- Email: [email protected]
Liver Recovery and Transplantation From Deceased Donors in the Metropolitan Area of the Valley of Mexico
Liver Recovery and Transplantation From Deceased Donors in the Metropolitan Area of the Valley of Mexico Daniel Zamora-Valdésa,*, Pilar Leal-Leytea, Inés Díaz-Muñozb, and Nahum Méndez-Sáncheza a
Liver Research Unit, Medica Sur Clinic & Foundation, Mexico City, Mexico; and bMexico State Tissue Bank, Toluca, México
ABSTRACT Background. Evaluation of donation and transplantation activity allows for strategic planning. Liver donation and transplantation activity in the Metropolitan Area of the Valley of Mexico (MAVM) has never been published. The aim of this study was to analyze deceased liver donation and transplantation, liver use, and observed-to-expected (O:E) ratio in the MAVM. Methods. Information from 2014 to 2018 was obtained from the National Center of Transplantation and adjusted per million persons. O:E ratio was analyzed and compared between regions. Results. From all Mexican states, Mexico City (CDMX) had the highest liver donation and transplantation per million persons rates in the country. In contrast, when the MAVM was considered, the region was sixth in liver donation and first in transplantation, although the latter was not statistically different to Nuevo Leon (5.4 vs 4.3; P ¼ .52). Liver use in Mexico State within the MAVM (37.8%) was not different from that of CDMX (15th in the nation, 35.2%, P ¼ .78), while deceased donor liver use in the rest of the state was statistically higher (52.4%, P ¼ .01; third in the nation). O:E ratio was higher in Mexico states outside the MAVM (CDMX 10.1, 2.1 vs 29.4, 26.5; P ¼ .009). Conclusions. Analysis of deceased donation and transplantation of Mexican states without considering the metropolitan areas is insufficient. To consider CDMX as a region without acknowledging the MAVM leads to an inappropriately small denominator during efficiency analysis.
C
IRRHOSIS-RELATED mortality in Mexico is the highest in the Americas [1]. Liver transplant is the standard of care for end-stage liver disease, acute liver failure, some metabolic liver diseases, and selected liver malignant neoplasms [2]. The early development of liver transplantation in our country was unfortunately not accompanied by progressive growth [3]. Fortunately, in the last decade, the deceased organ donation rate per million persons (pmp) has increased by 50% (3.2 pmp in 2008 to 4.8 pmp in 2018) [2], while the deceased donor liver transplant (DDLT) rate increased by 125% (0.8 pmp in 2008 to 1.8 pmp in 2018) [4]. Despite this remarkable improvement, the DDLT rate pmp in Mexico is the third lowest across all countries reporting to the International Registry of Organ Donation and Transplantation [5]. 0041-1345/20 https://doi.org/10.1016/j.transproceed.2020.02.009
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Careful, data-driven planning is essential for proper distribution of human and economic resources during the development of programs directed toward potential donor identification, organ recovery, and liver transplantation [6]. Currently available data are limited to nationwide and statebased data. This leads to a limited view of the donation and transplantation activity considering that some metropolitan areas in the country exceed state limits, such as the Metropolitan Area of the Valley of Mexico (MAVM), the *Address correspondence to Daniel Zamora-Valdés, Liver Research Unit, Medica Sur Clinic & Foundation, Puente de Piedra 150, Col. Toriello Guerra, 14050, Mexico City, Mexico. Tel: þ52555-4247200-4453; Fax: þ525-55-6664031. E-mail: dzamorav@ medicasur.org.mx ª 2020 Elsevier Inc. All rights reserved. 230 Park Avenue, New York, NY 10169
Transplantation Proceedings, 52, 1062e1065 (2020)
DECEASED DONOR LIVER TRANSPLANT
fifth largest urban concentration in the world (after Tokyo, New Delhi, Shanghai, and Sao Paolo), which extends through Mexico City (CDMX), Mexico State (EdoMex), and Hidalgo, hosting 17.4% of the Mexican population (Fig 1) [7]. Until recently, data needed to analyze this phenomenon were unavailable. After the Federal Decree for Transparency on Public Information in 2016, the platform Datos Abiertos de México became available. This database contains privacy-respectful information from donors, recipients, and patients on the waiting list, constituting a great tool to understand the current state of donation and transplantation in Mexico. Proper analysis of this database can lead to the creation of evidence-based policy changes. The aims of this study were 1. to describe the total and population-adjusted activity of donation after brain death (DBD), deceased liver donation (DLD), DLD use, and DDLT in the Mexican states forming the MAVM and compare it with other Mexican states and 2. to compare observed DBD activity with the expected DBD activity in these regions.
