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Human Liver Spheroids from Peripheral Blood for Liver Disease Studies

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Heterogeneous Circles for Liver Allocation.

Nicholas L Wood¹, Amber B Kernodle², Andrew J Hartley³

¹Department of Mathematics, United States Naval Academy, Annapolis, MD.

Hepatology (Baltimore, Md.)

|November 21, 2020

Summary

This summary is machine-generated.

New liver allocation circles, called acuity circles, have been criticized for geographic disparities. This study shows that heterogeneous circles significantly reduce these disparities by accounting for population density and borders.

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Area of Science:

Organ transplantation research
Public health policy
Geographic information systems in healthcare

Background:

The Organ Procurement and Transplantation Network (OPTN) replaced donor service area-based liver allocation with acuity circles in February 2020.
The acuity circles system, based on homogeneous circles around donor hospitals, has faced criticism for not accounting for population density and proximity to borders.

Purpose of the Study:

To design and evaluate heterogeneous circles for liver allocation to reduce geographic disparities in supply/demand ratios.
To compare the variation in supply/demand ratios between proposed heterogeneous circles and existing homogeneous acuity circles.

Main Methods:

Utilized Scientific Registry of Transplant Recipients data from July 2013 to June 2017.
Developed heterogeneous circles considering population density, national borders, and geographic variation in liver supply and demand.
Weighted liver demand by Model for End-Stage Liver Disease (MELD)/Pediatric End-Stage Liver Disease (PELD) scores.

Main Results:

Heterogeneous circles demonstrated significantly lower variation in liver supply/demand ratios compared to homogeneous circles.
A 500 nautical mile homogeneous circle showed 16 times higher variance in supply/demand ratios than the heterogeneous circles.
The median radius of heterogeneous circles was 326 nm, effectively reducing disparities.

Conclusions:

Heterogeneous circles offer a more equitable approach to liver allocation by minimizing geographic disparities.
The proposed system addresses limitations of the current acuity circles, which can create logistical burdens or increase disparity.
Carefully designed heterogeneous circles can improve the fairness of liver transplant allocation.