Liver Exchange

Boston College, Chestnut Hill MA

Investigators

Abstract

Liver transplants can save the lives of people with liver failure, but the need for transplants exceeds the number of donors. As a result, lives can be saved if we find better ways to use all potential donors. This award funds research that builds on previous efforts to use economic theory to improve outcomes for transplant patients. The team will focus on new theories and methods that can be applied to the unique aspects of liver transplant from living donors. Donors have two lobes (left and right) and can donate one. The left lobe is smaller, and donating this lobe is less risky for the donor. However, the lobe must be large enough to support the recipient. Tissue compatibility is also an issue. Many willing donors either cannot donate to their loved one or can only do so by making a larger, riskier donation. The team wants to develop methods that will make it possible to match more patients with donors while also minimizing donor risks. The project will require new technical methods beyond previous work in organ (kidney) exchange. This project develops new ideas in economic theory and proposes specific methods that can be implemented in clearinghouses that can match donors with recipients. The award therefore has the potential to save lives. The project will proceed in several distinct stages. The first will consider the size compatibility issue assuming that each recipient is matched to one living donor. The second stage will model a medically feasible alternative: a recipient needing a large liver might be matched with two donors who each donate a small lobe. In this case the recipient receives two donor organs. The research team will first develop an exchange method assuming that each recipient has two loved ones who are willing to donate (at least one tissue incompatible) and will be matched with two donors. The third stage examines whether or not even better outcomes might be possible if unbalanced exchanges are allowed; that is, a patient may provide only one donor (with a large liver and therefore a large donation) and receive two small donations. The team will develop new theoretical tools in mechanism design, using discrete and continuum graphs with multi-dimensional lattice compatibility requirements to model size compatibility and blood type compatibility.