METHODS The database Datos Abiertos de México from the National Institute of Statistics and Geography, the National Council of Population, and the National Transplant Center was accessed on January 14, 2019, to obtain the population of each Mexican state to municipality level during the 2015 national census [7]. Population density was
Fig 1. MAVM extends through 3 Mexican states: Mexico City (orange), Mexico State (MAVM in purple, the rest in green), and Hidalgo (MAVM in yellow, the rest in blue). CDMX, Mexico City; MAVM, Metropolitan Area of the Valley of Mexico.
1063 calculated in square kilometers. DBD, DLD, and DDLT activity during 2014 to 2018 is presented in total numbers and rate pmp. Relative use (liver allografts transplanted from total number of DBD) is presented as a percentage. The number of hospital beds and intensive care beds is reported to municipality level within the Federal and State Secretary of Health and Assistance (SSA) [8]. We calculated the expected number of DBD based on the formula 50 DBD per 100 intensive care beds per year [9]. The information was analyzed using SPSS version 19 (IBM, Armonk, NY, United States). Data are presented as median and range. We compared the rates pmp of each region through MannWhitney U test; relative liver use was compared through Fisher exact test, and the range of the median among geographic areas was compared through Kruskal-Wallis test. We considered a P value < .05 statistically significant. All the data contained in this article are public; therefore, the study was exempt from review by our ethics committee.
RESULTS
The population of the MAVM was 20,892,724 inhabitants (within 17 delegations of CDMX, 59 municipalities in EdoMex, and 1 municipality in Hidalgo). The rest of EdoMex (66 municipalities) had 4,332,979 inhabitants, and the rest of Hidalgo (83 municipalities) had 2,738,917 inhabitants. The population density of the MAVM was 2656 inhabitants per km2, 270 inhabitants per km2 in the rest of EdoMex and 132 inhabitants per km2 in the rest of Hidalgo. The latter state had no donation or transplantation activity in the municipality included in the MAVM, while the CDMX is completely included in the MAVM; therefore, only activity in the EdoMex within the MAVM and the rest of the state is further analyzed. CDMX had a median DBD rate of 11.5 pmp, the highest in the country. EdoMex had a median DBD rate of 3.0 pmp (range, 0.6; 18th in the country). Considering the MAVM as a region, the DBD rate (6.5, 2.4) is close to San Luis Potosí, rated seventh (6.6, 2.6). EdoMex DBD rate pmp within the MAVM is not statistically different from the rest of the state (2.8, 0.8 vs 3.2, 2.5, respectively; P > .99). DLD pmp in CDMX (3.78, 1.4) is the second highest in the country after Sonora (3.83, 3.8), although there is no statistical difference (P ¼ .916). In contrast, DLD pmp in the MAVM (2.2, 0.4) is close to Jalisco, rated sixth (2.3, 1.4). DLD pmp in EdoMex within MAVM is not statistically different from the rest of the state (1.1, 0.5 vs 1.4, 1.4, respectively; P ¼ .14). DLD relative use in CDMX was 35.2% (rated 15th), and it was not different from that observed in the MAVM (35.9%; P ¼ .85). DLD use was statistically lower in EdoMex within MAVM compared with the rest of the state (52.3% vs 35.8%, respectively; P ¼ .01; rated third). The DDLT rate in CDMX was the highest in the country (12.6, 7.8). After considering the CDMX as part of the MAVM, the rate was not statistically different to that of Nuevo León, rated second (4.3, 1.4; P ¼ .52). Observed, expected, and observed-to-expected (O:E) DBD ratio in the SSA hospitals are shown in Table 1. O:E
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Table 1. No. of Intensive Care Beds in the Mexican States of the MAVM, Mean DBD Between 2014 and 2018, and Expected DBD Calculated According to Intensive Care Beds DBD (Observed) ICU Beds DBD (Expected)
Mexico City Mexico State Hidalgo MAVM Mexico State (MAVM) Mexico State (rest) Total
33.2 29.4 3.6 51.4 18.2 11.2 66.2
769 274 78 975 206 68 1121
384 137 39 488 103 34 560
O:E
0.086 0.214 0.092 0.105 0.176 0.329 0.118
Abbreviations: DBD, donation after brain death; ICU, intensive care unit; MAVM, Metropolitan Area of the Valley of Mexico; O:E, observed-to-expected.
