Cholangiography with a viscous, water-soluble medium; diodrast in methylcellulose.

Abstract

Numerous attempts have been made to develop a water-soluble, viscous contrast medium suitable for bronchography, cholangiography, and similar examinations, without the disadvantages of oily substances such as Lipiodol. Diodrast (and other iodinated organic compounds) dissolved in an aqueous solution of methylcellulose has been investigated rather extensively as a contrast medium for bronchography (3, 7, 10). Recent reports and our own experience would indicate that it is not entirely satisfactory for this purpose in that a greater degree of local anesthesia is required than with Lipiodol, absorption is so rapid that it is difficult to obtain adequate roentgenograms, and there is the possibility that granulomatous lesions may be produced in the lung (11). Diodrast in methylcellulose, however, we have found to be an ideal contrast medium for cholangiography. Of the various concentrations of the two substances which were tried, 35 per cent Diodrast and 1 per cent methylcellulose produced a contrast medium of optimum density and viscosity. No reactions attributable to either Diodrast or methylcellulose have been observed in approximately 100 cholangiographies at the Los Angeles County Hospital during the past year. When given parenterally, Diodrast may give rise to so-called “allergic” reactions of varying degrees. When the Diodrast-methylcellulose mixture is injected into an unobstructed common bile duct, however, it passes into the duodenum with sufficient rapidity that little or none of the Diodrast is absorbed from the biliary system. When the mixture is injected into an obstructed common duct and the T tube clamped off, the Diodrast is absorbed slowly over a period of several hours. Usually the T tube is not clamped and the contrast medium drains off rather rapidly. We do not feel that it is necessary to test for sensitivity to Diodrast before making the injection into the common bile duct, since ordinarily none of the medium is absorbed and no reactions occurred in any of our patients. Furthermore, there is no convincing correlation between tests for sensitivity and reactions to the drug (2, 4, 8, 12). To date, we have used only methylcellulose to increase viscosity. Sodium carboxymethylcellulose may be substituted, however, with some advantage, since its properties are similar to those of methylcellulose, and in addition it can be heat-sterilized (9). Methylcellulose has been used, among other things, as a blood substitute. When administered intravenously, it accumulates in the reticuloendothelial system, from which it is removed slowly. The function of this system may be interfered with when the deposits are extensive. Methylcellulose is excreted by the kidneys and possibly to some degree by the intestinal mucosa (5, 6). It is entirely non-toxic when given by mouth and has been used in the food industry (1,9).