Water-Soluble Contrast Myelography Using Meglumine Iothalamate (Conray) with Methylprednisolone Acetate (Depo-Medrol)

Abstract

Since 1922, when Sicard and Forestier (21) first described the technic of myelography with Lipiodol, the search for an ideal contrast medium has continued. Such a contrast medium should be soluble, nontoxic, nonirritating, and hyperbaric and should provide good roentgenographic contrast. Currently, in the United States, insoluble iophendylate (Pantopaque) is widely used, whereas in Scandinavia water-soluble sodium iodomethanesulfonate (abrodil, Skiodan, Kontrast U) is popular. Arachnoiditis and other adverse effects of oil-based insoluble media, such as iophendylate, are well known (2, 3, 8, 10, 11, 13–15, 18, 23–26). The irritating properties of monoiodomethane (6, 7, 12, 22) have necessitated administration of a spinal anesthetic before performance of myelography (9). In 1964, Campbell and his associates (1) reported use of meglumine iothalamate (Conray) for ventriculography and myelography. Their studies demonstrated the low toxicity of this substance. They obtained roentgenograms of good diagnostic quality in 12 patients on whom myelography had been performed with Conray as the contrast medium, but they concluded that muscle spasm and paresthesia occurred with sufficient frequency to limit the usefulness of this material for myelography. The reports of others (4, 5, 16, 17, 19, 20) and our own experience with intrathecal injections of steroids in the treatment of painful reactions involving the cauda equina led to the present study. It was reasoned that if a simultaneously injected steroid preparation would inhibit or reduce the side-effects of a water-soluble contrast medium such as Conray, such a contrast medium might be more ideally suited for myelography. Laboratory Study Although Campbell and his associates had demonstrated the low toxicity of Conray in laboratory animals, a pilot study was done to determine possible harmful effects of intrathecal injections of Conray with various steroid preparations on the spinal cord and cauda equina of dogs. Conray alone, or with dexamethasone (Decadron), methylprednisolone acetate (Depo-Medrol), or cortisone acetate, was injected intrathecally two or three times in 6 mongrel dogs to compound any untoward effect. On pathologic studies no significant harmful effect of the substance was observed, although injection of Decadron consistently produced a painful response from the lightly anesthetized animal. Systemic blood pressure showed consistent transient drop (average 22 mm Hg) after injection of Conray but returned to normal levels within forty-five minutes. Clinical Investigation From July 1966 to May 1967, lumbar myelography was performed on 50 patients at the Veterans Administration Hospital, New Orleans, La., using Conray (meglumine iothalamate) with Depo-Medrol. Technic: The technic of myelography with Conray and Depo-Medrol differs little from the usual one with Pantopaque.