- Email: [email protected]
Liver Graft Allocation by Means of a New, Regionally Shared “Mixed” Model: The Experience in Lazio
Liver Graft Allocation by Means of a New, Regionally Shared “Mixed” Model: The Experience in Lazio R. Zaccaria*, G. Teti, A. Mecule, N. Torlone, M. Valeri, and D. Adorno Centro Regionale Trapianti Lazio, Università “Tor Vergata”, Rome, Italy
ABSTRACT Introduction. Since 2013, the regional network of transplantation centers “LAZIO TRANSPLANT” have adopted a new, mixed system for the allocation of liver grafts. Methods. The organs from donors aged <65 are assigned to patients with higher Model for End-stage Liver Disease (MELD) scores on a common regional waiting list, whereas those from donors aged >65 are allocated to patients with higher MELD scores on a specific local waiting list (LWL) at each center, on a rotational basis. Results. The new mixed allocation model grants a more rational allocation of the “standard” organs to the patients with the actual worst MELD score in the entire region, avoiding the possibility that a patient in relatively better clinical condition might be transplanted before a more severely ill patient on another center’s waiting list. Nonstandard organs, presenting slightly increased transplant risks, are still allocated on a rotational basis among the different transplant centers, ensuring them the possibility to select, on the basis of a global clinical risk evaluation, those patients in their LWL whose MELD score would not grant any possibility to compete for the “standard” organ allocation. Conclusions. The application of the new model had no negative impact on the overall number of transplants performed or on the global list-satisfaction percentages, but has slightly improved the cumulative mortality of the patients in the waiting list, granting to the clinically worst patients a prompt graft allocation, independent of the local center belonging.
T
O SHARE A COMMON regional waiting list (CRWL) for the liver transplantations performed in any of the 4 active adult transplant centers in Lazio, the regional network of transplantation centers called “LAZIO TRANSPLANT” decided to adopt a new allocation system for liver graft. For this purpose, since 2013 the allocation of liver grafts to the 4 different adult transplant Centers of Lazio, Italy, has been based on a “mixed” allocation system: the organs from donors aged <65 are assigned to the patient with the higher Model for End-stage Liver Disease (MELD) score [1,2] on the CRWL, whereas those from donors aged >65 are allocated to the patient with the higher MELD value in the specific local waiting list (LWL) of each center, on a rotational basis. To improve the patient’s individual assessment, the plain MELD score (0.957 log [serum creatinine mg/ dL] þ 0.378 log [total bilirubin mg/dL] þ 1.120 log
[International Normalized Ratio] þ 0.643) is integrated also by the evaluation of MELDNa (MELD - Na [mmol/L] e [0.025 MELD (140-Na)] þ 140) and of the so-called RegionalMELD (MELD-R), that is, the MELDNa value adjusted for specific parameters, such as time elapsed from list enrollment, and type of liver disease [3]. The individual MELDR scores are periodically updated (every week for MELD-R scores >23, every 2 weeks for MELD-R scores between 20 and 23, every 4 weeks for scores <20, every 90 days for patients with particular situations, such as combined transplant, biliary disease, and liver polycystosis). The algorithm for the allocation of
*Address correspondence to Raffaella Zaccaria, MD, Centro Regionale Trapianti Lazio, Università “Tor Vergata”, c/o Pad. Marchiafava, Ospedale S. Camillo, Circonvall. Gianicolense 87, 00152 Rome, Italy. E-mail: [email protected]
ª 2015 by Elsevier Inc. All rights reserved. 360 Park Avenue South, New York, NY 10010-1710
0041-1345/15 http://dx.doi.org/10.1016/j.transproceed.2014.11.075
Transplantation Proceedings, 47, 2113e2115 (2015)
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ZACCARIA, TETI, MECULE ET AL Table 1. Results of the New Model 2013/2014 (Through July 21, 2014) Period
2011/2012
Overall
Patient listed for elective OLT Non HCC HCC Patients listed UNOS 1 or MELD > 30 No. of transplant performed (overall) No. of transplants (elective) Non HCC HCC No. of transplants (nation-wide urgency) No. of transplants (regional priority, MELD > 30) Per-year list satisfaction % (overall OLT) Per-year list satisfaction % (elective OLT) Non HCC HCC Deaths while on the waiting list HCC Non HCC Mean waiting time for elective OLT (d) Non HCC HCC
221 136 (61.6%) 85 (38.4%) 20 184 165 96 (58.2%) 69 (41.8%) 7 12 38.2% 37.3% 35.3% 40.6% 49 (22.2%) 39 (28.7%) 10 (11.8%) 189 219 147
220 135 (61.4%) 85 (38.6%) 32 167 139 77 (55.4%) 62 (44.6%) 9 19 41.9% 39.9% 36.0% 46.1% 31 (14.1%) 22 (16.3%) 9 (10.6%) 164 180 141
CRWL
LWL
99 (71.2%) 53 (53.5%) 46 (46.5%)
40 (28.8%) 24 (60.0%) 16 (40.0%)
162 183 135
165 168 159
Abbreviations: CRWL, common regional waiting list; HCC, hepatocellular carcinoma; LWL, local waiting list; MELD, Model for End-stage Liver Disease; OLT, orthotopic liver transplantation; UNOS, United Network for Organ Sharing.