ratio for each state is presented in Fig 2A, while Fig 2B shows the results after considering the MAVM. The O:E DBD ratio was statistically different in the 3 regions (MAVM, the rest of EdoMex, and the rest of Hidalgo) (Fig 2B) because of a statistically higher median in EdoMex outside of the MAVM (29.4, 26.5; P ¼ .002). EdoMex within MAVM had a lower O:E ratio than the rest of the state (17.5, 7.7 vs 29.4, 26.5; P ¼ .016). DISCUSSION
CDMX has the highest number of hospitals and installed beds in the country, both total and population adjusted [8]. The growth of the MAVM outside of the CDMX into neighboring states represents a complex situation to analyze in our country, as resource allocation is state based. The tertiary care centers of the country are concentrated in CDMX, resulting in the movement of population from the neighboring states across borders to access these hospitals, particularly the EdoMex within the MAVM (11,974,071 inhabitants) into CDMX. When analyzed separately, donation and transplantation activity in CDMX is the highest in the country (high numerator, low denominator), but when the MAVM is taken into account, the rates are much lower (higher numerator, higher denominator).
Population density along with installed capacity make the MAVM an ideal area to maximize donation and transplantation activity in our country. This task is much harder in other regions where population density is lower and resources are scarce. Tertiary care centers are concentrated in the largest metropolitan areas (MAVM, Guadalajara, and Monterrey, joint population 30,126,970 inhabitants; 25.2% of the country). This phenomenon forces the rest of the population (89,811,467 inhabitants; 74.8% of the country) to travel to these areas seeking liver transplant care. Currently, one of the main limiting factors for DLD use is the lack of an organ transportation system. Liver use from DBD in CDMX is therefore critical because these organs can be transplanted locally. However, the DLD utilization rate in CDMX is dramatically low (w35%). If the use of currently available resources would be maximized, the need for air transportation of organs would be reduced and the organ demand of CDMX could almost be satisfied, even without increasing DBD rate. For example, in 2017, 113 DDLTs were performed in CDMX, while only 36 livers were recovered from 118 DBDs. The present study shows that, considering installed resources, DBD activity in the MAVM is 10% of its potential. In contrast, even when the total numbers are much lower, both DLD use (w50%) and O:E DBD ratio (w30%) are higher in EdoMex outside of the MAVM, even despite a much lower population density and a smaller installed capacity. These data show that MAVM is a low-efficiency region with a large installed capacity, while the EdoMex outside of the MAVM has a comparatively higher efficiency with a much smaller installed capacity. Therefore, the strategies directed to increase donation and transplantation in these 2 neighboring regions must be different. In the MAVM, human resources should be increased to improve the efficiency of the system according to its installed capacity, while in the neighboring regions, this strategy should be accompanied by an increase in the infrastructure.
Fig 2. Observed DBD compared with expected DBD. (A) O:E ratio median of the 3 states (P ¼ .009); Mexico State (orange, 22.6, 8.7 vs rest; P ¼ .002), Mexico City and Hidalgo (blue, 8.3, 2.3 vs gray, 10.3, 10.2; P ¼ .599). (B) O:E ratio median considering the MAVM (P ¼ .009); EdoMex outside the MAVM (green, 29.4, 26.5 vs rest; P ¼ .002), MAVM and Hidalgo (purple, 10.1, 2.1 vs gray, 10.3, 10.2; P ¼ .917). CDMX, Mexico City; DBD, donation after brain death; EdoMex, Mexico State; MAVM, Metropolitan Area of the Valley of Mexico; O:E, observed-to-expected.
