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Ann Surg Open
Ann Surg Open
AS9
Annals of Surgery Open
2691-3593
Wolters Kluwer Health, Inc. Two Commerce Square, 2001 Market Street, Philadelphia, PA 19103

AOSO-D-24-00115
00024
10.1097/AS9.0000000000000475
3
Letter to the Editor
Comment on “Age Matters: What Affects the Cumulative Lifespan of a Transplanted Liver?”
Akabane Miho MD *
Imaoka Yuki MD, PhD *
Nakayama Toshihiro MD *
Sasaki Kazunari MD *
* From the Division of Abdominal Transplant, Department of Surgery, Stanford University Medical Center, Stanford, CA.
Reprints: Kazunari Sasaki, MD, Division of Abdominal Transplant, Department of General Surgery, Stanford University School of Medicine, 1265 Welch Rd, Stanford, CA 94305. Email: sasakik@stanford.edu.
29 7 2024
9 2024
5 3 e475e475
20 5 2024
27 5 2024
Copyright © 2024 The Author(s). Published by Wolters Kluwer Health, Inc.
2024
https://creativecommons.org/licenses/by-nc-nd/4.0/ This is an open-access article distributed under the terms of the Creative Commons Attribution-Non Commercial-No Derivatives License 4.0 (CCBY-NC-ND), where it is permissible to download and share the work provided it is properly cited. The work cannot be changed in any way or used commercially without permission from the journal.

OPEN-ACCESSTRUE
SDCT
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pmcWe read the article titled “Age Matters: What Affects the Cumulative Lifespan of a Transplanted Liver?” with great interest.1 The concept of cumulative lifespan of a transplanted liver introduced by Wehrle et al is both innovative and intriguing, offering a fresh perspective on the impact of age in liver transplantation studies. However, there are 2 critical points that need careful consideration.

First, as the authors themselves discuss in the limitations, recent cases lack sufficient follow-up for graft survival. This leads to an underestimation of overall graft survival in their study. The study population includes cases up to 2022, meaning grafts transplanted in that year would all appear to have a survival of less than 2 years, significantly below the reported overall median graft survival of 4.7 years. To address this skew, the study population should ideally exclude cases within the last 4.7 years from the evaluation point to ensure more reliable results. The authors clearly demonstrate that the focus of this study is mostly relevant to transplants occurring in the 1990s to 2000s and does not accurately reflect recent conditions. Therefore, setting the end time of the study population at least 4.7 years prior to the evaluation point would enhance the reliability of the results.

Second, the interpretation of the findings warrants caution. The authors state that the results justify using older donor livers regardless of donation type, even in sicker recipients with limited options. However, this seems to be an overstatement. Using publicly available data from the United Network for Organ Sharing (UNOS) registry, we evaluated graft survival for transplants from deceased donors aged over 60 during the same period (1988–2021). In our analysis, we limited the study population to cases with donor age and graft survival data as defined by the authors. Our analysis showed different results from the authors’ Figure 2H, indicating that graft survival in recipients of livers from donors aged over 60 is significantly worse compared to those from younger donors (Supplemental Figure 1, see http://links.lww.com/AOSO/A396). While it is quite impressive that about half of donor organs achieve a lifespan comparable to the general population despite the stress of the donation process and preservation, caution is still necessary. Our team has previously reported that assigning older donors to younger recipients can worsen graft survival.2 The importance of donor–recipient age matching should be still considered in decision-making. Therefore, the claim regarding the general acceptability of older donors appears to be overly optimistic.

Nevertheless, the idea of the cumulative lifespan of a transplanted liver holds significant potential for advancing future outcome research on the relationship between liver transplantation and donor age. I commend the authors for their efforts in this study.

Supplementary Material

Disclosure: The authors declare that they have nothing to disclose.

Supplemental digital content is available for this article. Direct URL citations appear in the printed text and are provided in the HTML and PDF versions of this article on the journal’s Web site (www.annalsofsurgery.com).
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REFERENCES

1. Wehrle CJ Maspero M Pinna AD . Age matters: what affects the cumulative lifespan of a transplanted liver? Ann Surg. doi: 10.1097/SLA.0000000000006259
2. Snyder A Kojima L Imaoka Y . Evaluating the outcomes of donor-recipient age differences in young adults undergoing liver transplantation. Liver Transpl. 2023;29 :793–803.36847140
