Advertisement

Reply to: “Outcomes of living donors are worse than those of matched healthy controls: Is the matching group appropriate?”

Published:February 22, 2022DOI:https://doi.org/10.1016/j.jhep.2022.02.008

      Linked Article

      To the Editor:
      We appreciate the interest of Drs Selzner and Cattral
      • Selzner N.
      • Cattral M.S.
      Outcomes of living donors are worse than those of matched healthy controls: is the matching group appropriate?.
      in our recent study
      • Choi J.Y.
      • Kim J.H.
      • Kim J.M.
      • Kim H.J.
      • Ahn H.S.
      • Joh J.W.
      Outcome of living liver donrs are worse than those of matched healthy controls.
      and their comments, particularly on the matching control groups for living liver donors (LLDs).
      As mentioned, choosing an appropriate matching control group for the LLD group was a major challenge. The National Health Insurance Services (NHIS) and National Health Screening Program (NHSP) data contain ICD-10 codes, related fee for service and medication, individual demographic data etc., but are limited in specific, detailed information related to liver function and imaging study data.
      Although Group II shared similarity to the LLD group, Group II included those with undetected comorbidities, malignancies, hepatic steatosis, or high BMI who were not eligible for living liver donation, therefore, the LLD group was healthier than Group II. We compared the mortality and various clinical outcomes of the LLD group to a matched healthy control group selected from NHSP database who were considered as appropriate liver donors.
      In East Asia (e.g. Korea, Taiwan, and Japan) where the number of liver grafts from deceased donors is low, patients with end-stage liver disease or hepatocellular carcinoma who require liver transplantation (LT) for curative treatment are unlikely to receive deceased donor grafts. Small families, low birth rate, increasing obesity and societal trend towards individualism seem to have lowered the likelihood of finding an appropriate LLD. Thus, if an appropriate healthy LLD is not available, the liver transplantation surgeons in Korea tend to conduct living liver donation surgeries despite donor age or comorbidities, such as drug-controlled diabetes or hypertension, ABO-incompatibility, high BMI, moderate fatty liver, estimated small remnant liver volume or psychological histories. All LLDs receive a mandatory psychiatric evaluation as a psychiatrist’s approval is one of the pre-requisites for living liver donation.
      Nevertheless, the LDLT can continue only when the safety of LLDs is guaranteed. A lot of LDLTs have been conducted globally and many studies focusing on short-term outcomes have been accumulated whereas long-term follow-up outcomes are yet to be reported. In our study, 6 deaths were identified during 6 months after 12,371 living liver donations between 2002 and 2018, yet the direct relation between the death and donor hepatectomy could not be determined due to the limitations of the NHIS database mentioned previously. Most LLDs did not manifest notable short-term postoperative complications and continued their normal activities; hospital visits were rare which led to an absence of long-term follow-up data.
      Our study reported that diabetes, hypertension, and history of depression existed in 3.8%, 5.8%, and 4.6% of the LLDs, respectively, prior to surgery.
      • Choi J.Y.
      • Kim J.H.
      • Kim J.M.
      • Kim H.J.
      • Ahn H.S.
      • Joh J.W.
      Outcome of living liver donrs are worse than those of matched healthy controls.
      Clinical outcomes of LLDs with such comorbidities were worse, which we found disconcerting. The incidences of depression, cancer, diabetes, hypertension, cerebrovascular accidents, liver failure, end-stage renal disease and mortality were higher in LLDs during the post-donation period than in Group I, possibly due to the disease that they had before the donation in the LLD group. Nevertheless, sensitivity analysis (Table S6) in our study showed that the mortality of the LLD group with or without comorbidities was comparable with Group I.
      • Choi J.Y.
      • Kim J.H.
      • Kim J.M.
      • Kim H.J.
      • Ahn H.S.
      • Joh J.W.
      Outcome of living liver donrs are worse than those of matched healthy controls.
      The high mortality rate in the LLD group was not dependent on the underlying comorbidities. Considering that the median follow-up duration was 8 years in our study, we expect that longer follow-up may provide us more definitive outcomes.
      Our study revealed that self-harm and cancer are the important causes of death in LLDs. Most LLDs being young and healthy, long-term psychological support and continuous regular medical monitoring after liver donation is necessary. The safety of LLDs cannot be sacrificed for any reason and we need to be vigilant against continued expansion of LLD selection. We believe that not only short-term but also long-term management plans are needed for LLDs.

      Financial support

      The authors received no financial support for this manuscript.

      Authors’ contributions

      JMK, HJK, and JWJ contributed to the writing of this reply letter.

      Conflict of interest

      The authors have no conflicts of interest to declare that pertain to this work.
      Please refer to the accompanying ICMJE disclosure forms for further details.

      Supplementary data

      The following are the supplementary data to this article:

      References

        • Selzner N.
        • Cattral M.S.
        Outcomes of living donors are worse than those of matched healthy controls: is the matching group appropriate?.
        J Hepatol. 2022; 76: 1234-1235https://doi.org/10.1016/j.jhep.2021.12.021
        • Choi J.Y.
        • Kim J.H.
        • Kim J.M.
        • Kim H.J.
        • Ahn H.S.
        • Joh J.W.
        Outcome of living liver donrs are worse than those of matched healthy controls.
        J Hepatol. 2022; 76: 628-638https://doi.org/10.1016/j.jhep.2021.10.031