ESOT 2011 Report – Liver transplantation: a question of MELD

The model for end stage liver disease (MELD score) is used in many countries to allocate liver grafts to the sickest patients on the waiting list. Several authors have reported unacceptable mortality in recipients with a MELD score ≥30. Therefore, a challenging task is to predict the outcome in high MELD recipients.

Philipp Dutkowski and colleagues from Switzerland and the USA developed a new and simple score system (balance-of-risk, BAR score) by combining worldwide readily available pre-transplant donor and recipient factors, and compared this new score with other prediction systems.

Using a UNOS database, Dutkowski and colleagues first performed a risk analysis in adult (≥18yrs) recipients of Orthotic Liver Transplantation (OLT) in the USA between March 2002 and September 2010 (n=37,255). They excluded DCD liver transplants, living donor, and partial or combined liver transplants. They then calculated a risk score based on logistic regression factors, and validated this score using their own OLT database from January 2003 to October 2010 (n=233). Finally, they compared the new score with other prediction systems including DRI (donor-risk-index), SOFT (survival-outcome following-liver-transplantation), D-MELD (donor-age combined with MELD), and MELD score alone.

The results of the study identified the six strongest predictors of post-transplant survival: recipient MELD score, cold ischaemia time, recipient age, donor age, previous OLT, and life support dependence prior to transplant. The new balance of risk (BAR) score stratified recipients best in terms of patient survival in the UNOS data, as in the European population.

The researchers concluded that “The BAR system provides a new, simple and reliable tool to detect unfavourable combinations of donor and recipient factors, which is readily available prior to decision making of accepting or not an organ for a specific recipient. This score may offer great potential for better justice and utility, as it revealed to be superior to recent developed other prediction scores.”

 

The MELD calculation was further discussed by A. W. Avolio from Torino Italy who with colleagues developed an online prognostic calculator to optimize donor-recipient match.

Optimization of donor-recipient match represents one of the major challenges in liver transplantation. The variable donor organ quality and recipient liver disease severity explain the various types of match adopted. Sometimes the match or the mismatch is purely the results of chance. Nevertheless, in the majority of cases surgeons and hepatologists can take the opportunity to combine organ and recipient on the basis of specific risk assessment methods.

In order to develop an algorithm able to guide organ allocation and avoid futile matches (life-expectancy <50% at 5 years) a database was created by Avolio and colleagues and filled with data from 5946 liver transplants performed in 21 Italian Centres during the 2002-2009 period. A web-based prognostic calculator was developed using D-MELD (donor age x biochemical MELD) and other prognostic factors. The calculator is available online at the web address www.d-meld.com (ESOT password: D-MELD123).

Using logistic regression at 3 years the following significant prognostic factors were identified: D-MELD>1628 (OR=2.03; 95%CI 1.44-2.85), recipient age (OR=1.015; 95%CI 1.002-1.028), HCV (OR=1.42; 95%CI 1.11-1.81), HBV (OR=0.69; 95%CI 0.51-0.93), re-transplant (OR=1.82; 95%CI 1.16-2.87). Cox regression analyses performed at 1-90 months confirmed the results.

For a given donor (expressed by donor age) and for 3 potential recipients (expressed by values of biochemical MELD, recipient age, HCV, HBV, portal thrombosis, re-transplant status), the web-site calculates the patient survival at 90 days, 1 year, 3 years and allows the detection of futile matches.

Aviolo concluded “This innovative approach allows the identification of the best patient for each referred donor and avoids futile matches. Use of the d-meld.com web-site could help hepatologists, transplant surgeons and transplant co-ordinators in the everyday practice of matching donor and recipients.”

 

References:

O-122 – LIVER TRANSPLANTATION: WHO SHOULD OR SHOULD NOT DIE? A NOVEL SCORE TARGETING JUSTICE AND UTILITY IN THE MELD ERA. Philipp Dutkowskiet al. Zurich, Switzerland and Baltimore, USA

O-123 – www.D-MELD.com. THE ONLINE PROGNOSTIC CALCULATOR TO OPTIMIZE DONOR-RECIPIENT MATCH. A. W. Avolioet al. Various Italy