Protection of Bile Ducts in Liver Transplantation: Looking Beyond Ischemia

Biliary complications, especially nonanastomotic biliary strictures (NAS), are a major cause of morbidity after orthotopic liver transplantation. Of all donor and recipient characteristics known to increase the risk of developing NAS, the role of prolonged ischemia times is most extensively described in the literature. However, there is increasing evidence that several other, non-ischemia-related factors play a critical role in the pathogenesis of NAS as well. The clinical presentation of NAS may vary considerably among liver transplant recipients, including large variations in time of occurrence, and in location and severity of the strictures. Additional underlying causes such as bile salt toxicity and immune-mediated injury are believed to explain the wide spectrum of biliary strictures after orthotopic liver transplantation. Current and emerging insight in the pathogenesis of NAS and potential targets to reduce biliary injury and preserve bile ducts are discussed in this overview.