Crystalloid flush with backward unclamping may decrease post-reperfusion cardiac arrest and improve short-term graft function when compared to portal blood flush with forward unclamping during liver transplantation Fukazawa K, Nishida S, Hibi T, Pretto EA Jr. Crystalloid flush with backward unclamping may decrease post-reperfusion cardiac arrest and improve short-term graft function when compared to portal blood flush with forward unclamping during liver transplantation. Abstract: During liver transplant (LT), the release of vasoactive substances into the systemic circulation is associated with severe hemodynamic instability that is injurious to the recipient and/or the post- ischemic graft. Crystalloid flush with backward unclamping (CB) and portal blood flush with forward unclamping (PF) are two reperfusion methods to reduce reperfusion-related cardiovascular perturbations in our center. The primary aim of this study was to compare these two methods. After institutional review board (IRB) approval, cadaveric whole LT cases performed between 2003 and 2008 were reviewed. Patients were divided into two groups based on reperfusion methods: CB or PF. After background matching with propensity score, the effect of each method on post-operative graft function was assessed in detail. In our cohort of 478 patients, CB was used in 313 grafts and PF in 165. Thirty-day graft survival was lower, and risk of retransplantation was higher in PF. Multivariable model showed that CB is an independent factor to reduce primary non-function, cardiac arrest and improve 30-d graft survival. Also, the incidence of ischemic-type biliary lesions was significantly higher in the PF group. Reperfusion methods affect intraoperative hemodynamics and post-transplant outcome. CB allows for control over temperature and composition of the perfusate, perfusion pressure, and the rate of infusion. Kyota Fukazawa a , Seigo Nishida b , Taizo Hibi b and Ernesto A. Pretto Jr a a Division of Solid Organ Transplantation, Department of Anesthesiology, Perioperative Medicine and Pain Management, University of Miami Miller School of Medicine, Miami, FL, USA and b Division of Liver and Gastrointestinal Transplant, Department of Surgery, University of Miami Miller School of Medicine, Miami, FL, USA Key words: cardiac arrest – flush – graft function – liver transplant – portal Corresponding author: Kyota Fukazawa, MD, Division of Solid Organ Transplantation, Department of Anesthesiology, Perioperative Medicine and Pain Management, University of Miami Miller School of Medicine, 1611 NW 12th Avenue, D318, Miami, FL 33136, USA. Tel.: +1 (305) 585 7433; fax: +1 (305) 585 7477; e-mail: kfukazawa@med.miami.edu Conflicts of Interest: None. Accepted for publication 24 January 2013 Major advances in the intraoperative management of the liver transplant (LT) recipient over the past two decades have not resulted in reduced incidence of post-reperfusion syndrome (PRS) (1). PRS is defined as major cardiovascular collapse following reperfusion and in some cases, release of large amounts of vasoactive inflammatory factors from the ischemic donor graft due to hypotension or delayed hemodynamic recovery following reperfu- sion, which further aggregates ischemia and reper- fusion-related graft injury (1–4). PRS is multifactorial and is associated with volume shifts (hepatic reservoir), and the release of residual pres- ervation solution saturated with ischemic metabo- lites, including high concentrations of vasoactive proinflammatory mediators in the form of cyto- kines and eicosanoids (originating in post-ischemic activated Kupffer cells), into the recipient systemic circulation (4, 5). Flushing out the retained hy- perkalemic preservation solution and inflammatory mediators, which has been proved to be the most effect way of alleviating PRS, has been routinely utilized during the transplant procedure (2, 6–8). Currently, several flushing methods for each caval anastomosis technique (conventional and piggy- back) have been proposed (e.g., initial portal 492 © 2013 John Wiley & Sons A/S. Clin Transplant 2013: 27: 492–502 DOI: 10.1111/ctr.12130