Investigate the rate and types of biliary complications post-liver transplant and the management via endoscopic treatment in Bulgaria.

A retrospective observational study was conducted on 37 patients who underwent orthotopic liver transplantation (OLT) from a deceased donor over five years (from May 2021 until Sept 2025). Biliary complications were assessed through patient history, lab tests, and imaging (computed tomography (CT)/magnetic resonance cholangiopancreatography (MRCP). Endoscopic treatment was performed via endoscopic retrograde cholangiopancreatography (ERCP). We utilized frequency distribution to analyze the occurrence of various biliary complications and descriptive statistics to assess the proportion of patients who achieved successful endoscopic treatment.

Fourteen patients (approximately 37.8%) experienced biliary complications - had signs of cholangitis, jaundice or pruritus, presented with elevated liver enzymes with or without high bilirubin levels, had CT/MRCP showing biliary changes. Early complications (within 6 months) were noted in 11 patients; late complications (after 6 months) in 3. Main complication was stenosis of the biliary anastomosis (10 patients), the remaining 4 patients experienced the following complications: 2 had necrosis at the biliary anastomosis site, 1 presented with a leakage, and 1 had both leakage and stenosis at the biliary anastomosis. Nine patients were treated endoscopically, 4 surgically, and 1 conservatively. Eight of these 9 patients had stenosis of the anastomosis. The endoscopic group showed a resolution rate of 66.7% (6 out of 9), 2 other patients are still undergoing treatment, and 1 patient unfortunately passed away due to complications related to thrombosis of the arterial anastomosis and sepsis. Six patients were treated with multiple plastic stents, and 3 patients received self-expandable metal stents (SEMS). For the group treated with plastic stents, an average of 5 ERCP procedures and 3 or 4 stents were required for successful treatment. In the SEMS group, 2 patients achieved resolution of the stenosis after a single ERCP session for stent insertion, with the SEMS removed after 10 months. The use of single-operator cholangioscopy (SOC) aided complex cases (3 patients). 

The incidence of biliary complications has decreased in recent years (from 42.8% in previous years (2007-2019, no OLT were performed in 2020) to 37.8% in the study period). The predominant issue identified was stenosis of the biliary anastomosis, which occurred in the majority of cases. Endoscopic treatment emerged as a key approach. Notably, the use of SEMS proved effective, with successful outcomes achieved after fewer ERCP sessions compared to plastic stents which leads to lower risk of infections in this immunocompromised cohort of patients and also lower costs. However, the small sample size limits definitive conclusions. The implementation of single-operator cholangioscopy (SOC) also showed promise in addressing complex cases. Further studies with larger cohorts are warranted to refine treatment protocols and improve patient outcomes in this challenging area of post-transplant care.