DECEASED DONOR LIVER TRANSPLANT
Our study has several limitations. First, the information is obtained from multiple sources. Unfortunately, in our country, there is no single database that concentrates information with the granularity needed to analyze this issue. Second, the number of expected organ donors can be calculated in many ways. The ideal way to calculate it would be to study each death as a potential donor, but this information is not available in our country. We decided to use the number of intensive care beds as a surrogate. The Donation and Transplantation Institute has proposed the use of simple indicators to calculate the organ donation potential of a hospital or region [9]. We chose to use the number of intensive care beds because hospitals in Mexico are highly heterogeneous, and some hospitals have no or minimal potential for donation; by considering intensive care beds only, the likelihood of analyzing hospitals with true donation potential is higher. We acknowledge that hospitals in Mexico must have a license to recover organs, and some hospitals could have intensive care beds but no license [10]. Third, the information of health resources to the municipality level is not available in all health care subsystems. We used the number of intensive care beds in SSA hospitals because this system represents 46.5% of the hospital beds in the country and had the highest number of DBDs consistently over the last decade. In conclusion, this study shows that to analyze deceased donation and transplantation in CDMX and EdoMex without considering the MAVM is insufficient. The analysis of the national donation and transplantation system cannot be
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limited to Mexican states, and it must include a detailed study of the metropolitan areas in the country. Strategies directed to increase organ donation and transplantation in the MAVM must be different from those of neighboring regions.
REFERENCES [1] Mokdad AA, Lopez AD, Shahraz S, Lozano R, Mokdad AH, Stanaway J, et al. Liver cirrhosis mortality in 187 countries between 1980 and 2010: a systematic analysis. BMC Med 2014;12:145. [2] Alexopoulos SP. Editorial: advances in clinical liver transplantation: expanding indications and improving peri- and posttransplant care. Curr Opin Organ Transplant 2019;24:111e2. [3] Orozco-Zepeda H. A little history about liver transplantation. Rev Invest Clin 2005;57:124e8 [in Spanish]. [4] Centro Nacional de Trasplantes. Datos abiertos de México, https://datos.gob.mx/busca/organization/cenatra; [accessed 14.01.19]. [5] IRODaT. International Registry on Organ Donation and Transplantation 2018, http://www.irodat.org/; [accessed 14.01.19]. [6] Whiting JF, Kiberd B, Kalo Z, Keown P, Roels L, Kjerulf M. Cost-effectiveness of organ donation: evaluating investment into donor action and other donor initiatives. Am J Transplant 2004;4: 569e73. [7] Consejo Nacional de Población. Datos abiertos de México, https://datos.gob.mx/busca/organization/conapo; [accessed 14.01.19]. [8] Dirección General de Información en Salud. Recursos en salud 2017, http://www.dgis.salud.gob.mx/contenidos/basesdedatos/ da_recursos_gobmx.html; 2019 [accessed 14.01.19]. [9] Donation & Transplantation Institute. Transplant & procurement management, https://tpm-dti.com/; [accessed 14.01.19]. [10] Miranda B, Fernandez Lucas M, de Felipe C, Naya M, Gonzalez-Posada JM, Matesanz R. Organ donation in Spain. Nephrol Dial Transplant 1999;14(Suppl. 3):15e21.
Liver Research Unit, Medica Sur Clinic & Foundation, Mexico City, Mexico; and bMexico State Tissue Bank, Toluca, México
ABSTRACT Background. Evaluation of donation and transplantation activity allows for strategic planning. Liver donation and transplantation activity in the Metropolitan Area of the Valley of Mexico (MAVM) has never been published. The aim of this study was to analyze deceased liver donation and transplantation, liver use, and observed-to-expected (O:E) ratio in the MAVM. Methods. Information from 2014 to 2018 was obtained from the National Center of Transplantation and adjusted per million persons. O:E ratio was analyzed and compared between regions. Results. From all Mexican states, Mexico City (CDMX) had the highest liver donation and transplantation per million persons rates in the country. In contrast, when the MAVM was considered, the region was sixth in liver donation and first in transplantation, although the latter was not statistically different to Nuevo Leon (5.4 vs 4.3; P ¼ .52). Liver use in Mexico State within the MAVM (37.8%) was not different from that of CDMX (15th in the nation, 35.2%, P ¼ .78), while deceased donor liver use in the rest of the state was statistically higher (52.4%, P ¼ .01; third in the nation). O:E ratio was higher in Mexico states outside the MAVM (CDMX 10.1, 2.1 vs 29.4, 26.5; P ¼ .009). Conclusions. Analysis of deceased donation and transplantation of Mexican states without considering the metropolitan areas is insufficient. To consider CDMX as a region without acknowledging the MAVM leads to an inappropriately small denominator during efficiency analysis.
