Intact stones or fragments? Potential pitfalls in the imaging of patients after biliary extracorporeal shock wave lithotripsy.

Ultrasound is used after extracorporeal shock wave lithotripsy of gallbladder stones to assess fragmentation. In many patients with apparently successful fragmentation, the posttreatment studies show an intraluminal, echogenic focus within the gallbladder, with posterior acoustic shadowing characteristic of an intact stone. Cholesterol gallstones were fragmented in vitro by means of lithotripsy, and the sonographic appearance of the fragmented stones was followed up over time to study factors that might affect the process. After lithotripsy, fragments settled and produced an echogenic focus with posterior shadowing indistinguishable from the appearance of an intact stone. These experimental observations led to the development of a clinical maneuver to overcome the diagnostic pitfalls posed by the reaggregation of stone fragments in situ. This rollover maneuver helps distinguish between intact stones and fragments, and prevents both diagnostic errors in follow-up and unnecessary retreatment.

Fecal triglyceride excretion is not excessive in pancreatic insufficiency.

Steatorrhea can result from maldigestion or malabsorption. As the pathophysiology underlying impaired digestion differs from impaired absorption, it is important to differentiate these two disorders. It is generally accepted that patients with maldigestion excrete an excessive amount of triglyceride and patients with malabsorption excrete an excess of the lipolytic product of triglyceride, fatty acid. The two-step Sudan stain has been used as a simple test to differentiate these disorders. The validity of the test has not yet been established. In this study, fecal fatty acid and triglyceride were measured after extraction and thin-layer chromatographic separation. Our results indicate that in adult patients with pancreatic insufficiency, the fecal triglyceride content does not differ from the controls. However, a fivefold to sixfold increase in fecal fatty acid content in patients with pancreatic insufficiency was revealed. As patients with maldigestion do not excrete an excess of undigested triglyceride, it is not possible to differentiate maldigestion from malabsorption by quantifying fecal triglyceride and fatty acid.

Sudan stain of fecal fat: new insight into an old test.

The 72-h fecal fat determination is used as the gold standard to document the presence of steatorrhea. Although the Sudan stain for fecal fat is advocated as a sensitive screening test, a quantitative correlation between the 72-h fecal fat quantitation and the fecal Sudan stain is lacking. This study was designed to examine the staining properties of different classes of purified lipids in an experimentally defined artificial matrix, and to elucidate the reasons for the lack of quantitative correlation between these two tests. Our results indicate that the "neutral fat" stain without acidification or heating identifies triglyceride; and at an appropriate pH, the "neutral stain" also identifies fatty acid. The "split fat" stain with acidification and heating identifies both triglyceride and fatty acid. After acidification, fatty acid soaps are converted to the nonionized fatty acid. Thus, fatty acid soaps can be identified indirectly as fat droplets that are stained by the split fat stain. Although cholesterol is stained with Sudan stain after heating, upon cooling, cholesterol forms crystals of anhydrous cholesterol, making its staining pattern distinct. Neither the neutral fat nor the split fat stain can detect phospholipid or cholesteryl ester. The 72-h fecal fat determination is a measure of the total fatty acid content after a specimen is saponified. The resulting fatty acids are derived from a variety of endogenous and exogenous sources, including free fatty acids, soaps of fatty acids, triglycerides, cholesterol esters, and phospholipids. Therefore, the 72-h fecal fat quantitation does not differentiate between the primary sources of the measured fatty acid. It is concluded that the 72-h fecal fat determination is not specific for documenting triglyceride (fat) malabsorption. Until new methods are developed that specifically measure fecal triglyceride and fatty acid, the Sudan stain of fecal fat appears to be a more specific method for detecting the presence of triglyceride and fatty acid in a matrix.

Benign pneumoperitoneum in a patient with celiac sprue.

A patient with celiac sprue was found to have an asymptomatic pneumoperitoneum. Prompt recognition that the pneumoperitoneum was due to pneumatosis cystoides intestinalis prevented unnecessary surgical intervention. Severe mucosal disease of the small intestine can be associated with an asymptomatic pneumoperitoneum.

Aneurysmal dilatation of a patent umbilical vein masquerading as a pancreatic pseudocyst: CT characteristics.

A large cystic mass in a jaundiced patient had the appearance by sonography of a pancreatic pseudocyst. Computed tomography showed that the mass represented an aneurysmally dilated patent umbilical vein.

Bile salt binding properties of commonly used gastrointestinal drugs: maalox, carafate, and questran.

We have validated a method to measure bile salt binding by Maalox (aluminum hydroxide and magnesium hydroxide), Carafate (sucralfate), and Questran (cholestyramine) in vitro. The method used in this study involves a correction for adherent water volume and thus provides a correct measure of bile salt binding. With this approach, we described the binding properties of Maalox, Carafate, and Questran. The bile salt binding capacities of Carafate and Maalox are limited and do not have physiological or pharmacological significance. On the other hand, we found that Questran has substantial bile salt binding capacity. At the recommended dosage, Questran could deplete the total bile salt pool. We also found that Carafate, although not used as an antacid, has buffering capacity (maintaining a pH of solution in the range 4.2-4.8) which might contribute to its effectiveness as an ulcer treatment drug.

Hepatocanalicular injury associated with vitamin A derivative etretinate. An idiosyncratic hypersensitivity reaction.

A patient with pustular psoriasis developed jaundice, peripheral blood eosinophilia, and biochemical evidence of hepatocanalicular dysfunction four weeks after the initiation of etretinate therapy. A liver biopsy specimen showed bile duct damage, a periportal inflammatory infiltrate composed of neutrophils, eosinophils and lymphocytes, canalicular cholestasis, and focal hepatocyte necrosis. Clinical exclusion of other possible etiologic factors coupled with near resolution of the biochemical abnormalities within six weeks after complete discontinuation of the drug indicates that etretinate may induce an idiosyncratic hypersensitivity reaction. This is the first report to document etretinate associated bile duct injury.