肝内結石症の疫学

The Epidemiology of Hepatolithiasis in Japan

要旨　肝内結石症の疫学について，その年次的推移，地域的差異，年齢分布などの面から検討を行い，その成因との関連についても考察を行った．年次的推移では，近年肝内結石症は減少してきているようであるが，コレステロール系胆石の増加が著明であり，みかけ上の減少とも考えられた．地域的な面では，やはり農漁村地区に多く都市部では少ない疾患であることに変わりはないが，成因との関連よりビリルビン系胆石の原因との関連が注目された．年齢分布でみると，一般の胆石症とは異なり，若年者にも多くみられ，先天的因子の関与も考えられる．

　The incidence of hepatolithiasis is higher in the East Asia than in the other part of the world such as Europe and the United States. It is higher in the rural district than in the city, but the nature of pathogenesis is still unknown. In this paper, we have studied the epidemiology of hepatolithiasis with clinical and autopsy cases. In the surgically treated 1,512 gallstone cases, 28 cases had hepatolithiasis, an incidence of 1.9 percent. In the 712 gallstone cases which underwent autopsy, 26 cases had hepatolithiasis, an incidence of 3.7 percent. Recently, proportion of hepatolithiasis in gallstone is declining due to the increasing incidence of cholesterol gallstone, however, the absolute number of the patients with hepatolithiasis has never been declining.

　There has been an extreme difference in the incidence of hepatolithiasis between the rural district and the city. The incidence in the rural district was extremely higher. In addition, the incidence of bilirubin gallstone was higher than that of cholesterol gallstone in the rural district.

　Regarding this finding, it is suggested that hepatolithiasis and bilirubin gallstone are related in their pathogenesis.