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©The Author(s) 2018. Published by Baishideng Publishing Group Inc. All rights reserved.
Effect of transplant center volume on post-transplant survival in patients listed for simultaneous liver and kidney transplantation
Rohan M Modi, Dmitry Tumin, Andrew J Kruger, Eliza W Beal, Don Hayes Jr, James Hanje, Anthony J Michaels, Kenneth Washburn, Lanla F Conteh, Sylvester M Black, Khalid Mumtaz
Rohan M Modi, Andrew J Kruger, Department of Internal Medicine, Ohio State University Wexner Medical Center, Columbus, OH 43210, United States
Dmitry Tumin, Department of Anesthesiology and Pain Medicine, Nationwide Children’s Hospital, Columbus, OH 43205, United States
Eliza W Beal, Kenneth Washburn, Sylvester M Black, Department of General Surgery, Division of Transplantation, Ohio State University Wexner Medical Center, Columbus, OH 43210, United States
Eliza W Beal, Don Hayes Jr, James Hanje, Anthony J Michaels, Kenneth Washburn, Lanla F Conteh, Sylvester M Black, Khalid Mumtaz, Comprehensive Transplant Center, Ohio State University Wexner Medical Center, Columbus, OH 43210, United States
Don Hayes Jr, Section of Pulmonary Medicine, Nationwide Children’s Hospital, Columbus, OH 43205, United States
James Hanje, Anthony J Michaels, Lanla F Conteh, Khalid Mumtaz, Department of Internal Medicine, Division of Gastroenterology, Hepatology and Nutrition, Ohio State University Wexner Medical Center, Columbus, OH 43210, United States
Author contributions: Modi RM, Tumin D, Kruger AJ, Beal EW, Hayes Jr D, Hanje J, Michaels AJ, Washburn K, Conteh LF, Black SM, and Mumtaz K made substantial contributions to the conception, design of the study, acquisition of data, analysis/contribution of data, drafting and critically revising the manuscript; all authors have given final approval of the final version.
Institutional review board statement: The institutional review board at Nationwide Children’s Hospital exempted the study from review (IRB16-01193).
Informed consent statement: Due to the nature of this research, informed consent was not required.
Conflict-of-interest statement: None of the above listed authors have any reported conflicts of interest to disclose.
Open-Access: This article is an open-access article which was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: http://creativecommons.org/licenses/by-nc/4.0/
Correspondence to: Khalid Mumtaz, MD, MSC, Assistant Professor, Doctor, Department of Internal Medicine, Division of Gastroenterology, Hepatology and Nutrition, Ohio State University Wexner Medical Center, 410 W. 10th Ave., North 235 Doan Hall, Columbus, OH 43210, United States. khalid.mumtaz@osumc.edu
Telephone: +1-614-2936255 Fax: +1-614-2938516
Received: September 26, 2017
Peer-review started: October 1, 2017
First decision: November 27, 2017
Revised: December 1, 2017
Accepted: December 13, 2017
Article in press: December 13, 2017
Published online: January 27, 2018
ARTICLE HIGHLIGHTS
Research background
There has been an increase in the number of simultaneous liver kidney transplantation (SLKT) performed over the past decade. Recently, it has been noted that SLKT listing was influenced by center-size rather than by guidelines. Inconsistent outcomes of SLKT vs liver transplantation alone (LTA) have been reported.
Research motivation
The effect of transplant center volume on outcome differences between SLKT vs LTA has not been evaluated. As such, the authors examined transplant center volume as a potential moderating factor in patients initially listed for SLKT.
Research objectives
The authors hypothesized that the survival disadvantage associated with LTA (compared to SLKT) in patients listed for SLKT would be smaller in more experienced centers performing a greater number of SLKT.
Research methods
The United Network of Organ Sharing database was queried for patients ≥ 18 years of age listed for SLKT between February 2002 and December 2015. Post-transplant survival was evaluated using stratified Cox regression with interaction between transplant type (LTA vs SLKT) and center volume.
Research results
Overall, 393 of 4580 patients (9%) listed for SLKT underwent LTA. Mortality was higher among LTA recipients (180/393, 46%) than SLKT recipients (1107/4187, 26%). The Cox model predicted a significant survival disadvantage for patients receiving LTA vs SLKT (HR: 2.85; 95%CI: 2.21-3.66) in centers performing 30 SLKT over the study period. This disadvantage was modestly attenuated as center SLKT volume increased, with a 3% reduction (HR: 0.97; 95%CI: 0.95-0.99) for every 10 SLKs performed.
Research conclusions
LTA is associated with increased mortality among patients listed for SLKT. This difference is modestly attenuated at more experienced centers and may explain inconsistencies between smaller-center and larger registry-wide studies comparing SLKT and LTA outcomes.
Research perspectives
The findings of this study may help to reconcile the current controversy regarding center size and outcomes of LTA. Future research should focus on the apparent need for standardization of SLKT listing guidelines.
