Recipient warm ischemic time negatively influences biliary complications and graft survival -a single center retrospective analysis

Sophie Reichelt¹Alexander Semaan¹Philipp Lutz²Jörg C. Kalff¹Cornelius J. Van Beekum^3*Steffen Manekeller^1*

• ¹Department of General, Visceral, Vascular and Thoracic Surgery, University Hospital Bonn, Bonn, Germany
• ²Department of Internal Medicine I, University Hospital Bonn, Bonn, Germany
• ³Clinic for General, Visceral and Transplant Surgery, Center for Surgery, Hannover Medical School, Hanover, Germany

Recipient warm ischemia time (rWIT) in liver transplantation (LT) -which is defined as the time from removal of the graft from cold storage until reperfusion with portal and/or arterial blood flow -has been linked to negative outcomes. Biliary complications, particularly biliary strictures, are a major cause of morbidity after LT. However, the relationship between rWIT in donation after brain death (DBD) LT and biliary strictures has not been well explored. This single-center study retrospectively analyzed data from 162 DBD-LT recipients (2013)(2014)(2015)(2016)(2017)(2018)(2019)(2020)(2021)(2022). Patients were divided into two groups: rWIT ≤30 minutes (n=33) and rWIT >30 minutes (n=129). Livers did not undergo any in situ or ex situe machine perfusion techniques. Biliary complications occurred at similar rates in both groups (p=0.5). Biliary strictures tended to be more common in the rWIT >30 minutes group, although without statistical significance Bile duct strictures were more common in the WIT >30-minute group (40% vs. 24%; p=0.1). The median serum bilirubin levels on day 5 were significantly higher in the rWIT >30-minute group (5.2 (IQR 2.6, 8.9) mg/dl vs. 3.7 (IQR 1.9, 5.9) mg/dl; p=0.013). Patients with rWIT >30 minutes also required significantly more blood transfusions intraoperatively (p=0.021). There was a high tendency for higher severe complication rates in the rWIT >30-minute group, which was not significant (58% vs. 39%; p=0.054). Prolonged rWIT in LT was associated with a trend toward a higher incidence of bile duct strictures and elevated liver enzymes. However, due to the retrospective design and risk of selection bias, rWIT should be interpreted as one of several contributing factors. Our findings suggest that minimizing rWIT may support better outcomes, but causality cannot be definitively established.