Published online Jun 28, 2017. doi: 10.4254/wjh.v9.i18.823
Peer-review started: February 9, 2017
First decision: March 7, 2017
Revised: March 28, 2017
Accepted: April 18, 2017
Article in press: April 19, 2017
Published online: June 28, 2017
To investigate the additional clinical impact of hepatic ischaemia reperfusion injury (HIRI) on patients sustaining acute kidney injury (AKI) following liver transplantation.
This was a single-centre retrospective study of consecutive adult patients undergoing orthotopic liver transplantation (OLT) between January 2013 and June 2014. Early AKI was identified by measuring serum creatinine at 24 h post OLT (> 1.5 × baseline) or by the use of continuous veno-venous haemofiltration (CVVHF) during the early post-operative period. Patients with and without AKI were compared to identify risk factors associated with this complication. Peak serum aspartate aminotransferase (AST) within 24 h post-OLT was used as a surrogate marker for HIRI and severity was classified as minor (< 1000 IU/L), moderate (1000-5000 IU/L) or severe (> 5000 IU/L). The impact on time to extubation, intensive care length of stay, incidence of chronic renal failure and 90-d mortality were examined firstly for each of the two complications (AKI and HIRI) alone and then as a combined outcome.
Out of the 116 patients included in the study, 50% developed AKI, 24% required CVVHF and 70% sustained moderate or severe HIRI. Median peak AST levels were 1248 IU/L and 2059 IU/L in the No AKI and AKI groups respectively (P = 0.0003). Furthermore, peak serum AST was the only consistent predictor of AKI on multivariate analysis P = 0.02. AKI and HIRI were individually associated with a longer time to extubation, increased length of intensive care unit stay and reduced survival. However, the patients who sustained both AKI and moderate or severe HIRI had a longer median time to extubation (P < 0.001) and intensive care length of stay (P = 0.001) than those with either complication alone. Ninety-day survival in the group sustaining both AKI and moderate or severe HIRI was 89%, compared to 100% in the groups with either or neither complication (P = 0.049).
HIRI has an important role in the development of AKI post-OLT and has a negative impact on patient outcomes, especially when occurring alongside AKI.
Core tip: Acute kidney injury (AKI) is common after liver transplantation (LT), and has a significant impact on patient outcomes. It is multifactorial in aetiology and has been shown to correlate with the use of higher risk grafts, due to an increased risk of hepatic ischaemia reperfusion injury. In context of the growing use of marginal grafts to meet demands, this study has demonstrated that hepatic ischaemia reperfusion injury was the only variable that predicted early AKI post-LT and that the presence of both HIRI and AKI led to worse clinical outcomes and higher mortality than either complication alone.