Perioperative Management of the Recipient of the Extended Criteria Cadaveric Donor Liver (ECDL)

Hemodynamic recovery following postreperfusion syndrome in liver transplantation

OBJECTIVES

The authors' current understanding of the phenomenon of significant and sustained decrease in arterial pressure following liver graft reperfusion (postreperfusion syndrome [PRS]), is derived from relatively small observational reports, and no large scale analysis of PRS exists up to date. This study investigated its incidence, risk factors, temporal course of hemodynamic recovery, and its impact on functional graft outcome.

DESIGN

Retrospective observational study of 1,024 electronic records of orthotopic liver transplant recipients.

SETTING

Major transplant center.

MEASUREMENTS

Out of 1,024, 715 records satisfied the inclusion criteria. Data were analyzed by multivariable Cox's proportional hazard model to identify risk factors for PRS. Hemodynamic recovery patterns and functional graft outcomes were compared between the cohorts of interest (intraoperative PRS) and control (no intraoperative PRS) after propensity score-matching. Association between donor risk index and hemodynamic recovery after hepatic artery reperfusion was analyzed by a multivariable regression model.

RESULTS

The overall incidence of PRS was 31.6% with associated mortality of 0.3%. Independent risk factors for PRS included older donor age, higher donor risk index, and lower central venous pressure at reperfusion. Hemodynamic recovery after PRS following portal vein reperfusion was delayed until hepatic artery reperfusion. The slope of hemodynamic recovery, expressed as %MAP/min, correlated negatively with donor risk index (p=0.014). Immediate and 1-year graft survival rates were similar in both cohorts.

CONCLUSIONS

Host hemodynamic response to graft reperfusion appeared to be phasic: initial abrupt hypotension after portal vein reperfusion was followed by a period of gradual decline of blood pressure until hepatic artery reperfusion, and sustained hemodynamic recovery afterwards. The slope of hemodynamic recovery correlated negatively with the donor risk index. PRS was not associated with deterioration of post-transplant graft survival and function.

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

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.

The effect of methylene blue during orthotopic liver transplantation on post reperfusion syndrome and postoperative graft function

BACKGROUND/PURPOSE

In orthotopic liver transplantation (OLT), a major component of the post-reperfusion syndrome is hypotension, which may lead to additional graft liver ischemia-reperfusion injury. A proposed mechanism of reperfusion hypotension is the massive induction of oxidative stress triggering the release of pro-inflammatory mediators, including nitric oxide (NO). Methylene blue (MB) is an inhibitor of inducible NO synthase and an NO scavenger that has been shown to attenuate reperfusion hypotension. Of note, recent reports have shown that the exogenous administration of NO during OLT significantly improved the recovery of the graft liver. Therefore, we sought to investigate the effects of MB on the functional recovery of the graft liver following OLT.

METHODS

We analyzed retrospective data from 715 patients who underwent OLT between 2003 and 2008. We classified patients into those who received a 1-1.5 mg/kg intravenous bolus of MB immediately prior to reperfusion (MB group) and those who did not (control group). Propensity score matching was used to adjust for differences between patients who received intraoperative MB and those who did not, and these data were used to determine the association between a single MB bolus during OLT and postoperative graft dysfunction.

RESULTS

Our study cohort consisted of 715 OLT patients, of whom 105 received MB and 610 did not. After propensity score matching, demographic and donor data were similar in the two groups, except for the older age of recipients in the MB group (55.5 ± 0.9 vs 53.1 ± 0.8 years, p = 0.026). No differences were seen in mean arterial pressure changes after reperfusion and no differences were found in vasopressor requirements (bolus or infusion) or transfusion requirements. In addition, there was no significant difference in the incidence of primary nonfunction, retransplantation within 60 days, acute rejection, or graft survival between the groups by multivariate analysis or Kaplan-Meier survival analysis.

CONCLUSIONS

In our study, the administration of MB at 1-1.5 mg/kg immediately prior to reperfusion did not prevent post-reperfusion hypotension and did not decrease vasopressor usage or transfusion requirements after reperfusion. Also, MB did not have any impact on postoperative graft function. These findings may argue against the routine use of MB during OLT.