“standard” donors first select the patients awaiting a combined transplant, then the other patient of CRWL, ordered by 3 MELD-R categories (MELD 24, 20e23, and 15e19), and taking into account the individual ABO compatibility. Patients temporarily suspended or with nonupdated data are excluded from the selection. RESULTS
The result obtained in these 2 first years of utilize of the new “mixed allocation” model are summarized in Table 1. The comparison between 2011/2012 and 2013/2014 data should take into account that 2013/2014 results have been recorded over a 19-month period only (and not on a 2-year basis as 2011/2012 results). In 2013/2014, 167 of 252 listed patients have been transplanted, with an overall per-year list satisfaction percentage of 42%. The organ procurement was on a regional basis in about two-thirds of cases, with a total of 153 livers drawn, and 111 (73%) actually used. There were 83 grafts drawn from other regions, and 56 (68%) were transplanted. The main raison for organ refusal (86%) was unsuitable liver histology. Among the 167 transplanted patients, 9 were on the “nationwide” urgency list, and 19 on list priority (MELD > 30); of the 139 remaining recipients (elective transplants), 99 (71%) were transplanted from CRWL and 40 (29%) from LWL, presenting mean MELD values of 17.1 and MELDNa of 18.7. The introduction of the new “mixed” allocation system could not significantly change the overall number of transplants performed, or the global per-year list satisfaction percentages (about 40%). However, with respect to the
previously adopted allocation system (assigning the graft to the different centers on a simple rotational basis), the new model grants a better and more rational allocation of the “standard” organs to the patients with the actual worst MELD score in the entire region, avoiding the possibility that a patient in relatively better clinical condition might be transplanted before a more severe one belonging to another LWL. This fact might have had a considerable impact on the cumulative mortality of the patients listed for liver transplant, which has been reduced from an overall figure of 22% to just 14% in 2013/2014 (Table 1). DISCUSSION
The new liver “mixed” allocation model adopted by the LAZIO TRANSPLANT grants a number of benefits: beside the constant and periodic updating of the patients on the waiting list, they include a complete sharing among the different transplant centers of the clinical evaluation of the listed patients, and the possibility to effectively allocate the “standard” liver graft to the patients with the most severe clinical status. “Nonstandard” organs, presenting slightly increased transplant risks, are still allocated on a rotational basis among the different transplant centers. This fact grants to the single centers the possibility to select, on the basis of a global clinical risk evaluation, those patients in their LWL whose MELD score would not grant any possibility to compete for the “standard” organ allocation. In this way, the new “mixed” allocation model seems to be more fair and ethically correct [4,5]. Its application had
LIVER GRAFT ALLOCATION
no negative impact on the overall number of transplants performed or on the global list satisfaction percentages, but has slightly improved the cumulative mortality of the patients in the waiting list, granting to the clinically worst patients prompt graft allocation, independent of the local center. In our opinion, this new “mixed” allocation system has still some unresolved problems, such as the “competition” among the different transplant centers, the difficulty of allocating grafts with nonstandard risk levels (increased, potentially increased, nonevaluable, etc), and probably the necessity to review the criteria of the clinical status evaluation for the patients in the waiting list.
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REFERENCES [1] Angeli P, Gines P. Hepatorenal syndrome, MELD score and liver transplantation: an evolving issue with relevant implications for clinical practice. J Hepatol 2012;57:1135e40. [2] Freeman RB. A decade of model for end-stage liver disease: lessons learned and need for re-evaluation of allocation policies. Curr Opin Organ Transplant 2012;17:211e5. [3] Massie AB, Caffo B, Gentry SE, et al. MELD exceptions and rates of waiting list outcomes. Am J Transplant 2011;11:2362e71. [4] Keller EJ, Kwo PY, Helft PR. Ethical considerations surrounding survival benefit-based liver allocation. Liver Transpl 2014;20:140e6. [5] Cholongitas E, Germani G, Burroughs AK. Prioritization for liver transplantation. Nat Rev Gastroenterol Hepatol 2010;7: 659e68.
