"Picture-in-picture" endoscopic images in the microscope.
The authors describe a new piece of equipment that enables simultaneous monitoring of the endoscopic image and unilateral microscopic image; that is, "picture-in-picture" images for endoscope-assisted microsurgery. The system is simple and purely optical, consisting of light-weight semi-rigid fibers and a special adapter incorporated in the microscope. Throughout the initial neurosurgical procedures in which it was tested, the system proved particularly useful for inspecting the facial nerve behind the acoustic neurinoma and for observing the contact between arteries and the facial nerve during decompressive procedures for hemifacial spasm.