J Korean Med Sci.  2021 Mar;36(12):e79. 10.3346/jkms.2021.36.e79.

Performance Changes Following the Revision of Organ Allocation System of Lung Transplant: Analysis of Korean Network for Organ Sharing Data

• Yeo HJ
• Kim DH
• Kim YS
• Jeon D
• Cho WH

• KMID: 2514124
• DOI: http://doi.org/10.3346/jkms.2021.36.e79

Abstract

Background
There is currently a lack of data on the impact of the recent revision of the domestic lung allocation system on transplant performance.
Methods
We conducted a retrospective analysis of transplant candidates and transplant patients registered in Korean Network for Organ Sharing between July 2015 and July 2019. Study periods were classified according to the introduction of the revised lung allocation system as follows: period 1 from July 2015 to June 2017 and period 2 from August 2017 to July 2019.
Results
During the study period, a total of 627 patients were on the waiting list, of which 398 lung transplantations were performed. Total waiting list size increased by 98.6%, from 210 in period 1 to 417 in period 2. The number of transplant patients also increased by 32.7%, from 171 in period 1 to 227 in period 2. The number of donors decreased from 1,042 to 878, whereas the usage rate, i.e., the number of lung donors used for transplantation among the total number of reported lung donors, increased from 16.4% to 25.9%. The proportion of patients with high urgent status at transplantation increased from 45% to 60.4%, whereas those with urgent status decreased from 46.8% to 35.7% (P = 0.006). The use of marginal donor lungs increased from 29.8% to 53.7% (P < 0.001). To adjust urgency status and marginal donor usage between two groups, we conducted a propensity score matching analysis. No significant differences were detected in 1-year survival rates between the two periods after propensity score matching. As well, no significant difference was observed in mortality on the waiting list between the two periods.
Conclusion
The recent revision of the lung allocation system in Korea did not change the performance of lung transplant in terms of waiting list mortality and 1-year survival. The rapid increase in the volume of waiting list between the two periods increased the waiting time, transplantation of high-urgency patients, and use of marginal lung donors.

Keyword

Lung Transplantation; Lung Allocation System; Korea; Mortality

Figure

• 

  Fig. 1 Number of patients on the lung transplant waiting list in Korea according to period, by urgency status.(A) Total waiting list size increased by 98.6%, from 210 in period 1 to 417 in period 2. (B) There were no differences related to urgency status among candidates listed for transplant between the two periods. A total of 35.4% of candidates had high urgent status requiring mechanical ventilation and/or extracorporeal membrane oxygenation support (37.1% vs. 34.5%, P = 0.519).

• 

  Fig. 2 Number of lung transplants performed in Korea according to urgency status and periods.The proportion of patients with high urgent status at transplantation increased from 45% to 60.4% (P = 0.006).**P < 0.01.

• 

  Fig. 3 1-year survival rates of lung transplantations after propensity score matching analysis.There were no significant differences in 1-year survival rates of each subgroup between the two periods after propensity score matching.

Reference

1. Khush KK, Cherikh WS, Chambers DC, Goldfarb S, Hayes D Jr, Kucheryavaya AY, et al. The International Thoracic Organ Transplant Registry of the International Society for Heart and Lung Transplantation: thirty-fifth adult heart transplantation report-2018; focus theme: multiorgan transplantation. J Heart Lung Transplant. 2018; 37(10):1155–1168. PMID: 30293612.

2. Korean Network for Organ Sharing. 2018 annual report for organ transplant and tissue donation. Accessed October 30, 2020. https://www.konos.go.kr/konosis/common/bizlogic.jsp.

3. Yu WS, Suh JW, Song SH, Paik HC, Kim SY, Park MS, et al. The lung allocation score could evaluate allocation systems in countries that do not use the score. PLoS One. 2019; 14(4):e0214853. PMID: 30943262.

4. Korean Network for Organ Sharing. Organ transplantation law. Accessed October 30, 2020. https://www.konos.go.kr/konosis/common/bizlogic.jsp.

5. Russo MJ, Iribarne A, Hong KN, Davies RR, Xydas S, Takayama H, et al. High lung allocation score is associated with increased morbidity and mortality following transplantation. Chest. 2010; 137(3):651–657. PMID: 19820072.

6. Smits JM, Nossent G, Evrard P, Lang G, Knoop C, Kwakkel-van Erp JM, et al. Lung allocation score: the Eurotransplant model versus the revised US model - a cross-sectional study. Transpl Int. 2018; 31(8):930–937. PMID: 29665090.

7. Riou J, Boëlle PY, Christie JD, Thabut G. High emergency organ allocation rule in lung transplantation: a simulation study. ERJ Open Res. 2017; 3(4):00020-2017. PMID: 29181383.

8. Yeo HJ, Yoon SH, Lee SE, Jeon D, Kim YS, Cho WH, et al. Current status and future of lung donation in Korea. J Korean Med Sci. 2017; 32(12):1953–1958. PMID: 29115076.

9. Bennett D, Fossi A, Bargagli E, Refini RM, Pieroni M, Luzzi L, et al. Mortality on the waiting list for lung transplantation in patients with idiopathic pulmonary fibrosis: a single-centre experience. Lung. 2015; 193(5):677–681. PMID: 26216722.

10. Egan TM, Murray S, Bustami RT, Shearon TH, McCullough KP, Edwards LB, et al. Development of the new lung allocation system in the United States. Am J Transplant. 2006; 6(5 Pt 2):1212–1227. PMID: 16613597.

11. Merlo CA, Weiss ES, Orens JB, Borja MC, Diener-West M, Conte JV, et al. Impact of U.S. Lung Allocation Score on survival after lung transplantation. J Heart Lung Transplant. 2009; 28(8):769–775. PMID: 19632571.

12. Maxwell BG, Levitt JE, Goldstein BA, Mooney JJ, Nicolls MR, Zamora M, et al. Impact of the lung allocation score on survival beyond 1 year. Am J Transplant. 2014; 14(10):2288–2294. PMID: 25208599.

13. Gottlieb J, Greer M, Sommerwerck U, Deuse T, Witt C, Schramm R, et al. Introduction of the lung allocation score in Germany. Am J Transplant. 2014; 14(6):1318–1327. PMID: 24854023.

14. Gottlieb J, Smits J, Schramm R, Langer F, Buhl R, Witt C, et al. Lung transplantation in Germany since the introduction of the Lung Allocation Score. Dtsch Arztebl Int. 2017; 114(11):179–185. PMID: 28382903.

15. Smits JM, Nossent GD, de Vries E, Rahmel A, Meiser B, Strueber M, et al. Evaluation of the lung allocation score in highly urgent and urgent lung transplant candidates in Eurotransplant. J Heart Lung Transplant. 2011; 30(1):22–28. PMID: 20851639.