Combination of Donor Anthropometrics With Recipient Imaging to Improve Matching in Liver Transplantation

Perspectives and Tools in Liver Graft Assessment: A Transformative Era in Liver Transplantation

Liver transplantation is a critical and evolving field in modern medicine, offering life-saving treatment for patients with end-stage liver disease and other hepatic conditions. Despite its transformative potential, transplantation faces persistent challenges, including a global organ shortage, increasing liver disease prevalence, and significant waitlist mortality rates. Current donor evaluation practices often discard potentially viable livers, underscoring the need for refined graft assessment tools. This review explores advancements in graft evaluation and utilization aimed at expanding the donor pool and optimizing outcomes. Emerging technologies, such as imaging techniques, dynamic functional tests, and biomarkers, are increasingly critical for donor assessment, especially for marginal grafts. Machine learning and artificial intelligence, exemplified by tools like LiverColor, promise to revolutionize donor-recipient matching and liver viability predictions, while bioengineered liver grafts offer a future solution to the organ shortage. Advances in perfusion techniques are improving graft preservation and function, particularly for donation after circulatory death (DCD) grafts. While challenges remain-such as graft rejection, ischemia-reperfusion injury, and recurrence of liver disease-technological and procedural advancements are driving significant improvements in graft allocation, preservation, and post-transplant outcomes. This review highlights the transformative potential of integrating modern technologies and multidisciplinary approaches to expand the donor pool and improve equity and survival rates in liver transplantation.

Graft reduction in adult liver transplantation: indications, techniques, and outcomes

PURPOSE

Graft reduction can be a patient's graft-saving option to avoid large-for-size (LFS) syndrome. This study aimed to summarize the literature on graft reduction in adult liver transplantation and to demonstrate the technique of H67 graft hepatectomy.

METHODS

The technique, shown in a didactical video, entails an ex situ posterior sectionectomy under hypothermic perfusion. The right hepatic vein is identified, and the transection line follows the right hepatic fissure. The Glissonean pedicles are ligated during parenchymal transection.

RESULTS

A narrative review of the literature yielded 7 studies. A total of 15 liver grafts were reduced in adult liver transplantations. Most of the reductions were ex situ (11/15 [73.3%]). Graft reduction entailed an H67 sectionectomy in 10 cases and an H23 sectionectomy in 1 case. In situ reduction included 1 right hepatectomy (H5678), 2 H67 sectionectomies, and 1 H23 left lateral sectionectomy. The duration of the ex situ reduction averaged 56 minutes (median: 40.5 minutes; IQR, 33.0-130.0), and the graft weight-to-recipient weight ratio decreased from 3.57% ± 0.40% to 2.70% ± 0.50% after graft reduction. The average cold ischemia time was 390 minutes (IQR, 230-570). There was no liver retransplantation.

CONCLUSION

Graft reduction in adult liver transplantation may be necessary to avoid LFS syndrome. Ex-situ H67 posterior sectionectomy represents the easiest graft reduction hepatectomy and is able to minimize the occurrence of graft compression while leaving enough functional liver parenchyma.

From large-for-size to large-for-flow: A paradigm shift in liver transplantation

Liver graft-recipient matching remains challenging, and both morphologic and hemodynamic characteristics have been shown to be relevant indicators of post-transplant outcomes. However, no combined analysis is available to date. To study the impact of both morphologic and hemodynamic characteristics of liver grafts on transplantation outcomes, we retrospectively evaluated all consecutive 257 liver transplantations with prospective hemodynamic measurements from 2017 to 2020 in a single-center perspective. First, a morphologic analysis compared recipients with or without large-for-size (LFS), defined by a graft/recipient weight ratio >2.5% and excluding extreme LFS. Second, a hemodynamic analysis compared recipients with or without low portal flow (LPF; <80 mL/min per 100 g of liver tissue). Third, an outcome analysis combining LPF and LFS was performed, focusing on liver graft-related morbidity (LGRM), graft and patient survival. LGRM was a composite endpoint, including primary nonfunction, high-risk L-Graft7 category, and portal vein thrombosis. Morphologic analysis showed that LFS (n=33; 12.9%) was not associated with an increased LGRM (12.1% vs 9.4%; p =0.61) or impaired graft and patient survival. However, the hemodynamic analysis showed that LPF (n=43; 16.8%) was associated with a higher LGRM (20.9% vs 7.5%, p = 0.007) and a significantly impaired 90-day graft and patient survival. Multivariable analysis identified LPF but not LFS as an independent risk factor for LGRM (OR: 2.8%; CI:1.088-7.413; and p = 0.03), 90-day (HR: 4%; CI: 1.411-11.551; and p = 0 .01), and 1-year patient survival. LPF is a significant predictor of post-liver transplantation morbi-mortality, independent of LFS when defined as a morphologic metric alone. Consequently, we propose the novel concept of large-for-flow, which may guide graft selection and improve perioperative management of LPF.