Are Biliary Complications after Liver Transplantation a Problem Caused by Surgery?

Abstract

Aims: Impairment of the peribiliary plexus is one of the potential pathomechanisms discussed in the context of non-anastomotic strictures - also known as ischemic type biliary lesions (ITBL). Very recently we identified vascular and mural necroses of the bile duct to occur as early as after preservation. ITBL are clearly related to the occurrence of this damage. Are “surgical” complications such as stenosis and leakage of the biliary anastomosis associated with microcirculatory impairment? Methods: Bile duct specimens of 93 donors were retrieved during LT (abundant portion of graft ducts), fixed in PBS-buffered formalin and processed according to standard protocols. The following features were assessed: epithelial loss (EL), subendothelial edema (SE), mural hemorrhage (MH), thrombi formation (TF) inflammatory changes (IC), damage to arterioles (AD) and mural necrosis (MN). Results: EL was demonstrable in 92/93 specimens. In 77/92 more than 50% of the mucosa were affected. IC were detected in 85%. 69% showed SE, 20% marked MH and 79% TF in the bile ducts. Most remarkably, 42% of donor bile ducts showed necrotic areas of the arterioles and in 46% necroses of the bile duct wall were demonstrable. In 19 of 93 patients (20%) ITBL developed and in 21 (23%) stenoses or leakages occurred. Complications were associated with arteriolonecrosis and mural damage (p< 0.0001) of the ductal wall demonstrable before transplantation. In the logistic regression analysis, in addition to preexisting arteriolonecrosis, donor age was a significant predictor for the development of biliary complication (p< 0.0001 and 0.017). Conclusions: According to our morphological study analyzing donor bile ducts immediately after preservation it may be concluded, that not only ITBL are a pre-existing problem caused be microcirculatory impairment of the bile ducts but also “surgical” complications such as leakage and stenosis. Even if this result needs further confirmation, the central role of mural microcirculation of the bile duct deserves closer attention. The rate of true surgical biliary complications may be much lower than assumed so far.