Post-operative heparin reduces early venous thrombotic complications after orthotopic paediatric liver transplantation

Background - Despite significant improvements in surgical techniques and medical care, thrombotic complications still represent the primary cause of early graft failure and re-transplantation following paediatric liver transplantation. There is still no standardized approach for thrombosis prevention. Materials and methods - The study aimed to evaluate the effectiveness of early intravenous unfractionated heparin started 12 hours postoperatively at 10 UI/kg per hour and used a retrospective "before and after" design to compare the incidence of early thrombotic complications prior to (2002-2010) and after (2011-2016) the introduction of heparin in our institute. Results - From 2002 to 2016, 479 paediatric patients received liver transplantation in our institution with an overall survival rate over one year of 0.91 (95% CI: 0.87-0.94). Of 365 eligible patients, 244 did not receive heparin while 121 did receive heparin. We reported a lower incidence of venous thrombosis (VT) in the group treated with heparin: 2.5% (3/121) vs 7.9% (19/244) (p=0.038). All clinical and laboratory variables considered potential risk factors for VT were studied. By multivariate stepwise Cox proportional hazards models, heparin prophylaxis resulted significantly associated to a reduction in VT (HR=0.29 [95% CI: 0.08-0.97], p=0.045), while age <1 year was found to be an independent risk factor for VT (HR=2.62 [95% CI: 1.11-6.21]; p=0.028). Discussion - Early postoperative heparin could be considered a valid and safe strategy to prevent early VT after paediatric liver transplantation without a concomitant increase in bleeding. A future randomised control trial is mandatory in order to strengthen this conclusion.