Acute and chronic acalculous cholecystitis associated with aortic dissection.

Acalculous cholecystitis is a rare but life-threatening disease, but its pathogenesis is not fully revealed yet. We experienced two acalculous cholecystitis cases associated with aortic dissection. In Case 1, acalculous cholecystitis occurred just after the exacerbation of the aortic dissection. Laparotomy showed necrotized cholecystitis with fresh thrombi formation. Case 2 developed acalculous cholecystitis on the 65th hospital day of aortic dissection. Laparotomy revealed the perforation of the gallbladder. Histological study revealed fibrosis and hemosiderosis in the subserosal layer. The histological findings of these two patients are quite different: Case 1 is acute ischemic and Case 2 is chronic ischemic. While a few cases of acute ischemic cholecystitis have been reported previously, chronic acalculous cholecystitis (CAC) has not been documented. History of aortic dissection could be a risk factor of acute and CAC due to relatively decreased splanchnic blood flow.