illumination that may replace or supplement the operating microscope.

To evaluate the clinical utility of an exoscope system as an alternative to the operating microscope.

A custom-designed 10-mm-diameter rigid-lens telescope with a focal distance of 20 cm was attached to a 3-chip high-definition digital camera and displayed on a high-definition video monitor during surgery. A pneumatic scope holder positioned the scope over the operative field. This system was used in 16 procedures. The optical quality of the device was compared with that of an operating microscope during each procedure via a data entry form that evaluated optical quality, ease of manipulation, and overall ability to perform surgery.

The high-definition exoscope was used in 9 craniotomies, 6 spinal procedures, and 1 neurostimulator placement. Image quality was almost equal to that of the operating microscope in all cases. Surgeons felt that the lack of stereopsis with a monitor-based system was compensated for with repeated procedures, but the absence of true 3-dimensional viewing limited use in some cases. Scope repositioning was not as easy as the operating microscope counterbalance mechanism, and focusing was more cumbersome. These relative limitations minimized as experience was accumulated.

An exoscope has been developed for microneurosurgery with outstanding image quality and ease of manipulation that compares favorably with the microscope for many procedures. Refinement in the scope holder and the addition of 3-dimensional image display will improve user satisfaction. The current configuration is best suited for spinal neurosurgery and with refinement should have widespread application in neurosurgery.