Assessment of safety and feasibility of spinal endoscope in the thoracic and lumbar region: a cadaveric study.

BACKGROUND Endoscope has been used far less in the spinal region than in the intracranial cavity. One of the reasons is its safety and feasibility has not been established. To evaluate its safety and feasibility, we performed preliminary cadaveric study prior to clinical endoscopic intervention in the thoracic and lumbar spinal canal. METHODS The endoscope that had a directable tip with external diameters of 2.2mm was used in this study. The endoscope was inserted percutaneously in the lumbar region (lumbar puncture method) in nine cadavers and was advanced rostrally under endoscopic monitoring. In advancing the endoscope to the upper thoracic region, dorsal, lateral and ventral route was applied. When the endoscope was advanced to the upper thoracic region, vertebral canal from Th 1 to L4 was opened to examine whether there were any injuries to spinal cord and nerves. RESULTS The endoscope could be manipulated and advanced under endoscopic image in the lumbar region. However, the filum terminale could not be detected under endoscopic view. In the thoracic region, the endoscope could be advanced in dorsal and lateral route. However, in advancing the endoscope in ventral route, the endoscope could not be advanced more rostrally. In cadavers that the endoscope was advanced in dorsal and lateral route, macroscopic and microscopic investigation revealed no injuries including compression marks or trace of cord were observed on the surface of the spinal cord and nerves. CONCLUSIONS From this preliminary cadaver study, the safe route to advance the endoscope from the lumbar to the thoracic region was established and possibilities of clinical interventions in safe methods could be suggested.