Related Experiment Video
Updated: Oct 23, 2025
Porcine Liver Transplantation Without Veno-Venous Bypass As an Extended Criteria Donor Model
Published on: August 17, 2022
Impact of the acuity circle model for liver allocation on multivisceral transplant candidates
Tommy Ivanics1,2, Rodrigo Vianna3, Chandrashekhar A Kubal4
1Division of Transplant and Hepatobiliary Surgery, Henry Ford Hospital, Michigan, USA.
Insights
The 2020 liver allocation policy change reduced transplant probability for multivisceral transplantation (MVT) patients, particularly adults. This may increase waitlist mortality, highlighting the need for equitable organ allocation for this vulnerable group.
Area of Science:
- Transplantation research
- Organ allocation policy
- Health services research
Background:
- Liver allocation policy was updated on February 4, 2020, replacing Donor Service Areas (DSA) with acuity circles (AC).
- The impact of this policy change on multivisceral transplantation (MVT) waitlist outcomes was previously unknown.
- MVT involves combined liver-intestine transplantation, a complex procedure with unique allocation challenges.
Purpose of the Study:
- To evaluate the impact of the acuity circle (AC) policy on waitlist outcomes for multivisceral transplantation (MVT) candidates.
- To compare 90-day waitlist mortality and transplant probability between the pre-AC and post-AC eras for MVT patients.
- To assess changes in the use of exception points for MVT transplants after the AC policy implementation.
Main Methods:
- Utilized the Organ Procurement and Transplantation Network/United Network for Organ Sharing database.
- Identified adult and pediatric candidates listed for MVT between January 1, 2018, and March 5, 2021.
- Defined two eras: pre-AC (2018-2020) and post-AC (2020-2021) for comparative analysis.
Main Results:
- In adults, post-AC era showed a significantly lower transplant probability (sHR: 0.33, p=0.008) and a trend towards higher mortality (sHR: 8.45, p=0.054).
- Pediatric MVT patients showed similar waitlist mortality and transplant probability between eras.
- The proportion of MVT transplants utilizing exception points decreased significantly post-AC in both adults and pediatric recipients.
Conclusions:
- The acuity circle (AC) policy may negatively impact organ access for adult multivisceral transplantation (MVT) candidates, potentially increasing waitlist mortality.
- Pediatric MVT outcomes remained stable, but reduced exception point use warrants further investigation.
- Ensuring equitable organ allocation for vulnerable MVT patients requires ongoing evaluation and potential policy adjustments.
Abstract:
Liver allocation was updated on February 4, 2020, replacing a Donor Service Area (DSA) with acuity circles (AC). The impact on waitlist outcomes for patients listed for combined liver-intestine transplantation (multivisceral transplantation [MVT]) remains unknown. The Organ Procurement and Transplantation Network/United Network for Organ Sharing database was used to identify all candidates listed for both liver and intestine between January 1, 2018 and March 5, 2021. Two eras were defined: pre-AC (2018-2020) and post-AC (2020-2021). Outcomes included 90-day waitlist mortality and transplant probability. A total of 127 adult and 104 pediatric MVT listings were identified. In adults, the 90-day waitlist mortality was not statistically significantly different, but transplant probability was lower post-AC. After risk-adjustment, post-AC was associated with a higher albeit not statistically significantly different mortality hazard (sub-distribution hazard ratio[sHR]: 8.45, 95% CI: 0.96-74.05; p = .054), but a significantly lower transplant probability (sHR: 0.33, 95% CI: 0.15-0.75; p = .008). For pediatric patients, waitlist mortality and transplant probability were similar between eras. The proportion of patients who underwent transplant with exception points was lower post-AC both in adult (44% to 9%; p = .04) and pediatric recipients (65% to 15%; p = .002). A lower transplant probability observed in adults listed for MVT may ultimately result in increased waitlist mortality. Efforts should be taken to ensure equitable organ allocation in this vulnerable patient population.