ABSTRACT Introduction. Since 2013, the regional network of transplantation centers “LAZIO TRANSPLANT” have adopted a new, mixed system for the allocation of liver grafts. Methods. The organs from donors aged <65 are assigned to patients with higher Model for End-stage Liver Disease (MELD) scores on a common regional waiting list, whereas those from donors aged >65 are allocated to patients with higher MELD scores on a specific local waiting list (LWL) at each center, on a rotational basis. Results. The new mixed allocation model grants a more rational allocation of the “standard” organs to the patients with the actual worst MELD score in the entire region, avoiding the possibility that a patient in relatively better clinical condition might be transplanted before a more severely ill patient on another center’s waiting list. Nonstandard organs, presenting slightly increased transplant risks, are still allocated on a rotational basis among the different transplant centers, ensuring them the possibility to select, on the basis of a global clinical risk evaluation, those patients in their LWL whose MELD score would not grant any possibility to compete for the “standard” organ allocation. Conclusions. The application of the new model had no negative impact on the overall number of transplants performed or on the global list-satisfaction percentages, but has slightly improved the cumulative mortality of the patients in the waiting list, granting to the clinically worst patients a prompt graft allocation, independent of the local center belonging.
T
O SHARE A COMMON regional waiting list (CRWL) for the liver transplantations performed in any of the 4 active adult transplant centers in Lazio, the regional network of transplantation centers called “LAZIO TRANSPLANT” decided to adopt a new allocation system for liver graft. For this purpose, since 2013 the allocation of liver grafts to the 4 different adult transplant Centers of Lazio, Italy, has been based on a “mixed” allocation system: the organs from donors aged <65 are assigned to the patient with the higher Model for End-stage Liver Disease (MELD) score [1,2] on the CRWL, whereas those from donors aged >65 are allocated to the patient with the higher MELD value in the specific local waiting list (LWL) of each center, on a rotational basis. To improve the patient’s individual assessment, the plain MELD score (0.957 log [serum creatinine mg/ dL] þ 0.378 log [total bilirubin mg/dL] þ 1.120 log
[International Normalized Ratio] þ 0.643) is integrated also by the evaluation of MELDNa (MELD - Na [mmol/L] e [0.025 MELD (140-Na)] þ 140) and of the so-called RegionalMELD (MELD-R), that is, the MELDNa value adjusted for specific parameters, such as time elapsed from list enrollment, and type of liver disease [3]. The individual MELDR scores are periodically updated (every week for MELD-R scores >23, every 2 weeks for MELD-R scores between 20 and 23, every 4 weeks for scores <20, every 90 days for patients with particular situations, such as combined transplant, biliary disease, and liver polycystosis). The algorithm for the allocation of
*Address correspondence to Raffaella Zaccaria, MD, Centro Regionale Trapianti Lazio, Università “Tor Vergata”, c/o Pad. Marchiafava, Ospedale S. Camillo, Circonvall. Gianicolense 87, 00152 Rome, Italy. E-mail: [email protected]
ª 2015 by Elsevier Inc. All rights reserved. 360 Park Avenue South, New York, NY 10010-1710
0041-1345/15 http://dx.doi.org/10.1016/j.transproceed.2014.11.075
Transplantation Proceedings, 47, 2113e2115 (2015)
2113
2114
ZACCARIA, TETI, MECULE ET AL Table 1. Results of the New Model 2013/2014 (Through July 21, 2014) Period
2011/2012
Overall
Patient listed for elective OLT Non HCC HCC Patients listed UNOS 1 or MELD > 30 No. of transplant performed (overall) No. of transplants (elective) Non HCC HCC No. of transplants (nation-wide urgency) No. of transplants (regional priority, MELD > 30) Per-year list satisfaction % (overall OLT) Per-year list satisfaction % (elective OLT) Non HCC HCC Deaths while on the waiting list HCC Non HCC Mean waiting time for elective OLT (d) Non HCC HCC
221 136 (61.6%) 85 (38.4%) 20 184 165 96 (58.2%) 69 (41.8%) 7 12 38.2% 37.3% 35.3% 40.6% 49 (22.2%) 39 (28.7%) 10 (11.8%) 189 219 147
220 135 (61.4%) 85 (38.6%) 32 167 139 77 (55.4%) 62 (44.6%) 9 19 41.9% 39.9% 36.0% 46.1% 31 (14.1%) 22 (16.3%) 9 (10.6%) 164 180 141
CRWL
LWL
99 (71.2%) 53 (53.5%) 46 (46.5%)
40 (28.8%) 24 (60.0%) 16 (40.0%)
162 183 135
165 168 159
Abbreviations: CRWL, common regional waiting list; HCC, hepatocellular carcinoma; LWL, local waiting list; MELD, Model for End-stage Liver Disease; OLT, orthotopic liver transplantation; UNOS, United Network for Organ Sharing.
