Assessment of causes of early death after twenty years of liver transplantation

Children undergoing early liver re-transplantation for primary non-function have improved survival

BACKGROUND

Primary non-function (PNF) in the early post-LT period in children leads to prolonged hospitalization, high graft loss, and significant mortality. However, there is a paucity of data available on the natural history of children relisted for LT due to PNF, including those who recover graft function and survive with their original allograft.

METHODS

We interrogated the United Network of Organ Sharing (UNOS) database for pediatric LT recipients who were relisted with a primary diagnosis of PNF from 2000 to 2020. Patients >21-year-old and multiple organ transplants were excluded. Logistic regression and Cox proportional hazard models were employed to identify risk factors for early re-transplantation (within 30 days of relisting) and mortality after adjusting for baseline clinical characteristics.

RESULTS

One hundred and eight patients were relisted for LT for PNF during the study period. Twenty-five patients survived beyond 30 days from relisting with their original LT, 76 underwent early re-transplantation, and 7 did not survive. Having a high-risk EBV mismatch (OR 2.03, 95% CI 0.66-6.27) and an elevated donor serum creatinine (OR: 2.19, 95% CI 0.54-8.84) were associated with increased odds of a patient requiring early re-transplantation. Donor characteristics including age, final total bilirubin, final AST/ALT, and final serum sodium, as well as vasopressor use prior to procurement, were not associated with increased odds of early re-transplantation (p > 0.05). Operative characteristics including allograft type and cold-ischemia time were also not associated with early re-transplantation (p > 0.05). Patients undergoing early re-transplantation showed a trend toward improved 1-year graft survival (69% vs 55%, p = 0.24). On multivariable Cox proportional hazards modeling, early re-transplantation was associated with reduced risk of overall patient mortality compared to those who survived with their original LT (HR 0.27, 95% CI 0.12-0.67).

CONCLUSION

Early re-transplantation for PNF is associated with improved patient survival compared with patients who survive with their original LT.

[Validation of APACHE IV score in postoperative liver transplantation in southern Brazil: a cohort study]

BACKGROUND

Liver transplantation is the only curative therapeutic modality available for individuals at end-stage liver disease. There is no reliable method of predicting the early postoperative outcome of these patients. The Acute Physiology and Chronic Health Evaluation (APACHE) is a widely used model for predicting hospital survival and benchmarking in critically ill patients. This study evaluated the calibration and discrimination of APACHE IV in the postoperative period of elective liver transplantation in the southern Brazil.

METHODS

This was a clinical prospective and unicentric cohort study that included 371 adult patients in the immediate postoperative period of elective liver transplantation from January 1, 2012 to December 31, 2016.

RESULTS

In this study, liver transplant patients who evolved to hospital death had a significantly higher APACHE IV score (82.7±5.1 vs. 51.0±15.8; p<0.001) and higher predicted mortality (6.5% [4.4-20.2%] vs. 2.3% [1.4-3.5%]; p<0.001). The APACHE IV score showed an adequate calibration (Hosmer-Lemeshow - H-L=11.37; p=0.181) and good discrimination (Receiver Operator Curve - ROC of 0.797; Confidence Interval 95% - 95% CI 0.713-0.881; p<0.0001), although Standardized Mortality Ratio (SMR=2.63), (95% CI 1.66-4.27; p<0.001) underestimate mortality.

CONCLUSIONS

In summary, the APACHE IV score showed an acceptable performance for predicting a hospital outcome in the postoperative period of elective liver transplant recipients.

The role of autonomic dysfunction in cirrhotic patients before and after liver transplantation. Review of the literature

In patients affected by hepatic cirrhosis, autonomic dysfunction is a common finding; usually it is asymptomatic but it may correlate with increased mortality and morbidity before, during and after liver transplant, due to hemodynamic instability in the course of stressful events like sepsis, gastrointestinal bleeding and reperfusion after transplantation surgery. Hyperdynamic circulation and hepatic dysfunction seem to play a role in the pathogenesis of autonomic dysfunction, even if pathophysiological mechanisms are not completely known. We present a revision of previous literature about prevalence, pathophysiological mechanisms, clinical features, and mortality and morbidity of autonomic dysfunction secondary to hepatic cirrhosis.

