Hilar biliary cysts in hepatic transplantation. Report of three symptomatic cases and occurrence in resected liver grafts

Hilar cysts are infrequent post-transplant biliary tract complications. Thirteen cases were discovered among 393 consecutive liver transplants (2.6 %). Three (0.60 %) were symptomatic (obstructive jaundice) while the other ten were found by systematically searching in the hilum in a series of 129 consecutive, resected grafts at retransplantation or autopsy (n = 54). Two types of cysts were detected: in eight grafts (1.6 %), these were blind unilocular cavities with viscid mucous content, located adjacent to the biliary tract anastomoses. These had been inadvertently created as a result of the sequestered remnant cystic duct after cholecystectomies and biliary tract reconstructions, where a double-barreled common duct and long cystic duct had been present in the donor liver, These mucoceles ranged from 0.5 to 5.5 cm in diameter (median 1.7 cm). The three symptomatic cases were diagnosed by imaging techniques 3.5 years after transplantation; however, this type of cyst was found as early as the 2nd month post-transplantation when detected in lost liver grafts. Five livers (1%), lost between 5 months and 2.8 years post-transplantation, showed cystically dilated peribiliary glands, sometimes with multilocular, and occasionally multiple, cavities ranging from 0.5 to 2 cm in diameter (median 0.8 cm). This type of cyst was asymptomatic and located adjacent to the left, right, or common hepatic ducts. Threads were found near four cysts, suggesting that surgical injury may have been responsible for obstructing the neck of the glands. With the increasing number of long-term survivors of liver transplantation, unless preventive surgical methods are implemented, the number of symptomatic cysts of these origins can be expected to grow. Transplantation teams should, therefore, be aware of these potential causes of biliary tract complications.