Clinical Application of Thorotrast Myelography and Subsequent Forced Drainage*
In a high percentage of surgical lesions of the spinal cord, no changes in the bony structure are demonstrable by the ordinary methods of roentgen examination, even when the clinical findings are suggestive of a certain cord level. In the interest of an accurate preoperative diagnosis, so essential to the surgeon, it is necessary to resort to the use of certain substances which, when injected intraspinally and followed by roentgen examination, will outline the offending lesion and establish not only its location but often its character.
The radio-opaque oils, particularly lipiodol, have been favored for clinical usage, but not without certain reservations as to their adequacy as diagnostic media. It is obvious that they do not meet the requirements of the ideal intraspinal agent, namely: (1) that it should be non-toxic, (2) of sufficient atomic weight to cast a clear-cut shadow, (3) non-irritating, (4) miscible with the spinal fluid, and (5) readily eliminated (Coe, Otell and Hedley1).
Because it most nearly fulfilled the qualifications of the ideal medium, thorotrast attracted much attention, particularly since the work of Schoenfeld and Freeman2, and Twining and Rowbotham3 in their application of this agent to encephalography and ventriculography with apparently good results but with evidence of meningeal irritation. In spite of the mild irritative reaction that attends the introduction of thorotrast, like any other foreign body, into the subarachnoidal space and also the fact that the body is forced to dispose of the injected material through its own agencies, this substance gave such a. . .