Endoscopic sonographic evaluation of the thickened gallbladder wall in patients with acute hepatitis

Thickening of the gallbladder wall is often observed during abdominal sonographic examination in patients with acute hepatitis. However, there is rarely an opportunity for a histopathologic analysis of these structural changes. Endoscopic sonography (EUS) can accurately delineate the structure of the gallbladder wall and therefore may be useful for visualizing changes in the gallbladder wall in patients with acute hepatitis. Hence, we prospectively studied the ability of EUS to detect specific structural changes in the gallbladder wall in patients with acute hepatitis and examined the effect of high elevation of serum liver enzyme levels on the gallbladder wall.

A study group of patients diagnosed with acute hepatitis who had gallbladder wall thickening and a control group of patients without acute hepatitis or gallbladder disease underwent EUS between May 1, 1999, and June 1, 2002. EUS was used to measure the thickness of the gallbladder wall and to visualize each of its layers. Serum aspartate aminotransferase (AST) and alanine aminotransferase (ALT) levels of the patients with acute hepatitis were measured at the time of the EUS examination. Statistically significant differences were determined using an independent t test and the chi-squared test. A p value of less than 0.05 was considered statistically significant.

The acute hepatitis group comprised 28 men and 24 women with a mean age of 40.8 years. The control group comprised 25 men and 25 women with a mean age of 45.1 years. The mean gallbladder wall thickness +/- standard deviation in the acute hepatitis group (6.3 +/- 2.6 mm) was significantly greater than that in the control group (1.6 +/- 0.4 mm; p < 0.01). The mean thickness of the gallbladder wall for patients in whom both the AST and the ALT levels were 500 U/l or higher (7.0 +/- 2.6 mm) was significantly greater than that for patients with levels below 500 U/l (5.4 +/- 2.3 mm; p < 0.05). In the acute hepatitis group, EUS showed thickened, well-defined muscular and serosal layers of the gallbladder wall in 24 of the patients and a diffusely thickened gallbladder wall, in which each layer was ill defined, in the other 28 patients. The mean thickness of the gallbladder wall for patients with the pattern of ill-defined layers was significantly greater than that for the patients with the pattern of well-defined layers (p < 0.05). The pattern of ill-defined layers was more common among patients in whom the serum AST and ALT levels were at least 500 U/l than among patients with levels below 500 U/l (p < 0.05).

We propose that gallbladder wall thickening in patients with acute hepatitis is associated with prominent changes in the muscular and serosal layers. Patients with highly elevated serum liver enzyme levels are more likely to have gallbladder wall thickening and disruption of planes between the muscular and serosal layers than are patients with normal liver enzyme levels.