BACKGROUND/ PURPOSE: The association of intrahepatic biliary cysts in biliary atresia (BA) after hepatic portoenterostomy has drawn the attention of many pediatric surgeons and has become an important subject in clinical management, but the incidence and causes of this association are not well known. METHODS: During the last 14 years, we operated on 33 BA patients by hepatic portoenterostomy. Five patients could not be followed up over a 1-year period, so the remaining 28 patients had their intrahepatic structure investigated by periodic magnetic resonance imaging (MRI), and were confirmed at autopsy. The authors also reviewed the preoperative conditions of these patients and the histopathologic changes in the liver biopsy and the porta hepatis specimens taken at portoenterostomy. RESULTS: (1) Intrahepatic biliary cysts were found in 6 of the 28 patients studied (21%). Of 16 patients who were operated on after 1989 and are undergoing follow-up by MRI, 4 (25%) had cysts. (2) Five of the 6 patients with cysts had episodes of cholangitis before or at the time of discovery of the cysts, and 4 of them have had their jaundice reappear since the discovery of the cysts. (3) The intralobular spaces (ILS) with fibrosis and the number of bile ducts had increased in the group with cysts compared with those in the group without cysts. (4) The bile duct maximum size in the porta hepatis (PH) was similar in the groups with and without cysts, but a denudation of the mucosal lining cells in the duct, and a fibrosis and inflammation around the duct had increased in the group with cysts compared with those in the group without cysts. (5) Statistically, the fibrosis found in the ILS and the inflammation around the bile duct found in the PH were induced as a correlative factor affecting cyst formation. CONCLUSIONS: The association of intrahepatic biliary cysts in BA after portoenterostomy is frequent. The fibrous change in the ILS and the inflammatory process around the bile ducts might be potential causes of cyst formation.
BACKGROUND/ PURPOSE: The association of intrahepatic biliary cysts in biliary atresia (BA) after hepatic portoenterostomy has drawn the attention of many pediatric surgeons and has become an important subject in clinical management, but the incidence and causes of this association are not well known. METHODS: During the last 14 years, we operated on 33 BA patients by hepatic portoenterostomy. Five patients could not be followed up over a 1-year period, so the remaining 28 patients had their intrahepatic structure investigated by periodic magnetic resonance imaging (MRI), and were confirmed at autopsy. The authors also reviewed the preoperative conditions of these patients and the histopathologic changes in the liver biopsy and the porta hepatis specimens taken at portoenterostomy. RESULTS: (1) Intrahepatic biliary cysts were found in 6 of the 28 patients studied (21%). Of 16 patients who were operated on after 1989 and are undergoing follow-up by MRI, 4 (25%) had cysts. (2) Five of the 6 patients with cysts had episodes of cholangitis before or at the time of discovery of the cysts, and 4 of them have had their jaundice reappear since the discovery of the cysts. (3) The intralobular spaces (ILS) with fibrosis and the number of bile ducts had increased in the group with cysts compared with those in the group without cysts. (4) The bile duct maximum size in the porta hepatis (PH) was similar in the groups with and without cysts, but a denudation of the mucosal lining cells in the duct, and a fibrosis and inflammation around the duct had increased in the group with cysts compared with those in the group without cysts. (5) Statistically, the fibrosis found in the ILS and the inflammation around the bile duct found in the PH were induced as a correlative factor affecting cyst formation. CONCLUSIONS: The association of intrahepatic biliary cysts in BA after portoenterostomy is frequent. The fibrous change in the ILS and the inflammatory process around the bile ducts might be potential causes of cyst formation.