Cholecystography after Rectal Administration of Ipodate Salts

Abstract

X-ray examination of the biliary system is often necessary in an acutely ill patient. Oral cholecystography and cholangiography may fail in adynamic ileus, upper intestinal obstruction or inflammatory disease, or vomiting which interferes with absorption of the contrast material from the upper intestinal tract. An intravenous study may be contraindicated because of previous reactions. The rectal route of administration of biliary contrast material offers an alternative approach and led to our evaluation of salts of Ipodate.2 Since the venous drainage of both the upper and lower intestinal tracts is mainly through the portal system, the rectal administration of biliary contrast agents anatomically favors the same venous route to the liver as does the oral. The clinical, pharmacologic, and chemical properties of the salts of Ipodate have been reported by several investigators (3–6). The structural formulas of these salts are shown in Figure 1. Because both the sodium and calcium salts of Ipodate are heat-sensitive and decompose at room temperature when in solution or suspension, they must be freshly prepared before administration. Following the oral intake of these salts, unaltered forms are found in the urine and the bile (48 per cent excreted in the urine in twenty-four hours). Excretion products in the form of metabolites with an intact ring structure and strongly bound iodine are found chiefly in the bile and in the urine. Fecal excretion is small (4.8 per cent). Maximum blood concentrations following oral administration are reached in two to three hours. After twenty-four hours only a minute amount can be measured in the blood stream (0.4 per cent). Material and Methods Thirty-five examinations were performed in 34 subjects (TABLE I). These patients were in no distress, and for the most part they were recovering from elective nonbiliary surgery; in a few, symptoms suggested biliary-tract disease. From a plastic compressible container a fresh preparation of a 60 cc aqueous solution of 6 g of sodium Oragrafin was introduced rectally in 17 cases; a fresh preparation of 6 g of calcium Oragrafin in 18. Each patient was urged to retain the contrast material until the examination was completed. Films were exposed at intervals until the biliary system had been visualized adequately or until six hours had elapsed from the time of administration of the contrast medium. Results Rectal retention was definitely more successful with the calcium Oragrafin than with sodium Oragrafin (Table II). Nine of the 17 subjects receiving the sodium Oragrafin expelled the contrast agent prematurely, but 16 retained it for at least thirty minutes. Only 2 of those receiving the calcium preparation expelled it prematurely. Over 90 per cent of the patients had an urge to evacuate, regardless of the contrast agent. The two materials are compared as to visualization of the biliary system in Table III.