Caroli disease is a rare congenital health condition characterized by the dilation of intrahepatic bile ducts. These are ducts whose primary function is to transport bile from the liver. This condition exists in two forms – Caroli disease and Caroli syndrome. While in the first form bile ducts are dilated, the second form is more complex, and it is characterized by the “presence of bands of fibrous tissue in the liver (congenital hepatic fibrosis) and high blood pressure in the portal artery (portal hypertension…associated, in ways that are not well understood, with polycystic kidney disease, and, in severe cases, liver failure” (National Organization of Rare Diseases (NORD), n.d., para. 1). This paper discusses the origin, prevalence, clinical indications, prognosis, and treatment options of Caroli disease coupled with how the condition appears sonographically, and how sound waves will react with the type of tissue the pathology demonstrates.
The origin of this disease is associated with Jacques Caroli, a French gastroenterologist, who for the first time in 1958, described this condition in Paris, France. According to Smolović et al. (2018), Caroli first described this disease as “a rare congenital condition characterized by localized or diffuse, non-obstructive, saccular or fusiform, multifocal segmental dilatation of the intrahepatic bile ducts” (p. 49). Initially, the disease was poorly diagnosed due to the lack of proper diagnosis tools, but with advanced technology, sonographic machines are now available for a comprehensive diagnosis.
Even though this disease is rare, its prevalence is currently at 1 case per 10,000 live births, with the general population having 1 case per 1,000,000. However, Smolović et al. (2018) argue that with the emergence of better imaging techniques, the prevalence of this disease could be more than indicated in the available literature. While the condition affects both genders equally, it is highly prevalent among young individuals with those aged less than 30 years, accounting for more than 80 percent of cases.
Clinical indications of Caroli disease include the unusual widening of intrahepatic bile ducts, due to the formation of choledochal cysts (fluid-filled lumps). As such, the bile ducts inside the liver experience recurring inflammation. People with this disease could also have abscesses and stones in the ducts, which lead to abdominal pains accompanied by fever. In some cases, albeit rarely, this condition could be characterized by jaundice, hepatomegaly, mucous membranes, and yellowing of the skin.
The prognosis of this condition varies widely based on the severity and frequency of the infection of bile ducts. Additionally, individuals suffering from associated diseases, such as various liver diseases and bile duct cancer, are likely to develop this disease. The available treatment options depend on the presenting signs and symptoms. For example, if the inflammation of bile ducts is being caused by bacterial infections, it could be treated with antibiotics. Similarly, those presenting cholestasis could be treated using fat-soluble vitamin supplements. However, in severe cases, surgery could be recommended to remove the stones and reverse the widening of the affected bile ducts. In cases where patients have portal hypertension, various drugs could be given to stop bleeding accompanied with portosystemic shunting whereby blood flow is rerouted (National Center for Advancing Translational Sciences, 2017). However, with recurrent complications due to portal hypertension, liver transplantation might be necessary.
On ultrasound, Caroli disease “appears as intrahepatic cystic anechoic areas, which may include fibrovascular bundles, stones, and linear bridging or septa” (Wang et al., 2015, p. 281). The bundles observed in this case are made of hepatic arteries and portal veins. However, according to Wang et al. (2015), ultrasound imaging has low accuracy levels of less than 30 percent, and thus it becomes difficult to differentiate cysts associated with Caroli disease and other related conditions, such as polycystic liver disease. Therefore, there is a need to use other advanced diagnostic tools, including computed tomography scans (CT scan) and magnetic resonance imaging (MRI), as both have high accuracies of 71.4 percent and 77.8 percent, respectively (Wang et al., 2015).
Sound waves in ultrasound imaging will react differently with the type of tissue the pathology demonstrates. For instance, if the fibrovascular bundles are not thick, the sound waves will be absorbed and pass through, thus sending back faint echoes, appearing black on the display screen. However, in case stones or calcifications have formed, the sound waves will be prevented from penetrating, and thus they will bounce off and send back patterns of echoes shown on the screen as light-colored images.
Caroli disease is a hereditary condition, which was first described by a French gastroenterologist, Jacques Caroli, in 1958. Widening of bile ducts in the liver characterizes this disease, which could be caused by various factors, including bacterial infection. The disease affects young people disproportionately as those aged under 30 years account for over 80 percent of the diagnosed cases, with a prevalence rate of 1 in 1,000,000 persons. Treatment options include surgery and liver transplant depending on the presenting symptoms. Ultrasound is mainly used for diagnosis, but MRI and CT scans could offer better results.
National Center for Advancing Translational Sciences. (2017). Caroli disease. Web.
NORD. (N.d.). Caroli disease. Web.
Smolović, B., Muhović, D., Hodžić, A., Bergant, G., & Peterlin, B. (2018). The role of next-generation sequencing in the differential diagnosis of Caroli’s syndrome. Balkan Journal of Medical Genetics, 21(2), 49-53.
Wang, Z. X., Li, Y. G., Wang, R. L., Li, Y. W., Li, Z. Y., Wang, L. F., Yang, H. Y., Zhu, Y., Wang, Y., Bai, Y. F., He, T. T., Zhang, X. F., & Xiao, X. H. (2015). Clinical classification of Caroli’s disease: An analysis of 30 patients. HPB, 17(3), 278-283.