Biliary complications after orthotopic liver transplantation

The incidence, pathogenesis and management of the most common biliary complications are summarized, with an emphasis on nonanastomotic biliary strictures (NAS) and potential strategies to prevent NAS after liver transplantation.

NAS have variable presentations in time and localization, suggesting various underlying pathogeneses. Early-onset NAS (presentation within 1 year) have shown to be largely related to ischemia-induced bile duct injury, whereas late-onset NAS [>1 year after orthotopic liver transplantation (OLT)] have more immune-mediated causes. Cytotoxic hydrophobic bile salts and impaired biliary HCO3 secretion may also play a role in the occurrence of NAS. Recently, insufficient biliary epithelial regeneration capacity after transplantation has also been suggested to play a major role in the pathogenesis of NAS. A potential strategy to prevent NAS has been proposed to be preservation by machine perfusion instead of classical static cold storage. Although machine perfusion has been shown to be a better preservation method for the liver parenchyma, efficacy in preventing ischemic injury of the biliary epithelium is largely unknown.

The potential advantages of machine perfusion are very promising as it may provide better protection of the vulnerable bile ducts against ischemia-reperfusion injury. Clinical trials will be needed to demonstrate the impact of machine perfusion in reducing the incidence of biliary complications, especially NAS, after OLT.