“standard” donors first select the patients awaiting a combined transplant, then the other patient of CRWL, ordered by 3 MELD-R categories (MELD 24, 20e23, and 15e19), and taking into account the individual ABO compatibility. Patients temporarily suspended or with nonupdated data are excluded from the selection. RESULTS
The result obtained in these 2 first years of utilize of the new “mixed allocation” model are summarized in Table 1. The comparison between 2011/2012 and 2013/2014 data should take into account that 2013/2014 results have been recorded over a 19-month period only (and not on a 2-year basis as 2011/2012 results). In 2013/2014, 167 of 252 listed patients have been transplanted, with an overall per-year list satisfaction percentage of 42%. The organ procurement was on a regional basis in about two-thirds of cases, with a total of 153 livers drawn, and 111 (73%) actually used. There were 83 grafts drawn from other regions, and 56 (68%) were transplanted. The main raison for organ refusal (86%) was unsuitable liver histology. Among the 167 transplanted patients, 9 were on the “nationwide” urgency list, and 19 on list priority (MELD > 30); of the 139 remaining recipients (elective transplants), 99 (71%) were transplanted from CRWL and 40 (29%) from LWL, presenting mean MELD values of 17.1 and MELDNa of 18.7. The introduction of the new “mixed” allocation system could not significantly change the overall number of transplants performed, or the global per-year list satisfaction percentages (about 40%). However, with respect to the
previously adopted allocation system (assigning the graft to the different centers on a simple rotational basis), the new model grants a better and more rational allocation of the “standard” organs to the patients with the actual worst MELD score in the entire region, avoiding the possibility that a patient in relatively better clinical condition might be transplanted before a more severe one belonging to another LWL. This fact might have had a considerable impact on the cumulative mortality of the patients listed for liver transplant, which has been reduced from an overall figure of 22% to just 14% in 2013/2014 (Table 1). DISCUSSION
The new liver “mixed” allocation model adopted by the LAZIO TRANSPLANT grants a number of benefits: beside the constant and periodic updating of the patients on the waiting list, they include a complete sharing among the different transplant centers of the clinical evaluation of the listed patients, and the possibility to effectively allocate the “standard” liver graft to the patients with the most severe clinical status. “Nonstandard” organs, presenting slightly increased transplant risks, are still allocated on a rotational basis among the different transplant centers. This fact grants to the single centers the possibility to select, on the basis of a global clinical risk evaluation, those patients in their LWL whose MELD score would not grant any possibility to compete for the “standard” organ allocation. In this way, the new “mixed” allocation model seems to be more fair and ethically correct [4,5]. Its application had
LIVER GRAFT ALLOCATION
no negative impact on the overall number of transplants performed or on the global list satisfaction percentages, but has slightly improved the cumulative mortality of the patients in the waiting list, granting to the clinically worst patients prompt graft allocation, independent of the local center. In our opinion, this new “mixed” allocation system has still some unresolved problems, such as the “competition” among the different transplant centers, the difficulty of allocating grafts with nonstandard risk levels (increased, potentially increased, nonevaluable, etc), and probably the necessity to review the criteria of the clinical status evaluation for the patients in the waiting list.
2115
REFERENCES [1] Angeli P, Gines P. Hepatorenal syndrome, MELD score and liver transplantation: an evolving issue with relevant implications for clinical practice. J Hepatol 2012;57:1135e40. [2] Freeman RB. A decade of model for end-stage liver disease: lessons learned and need for re-evaluation of allocation policies. Curr Opin Organ Transplant 2012;17:211e5. [3] Massie AB, Caffo B, Gentry SE, et al. MELD exceptions and rates of waiting list outcomes. Am J Transplant 2011;11:2362e71. [4] Keller EJ, Kwo PY, Helft PR. Ethical considerations surrounding survival benefit-based liver allocation. Liver Transpl 2014;20:140e6. [5] Cholongitas E, Germani G, Burroughs AK. Prioritization for liver transplantation. Nat Rev Gastroenterol Hepatol 2010;7: 659e68.