Small vessel occlusion in acute acalculous cholecystitis.

Ischemia is one mechanism implicated in the pathogenesis of acute acalculous cholecystitis. Gallbladder specimen arteriography was performed to define the comparative status of cystic artery runoff in the macroscopically normal gallbladder (n = 10), in acute gallstone-associated cholecystitis (n = 10), and in acute acalculous cholecystitis (n = 7). Standardized film exposure and quantity of contrast medium administered permitted objective intergroup comparison. Compared to the macroscopically normal gallbladder, specimens of acute gallstone-associated cholecystitis exhibited arterial dilatation and extensive venous filling. In contrast, multiple arterial occlusions, with absent or minimal venous filling, were consistent features of acute acalculous cholecystitis; the degree of arteriographic abnormality for acute acalculous cholecystitis corresponded to the severity of gallbladder pathologic findings. Small vessel occlusion, on the basis of low splanchnic flow or intravascular coagulation, may be a fundamental element in the pathogenesis of acute acalculous cholecystitis.