C
IRRHOSIS-RELATED mortality in Mexico is the highest in the Americas [1]. Liver transplant is the standard of care for end-stage liver disease, acute liver failure, some metabolic liver diseases, and selected liver malignant neoplasms [2]. The early development of liver transplantation in our country was unfortunately not accompanied by progressive growth [3]. Fortunately, in the last decade, the deceased organ donation rate per million persons (pmp) has increased by 50% (3.2 pmp in 2008 to 4.8 pmp in 2018) [2], while the deceased donor liver transplant (DDLT) rate increased by 125% (0.8 pmp in 2008 to 1.8 pmp in 2018) [4]. Despite this remarkable improvement, the DDLT rate pmp in Mexico is the third lowest across all countries reporting to the International Registry of Organ Donation and Transplantation [5]. 0041-1345/20 https://doi.org/10.1016/j.transproceed.2020.02.009
1062
Careful, data-driven planning is essential for proper distribution of human and economic resources during the development of programs directed toward potential donor identification, organ recovery, and liver transplantation [6]. Currently available data are limited to nationwide and statebased data. This leads to a limited view of the donation and transplantation activity considering that some metropolitan areas in the country exceed state limits, such as the Metropolitan Area of the Valley of Mexico (MAVM), the *Address correspondence to Daniel Zamora-Valdés, Liver Research Unit, Medica Sur Clinic & Foundation, Puente de Piedra 150, Col. Toriello Guerra, 14050, Mexico City, Mexico. Tel: þ52555-4247200-4453; Fax: þ525-55-6664031. E-mail: dzamorav@ medicasur.org.mx ª 2020 Elsevier Inc. All rights reserved. 230 Park Avenue, New York, NY 10169
Transplantation Proceedings, 52, 1062e1065 (2020)
DECEASED DONOR LIVER TRANSPLANT
fifth largest urban concentration in the world (after Tokyo, New Delhi, Shanghai, and Sao Paolo), which extends through Mexico City (CDMX), Mexico State (EdoMex), and Hidalgo, hosting 17.4% of the Mexican population (Fig 1) [7]. Until recently, data needed to analyze this phenomenon were unavailable. After the Federal Decree for Transparency on Public Information in 2016, the platform Datos Abiertos de México became available. This database contains privacy-respectful information from donors, recipients, and patients on the waiting list, constituting a great tool to understand the current state of donation and transplantation in Mexico. Proper analysis of this database can lead to the creation of evidence-based policy changes. The aims of this study were 1. to describe the total and population-adjusted activity of donation after brain death (DBD), deceased liver donation (DLD), DLD use, and DDLT in the Mexican states forming the MAVM and compare it with other Mexican states and 2. to compare observed DBD activity with the expected DBD activity in these regions.
METHODS The database Datos Abiertos de México from the National Institute of Statistics and Geography, the National Council of Population, and the National Transplant Center was accessed on January 14, 2019, to obtain the population of each Mexican state to municipality level during the 2015 national census [7]. Population density was
Fig 1. MAVM extends through 3 Mexican states: Mexico City (orange), Mexico State (MAVM in purple, the rest in green), and Hidalgo (MAVM in yellow, the rest in blue). CDMX, Mexico City; MAVM, Metropolitan Area of the Valley of Mexico.