The role of liver transplantation or resection for patients with early hepatocellular carcinoma

Liver resection (LR) and liver transplantation (LT) are curative treatments for early hepatocellular carcinoma (HCC), although their performance remains debated. We compared the survival of patients with HCC conforming to the Milan criteria (MC) after LT and LR and analyzed factors affecting clinical outcomes. Between January 2006 and January 2013, 65 and 184 patients received LT and LR for HCCs fulfilling the MC, respectively. Overall survival (OS) and disease-free survival (DFS) rates were compared between the two groups. To investigate effects of liver function and living donor liver transplantation (LDLT) on survival, two subgroup analyses were performed and associations with OS and DFS were examined. We found that OS rates were higher after LT than after LR since 3 years postoperatively. DFS rates were significantly better after LT than after LR. Performance of LR, vascular invasion, and tumor multiplicity were associated with poor DFS, and factors affecting OS included the presence of vascular invasions, liver cirrhosis, and tumor multiplicity. In conclusion, despite of the effects of tumor characteristics on clinical outcomes, LT, including LDLT, should be considered the treatment of choice for patients with HCCs who met the MC. The role of LR is to identify poor prognostic factors through pathological examination.

High early cardiovascular mortality after liver transplantation

Cardiovascular disease (CVD) contributes to excessive long-term mortality after liver transplantation (LT); however, little is known about early postoperative CVD mortality in the current era. In addition, there is no model for predicting early postoperative CVD mortality across centers. We analyzed adult recipients of primary LT in the Organ Procurement and Transplantation Network (OPTN) database between February 2002 and December 2012 to assess the prevalence and predictors of early (30-day) CVD mortality, which was defined as death from arrhythmia, heart failure, myocardial infarction, cardiac arrest, thromboembolism, and/or stroke. We performed logistic regression with stepwise selection to develop a predictive model of early CVD mortality. Sex and center volume were forced into the final model, which was validated with bootstrapping techniques. Among 54,697 LT recipients, there were 1576 deaths (2.9%) within 30 days. CVD death was the leading cause of 30-day mortality (40.2%), and it was followed by infection (27.9%) and graft failure (12.2%). In a multivariate analysis, 9 significant covariates (6 recipient covariates, 2 donor covariates, and 1 operative covariate) were identified: age, preoperative hospitalization, intensive care unit status, ventilator status, calculated Model for End-Stage Liver Disease score, portal vein thrombosis, national organ sharing, donor body mass index, and cold ischemia time. The model showed moderate discrimination (C statistic = 0.66, 95% confidence interval = 0.63-0.68). In conclusion, we provide the first multicenter prognostic model for the prediction of early post-LT CVD death, the most common cause of early post-LT mortality in the current transplant era. However, evaluations of additional CVD-related variables not collected by the OPTN are needed in order to improve the model's accuracy and potential clinical utility.

Transfusion and coagulation management in liver transplantation

There is wide variation in the management of coagulation and blood transfusion practice in liver transplantation. The use of blood products intraoperatively is declining and transfusion free transplantations take place ever more frequently. Allogenic blood products have been shown to increase morbidity and mortality. Primary haemostasis, coagulation and fibrinolysis are altered by liver disease. This, combined with intraoperative disturbances of coagulation, increases the risk of bleeding. Meanwhile, the rebalancing of coagulation homeostasis can put patients at risk of hypercoagulability and thrombosis. The application of the principles of patient blood management to transplantation can reduce the risk of transfusion. This includes: preoperative recognition and treatment of anaemia, reduction of perioperative blood loss and the use of restrictive haemoglobin based transfusion triggers. The use of point of care coagulation monitoring using whole blood viscoelastic testing provides a picture of the complete coagulation process by which to guide and direct coagulation management. Pharmacological methods to reduce blood loss include the use of anti-fibrinolytic drugs to reduce fibrinolysis, and rarely, the use of recombinant factor VIIa. Factor concentrates are increasingly used; fibrinogen concentrates to improve clot strength and stability, and prothrombin complex concentrates to improve thrombin generation. Non-pharmacological methods to reduce blood loss include surgical utilisation of the piggyback technique and maintenance of a low central venous pressure. The use of intraoperative cell salvage and normovolaemic haemodilution reduces allogenic blood transfusion. Further research into methods of decreasing blood loss and alternatives to blood transfusion remains necessary to continue to improve outcomes after transplantation.