Myelography with Pantopaque and a New Technic for Its Removal

Abstract

As the treatment of intraspinal protrusion of intervertebral disks becomes more common, increasing efforts are being made to find a simple and accurate but safe objective method for the diagnosis of this disorder. Without entering into a detailed discussion, it is safe to state that neither air, lipiodol, nor thorotrast has proved to be the ideal contrast medium. With air there is often insufficient contrast for clear definition of minor protrusions. With lipiodol the removal of the oil is often inadequate and at times uncomfortable for the patient. Removal of thorotrast is time-consuming and usually incomplete, so that its use is not without risk. In an effort to find a more satisfactory medium, Warren, Strain, Plati, and associates (1, 2) developed ethyl iodophenylundecylate, a mixture of isomers obtained by the addition of iodobenzene to ethyl undecylate in the presence of aluminum chloride. It contains 30.5 per cent of iodine in firm organic combination. It is called “Pantopaque.” The chemistry and the clinical uses of this product were described at the 1942 meeting of the Radiological Society of North America. These investigators state that Pantopaque is slowly absorbed from the spinal canal—3 c.c. being absorbed within a year. It is a clear, colorless oil, less viscid and lighter than lipiodol but heavier than spinal fluid. It is considered to be inert, and so far there have been no reports that it produces an irritation of the meninges. Because of these properties, Warren and his associates were able to aspirate it more easily from the spinal canal and recommended it as a medium for myelography. The product was manufactured by the Eastman Kodak Company, and its distribution was limited to the Armed Forces during the trial period. The second clinical report was made by Spurling and Thompson (3), who used Pantopaque in over 200 cases. Their results were so satisfactory that “Pantopaque myelograms are made routinely on all disk patients at the Walter Reed General Hospital, where surgery is contemplated.” They, like the Warren group, removed the oil by aspiration with a syringe. The purpose of this paper is (1) to relate our experiences with Pantopaque; (2) to describe a new and satisfactory method for the removal of the oil; (3) to comment briefly on the indications for spinal myelography. Pantopaque in our experience has been a satisfactory contrast medium for spinal myelography. It is of about the same opacity and hangs together in one mass almost as well as lipiodol. The glass ampule in which it comes contains 3 c.c., a sufficient quantity. Its use has produced no reactions of which either we or the patients are aware. Its great advantage lies in the fact that it is much easier to remove from the spinal canal than lipiodol. All in all, we consider it superior to other contrast media and will continue to use it until something better is developed. The radiographic examination is done in the usual way.