Liver Transplantation Evolves with Model for Prioritizing Candidacy

Liver transplantation moved into the realm of possibility in 1963 when a patient lived briefly after the first transplant performed in Denver, CO. This provided hope that the procedure could eventually be entirely successful. Surgeons at the University of California, Los Angeles (UCLA) first attempted an experimental procedure for liver transplant in 1968, albeit with fleeting success. Liver transplantation remained experimental through the 1970s, when patient survival held at approximately 25 percent at one year post-surgery. After cyclosporine became available in the 1980s and immunosuppression improved, patient survival increased to 70 percent at one year, and liver transplantation evolved into what is now a standard clinical treatment.

As Dumont-UCLA’s Transplant and Liver Cancer Center has performed more than 5,000 liver transplants since 1983, surgeons at the facility have conducted a comprehensive retrospective review of those procedures to identify the factors that influence survival. Additionally, the researchers sought to determine whether the model for end-stage liver disease (MELD) scoring system — which was created in 2002 for prioritizing liver transplant candidacy — is effective. MELD uses blood clotting, kidney function, and liver function testing to evaluate each patient’s acuity and move the sickest patients with the highest scores to the top of the recipient list. The review included children and adults who had no active alcohol or drug use.

The researchers recognized significant improvements in perioperative care and surgical technique, and they also reported that modern short- and long-term management approaches have improved surgical outcomes. Their study proved that the MELD scoring system has created a fundamental shift in liver donation and recipient selection, and it accurately predicts three-month mortality in patients with end-stage liver disease and prioritizes liver allocation to recipients in the most critical condition.

Additionally, wait-list mortality within a year has declined by 3.5 percent with no impact on one-year graft and patient survival, which has been a concern and criticism ever since MELD was developed. The “sickest first” allocation policy was proven reasonable.

Among their findings:

• Compared to the pre-MELD era, UCLA’s post-MELD recipients were older, had greater median MELD scores (28 versus 19), greater need for pre-transplant hemodialysis (34 percent versus 12 percent), and higher rates and duration of pre-transplant hospitalization.
• More than one-third of UCLA’s post-MELD adult recipients received pre-transplant renal replacement therapy, compared to 21 percent in other regional centers and 11 percent nationally.
• Recipients’ acuity increased and donor quality decreased post-MELD. Regardless, overall graft and patient survival improved significantly, and 30-day mortality and the need for early re-transplantation fell.
• Improved post-MELD survival was most profound in cancer patients and patients with high acuity.
• A MELD score of 34 or greater was an independent predictor of survival, as it increased risk of death by 39 percent.

The researchers noted that although the use of MELD scores confers certain advantages, safeguards to avoid futile transplants in recipients with high MELD scores are still needed. They predicted that strategies to induce tolerance, invigorate the donor pool, and ameliorate long-term side effects of immunosuppression will further reduce wait-list mortality and improve post-transplantation outcomes.