1063 calculated in square kilometers. DBD, DLD, and DDLT activity during 2014 to 2018 is presented in total numbers and rate pmp. Relative use (liver allografts transplanted from total number of DBD) is presented as a percentage. The number of hospital beds and intensive care beds is reported to municipality level within the Federal and State Secretary of Health and Assistance (SSA) [8]. We calculated the expected number of DBD based on the formula 50 DBD per 100 intensive care beds per year [9]. The information was analyzed using SPSS version 19 (IBM, Armonk, NY, United States). Data are presented as median and range. We compared the rates pmp of each region through MannWhitney U test; relative liver use was compared through Fisher exact test, and the range of the median among geographic areas was compared through Kruskal-Wallis test. We considered a P value < .05 statistically significant. All the data contained in this article are public; therefore, the study was exempt from review by our ethics committee.
RESULTS
The population of the MAVM was 20,892,724 inhabitants (within 17 delegations of CDMX, 59 municipalities in EdoMex, and 1 municipality in Hidalgo). The rest of EdoMex (66 municipalities) had 4,332,979 inhabitants, and the rest of Hidalgo (83 municipalities) had 2,738,917 inhabitants. The population density of the MAVM was 2656 inhabitants per km2, 270 inhabitants per km2 in the rest of EdoMex and 132 inhabitants per km2 in the rest of Hidalgo. The latter state had no donation or transplantation activity in the municipality included in the MAVM, while the CDMX is completely included in the MAVM; therefore, only activity in the EdoMex within the MAVM and the rest of the state is further analyzed. CDMX had a median DBD rate of 11.5 pmp, the highest in the country. EdoMex had a median DBD rate of 3.0 pmp (range, 0.6; 18th in the country). Considering the MAVM as a region, the DBD rate (6.5, 2.4) is close to San Luis Potosí, rated seventh (6.6, 2.6). EdoMex DBD rate pmp within the MAVM is not statistically different from the rest of the state (2.8, 0.8 vs 3.2, 2.5, respectively; P > .99). DLD pmp in CDMX (3.78, 1.4) is the second highest in the country after Sonora (3.83, 3.8), although there is no statistical difference (P ¼ .916). In contrast, DLD pmp in the MAVM (2.2, 0.4) is close to Jalisco, rated sixth (2.3, 1.4). DLD pmp in EdoMex within MAVM is not statistically different from the rest of the state (1.1, 0.5 vs 1.4, 1.4, respectively; P ¼ .14). DLD relative use in CDMX was 35.2% (rated 15th), and it was not different from that observed in the MAVM (35.9%; P ¼ .85). DLD use was statistically lower in EdoMex within MAVM compared with the rest of the state (52.3% vs 35.8%, respectively; P ¼ .01; rated third). The DDLT rate in CDMX was the highest in the country (12.6, 7.8). After considering the CDMX as part of the MAVM, the rate was not statistically different to that of Nuevo León, rated second (4.3, 1.4; P ¼ .52). Observed, expected, and observed-to-expected (O:E) DBD ratio in the SSA hospitals are shown in Table 1. O:E
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Table 1. No. of Intensive Care Beds in the Mexican States of the MAVM, Mean DBD Between 2014 and 2018, and Expected DBD Calculated According to Intensive Care Beds DBD (Observed) ICU Beds DBD (Expected)
Mexico City Mexico State Hidalgo MAVM Mexico State (MAVM) Mexico State (rest) Total
33.2 29.4 3.6 51.4 18.2 11.2 66.2
769 274 78 975 206 68 1121
384 137 39 488 103 34 560
O:E
0.086 0.214 0.092 0.105 0.176 0.329 0.118
Abbreviations: DBD, donation after brain death; ICU, intensive care unit; MAVM, Metropolitan Area of the Valley of Mexico; O:E, observed-to-expected.
ratio for each state is presented in Fig 2A, while Fig 2B shows the results after considering the MAVM. The O:E DBD ratio was statistically different in the 3 regions (MAVM, the rest of EdoMex, and the rest of Hidalgo) (Fig 2B) because of a statistically higher median in EdoMex outside of the MAVM (29.4, 26.5; P ¼ .002). EdoMex within MAVM had a lower O:E ratio than the rest of the state (17.5, 7.7 vs 29.4, 26.5; P ¼ .016). DISCUSSION
CDMX has the highest number of hospitals and installed beds in the country, both total and population adjusted [8]. The growth of the MAVM outside of the CDMX into neighboring states represents a complex situation to analyze in our country, as resource allocation is state based. The tertiary care centers of the country are concentrated in CDMX, resulting in the movement of population from the neighboring states across borders to access these hospitals, particularly the EdoMex within the MAVM (11,974,071 inhabitants) into CDMX. When analyzed separately, donation and transplantation activity in CDMX is the highest in the country (high numerator, low denominator), but when the MAVM is taken into account, the rates are much lower (higher numerator, higher denominator).
