Better allocation of donated livers in transplants

January 20, 2014, Plataforma SINC
Volume rendering image created with multi detector computed tomography (MDCT) source image./ Credit: I-Chen Tsai-Wikipedia

Researchers at the University of Cordoba (Spain) have developed a system that measures compatibility between donors and the most serious receivers in liver transplants. This is a mathematical method that includes the experience of almost 1,500 donations registered in transplant units in Spain and the United Kingdom.

The allocation criteria for organs in Spain, the worldwide transplant leader and example, are set according to territorial and clinical aspects that guarantee altruism in donations and equality of access. Nevertheless, there are still some aspects of the allocation of organs that could be improved, according to a study by researchers in the University of Cordoba.

In the case of liver transplants, the properties of the owner such as the blood group -which must match that of the receiver- as well as the seriousness of the patient, measured with the so-called Model for End Stage Liver Disease (MELD), are taken into account. The result is a number obtained from the patient's bilirubin, creatinine and prothrombin time figures that serve to prioritise the waiting list according to the risk of mortality in the following three months.

"In this donor/receiver assessment, other variables that would optimise the compatibility between them and that could be a decisive factor in the results of the transplant are not assessed," explained María Pérez Ortiz, one of the authors. "We therefore propose an improvement that favours the principles of justice for the receiver and of utility of the transplant, matches the waiting times to the mortality risk on the active list and improves survival."

Specifically, the team, comprising researchers in the University and Reina Sofía Hospital in Cordoba, has developed an allocation model that would allocate each organ to each of the most serious receivers from whom the one with the maximum survival probability is chosen. The details are published in the journal Applied Soft Computing.

"This system respects the principle of urgency required by the MELD model and discriminates between receivers on a waiting list who theoretically would have a better prognosis but who, transplanted with a specific liver, would benefit from a better survival," explain the researchers, adding, "The interactions set up in the are more complex than those arising simply from matching a good donor with a very serious receiver."

Automated learning techniques have been used to create the model, an area of computing that imitates the brain when it comes to learning from experience and from known data. In fact, the application is based on 38 variables (age, gender, , existence of diabetes, arterial hypertension, etc.) taken from almost 1,500 donor/receiver pairs in seven Spanish transplant units and one in King's College Hospital, London.

Together with the survival time of the transplanted liver, these variables serve to train the model which is then used to match donor/receiver pairs with a given survival time, specifically, whether the transplant survives for 15 days after the operation, for three months, for a year or more, so that it is very useful to assess the suitability of the allocations made.

According to data published this week by the Ministry of Health, Social Services and Equality, 1,093 were carried out in 2013 in Spain, where the historic series adds up to almost 22,000.

Explore further: Spain transplants hit record despite crisis

More information: M. Pérez-Ortiz, M. Cruz-Ramírez, M.D. Ayllón-Terán, N. Heaton, R. Ciria, C. Hervás-Martínez. "An organ allocation system for liver transplantation based on ordinal regression". Applied Soft Computing 14: 88-98, 2014.

Related Stories

Spain transplants hit record despite crisis

January 13, 2014
Surgeons in Spain transplanted a record number of organs in 2013, the government said Monday, keeping the country world leader in the field despite heavy health spending cuts.

Most liver transplant candidates receive donation offers

October 22, 2012
Most liver transplant candidates who died or were removed from the transplant list actually received one or more liver donation offers, according to a recent UCSF study.

Living donor liver transplantation improves survival over deceased donor transplants

September 27, 2011
New research shows liver transplantation candidates without hepatocellular carcinoma (HCC) derive a greater survival benefit from a living donor liver transplant (LDLT) than waiting for a deceased donor liver transplant (DDLT). ...

Could deceased heart attack victims expand donor pool?

November 11, 2013
Researchers from the U.K. suggest that using organs from donors after circulatory death (DCD) who also suffered a previous cardiac arrest out of the hospital environment could expand the pool of available livers for transplant. ...

Changes to distribution of livers for transplant proposed

September 9, 2011
Transplantation specialists have proposed changes to the allocation and distribution of organs used for liver transplants. The recommended policy modifications take into account the scarcity of available organs, ensuring ...

Split liver transplants for young children proven to be as safe as whole organ transplantation

June 10, 2013
A new study shows that when a liver from a deceased adult or adolescent donor is split into two separate portions for transplantation—with the smaller portion going to a young child and the larger to an adult—the smaller ...

Recommended for you

Best of Last Year—The top Medical Xpress articles of 2017

December 20, 2017
It was a good year for medical research as a team at the German center for Neurodegenerative Diseases, Magdeburg, found that dancing can reverse the signs of aging in the brain. Any exercise helps, the team found, but dancing ...

Pickled in 'cognac', Chopin's heart gives up its secrets

November 26, 2017
The heart of Frederic Chopin, among the world's most cherished musical virtuosos, may finally have given up the cause of his untimely death.

Sugar industry withheld evidence of sucrose's health effects nearly 50 years ago

November 21, 2017
A U.S. sugar industry trade group appears to have pulled the plug on a study that was producing animal evidence linking sucrose to disease nearly 50 years ago, researchers argue in a paper publishing on November 21 in the ...

Female researchers pay more attention to sex and gender in medicine

November 7, 2017
When women participate in a medical research paper, that research is more likely to take into account the differences between the way men and women react to diseases and treatments, according to a new study by Stanford researchers.

Drug therapy from lethal bacteria could reduce kidney transplant rejection

August 3, 2017
An experimental treatment derived from a potentially deadly microorganism may provide lifesaving help for kidney transplant patients, according to an international study led by investigators at Cedars-Sinai.

Exploring the potential of human echolocation

June 25, 2017
People who are visually impaired will often use a cane to feel out their surroundings. With training and practice, people can learn to use the pitch, loudness and timbre of echoes from the cane or other sounds to navigate ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.