COLORADO SPRINGS – A disproportionate share of donor lungs goes to local, low-priority recipients, according to an analysis of data from the United Network for Organ Sharing.
The current lung allocation system results in a high proportion of donor organs being distributed to low-priority candidates who often receive little survival benefit from their transplant. Meanwhile, higher-priority candidates who might derive more benefit from transplantation continue to die at high rates on the waiting list, Dr. Alexander Iribarne said at the annual meeting of the Western Thoracic Surgical Association.
He presented an argument for the sharing of donor lungs over a broader geographical range in the United States. The analysis involved all 7,171 lung transplants done in the United States between May 2005 and the end of 2010.
May 2005 was chosen as the starting date because that’s when the Lung Allocation Score (LAS) was introduced as a measure for allocating organs on the basis of medical urgency rather than waiting time. An LAS score lower than 50 defines a transplant candidate as low priority, a score of 50-75 is considered intermediate, and an LAS greater than 75 is high priority.
Among the 5,544 transplants that were performed in low-priority recipients, 54% of the donor organs were allocated locally, 17% regionally, and 29% nationally. In contrast, 40% of the 1,016 transplants in recipients with an LAS of 50-75 at the time of surgery were allocated locally, as were 33% of the donor organs used in patients with an LAS greater than 75.
What’s happening is that when an organ becomes available in one of the less-populated local donor service areas, there’s a lower likelihood that a suitable higher-priority candidate will be in place than in a more populous donor service area, said Dr. Iribarne of Columbia University, New York.
As a result, the organ often goes to a local patient with an LAS lower than 50.
The UNOS data showed that in donor service areas having a population of fewer than 6.1 million, nearly 75% of locally allocated donor lungs went to patients with an LAS lower than 50. In local donor service areas with a population in excess of 10.3 million people, a greater percentage of lungs are allocated to higher-priority recipients, according to Dr. Iribarne.
The next step in this research should be to determine whether organ sharing across broader geographical areas results in higher rates of lung allocation to higher-priority candidates and improved survival for those on the waiting list, he added.
Dr. Iribarne declared having no financial conflicts.