Population density along with installed capacity make the MAVM an ideal area to maximize donation and transplantation activity in our country. This task is much harder in other regions where population density is lower and resources are scarce. Tertiary care centers are concentrated in the largest metropolitan areas (MAVM, Guadalajara, and Monterrey, joint population 30,126,970 inhabitants; 25.2% of the country). This phenomenon forces the rest of the population (89,811,467 inhabitants; 74.8% of the country) to travel to these areas seeking liver transplant care. Currently, one of the main limiting factors for DLD use is the lack of an organ transportation system. Liver use from DBD in CDMX is therefore critical because these organs can be transplanted locally. However, the DLD utilization rate in CDMX is dramatically low (w35%). If the use of currently available resources would be maximized, the need for air transportation of organs would be reduced and the organ demand of CDMX could almost be satisfied, even without increasing DBD rate. For example, in 2017, 113 DDLTs were performed in CDMX, while only 36 livers were recovered from 118 DBDs. The present study shows that, considering installed resources, DBD activity in the MAVM is 10% of its potential. In contrast, even when the total numbers are much lower, both DLD use (w50%) and O:E DBD ratio (w30%) are higher in EdoMex outside of the MAVM, even despite a much lower population density and a smaller installed capacity. These data show that MAVM is a low-efficiency region with a large installed capacity, while the EdoMex outside of the MAVM has a comparatively higher efficiency with a much smaller installed capacity. Therefore, the strategies directed to increase donation and transplantation in these 2 neighboring regions must be different. In the MAVM, human resources should be increased to improve the efficiency of the system according to its installed capacity, while in the neighboring regions, this strategy should be accompanied by an increase in the infrastructure.
Fig 2. Observed DBD compared with expected DBD. (A) O:E ratio median of the 3 states (P ¼ .009); Mexico State (orange, 22.6, 8.7 vs rest; P ¼ .002), Mexico City and Hidalgo (blue, 8.3, 2.3 vs gray, 10.3, 10.2; P ¼ .599). (B) O:E ratio median considering the MAVM (P ¼ .009); EdoMex outside the MAVM (green, 29.4, 26.5 vs rest; P ¼ .002), MAVM and Hidalgo (purple, 10.1, 2.1 vs gray, 10.3, 10.2; P ¼ .917). CDMX, Mexico City; DBD, donation after brain death; EdoMex, Mexico State; MAVM, Metropolitan Area of the Valley of Mexico; O:E, observed-to-expected.
DECEASED DONOR LIVER TRANSPLANT
Our study has several limitations. First, the information is obtained from multiple sources. Unfortunately, in our country, there is no single database that concentrates information with the granularity needed to analyze this issue. Second, the number of expected organ donors can be calculated in many ways. The ideal way to calculate it would be to study each death as a potential donor, but this information is not available in our country. We decided to use the number of intensive care beds as a surrogate. The Donation and Transplantation Institute has proposed the use of simple indicators to calculate the organ donation potential of a hospital or region [9]. We chose to use the number of intensive care beds because hospitals in Mexico are highly heterogeneous, and some hospitals have no or minimal potential for donation; by considering intensive care beds only, the likelihood of analyzing hospitals with true donation potential is higher. We acknowledge that hospitals in Mexico must have a license to recover organs, and some hospitals could have intensive care beds but no license [10]. Third, the information of health resources to the municipality level is not available in all health care subsystems. We used the number of intensive care beds in SSA hospitals because this system represents 46.5% of the hospital beds in the country and had the highest number of DBDs consistently over the last decade. In conclusion, this study shows that to analyze deceased donation and transplantation in CDMX and EdoMex without considering the MAVM is insufficient. The analysis of the national donation and transplantation system cannot be
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limited to Mexican states, and it must include a detailed study of the metropolitan areas in the country. Strategies directed to increase organ donation and transplantation in the MAVM must be different from those of neighboring regions.
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