martes, 3 de septiembre de 2019

Waiting for a liver transplant

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By Dr. Ananya Mandal, MDReviewed by April Cashin-Garbutt, MA (Editor)

When a patient presents with end stage liver disease or liver failure he or she may be considered for a liver transplantation. The first step in this is often a rigorous assessment and being placed on a waiting list. 1-5

Evaluation and management for being placed on the waiting list

The patient’s liver disease undergoes a detailed evaluation.

The patient’s general health condition and ability to withstand a major surgery is evaluated.

Usually a liver specialist or hepatologist and a transplant surgeon along with other specialists like heart specialist, infectious disease specialists, and chest specialists are involved in this assessment. In addition, a social worker and psychiatrist meet with the patient as well as the family for motivation and support.

General work up includes chest X ray, routine blood and urine tests and electrocardiography (ECG). These determine general fitness as well as fitness to withstand general anesthesia and the major surgery.

Other tests include tests for viral hepatitis, HIV infection, liver function tests, blood coagulation tests, blood group and type.

Patients with drug or alcohol problems need to be helped to develop a plan prior to transplant to prevent a relapse after the operation.

Allocation of the organ from deceased donors

Once a patient has been accepted for liver transplant and undergoes the initial evaluation they are placed on the waiting list. Usually a national system like the United Network for Organ Sharing (UNOS) organizes collection and distribution of deceased donor organs along with organizations like Organ Procurement Organizations. Each patient on the list are listed as per their height, body weight and blood group.

Model for End Stage Liver Disease (MELD)

The final allocation is made based on a system called the Model for End Stage Liver Disease (MELD). MELD involves a few simple blood tests including creatinine (for kidney health), bilirubin (liver function assessment) and INR (blood coagulation profile assessment). These values are then put into a formula that gives the MELD Score.

This helps to determine the patient’s place on the waiting list. There are extra points for emergency requirements like hepatocellular carcinoma.

The MELD score usually increases as the liver disease worsens in the person on the waiting list. Calculated MELD scores range from 6 to 40. A MELD score can predict 3-month and 1-year mortality or risk of death in most patients with chronic liver disease.

The disadvantages of MELD includes the fact that it is based on short term mortality risk and may not be beneficial for those who are not at imminent risk of death but may benefit with a transplantation including those with compensated or stable liver cirrhosis.

In very urgent cases like drug over dose and acute liver failure, decisions for transplantation have to be made in a matter of days and this is usually made following the King's College criteria.

Pediatric End-Stage Liver Disease (PELD)

For children (less than 12 years of age) a similar formula called PELD (Pediatric End-Stage Liver Disease) exists. It also considers other factors like growth retardation in the children and ages less than 1 year for short time survival differences. The PELD score utilizes serum albumin and bilirubin levels and INR.

The system aims to direct organs to the sickest patients awaiting liver transplantation so as to reduce the rates of deaths while on the list. In spite of efforts, the continuing shortage of deceased donor organs makes the situation difficult.

Over the last two decades the need for donor livers has risen by 90% while the number of new organs donated has not risen by same proportions and has remained almost same as twenty years back.

Advice for patients while waiting

While waiting on the list patients are advised to stay as healthy as possible by eating a healthy balanced diet, taking regular exercise, completely avoiding alcohol, not smoking etc.

An average waiting time for a liver transplant is 149 days for adults and 86 days for children.

Being on the waiting list may predispose to anxiety and depression. It is found that one in four people waiting for a liver transplant have symptoms of moderate to severe depression. Counselling and help should be sought in these cases.