A variety of pathological conditions may affect the clivus and the craniovertebral junction (CVJ). These include congenital disorders, chronic inflammation, neoplasms, infections, and posttraumatic conditions that could all result in CVJ compression and myelopathy Endoscopic-assisted procedures have been further developed for CVJ decompression and they have now become conventional approaches. The aims of the present study were:(1) to compare "radiological" and "surgical" nasoaxial lines (NAxLs); (2) to introduce an analogous radiological line as a predictor of the superior extension of the transoral approach (palatine inferior dental arch line (PIA); (3) to compare the "radiological" nasopalatine line (NPL) with the "surgical" NPL (SNPL) and surgical PIA (SPIA); (4) to compare "our" SNPL with the NAxL; and (5) to find possible radiological reference points to predict, preoperatively, the maximal extent of superior dissection for the transoral approach (SPIA).
Keywords: Craniovertebral junction; Endoscopy; Transnasal approach; Transoral approach.